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okay good morning or good afternoon

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depending on your time zone welcome to

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the nai director seminar uh before we

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get started i wanted to say a couple of

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things

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one is please check out the new

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integrated astrobiology program website

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the website was a labor of love by a

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number of people here at nai central and

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working with folks at nasa headquarters

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and

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we've been getting a lot of good

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feedback on it we'd love to hear more

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feedback from you all

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and the nai website url has not changed

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it's still

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nai.nasa.gov and it's been integrated

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into the large overall website so do

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check it out and there's

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uh windows at the bottom of each page

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that enable you to provide us feedback

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and so please do provide us feedback

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uh compliments criticisms corrections

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anything

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are all welcome

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one other thing i wanted to mention is

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that the

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cover story in the april issue of

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scientific american is by one of our own

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researchers nancy kang

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from the uh virtual planetary laboratory

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university of washington team she is at

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the goddard institute for space studies

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in new york and the topic of the cover

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article is the shocking colors of alien

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plants and nancy and colleagues on

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vicki's team have been working on

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understanding

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what photosynthesis might be like if it

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developed under a different stellar

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spectrum than the spectrum of the sun so

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check that out as well and she also has

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papers that have been published in

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astrobiology and the references are

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given in there

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so

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let me now take a minute to introduce

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our speakers our speakers today as you

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know are jody deming and jim staley of

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the university of washington

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jody actually began her career with nasa

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at the goddard space flight center some

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time ago and then got her phd at the

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university of maryland

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what she has been interested in is for

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her entire career are the extremes of

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life

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one of the things that she

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did was early in her career to isolate a

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novel pressure requiring bacterium

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which she then named for her research

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advisor rita caldwell

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named it

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coldwellia

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and today jody students are using one of

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these as a model organism for cold

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attack for uh cold adapted microbes

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her research has taken a turn towards

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psychrophiles and looking at low

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temperature life particularly stimulated

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by the potential for there to be such

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life on mars and europa so today she

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does a lot of work in the high arctic

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and we're going to be hearing about some

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of that today

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our other speaker is jim staley and jody

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incidentally is professor of

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oceanography jim is a professor of

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microbiology of course both at the

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university of washington

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jim's major research area is microbial

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diversity and so he studies microbial

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ecology evolution taxonomy and applies

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it to both bacteria and archaea he's

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particularly interested in the genomics

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of unusual bacteria and these include

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sea ice bacteria as well as bacteria

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that are involved in nitrogen cycling in

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the suboxic zone of the black sea and

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the black sea work is particularly

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interesting because the whole redox

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gradient in the black sea which is

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anoxic

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at its lower level serves as an analog

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both for the early earth conditions

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as well as the possible redox and

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metabolic gradients that might exist on

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other worlds that are anoxic like mars

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and europa

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so

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organisms that are trapped in sea ice

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and we're going to be hearing today

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from jody and from jim about how their

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studies of life at

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low temperature on earth might apply to

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mars and europa and i will now turn it

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thank you carl for that nice

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introduction jim and i are both pleased

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to be able to address this audience on a

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topic that we think is pretty relevant

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am i on screen with this

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because after all it is cold out there

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i have been spending a lot of time

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recently in the high arctic as carl

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alluded to in the winter time in

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particular to get the coldest ice

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formations possible but that hasn't

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always been the case

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10 years ago in 1998 i thought it was a

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pretty big deal to have organized help

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organize an international project to be

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working in open waters of the arctic

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and there we were doing traditional

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oceanography collecting water samples

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and as my graduate student likes to say

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this is not the

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night sky of the arctic but rather the

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concentration of bacteria in a tiny drop

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of sea water displayed for you on a

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black background and visualized with a

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stain specific to dna

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so we're talking about a million

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bacteria in a milliliter of seawater and

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these smaller dots are the viruses that

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are known to attack these bacteria at 10

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times the concentrations of the bacteria

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so i want you to keep this in mind when

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while i was at sea for this expedition i

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was totally

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mesmerized by all the ice formations

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here we have a glacier pouring off of

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ellesmere island the sea ice cover

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itself lots of structure and some of the

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older ice formations and when i got off

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this ship

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and came home in july of 1998 the big

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news was all europa and these images

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these fantastic images were everywhere

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that we all know so well now this one in

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particular

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was very motivating for me because it

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resembles although on a different scale

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the sorts of ice features and iceberg

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breakups that we see in the arctic on

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our planet

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so

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this did cause me to take a turn in my

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professional life

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and i joined forces with the uw

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astrobiology program that started that

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year

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with my self-appointed role of studying

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and then i proceeded to learn that

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europa isn't the only place where there

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might be another ocean in the solar

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system i was behind in my astronomy

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mars though it doesn't have one today

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and now we have all the excitement about

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enceladus which i just saw these images

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in 2006 but last week we have all this

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new excitement of eruptions of water

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with organic material in this water so

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there's a lot of

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exciting stuff going on in our solar

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system and and the question may be is

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there any life associated with the ice

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that we might be able to sample at some

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point in our students future

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here is um a depiction of following the

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water on earth following the water is

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what we're instructed to do in

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astrobiology and the blue line here is

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where we find liquid water on earth

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here's the zero to 100 degree range for

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distilled water but you can keep that

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water liquid by virtue of hydrostatic

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pressure all the way up to some very

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severe

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high temperatures at deep sea

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hydrothermal vents below zero you keep

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it liquid by

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its content of salt and other impurities

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so i'm after learning more about what

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happens in this zone here this

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temperature around here which brings

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relevance to the martian surface and

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subsurface

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here's the europan surface but the

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european ocean

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tells us there must be a temperature

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gradient so i want to push these

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boundaries as much as possible and see

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what we know about life in very cold ice

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i'm in fact then following the ice in

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order to follow the water and i'm doing

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so in the north

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in in part because i think the original

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astrobiologists live there

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we might think of ice as frozen water

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but the native inuit think of water as

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melted ice

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and in fact ice is the natural state of

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water in our solar system so i think

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they knew something before we did it's

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it's also a perspective to bring in how

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you study ice up until recently

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microbiologists to study what was in ice

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would melt the ice return it to its

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liquid water state which completely

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changes the environment the habitat they

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were occupying so my aim is to study the

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microbes in the unaltered ice

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the north also gives us the possibility

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to study

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different types of ice formations i

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circle the arctic sea ice but we also

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have freshwater glacial ice on greenland

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and we have the permafrost siberian and

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alaskan canadian permafrost which is

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frozen soil

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if we look at

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average global tabulations of these

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types of bodies of ice on earth

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at any one time about 20 percent of the

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of the surface of our planet is covered

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with one form of ice or another

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it's the glacial ice sheets that win the

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prize for the greatest volume of ice but

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if we're following the water they have

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the smallest fraction of liquid water in

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them and this is because they have the

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least impurities to depress that

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freezing point so if we really want to

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follow the water sea ice wins the prize

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there and it's particular aspect is that

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you can get very cold temperatures and

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still have a considerable fraction of

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that's liquid in the ice

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the eutectic point or the freezing point

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for salt water is minus 55 which is

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again the average temperature of the

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surface of mars

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permafrost is also has a special

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interest

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it has the it ranks second with seasonal

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snow

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for the amount of water but it also

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brings us closer to geologic age because

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some of these permafrosts are quite old

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and one feature in permafrost that's

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understudied as an astrobiological

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habitat analog are cryopegs or lenses of

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briny liquid that are buried deeply

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in permafrost they might make nice

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analogs for future studs

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if we now look at the total number of

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microbes that are in these different ice

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formations so this is just number of

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bacteria remember that picture i showed

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you before

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freshwater ice has the lowest numbers

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and note that there's not a single

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sterile piece of ice that we know about

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they all contain some number of bacteria

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200 to 1000 in freshwater ice

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on the other end of the spectrum we have

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permafrost with over ten to the eighth

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bacteria per gram of that material and

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that isn't really a surprise to

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microbiologists because it's soil that's

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frozen and soils contain 10 of the ninth

282
00:11:13,350 --> 00:11:11,440
per per gram typically so this is not a

283
00:11:14,470 --> 00:11:13,360
surprise

284
00:11:18,550 --> 00:11:14,480
in between

285
00:11:21,670 --> 00:11:18,560
numerically are salt water forms of ice

286
00:11:23,670 --> 00:11:21,680
up to a million per ml as we saw before

287
00:11:26,470 --> 00:11:23,680
and the difference here is that in most

288
00:11:28,470 --> 00:11:26,480
cases these organisms are active they're

289
00:11:30,150 --> 00:11:28,480
doing something and it's because they

290
00:11:32,230 --> 00:11:30,160
are not restricted in terms of the

291
00:11:33,990 --> 00:11:32,240
amount of water available to them or

292
00:11:36,150 --> 00:11:34,000
nutrients

293
00:11:38,550 --> 00:11:36,160
the other interesting thing you can

294
00:11:40,790 --> 00:11:38,560
observe in this table is that

295
00:11:43,350 --> 00:11:40,800
if you're talking about particle poor

296
00:11:45,190 --> 00:11:43,360
ice you have lower numbers of bacteria

297
00:11:47,590 --> 00:11:45,200
as soon as you introduce

298
00:11:50,389 --> 00:11:47,600
particles mineral grains organic

299
00:11:53,750 --> 00:11:50,399
detritus any sort of attachment surface

300
00:11:55,509 --> 00:11:53,760
to ice your numbers zoom up

301
00:11:58,150 --> 00:11:55,519
we have plenty of examples on this

302
00:12:01,190 --> 00:11:58,160
planet of ice formations that are rich

303
00:12:02,470 --> 00:12:01,200
with mineral rains this is sea ice laden

304
00:12:06,069 --> 00:12:02,480
with sediment somewhere between

305
00:12:08,310 --> 00:12:06,079
permafrost and very clean ice

306
00:12:09,750 --> 00:12:08,320
well my first trips to the arctic and

307
00:12:12,629 --> 00:12:09,760
the dead of winter

308
00:12:14,470 --> 00:12:12,639
the march of 2001 north of barrow the

309
00:12:17,110 --> 00:12:14,480
temperature there was minus 40 at the

310
00:12:19,509 --> 00:12:17,120
time and this was work done with an nsf

311
00:12:21,350 --> 00:12:19,519
life and extreme environments award to

312
00:12:23,110 --> 00:12:21,360
meet ohio eiken who is a sea ice

313
00:12:24,550 --> 00:12:23,120
geophysicist at the university of

314
00:12:27,269 --> 00:12:24,560
fairbanks

315
00:12:29,350 --> 00:12:27,279
we went out on the rv sled the research

316
00:12:31,110 --> 00:12:29,360
vessel sled very sophisticated inuit

317
00:12:33,190 --> 00:12:31,120
device here which works perfectly to

318
00:12:35,990 --> 00:12:33,200
take you over the cold ice

319
00:12:38,069 --> 00:12:36,000
our aim was to core into the ice we had

320
00:12:39,750 --> 00:12:38,079
a little power generator because it's

321
00:12:41,829 --> 00:12:39,760
like drilling cement

322
00:12:44,069 --> 00:12:41,839
to get a temperature gradient here the

323
00:12:45,990 --> 00:12:44,079
coldest temperature we got was minus 20

324
00:12:47,670 --> 00:12:46,000
degrees because the snow overlying

325
00:12:49,750 --> 00:12:47,680
insulates

326
00:12:52,550 --> 00:12:49,760
and some of you may have heard of

327
00:12:54,389 --> 00:12:52,560
work by my graduate student karen younga

328
00:12:56,790 --> 00:12:54,399
that came from this project

329
00:12:59,110 --> 00:12:56,800
so here is a sea ice core pulled out of

330
00:13:01,030 --> 00:12:59,120
there and lying on its side here's the

331
00:13:03,509 --> 00:13:01,040
interface with the ocean so here's the

332
00:13:05,829 --> 00:13:03,519
warmest temperature and the darkness

333
00:13:07,990 --> 00:13:05,839
here is a visualization of all the

334
00:13:09,750 --> 00:13:08,000
microbes that live in it the sea ice

335
00:13:11,990 --> 00:13:09,760
microbial community which jim will talk

336
00:13:14,629 --> 00:13:12,000
about a little bit further

337
00:13:17,110 --> 00:13:14,639
i'm after again the coldest ice near the

338
00:13:18,949 --> 00:13:17,120
atmosphere the snow atmosphere interface

339
00:13:20,550 --> 00:13:18,959
there's kind of a rule of thumb in sea

340
00:13:23,030 --> 00:13:20,560
ice that once the temperature drops

341
00:13:24,870 --> 00:13:23,040
below minus five degrees the ice becomes

342
00:13:27,590 --> 00:13:24,880
impermeable

343
00:13:29,350 --> 00:13:27,600
it's mechanically strong and we think

344
00:13:32,550 --> 00:13:29,360
that little can

345
00:13:34,310 --> 00:13:32,560
squeeze out of it if you will

346
00:13:36,550 --> 00:13:34,320
and if you haven't really thought about

347
00:13:38,870 --> 00:13:36,560
fresh water versus sea ice

348
00:13:41,190 --> 00:13:38,880
here's a little kitchen demonstration

349
00:13:42,790 --> 00:13:41,200
that you can do for your own family and

350
00:13:45,430 --> 00:13:42,800
students if you like this is a

351
00:13:47,269 --> 00:13:45,440
freshwater ice cube made from tap water

352
00:13:49,670 --> 00:13:47,279
and this is an ice cube made from sea

353
00:13:52,150 --> 00:13:49,680
water with some blue stain dribbled over

354
00:13:55,110 --> 00:13:52,160
it the stain just washes off the fresh

355
00:13:57,590 --> 00:13:55,120
water ice it is not porous the sea ice

356
00:13:59,990 --> 00:13:57,600
is highly porous and soaks up the stain

357
00:14:02,629 --> 00:14:00,000
immediately that porosity is where the

358
00:14:06,389 --> 00:14:02,639
liquid phase is and that's the source of

359
00:14:08,949 --> 00:14:06,399
the habitats now this is very warm ice

360
00:14:10,550 --> 00:14:08,959
so there's a lot of porosity here

361
00:14:12,389 --> 00:14:10,560
but we're talking we want to get to the

362
00:14:14,310 --> 00:14:12,399
point of talking about very cold ice so

363
00:14:17,030 --> 00:14:14,320
let me do that more formally here for

364
00:14:18,790 --> 00:14:17,040
you this is a panel of artificially

365
00:14:21,269 --> 00:14:18,800
created sea ice

366
00:14:24,310 --> 00:14:21,279
30 millimeter square panel

367
00:14:26,150 --> 00:14:24,320
being shown here the white is where h2o

368
00:14:28,389 --> 00:14:26,160
is moved into the solid phase and the

369
00:14:31,670 --> 00:14:28,399
black is the brine liquid phase that

370
00:14:34,069 --> 00:14:31,680
remains so you can see that the pores in

371
00:14:36,790 --> 00:14:34,079
there are quite sizable

372
00:14:38,550 --> 00:14:36,800
just drop the temperature a degree and

373
00:14:41,430 --> 00:14:38,560
everything begins to

374
00:14:44,150 --> 00:14:41,440
narrow up the pores decrease in size

375
00:14:45,990 --> 00:14:44,160
overall porosity decreases take it to

376
00:14:48,710 --> 00:14:46,000
winter temperatures

377
00:14:50,790 --> 00:14:48,720
and boy you've moved all the h2o pretty

378
00:14:52,629 --> 00:14:50,800
much into the solid phase and

379
00:14:54,790 --> 00:14:52,639
conventional thinking at this time was

380
00:14:57,829 --> 00:14:54,800
that the pores were all closed up as i

381
00:14:59,509 --> 00:14:57,839
said an impermeable ice mass bad news

382
00:15:01,509 --> 00:14:59,519
for microbial life

383
00:15:03,189 --> 00:15:01,519
maybe you can be preserved in here but

384
00:15:04,230 --> 00:15:03,199
not much is going to happen as long as

385
00:15:06,230 --> 00:15:04,240
you are

386
00:15:08,069 --> 00:15:06,240
squished into

387
00:15:10,389 --> 00:15:08,079
impermeable zones here

388
00:15:12,870 --> 00:15:10,399
the problem with this or let me also say

389
00:15:14,389 --> 00:15:12,880
that you can see the brine concentrating

390
00:15:17,110 --> 00:15:14,399
factor here because

391
00:15:19,910 --> 00:15:17,120
as this closes up as i said drops below

392
00:15:21,430 --> 00:15:19,920
-5 the salt and the other impurities

393
00:15:23,350 --> 00:15:21,440
have no place to go so they get

394
00:15:24,389 --> 00:15:23,360
concentrated into these small pore

395
00:15:26,230 --> 00:15:24,399
spaces

396
00:15:29,590 --> 00:15:26,240
and it's not just the salt but we've

397
00:15:30,949 --> 00:15:29,600
learned that it's also the microbes

398
00:15:33,590 --> 00:15:30,959
but the problem here is that we're at

399
00:15:36,310 --> 00:15:33,600
the millimeter scale and a bacterium is

400
00:15:38,629 --> 00:15:36,320
on the order of one micrometer in size

401
00:15:41,110 --> 00:15:38,639
so we're way out of

402
00:15:43,750 --> 00:15:41,120
out of sync here in terms of size for

403
00:15:46,389 --> 00:15:43,760
examining a habitat for a microbe we

404
00:15:48,389 --> 00:15:46,399
wanted to get to the micrometer scale

405
00:15:50,470 --> 00:15:48,399
so we set up a laboratory a freezer

406
00:15:53,189 --> 00:15:50,480
laboratory with a factory modified

407
00:15:56,230 --> 00:15:53,199
epifluorescence microscope with computer

408
00:15:57,749 --> 00:15:56,240
image analysis next to it and a graduate

409
00:15:59,030 --> 00:15:57,759
student willing to spend her life in

410
00:16:01,829 --> 00:15:59,040
that freezer

411
00:16:03,590 --> 00:16:01,839
and she developed a way to take a slice

412
00:16:04,870 --> 00:16:03,600
of natural sea ice from the from the

413
00:16:06,870 --> 00:16:04,880
winter

414
00:16:10,230 --> 00:16:06,880
carefully cut it across the top to

415
00:16:12,629 --> 00:16:10,240
expose the to open up some of the pores

416
00:16:15,189 --> 00:16:12,639
with these are exaggerated pore spaces

417
00:16:17,269 --> 00:16:15,199
she had to develop a dappy stain or a

418
00:16:18,389 --> 00:16:17,279
dna specific stain so that when you

419
00:16:21,269 --> 00:16:18,399
dropped it on there it wouldn't

420
00:16:23,430 --> 00:16:21,279
immediately freeze but instead would

421
00:16:25,670 --> 00:16:23,440
diffuse into the brine pores so it had

422
00:16:26,710 --> 00:16:25,680
to be isothermal isohalene that took a

423
00:16:28,629 --> 00:16:26,720
while

424
00:16:31,430 --> 00:16:28,639
but once we figured out how to do that

425
00:16:33,590 --> 00:16:31,440
then we could peer into the ice without

426
00:16:36,389 --> 00:16:33,600
having melted it to see

427
00:16:39,590 --> 00:16:36,399
what kind of a habitat that was like

428
00:16:42,790 --> 00:16:39,600
the first image that i'll show you is

429
00:16:45,749 --> 00:16:42,800
unstained just transmit transmission

430
00:16:47,749 --> 00:16:45,759
light to look directly into the ice and

431
00:16:49,189 --> 00:16:47,759
what can we see at the scale of

432
00:16:51,110 --> 00:16:49,199
micrometers

433
00:16:53,110 --> 00:16:51,120
this was a very exciting image when we

434
00:16:55,030 --> 00:16:53,120
first saw it

435
00:16:57,670 --> 00:16:55,040
this is the solid phase of ice and these

436
00:17:00,230 --> 00:16:57,680
are the brine pores 50 micrometers

437
00:17:02,230 --> 00:17:00,240
scaled here what you're seeing what i

438
00:17:05,029 --> 00:17:02,240
want you to see is that these pores are

439
00:17:06,949 --> 00:17:05,039
not isolated they are all connected

440
00:17:09,350 --> 00:17:06,959
it's an interconnected system on the

441
00:17:11,990 --> 00:17:09,360
scale of the microbe

442
00:17:14,069 --> 00:17:12,000
and since this ice sea ice on our planet

443
00:17:14,949 --> 00:17:14,079
anyway has a temperature gradient across

444
00:17:20,390 --> 00:17:14,959
it

445
00:17:22,710 --> 00:17:20,400
convection and advection of fluids

446
00:17:27,510 --> 00:17:22,720
through this matrix through this network

447
00:17:32,390 --> 00:17:30,549
now this is also an unstained panel and

448
00:17:34,549 --> 00:17:32,400
what you're seeing are two pairs of

449
00:17:36,870 --> 00:17:34,559
diatoms sea ice algae that have been

450
00:17:39,669 --> 00:17:36,880
trapped in the ice and they are not

451
00:17:41,990 --> 00:17:39,679
frozen into the solid part of the ice

452
00:17:43,830 --> 00:17:42,000
they are excluded into the liquid phase

453
00:17:45,909 --> 00:17:43,840
this is the brine phase and they're

454
00:17:47,510 --> 00:17:45,919
fluorescing green not because of a stain

455
00:17:49,669 --> 00:17:47,520
but because they're chloroplasts are

456
00:17:51,590 --> 00:17:49,679
naturally autofluorescent and they're

457
00:17:53,430 --> 00:17:51,600
very healthy looking there's no cell

458
00:17:55,029 --> 00:17:53,440
damage that's visible we're not doing

459
00:17:56,950 --> 00:17:55,039
anything in the winter in the arctic

460
00:17:59,190 --> 00:17:56,960
because there's no sunlight but

461
00:18:01,190 --> 00:17:59,200
they appear undamaged we have to go to

462
00:18:03,430 --> 00:18:01,200
the epi fluorescent light and the dna

463
00:18:05,350 --> 00:18:03,440
stain to see the bacteria that they are

464
00:18:07,990 --> 00:18:05,360
plentiful and concentrated in these

465
00:18:10,310 --> 00:18:08,000
liquid phases

466
00:18:12,630 --> 00:18:10,320
using another stain a postdoc with me at

467
00:18:14,789 --> 00:18:12,640
the time christopher kremz

468
00:18:16,789 --> 00:18:14,799
he discovered that these sea ice algae

469
00:18:18,470 --> 00:18:16,799
were coating themselves with what we

470
00:18:21,029 --> 00:18:18,480
call eps

471
00:18:23,110 --> 00:18:21,039
extracellular polysaccharide substances

472
00:18:24,070 --> 00:18:23,120
or exopolymers these are basically

473
00:18:25,669 --> 00:18:24,080
sugars

474
00:18:29,029 --> 00:18:25,679
that take the form of gelatinous

475
00:18:32,470 --> 00:18:29,039
material or literally mucus and it turns

476
00:18:35,830 --> 00:18:32,480
out that the ice pores of

477
00:18:37,990 --> 00:18:35,840
sea ice pores the liquid phase is filled

478
00:18:40,310 --> 00:18:38,000
with this mucous material this is

479
00:18:42,470 --> 00:18:40,320
unstained even unstained you can see the

480
00:18:44,549 --> 00:18:42,480
model the appearance of what's in there

481
00:18:46,549 --> 00:18:44,559
the gelatinous material

482
00:18:49,590 --> 00:18:46,559
so the cells are coating themselves up

483
00:18:51,510 --> 00:18:49,600
to survive the winter

484
00:18:53,510 --> 00:18:51,520
well christopher did some very detailed

485
00:18:54,830 --> 00:18:53,520
analyses of

486
00:18:57,990 --> 00:18:54,840
artificially

487
00:18:59,510 --> 00:18:58,000
created sea ice with and without these

488
00:19:03,990 --> 00:18:59,520
exopolymers

489
00:19:06,310 --> 00:19:04,000
completely abiotic system you get these

490
00:19:10,549 --> 00:19:06,320
euclidean pores that appear to be

491
00:19:12,310 --> 00:19:10,559
disconnected with eps produced by life

492
00:19:14,870 --> 00:19:12,320
you've now got a completely altered

493
00:19:17,029 --> 00:19:14,880
habitat with fractal dimensions to the

494
00:19:20,070 --> 00:19:17,039
pores faces greater surface area to

495
00:19:23,270 --> 00:19:20,080
colonize in interiorly the ice holds

496
00:19:25,750 --> 00:19:23,280
more salt it stays holds more liquid at

497
00:19:28,950 --> 00:19:25,760
lower temperatures it's a remarkable

498
00:19:30,950 --> 00:19:28,960
example of microbes altering the physics

499
00:19:34,230 --> 00:19:30,960
of their environment to enhance its

500
00:19:38,150 --> 00:19:36,230
well what about the bacteria and here's

501
00:19:40,230 --> 00:19:38,160
a panel from the coldest ice we had at

502
00:19:41,750 --> 00:19:40,240
that time you're seeing three ice

503
00:19:43,830 --> 00:19:41,760
crystals together

504
00:19:46,710 --> 00:19:43,840
a triple point juncture and we blow up a

505
00:19:49,190 --> 00:19:46,720
little pour in here and voila there

506
00:19:51,110 --> 00:19:49,200
there's bacteria in there

507
00:19:53,350 --> 00:19:51,120
and this is my favorite slide at minus

508
00:19:54,710 --> 00:19:53,360
15 degrees we captured a bacterium in

509
00:19:56,870 --> 00:19:54,720
the act

510
00:19:58,789 --> 00:19:56,880
we can't really prove that but as you

511
00:20:01,029 --> 00:19:58,799
focused up and down on

512
00:20:06,710 --> 00:20:01,039
that you can see the break point in the

513
00:20:10,310 --> 00:20:08,310
which raises the question of what are

514
00:20:12,230 --> 00:20:10,320
these organisms doing in there okay

515
00:20:13,669 --> 00:20:12,240
they've altered the habitat to make it

516
00:20:15,510 --> 00:20:13,679
more habitable

517
00:20:16,870 --> 00:20:15,520
but are they able to do anything in

518
00:20:18,549 --> 00:20:16,880
there and

519
00:20:20,549 --> 00:20:18,559
in the interest of time i won't explain

520
00:20:21,669 --> 00:20:20,559
the methodology here but i'm happy to

521
00:20:23,350 --> 00:20:21,679
later

522
00:20:25,430 --> 00:20:23,360
what you're seeing here are sections of

523
00:20:27,190 --> 00:20:25,440
the ice from near the ocean to the

524
00:20:28,310 --> 00:20:27,200
atmosphere so the coldest section is

525
00:20:30,230 --> 00:20:28,320
here

526
00:20:32,470 --> 00:20:30,240
and 100

527
00:20:34,870 --> 00:20:32,480
of the cells that were active were

528
00:20:36,950 --> 00:20:34,880
attached to something

529
00:20:40,310 --> 00:20:36,960
to make a long story short short the

530
00:20:42,390 --> 00:20:40,320
bacteria were are also embedded in eps

531
00:20:44,950 --> 00:20:42,400
in this exopolymer material it's not

532
00:20:47,190 --> 00:20:44,960
just the sea ice algae all the microbes

533
00:20:49,029 --> 00:20:47,200
in there are embedded in this material

534
00:20:51,750 --> 00:20:49,039
that is facilitating their ability to

535
00:20:54,470 --> 00:20:51,760
metabolize and we think it's because the

536
00:20:56,870 --> 00:20:54,480
these gels are highly hydrated

537
00:20:59,190 --> 00:20:56,880
so they're providing greater water

538
00:21:00,870 --> 00:20:59,200
around the cell even while there's this

539
00:21:05,909 --> 00:21:00,880
serious brine

540
00:21:09,909 --> 00:21:07,990
since that project we've

541
00:21:12,950 --> 00:21:09,919
not been satisfied with just being able

542
00:21:15,029 --> 00:21:12,960
to get a single ice core or a set of ice

543
00:21:16,789 --> 00:21:15,039
cores from one trip so we've been

544
00:21:18,070 --> 00:21:16,799
overwintering in the arctic we've had

545
00:21:20,470 --> 00:21:18,080
two of these

546
00:21:22,230 --> 00:21:20,480
remarkable expeditions

547
00:21:24,070 --> 00:21:22,240
which are under the guise of canadian

548
00:21:26,710 --> 00:21:24,080
leadership especially during the

549
00:21:28,470 --> 00:21:26,720
international polar year and we froze in

550
00:21:30,549 --> 00:21:28,480
in the north

551
00:21:32,950 --> 00:21:30,559
and got to work with our

552
00:21:35,430 --> 00:21:32,960
astrobiology friends up there

553
00:21:37,830 --> 00:21:35,440
and as we're asking the question is this

554
00:21:39,990 --> 00:21:37,840
sea ice that we're standing on that the

555
00:21:41,750 --> 00:21:40,000
ship is immobilized in that you can land

556
00:21:44,149 --> 00:21:41,760
a plane on

557
00:21:45,990 --> 00:21:44,159
is this a museum for all the microbes in

558
00:21:49,669 --> 00:21:46,000
there or is there something going on

559
00:21:54,870 --> 00:21:51,750
so here is a

560
00:21:57,110 --> 00:21:54,880
contour map that shows you temperature

561
00:21:59,350 --> 00:21:57,120
cool colors are for cold warm colors for

562
00:22:00,789 --> 00:21:59,360
warm the sea ice grows at the bottom

563
00:22:02,390 --> 00:22:00,799
into the ocean if you haven't thought

564
00:22:04,310 --> 00:22:02,400
about that before

565
00:22:06,870 --> 00:22:04,320
so you can see the ice growth during the

566
00:22:09,510 --> 00:22:06,880
course of the winter we sampled

567
00:22:11,510 --> 00:22:09,520
periodically throughout the winter

568
00:22:13,350 --> 00:22:11,520
three different ice horizons to look at

569
00:22:15,029 --> 00:22:13,360
the microbes that were trapped in there

570
00:22:16,950 --> 00:22:15,039
when we started when we got there was

571
00:22:19,909 --> 00:22:16,960
already pretty cold for them

572
00:22:21,510 --> 00:22:19,919
and we got some colder temperatures here

573
00:22:23,190 --> 00:22:21,520
again in the interest of time i'm just

574
00:22:26,149 --> 00:22:23,200
going to summarize what we found from

575
00:22:28,390 --> 00:22:26,159
that first overwintering expedition

576
00:22:30,630 --> 00:22:28,400
graduate student thesis work here we

577
00:22:33,270 --> 00:22:30,640
found that in in the case of both

578
00:22:35,350 --> 00:22:33,280
bacteria and archaea which we confirmed

579
00:22:37,830 --> 00:22:35,360
are really present in sea ice

580
00:22:39,510 --> 00:22:37,840
they persist in numbers and diversity

581
00:22:41,510 --> 00:22:39,520
throughout the winter there's no

582
00:22:43,630 --> 00:22:41,520
die off of one group or another they're

583
00:22:46,070 --> 00:22:43,640
persisting and we can see that the

584
00:22:47,430 --> 00:22:46,080
exopolymeric content of that ice

585
00:22:49,110 --> 00:22:47,440
increases during the course of the

586
00:22:50,870 --> 00:22:49,120
winter so we obviously think those two

587
00:22:52,710 --> 00:22:50,880
things are connected

588
00:22:55,430 --> 00:22:52,720
this is a mechanism for

589
00:22:57,029 --> 00:22:55,440
surviving the winter but then my other

590
00:22:59,350 --> 00:22:57,039
student lead

591
00:23:01,510 --> 00:22:59,360
was fascinated by these viruses that

592
00:23:02,870 --> 00:23:01,520
were present at high concentrations we

593
00:23:05,190 --> 00:23:02,880
already knew they were present at high

594
00:23:06,950 --> 00:23:05,200
concentrations in summer ice but we

595
00:23:09,430 --> 00:23:06,960
didn't know for winter ice and here they

596
00:23:10,950 --> 00:23:09,440
are at very high concentrations what

597
00:23:12,710 --> 00:23:10,960
that means is that the viruses and

598
00:23:15,110 --> 00:23:12,720
bacteria have been brought together for

599
00:23:18,310 --> 00:23:15,120
some super high contact rates in these

600
00:23:20,549 --> 00:23:18,320
brine pores 600 times the rate at which

601
00:23:21,750 --> 00:23:20,559
they'd encounter each other in normal

602
00:23:23,909 --> 00:23:21,760
seawater

603
00:23:25,590 --> 00:23:23,919
so this is a dynamite situation for an

604
00:23:29,430 --> 00:23:25,600
interaction between a bacterium and a

605
00:23:31,990 --> 00:23:29,440
virus if you can do that positively

606
00:23:34,390 --> 00:23:32,000
and lee did some short-term experiments

607
00:23:37,750 --> 00:23:34,400
at the coldest conditions we could get

608
00:23:38,789 --> 00:23:37,760
stably on the ship minus 12 degrees 16

609
00:23:40,390 --> 00:23:38,799
salt

610
00:23:42,549 --> 00:23:40,400
and he was able to show that bacterial

611
00:23:45,590 --> 00:23:42,559
and viral numbers are not static they're

612
00:23:47,830 --> 00:23:45,600
changing bacteria are growing dying

613
00:23:49,990 --> 00:23:47,840
being hit by viruses viruses are

614
00:23:52,789 --> 00:23:50,000
increasing dropping it's a very dynamic

615
00:23:56,789 --> 00:23:54,470
when we're not at sea

616
00:23:59,350 --> 00:23:56,799
we're working with koelia our model

617
00:24:02,310 --> 00:23:59,360
organism that carl alluded to it holds a

618
00:24:04,630 --> 00:24:02,320
number of records its growth record is

619
00:24:07,430 --> 00:24:04,640
jim's bug got to it first he'll tell you

620
00:24:10,230 --> 00:24:07,440
about that one but they both grow at -12

621
00:24:13,830 --> 00:24:10,240
swims at -10 produces enzymes produces

622
00:24:16,230 --> 00:24:13,840
these excessive exopolymers as you move

623
00:24:19,110 --> 00:24:16,240
into frozen temperatures so we're going

624
00:24:22,230 --> 00:24:19,120
from seawater into ice here and zoom it

625
00:24:24,870 --> 00:24:22,240
over produces eps

626
00:24:27,909 --> 00:24:24,880
what we're pursuing now with this model

627
00:24:31,190 --> 00:24:27,919
system we're pursuing the physics of how

628
00:24:33,350 --> 00:24:31,200
ice grows this is an abiotic situation

629
00:24:34,789 --> 00:24:33,360
here with lamellae they're called of ice

630
00:24:37,190 --> 00:24:34,799
growing let me

631
00:24:39,750 --> 00:24:37,200
show you real sea ice growing this is a

632
00:24:42,149 --> 00:24:39,760
scale of one millimeter my newest

633
00:24:44,310 --> 00:24:42,159
graduate student is working on this

634
00:24:47,190 --> 00:24:44,320
where after understanding how these

635
00:24:49,750 --> 00:24:47,200
growing physical lamellae actually trap

636
00:24:51,909 --> 00:24:49,760
organics and microbes how that process

637
00:24:54,149 --> 00:24:51,919
works

638
00:24:56,870 --> 00:24:54,159
and we're um working

639
00:25:00,070 --> 00:24:56,880
further with the virus that we

640
00:25:02,549 --> 00:25:00,080
obtained that attacks coelia

641
00:25:05,190 --> 00:25:02,559
and does so at a record low of minus 12

642
00:25:07,350 --> 00:25:05,200
degrees and 16 percent salt so we have a

643
00:25:09,110 --> 00:25:07,360
model system of this microbe with its

644
00:25:10,149 --> 00:25:09,120
attacking virus

645
00:25:12,070 --> 00:25:10,159
so that

646
00:25:14,630 --> 00:25:12,080
presents the potential in the

647
00:25:16,789 --> 00:25:14,640
microbiology community being able to

648
00:25:18,710 --> 00:25:16,799
have what's called a genetic system

649
00:25:21,110 --> 00:25:18,720
where you can

650
00:25:22,870 --> 00:25:21,120
move genes about if we can get this to

651
00:25:24,230 --> 00:25:22,880
work out

652
00:25:26,630 --> 00:25:24,240
and that's what we're ultimately

653
00:25:28,470 --> 00:25:26,640
interested in is the concept of lateral

654
00:25:30,789 --> 00:25:28,480
gene transfer

655
00:25:33,269 --> 00:25:30,799
usually we think of inheriting genes by

656
00:25:35,590 --> 00:25:33,279
reproducing you inherit genes from your

657
00:25:37,430 --> 00:25:35,600
parents from from the daughter cells

658
00:25:39,029 --> 00:25:37,440
from the parents but lateral gene

659
00:25:41,190 --> 00:25:39,039
transfer is a case

660
00:25:43,909 --> 00:25:41,200
where a bacterium being attacked by

661
00:25:47,110 --> 00:25:43,919
viruses here's a close-up showing the

662
00:25:49,029 --> 00:25:47,120
virus actually injecting some dna into

663
00:25:52,070 --> 00:25:49,039
the cell

664
00:25:54,470 --> 00:25:52,080
that dna normally normally

665
00:25:56,789 --> 00:25:54,480
would take over the bacterial host and

666
00:25:58,950 --> 00:25:56,799
reproduce hundreds of viruses

667
00:26:01,110 --> 00:25:58,960
kill the host and that's the way viruses

668
00:26:04,390 --> 00:26:01,120
reproduce themselves but sometimes the

669
00:26:06,710 --> 00:26:04,400
virus moves into the cell and joins the

670
00:26:09,110 --> 00:26:06,720
bacterial genome and lives benignly with

671
00:26:11,669 --> 00:26:09,120
it generation after generation and in

672
00:26:13,669 --> 00:26:11,679
the process it can bring in a new gene

673
00:26:15,510 --> 00:26:13,679
that it picked up by mistake when it was

674
00:26:17,909 --> 00:26:15,520
killing another bacterium

675
00:26:20,310 --> 00:26:17,919
it's a different way of evolving and it

676
00:26:21,990 --> 00:26:20,320
has the potential of a more rapid way of

677
00:26:23,669 --> 00:26:22,000
evolving

678
00:26:25,590 --> 00:26:23,679
we have some clues from the genome

679
00:26:27,909 --> 00:26:25,600
sequence of coelia

680
00:26:29,510 --> 00:26:27,919
not only that the genome sequence told

681
00:26:32,149 --> 00:26:29,520
us what we already knew which is that it

682
00:26:34,710 --> 00:26:32,159
likes to release a lot of stuff

683
00:26:37,029 --> 00:26:34,720
but it also tells us potential for

684
00:26:38,390 --> 00:26:37,039
lateral gene transfer there's a gene

685
00:26:41,190 --> 00:26:38,400
that's involved in archaeal

686
00:26:42,549 --> 00:26:41,200
methanogenesis in our bug and our bug

687
00:26:45,430 --> 00:26:42,559
doesn't

688
00:26:47,190 --> 00:26:45,440
it's a bacterium that lights organics so

689
00:26:49,750 --> 00:26:47,200
it's not a methanogen

690
00:26:51,350 --> 00:26:49,760
and we have two viruses

691
00:26:53,350 --> 00:26:51,360
whole genomes of viruses that are

692
00:26:55,510 --> 00:26:53,360
sitting in here benignly

693
00:26:58,630 --> 00:26:55,520
so we think we're on to something and i

694
00:27:01,669 --> 00:26:58,640
want to leave you with the idea that

695
00:27:04,549 --> 00:27:01,679
these poor spaces and very cold

696
00:27:06,950 --> 00:27:04,559
ices especially saline ices

697
00:27:09,830 --> 00:27:06,960
are not museums but some very exciting

698
00:27:12,470 --> 00:27:09,840
things may be going on in there that

699
00:27:14,630 --> 00:27:12,480
touch upon the evolution of life at very

700
00:27:16,870 --> 00:27:14,640
cold temperatures and we'd like to make

701
00:27:19,669 --> 00:27:16,880
some more progress on this concept of

702
00:27:21,909 --> 00:27:19,679
lateral gene transfer as a very potent

703
00:27:23,590 --> 00:27:21,919
mechanism for adapting to an extreme

704
00:27:25,830 --> 00:27:23,600
environment

705
00:27:27,590 --> 00:27:25,840
to have just a couple minutes for

706
00:27:29,510 --> 00:27:27,600
pretty pictures from our last

707
00:27:31,110 --> 00:27:29,520
overwintering expedition we just got off

708
00:27:33,190 --> 00:27:31,120
the ship uh

709
00:27:35,190 --> 00:27:33,200
i guess a month or so ago

710
00:27:37,350 --> 00:27:35,200
so we don't have a lot of results yet

711
00:27:39,510 --> 00:27:37,360
but most westerners are not up in the

712
00:27:42,630 --> 00:27:39,520
arctic when the ice begins to freeze to

713
00:27:44,310 --> 00:27:42,640
witness this scene of frost flowers

714
00:27:46,630 --> 00:27:44,320
this is where the ice on the ocean is

715
00:27:49,110 --> 00:27:46,640
just beginning to freeze and instead of

716
00:27:51,430 --> 00:27:49,120
all of the brine rejecting downwards

717
00:27:52,950 --> 00:27:51,440
into the ocean as as the when the water

718
00:27:53,990 --> 00:27:52,960
when the ice is still

719
00:27:56,710 --> 00:27:54,000
warm

720
00:27:58,310 --> 00:27:56,720
some of it ejects upwards

721
00:28:01,110 --> 00:27:58,320
and the atmosphere is now getting cold

722
00:28:03,590 --> 00:28:01,120
so it freezes and you have frost flowers

723
00:28:06,230 --> 00:28:03,600
so this is a field of frost flowers

724
00:28:08,950 --> 00:28:06,240
not studied before by microbiologists

725
00:28:10,789 --> 00:28:08,960
studied by the physicists for issues of

726
00:28:13,590 --> 00:28:10,799
convection of brine

727
00:28:16,149 --> 00:28:13,600
well guess what's in those frost flowers

728
00:28:19,110 --> 00:28:16,159
again this is not the night scene there

729
00:28:20,789 --> 00:28:19,120
but but the many millions of viruses

730
00:28:23,029 --> 00:28:20,799
that are in those

731
00:28:25,029 --> 00:28:23,039
frost flowers being ejected into the

732
00:28:27,350 --> 00:28:25,039
atmosphere now that's something to think

733
00:28:32,310 --> 00:28:29,350
and at this point i'll transfer the

734
00:28:38,950 --> 00:28:32,320
torch or the ice as the case may be to

735
00:28:44,470 --> 00:28:41,269
jody thanks a lot and carl also thank

736
00:28:46,389 --> 00:28:44,480
you for inviting us to do this this is

737
00:29:09,590 --> 00:28:46,399
a

738
00:29:10,710 --> 00:29:09,600
get there

739
00:29:12,310 --> 00:29:10,720
and

740
00:29:13,669 --> 00:29:12,320
so it's a search for low temperature

741
00:29:15,909 --> 00:29:13,679
growth

742
00:29:17,750 --> 00:29:15,919
i want to say a few words

743
00:29:20,230 --> 00:29:17,760
here about the discovery and

744
00:29:22,789 --> 00:29:20,240
significance of marine gas vacuolate

745
00:29:25,269 --> 00:29:22,799
bacteria which seems perhaps somewhat

746
00:29:27,510 --> 00:29:25,279
bizarre to you but it's related here i

747
00:29:29,830 --> 00:29:27,520
think to our topic i'm actually going to

748
00:29:32,070 --> 00:29:29,840
skip this second copy because of time

749
00:29:33,750 --> 00:29:32,080
limitations

750
00:29:35,510 --> 00:29:33,760
then i want to talk most importantly

751
00:29:38,470 --> 00:29:35,520
about the low temperature growth and

752
00:29:41,190 --> 00:29:38,480
then finish it up with the genomics of

753
00:29:43,669 --> 00:29:41,200
an extreme psychophile

754
00:29:45,430 --> 00:29:43,679
so our work began in the antarctic we

755
00:29:47,029 --> 00:29:45,440
weren't looking for low temperature

756
00:29:49,830 --> 00:29:47,039
growth at all we were looking for

757
00:29:51,510 --> 00:29:49,840
bacteria that degraded chitin

758
00:29:54,070 --> 00:29:51,520
and we were working off the antarctic

759
00:29:57,110 --> 00:29:54,080
peninsula which is the peninsula just

760
00:29:58,149 --> 00:29:57,120
south of south america there

761
00:30:03,830 --> 00:29:58,159
and

762
00:30:06,470 --> 00:30:03,840
we came across some of bacteria that

763
00:30:08,389 --> 00:30:06,480
were growing in the water

764
00:30:09,510 --> 00:30:08,399
that had gas vacuoles and the way we

765
00:30:11,590 --> 00:30:09,520
told this

766
00:30:12,789 --> 00:30:11,600
was that you can see on the lower left

767
00:30:15,269 --> 00:30:12,799
plate here

768
00:30:18,149 --> 00:30:15,279
colonies that are quite uh chalky white

769
00:30:20,149 --> 00:30:18,159
in appearance in contrast organisms over

770
00:30:21,750 --> 00:30:20,159
here the same species

771
00:30:24,470 --> 00:30:21,760
are not that way and the difference is

772
00:30:25,909 --> 00:30:24,480
that these organisms have gas vacuoles

773
00:30:27,350 --> 00:30:25,919
inside of them

774
00:30:29,269 --> 00:30:27,360
and so you can sort of tell just by

775
00:30:31,669 --> 00:30:29,279
looking at the colony type whether or

776
00:30:33,190 --> 00:30:31,679
not they have these gas vacuoles

777
00:30:34,870 --> 00:30:33,200
and then when you look at them under the

778
00:30:36,950 --> 00:30:34,880
microscope you can see these bright

779
00:30:41,110 --> 00:30:36,960
areas inside the cells which are

780
00:30:42,789 --> 00:30:41,120
indicative of gas vacuoles

781
00:30:44,470 --> 00:30:42,799
the real proof of whether they have gas

782
00:30:47,110 --> 00:30:44,480
vacuoles is to look in the electron

783
00:30:49,590 --> 00:30:47,120
microscope and you can see these doesn't

784
00:30:53,269 --> 00:30:49,600
drop too well but these little vesicles

785
00:30:55,190 --> 00:30:53,279
are the subunits of the gas vacuum

786
00:30:57,590 --> 00:30:55,200
when these are isolated

787
00:30:59,909 --> 00:30:57,600
they look like this they're cylindrical

788
00:31:02,389 --> 00:30:59,919
and they have conical tips on them

789
00:31:05,510 --> 00:31:02,399
and they consist of a protein it's just

790
00:31:10,070 --> 00:31:05,520
a single protein uh that forms this

791
00:31:13,430 --> 00:31:10,080
membrane around the uh the gas vesicle

792
00:31:15,909 --> 00:31:13,440
and that protein is hydrophobic

793
00:31:18,870 --> 00:31:15,919
so in the cell cytoplasm water cannot

794
00:31:20,950 --> 00:31:18,880
get into the vesicle but gases whatever

795
00:31:22,230 --> 00:31:20,960
the gas is in the environment pretty

796
00:31:24,070 --> 00:31:22,240
diffuses

797
00:31:26,149 --> 00:31:24,080
into the vesicle

798
00:31:28,630 --> 00:31:26,159
result is these little vesicles are

799
00:31:30,310 --> 00:31:28,640
hollow spots in the cell they allow the

800
00:31:34,389 --> 00:31:30,320
organism to rise

801
00:31:35,750 --> 00:31:34,399
or to fall in a gradient

802
00:31:38,230 --> 00:31:35,760
um

803
00:31:40,710 --> 00:31:38,240
ecologically they're important then in

804
00:31:43,830 --> 00:31:40,720
buoyancy or motion

805
00:31:46,470 --> 00:31:43,840
these are enabling organisms to rise i

806
00:31:47,750 --> 00:31:46,480
said or to fall depending upon how many

807
00:31:49,830 --> 00:31:47,760
they need to produce to be at the

808
00:31:52,630 --> 00:31:49,840
location they wish to be

809
00:31:54,470 --> 00:31:52,640
and this is a simple organelle

810
00:31:58,149 --> 00:31:54,480
of motility

811
00:32:00,710 --> 00:31:58,159
it's made with a 7 500 molecular weight

812
00:32:02,950 --> 00:32:00,720
protein very small protein and it's a

813
00:32:04,870 --> 00:32:02,960
repeating subunit that forms the

814
00:32:06,310 --> 00:32:04,880
membrane

815
00:32:08,870 --> 00:32:06,320
because of the simplicity of this

816
00:32:11,269 --> 00:32:08,880
structure i argue that these are likely

817
00:32:13,830 --> 00:32:11,279
an early evolutionarily speaking

818
00:32:15,269 --> 00:32:13,840
organelle of prokaryotic motility very

819
00:32:16,710 --> 00:32:15,279
simple to form

820
00:32:19,269 --> 00:32:16,720
some of you may be aware of the

821
00:32:20,549 --> 00:32:19,279
creationist argument about the bacterial

822
00:32:22,070 --> 00:32:20,559
flagellum

823
00:32:24,149 --> 00:32:22,080
which is of course the organelle

824
00:32:26,630 --> 00:32:24,159
motility most people know about

825
00:32:29,029 --> 00:32:26,640
being so complex it must have been

826
00:32:30,789 --> 00:32:29,039
designed by intelligent design well

827
00:32:31,509 --> 00:32:30,799
here's a very simple structure

828
00:32:33,269 --> 00:32:31,519
that

829
00:32:37,350 --> 00:32:33,279
could be designed by unintelligent

830
00:32:38,630 --> 00:32:37,360
design or what we call evolution

831
00:32:40,950 --> 00:32:38,640
anyway

832
00:32:43,590 --> 00:32:40,960
seeing that these organisms were in the

833
00:32:45,509 --> 00:32:43,600
water here made us think that since they

834
00:32:47,909 --> 00:32:45,519
are organelles of motility that allow

835
00:32:50,630 --> 00:32:47,919
you to rise or fall on a gradient that

836
00:32:52,230 --> 00:32:50,640
perhaps they're associated with the sea

837
00:32:55,029 --> 00:32:52,240
ice microbial community which is a

838
00:32:56,950 --> 00:32:55,039
stratified community

839
00:32:58,389 --> 00:32:56,960
and uh this is the evidence that we had

840
00:33:00,950 --> 00:32:58,399
from that cruise

841
00:33:03,669 --> 00:33:00,960
looking at the depth samples that were

842
00:33:05,830 --> 00:33:03,679
taken in samples in which were positive

843
00:33:07,990 --> 00:33:05,840
over here for the gas vacuolate

844
00:33:11,350 --> 00:33:08,000
organisms were all collected in the

845
00:33:14,870 --> 00:33:11,360
upper zone of the marine habitat 10

846
00:33:17,509 --> 00:33:14,880
meters a few at 25 meters

847
00:33:19,909 --> 00:33:17,519
but absolutely none of them had 100 200

848
00:33:22,710 --> 00:33:19,919
and 500 meters this suggests that these

849
00:33:24,389 --> 00:33:22,720
were floating the bacteria up toward the

850
00:33:26,870 --> 00:33:24,399
surface

851
00:33:28,310 --> 00:33:26,880
of the water now at the time we had our

852
00:33:30,310 --> 00:33:28,320
hypothesis

853
00:33:32,149 --> 00:33:30,320
we were at the palmer station there was

854
00:33:34,470 --> 00:33:32,159
no sea ice left

855
00:33:36,070 --> 00:33:34,480
so what we proposed to nsf was to go the

856
00:33:38,230 --> 00:33:36,080
next year

857
00:33:40,630 --> 00:33:38,240
to mcmurdo to actually look in the sea

858
00:33:43,509 --> 00:33:40,640
ice microbial community to see whether

859
00:33:44,789 --> 00:33:43,519
or not these gas vacuum bacteria were

860
00:33:46,950 --> 00:33:44,799
there

861
00:33:48,389 --> 00:33:46,960
so we sampled off mcmurdo station

862
00:33:50,549 --> 00:33:48,399
there's a nice

863
00:33:52,149 --> 00:33:50,559
a bunch of sea ice over here it's

864
00:33:54,149 --> 00:33:52,159
actually

865
00:33:57,269 --> 00:33:54,159
used to land airplanes on part of the

866
00:33:59,269 --> 00:33:57,279
year it's two meters thick typically uh

867
00:34:00,710 --> 00:33:59,279
and of course as the season progresses

868
00:34:02,710 --> 00:34:00,720
the summer season this will eventually

869
00:34:04,470 --> 00:34:02,720
melt off and they closely monitor this

870
00:34:06,630 --> 00:34:04,480
to make sure the planes are all right

871
00:34:08,869 --> 00:34:06,640
these are c130s on it

872
00:34:10,869 --> 00:34:08,879
we collected samples uh

873
00:34:13,190 --> 00:34:10,879
near the airstrip here at this macro

874
00:34:15,829 --> 00:34:13,200
station here some samples here but also

875
00:34:17,589 --> 00:34:15,839
we went across the sound but sound

876
00:34:19,349 --> 00:34:17,599
and collected some samples over there as

877
00:34:21,510 --> 00:34:19,359
well

878
00:34:23,030 --> 00:34:21,520
and uh jody's already sort of explained

879
00:34:25,109 --> 00:34:23,040
this and of course i got a polar bear in

880
00:34:26,470 --> 00:34:25,119
there just to keep you guys alert we're

881
00:34:28,069 --> 00:34:26,480
going to go to the arctic but we're not

882
00:34:29,990 --> 00:34:28,079
there yet

883
00:34:32,069 --> 00:34:30,000
anyway the sea ice community is sort of

884
00:34:34,389 --> 00:34:32,079
at the interface here between the water

885
00:34:37,190 --> 00:34:34,399
and and it's in the ice but at that

886
00:34:41,909 --> 00:34:39,669
and this just shows a cord sample which

887
00:34:43,829 --> 00:34:41,919
has the black here not black but the

888
00:34:46,149 --> 00:34:43,839
dark amount of

889
00:34:48,790 --> 00:34:46,159
sea ice microbial community in it due to

890
00:34:50,790 --> 00:34:48,800
the diatoms primarily that

891
00:34:52,710 --> 00:34:50,800
are the primary producers

892
00:34:54,790 --> 00:34:52,720
and then this shows a completely

893
00:34:57,109 --> 00:34:54,800
extruded and full-length

894
00:34:59,109 --> 00:34:57,119
uh sea ice column with the sea ice

895
00:35:01,349 --> 00:34:59,119
community at the bottom as jody has

896
00:35:03,190 --> 00:35:01,359
shown also

897
00:35:04,790 --> 00:35:03,200
and so we sampled in that sea ice

898
00:35:06,710 --> 00:35:04,800
community

899
00:35:08,390 --> 00:35:06,720
and what we found were a lot of colonies

900
00:35:09,750 --> 00:35:08,400
that were like this

901
00:35:11,270 --> 00:35:09,760
and you can see there are pigmented

902
00:35:12,710 --> 00:35:11,280
colonies

903
00:35:14,790 --> 00:35:12,720
many of the sea ice bacteria are

904
00:35:16,550 --> 00:35:14,800
pigmented but they have a

905
00:35:19,510 --> 00:35:16,560
white fringe around the colonies and

906
00:35:21,270 --> 00:35:19,520
this is the chalkiness of gas vesicles

907
00:35:22,710 --> 00:35:21,280
and we verified these things for gas

908
00:35:25,109 --> 00:35:22,720
vacuums we went ahead and surveyed and

909
00:35:27,510 --> 00:35:25,119
sure enough you we did find the gas

910
00:35:29,829 --> 00:35:27,520
calculate bacteria in the sea ice

911
00:35:31,670 --> 00:35:29,839
so in this particular sample at site 4

912
00:35:33,270 --> 00:35:31,680
83

913
00:35:36,550 --> 00:35:33,280
of the bacteria in this sample which was

914
00:35:38,630 --> 00:35:36,560
in the ice 20 centimeters above the uh

915
00:35:40,069 --> 00:35:38,640
sea ice interface

916
00:35:42,390 --> 00:35:40,079
so there were a lot of them there not so

917
00:35:44,630 --> 00:35:42,400
many most of the sites but the point was

918
00:35:47,430 --> 00:35:44,640
they are in the ice and they are

919
00:35:49,190 --> 00:35:47,440
associated with that

920
00:35:50,950 --> 00:35:49,200
gradient of the ice

921
00:35:52,470 --> 00:35:50,960
and i'm going to skip this part because

922
00:35:55,270 --> 00:35:52,480
it's not so

923
00:35:58,230 --> 00:35:55,280
relevant to us except i wanted to

924
00:36:00,950 --> 00:35:58,240
point out we did go then to the north

925
00:36:02,310 --> 00:36:00,960
polar area and we sampled off point

926
00:36:04,150 --> 00:36:02,320
barrel

927
00:36:06,310 --> 00:36:04,160
there are several sites here and the

928
00:36:07,589 --> 00:36:06,320
site i want to talk about mostly is site

929
00:36:10,630 --> 00:36:07,599
number two

930
00:36:12,390 --> 00:36:10,640
which was in the elson lagoon

931
00:36:14,470 --> 00:36:12,400
and this is a different sort of habitat

932
00:36:15,589 --> 00:36:14,480
from the open marine habitat because as

933
00:36:17,589 --> 00:36:15,599
a lagoon

934
00:36:19,270 --> 00:36:17,599
there's a little more evaporation and

935
00:36:21,349 --> 00:36:19,280
concentration of salt

936
00:36:24,310 --> 00:36:21,359
so it's a sort of higher salt

937
00:36:29,190 --> 00:36:24,320
uh environment than the typical sea ice

938
00:36:29,200 --> 00:36:34,630
and i don't want to talk about this now

939
00:36:38,950 --> 00:36:36,950
so the question is

940
00:36:41,109 --> 00:36:38,960
are these sea ice bacteria good

941
00:36:43,510 --> 00:36:41,119
psychophiles we weren't set out

942
00:36:45,670 --> 00:36:43,520
initially to answer this question but

943
00:36:47,190 --> 00:36:45,680
and became of interest to us

944
00:36:49,349 --> 00:36:47,200
as we went along

945
00:36:52,829 --> 00:36:49,359
and so you might just ask yourself what

946
00:36:55,190 --> 00:36:52,839
would be the features of a psychophile

947
00:36:57,190 --> 00:36:55,200
um that's living

948
00:36:59,190 --> 00:36:57,200
that you want to believe is a very good

949
00:37:02,150 --> 00:36:59,200
psychophile one would be of course its

950
00:37:04,870 --> 00:37:02,160
ability to grow at zero degrees or below

951
00:37:08,390 --> 00:37:04,880
another possibility would that be uh

952
00:37:12,150 --> 00:37:08,400
have a low gc ratio

953
00:37:14,870 --> 00:37:12,160
and this relates to the dna the gc bond

954
00:37:18,310 --> 00:37:14,880
is a triple hydrogen bond the a t bond

955
00:37:20,550 --> 00:37:18,320
in contrast is a double hydrogen bond

956
00:37:22,230 --> 00:37:20,560
so if you think about replication

957
00:37:23,589 --> 00:37:22,240
it might be better to have double

958
00:37:25,510 --> 00:37:23,599
hydrogen bonds rather than triple

959
00:37:28,550 --> 00:37:25,520
hydrogen bonds to break

960
00:37:31,990 --> 00:37:28,560
uh so maybe a low gc organism is good

961
00:37:34,790 --> 00:37:32,000
ours is a 40 gc organism

962
00:37:37,670 --> 00:37:34,800
so that's pretty low in gc content by

963
00:37:39,990 --> 00:37:37,680
the way this argument does not apply to

964
00:37:41,829 --> 00:37:40,000
thermophilic bacteria we know this

965
00:37:42,950 --> 00:37:41,839
you can have low gc organs you might

966
00:37:44,230 --> 00:37:42,960
expect

967
00:37:45,750 --> 00:37:44,240
in the case of thermophiles that they

968
00:37:47,109 --> 00:37:45,760
would have more gc

969
00:37:49,589 --> 00:37:47,119
than at

970
00:37:51,990 --> 00:37:49,599
and that's not always the case

971
00:37:53,510 --> 00:37:52,000
so but i think uh evidence so far for

972
00:37:54,790 --> 00:37:53,520
the low temperature thing may indicate

973
00:37:56,230 --> 00:37:54,800
that this history

974
00:37:58,310 --> 00:37:56,240
we're not sure yet

975
00:37:59,270 --> 00:37:58,320
another thing is a habitat as jody's

976
00:38:02,950 --> 00:37:59,280
mentioned

977
00:38:05,670 --> 00:38:02,960
the coldest temperatures at the air

978
00:38:09,030 --> 00:38:05,680
interface with the ice so the father of

979
00:38:11,750 --> 00:38:09,040
the uh ice column for the surface

980
00:38:13,589 --> 00:38:11,760
is where you'd expect maybe to find your

981
00:38:15,670 --> 00:38:13,599
low temperature organisms

982
00:38:17,430 --> 00:38:15,680
you'd also like an organism and that's

983
00:38:19,750 --> 00:38:17,440
by the way where we did find it we found

984
00:38:22,630 --> 00:38:19,760
it in the upper

985
00:38:25,030 --> 00:38:22,640
50 centimeters of a 180 centimeter ice

986
00:38:27,910 --> 00:38:25,040
core near the surface

987
00:38:29,589 --> 00:38:27,920
of the toward the air

988
00:38:32,710 --> 00:38:29,599
also a toleration of freezing point

989
00:38:34,710 --> 00:38:32,720
depressants in the medium salt our bug

990
00:38:36,950 --> 00:38:34,720
grows at 12 percent salt i think joey's

991
00:38:39,030 --> 00:38:36,960
does at least that as well

992
00:38:40,870 --> 00:38:39,040
and and glycerol we find that this

993
00:38:42,870 --> 00:38:40,880
organism that we're growing

994
00:38:44,150 --> 00:38:42,880
can grow in glycerol utilizes glycerol

995
00:38:45,589 --> 00:38:44,160
as a carbon source that's a freezing

996
00:38:48,150 --> 00:38:45,599
point depressant it'll grow in the

997
00:38:50,150 --> 00:38:48,160
presence of five percent glycerol

998
00:38:52,710 --> 00:38:50,160
the other thing is that we would hope an

999
00:38:54,710 --> 00:38:52,720
organism would have a low maximum

1000
00:38:57,510 --> 00:38:54,720
temperature or growth

1001
00:39:00,310 --> 00:38:57,520
and i'll explain that in just a second

1002
00:39:02,310 --> 00:39:00,320
uh here is the ice column that we got

1003
00:39:03,829 --> 00:39:02,320
these organisms out of

1004
00:39:07,109 --> 00:39:03,839
this is a very different ice column the

1005
00:39:09,829 --> 00:39:07,119
dark areas in this ice column

1006
00:39:11,829 --> 00:39:09,839
are not sea ice microbial community

1007
00:39:14,150 --> 00:39:11,839
they are sediment

1008
00:39:16,310 --> 00:39:14,160
so in elsin lagoon

1009
00:39:19,109 --> 00:39:16,320
you have the phenomenon of anchor ice

1010
00:39:20,710 --> 00:39:19,119
formation the ice freezes on the bottom

1011
00:39:22,230 --> 00:39:20,720
and then it floats up and carries

1012
00:39:23,670 --> 00:39:22,240
sediment with it and then that gets

1013
00:39:25,910 --> 00:39:23,680
entrapped in the ice column so it's a

1014
00:39:27,910 --> 00:39:25,920
little bit different environment

1015
00:39:30,230 --> 00:39:27,920
and our bug was isolated near the

1016
00:39:33,990 --> 00:39:30,240
surface here in this sediment

1017
00:39:37,430 --> 00:39:35,589
so i wanted to say a little bit here

1018
00:39:38,710 --> 00:39:37,440
about growth rate of bacteria versus

1019
00:39:40,550 --> 00:39:38,720
temperature

1020
00:39:42,710 --> 00:39:40,560
we have e coli that you're all quite

1021
00:39:45,589 --> 00:39:42,720
familiar with its high temperature for

1022
00:39:47,670 --> 00:39:45,599
growth is 44 degrees its low temperature

1023
00:39:51,109 --> 00:39:47,680
for growth is 8 degrees

1024
00:39:52,710 --> 00:39:51,119
so that span is about 35 36 degrees

1025
00:39:54,390 --> 00:39:52,720
in temperature and that's typical for

1026
00:39:56,390 --> 00:39:54,400
bacteria

1027
00:39:59,990 --> 00:39:56,400
hyperthermophiles they can grow as high

1028
00:40:02,870 --> 00:40:00,000
as 121 and down in the upper 80s as

1029
00:40:06,230 --> 00:40:02,880
their minimum growth temperature

1030
00:40:07,990 --> 00:40:06,240
and in the case of our bug

1031
00:40:10,710 --> 00:40:08,000
it has a low

1032
00:40:13,589 --> 00:40:10,720
maximum temperature for growth it grows

1033
00:40:16,790 --> 00:40:13,599
at 10 degrees and not higher

1034
00:40:19,030 --> 00:40:16,800
so if you sort of superimpose a growth

1035
00:40:21,990 --> 00:40:19,040
situation on this organism you would

1036
00:40:24,950 --> 00:40:22,000
expect that it could grow perhaps as low

1037
00:40:26,870 --> 00:40:24,960
temperatures at minus 20 or so

1038
00:40:28,710 --> 00:40:26,880
we don't know that that's the case

1039
00:40:29,670 --> 00:40:28,720
but we have shown growth at minus 12

1040
00:40:31,190 --> 00:40:29,680
degrees

1041
00:40:33,990 --> 00:40:31,200
so

1042
00:40:36,069 --> 00:40:34,000
the problem with the minus 20 thing is a

1043
00:40:38,790 --> 00:40:36,079
technical problem it's difficult to

1044
00:40:41,190 --> 00:40:38,800
provide conditions where you have liquid

1045
00:40:42,790 --> 00:40:41,200
water available in an experiment in the

1046
00:40:45,670 --> 00:40:42,800
laboratory

1047
00:40:48,390 --> 00:40:45,680
but that's something that i think can be

1048
00:40:50,470 --> 00:40:48,400
addressed in the future

1049
00:40:52,790 --> 00:40:50,480
here are the bacteria

1050
00:40:54,710 --> 00:40:52,800
and unlike uh what you might expect from

1051
00:40:56,870 --> 00:40:54,720
something from a cold environment these

1052
00:41:00,230 --> 00:40:56,880
are quite large bacteria about a

1053
00:41:03,109 --> 00:41:00,240
micrometer in diameter and they're 10 to

1054
00:41:05,750 --> 00:41:03,119
i think about 16 or 17 micrometers in

1055
00:41:08,630 --> 00:41:05,760
length that's a big big bacterium

1056
00:41:10,390 --> 00:41:08,640
and they have gas vehicles in them

1057
00:41:11,270 --> 00:41:10,400
which are the bright areas that you see

1058
00:41:12,710 --> 00:41:11,280
here

1059
00:41:14,470 --> 00:41:12,720
and i don't think this shows up very

1060
00:41:16,069 --> 00:41:14,480
well i didn't think it would have been

1061
00:41:18,390 --> 00:41:16,079
but you actually have

1062
00:41:21,430 --> 00:41:18,400
two types of gas vesicles here this is

1063
00:41:23,589 --> 00:41:21,440
an electron micrograph showing the cell

1064
00:41:25,670 --> 00:41:23,599
and there is a larger gas vesicle that

1065
00:41:27,670 --> 00:41:25,680
you can see somewhat and i'm afraid the

1066
00:41:30,309 --> 00:41:27,680
smaller one because of the layer and

1067
00:41:33,510 --> 00:41:30,319
such it doesn't show but there's one

1068
00:41:35,750 --> 00:41:33,520
very thin long vesicle type so it forms

1069
00:41:38,230 --> 00:41:35,760
two different types of gas vesicles

1070
00:41:40,230 --> 00:41:38,240
and we think that this may be important

1071
00:41:42,150 --> 00:41:40,240
perhaps in the brain pocket somewhere

1072
00:41:44,230 --> 00:41:42,160
along the way they have a reason for

1073
00:41:45,910 --> 00:41:44,240
producing these two different types this

1074
00:41:48,470 --> 00:41:45,920
organism actually also produces a

1075
00:41:49,430 --> 00:41:48,480
flagellum but we've never seen

1076
00:41:50,550 --> 00:41:49,440
yet

1077
00:41:52,390 --> 00:41:50,560
in our

1078
00:41:53,829 --> 00:41:52,400
we've never seen flagellar motility in

1079
00:41:55,510 --> 00:41:53,839
our cultures

1080
00:41:56,630 --> 00:41:55,520
and so this is your organism in the

1081
00:41:58,790 --> 00:41:56,640
upper

1082
00:42:00,870 --> 00:41:58,800
cluster here is the psychomonas group

1083
00:42:03,829 --> 00:42:00,880
aren't our bug is cyclomonase ingrid

1084
00:42:05,510 --> 00:42:03,839
hamiah

1085
00:42:07,510 --> 00:42:05,520
and

1086
00:42:08,950 --> 00:42:07,520
i want to point out here that we've done

1087
00:42:09,829 --> 00:42:08,960
some comparison with the genome work

1088
00:42:12,550 --> 00:42:09,839
with

1089
00:42:15,510 --> 00:42:12,560
closely related organisms the idiomarina

1090
00:42:17,910 --> 00:42:15,520
lohinsis from hawaii

1091
00:42:20,550 --> 00:42:17,920
and also with the colwellia group

1092
00:42:22,230 --> 00:42:20,560
calwellia psychiatria

1093
00:42:25,349 --> 00:42:22,240
please note that joey's organism is

1094
00:42:30,470 --> 00:42:27,190
and then some other organisms as well

1095
00:42:33,510 --> 00:42:30,480
with the genome work

1096
00:42:35,349 --> 00:42:33,520
and this is a growth curve here

1097
00:42:36,309 --> 00:42:35,359
the organism

1098
00:42:38,790 --> 00:42:36,319
grows

1099
00:42:40,550 --> 00:42:38,800
at -12 as we've said now the way we did

1100
00:42:42,950 --> 00:42:40,560
this was to make a medium up with the

1101
00:42:44,870 --> 00:42:42,960
glycerol and i think the salinity was

1102
00:42:45,910 --> 00:42:44,880
that of green water

1103
00:42:48,870 --> 00:42:45,920
and

1104
00:42:51,270 --> 00:42:48,880
we set up 25 pre-cooled tubes

1105
00:42:52,870 --> 00:42:51,280
and we inoculated these tubes

1106
00:42:54,870 --> 00:42:52,880
and

1107
00:42:56,390 --> 00:42:54,880
incubated them in a

1108
00:42:58,470 --> 00:42:56,400
very

1109
00:43:00,550 --> 00:42:58,480
a good incubator one of these hocks that

1110
00:43:02,309 --> 00:43:00,560
keeps the temperature at -12 we have

1111
00:43:04,470 --> 00:43:02,319
maximum minimum thermometer in there to

1112
00:43:05,990 --> 00:43:04,480
make sure that it never got higher than

1113
00:43:08,630 --> 00:43:06,000
the -12

1114
00:43:10,710 --> 00:43:08,640
and then we incubated these for weeks

1115
00:43:12,950 --> 00:43:10,720
now it's a very long-term experiment for

1116
00:43:15,270 --> 00:43:12,960
bacterial growth

1117
00:43:17,670 --> 00:43:15,280
and within the first week about six or

1118
00:43:19,829 --> 00:43:17,680
seven of the tubes froze

1119
00:43:22,069 --> 00:43:19,839
um

1120
00:43:23,109 --> 00:43:22,079
this is not made necessarily unexpected

1121
00:43:24,950 --> 00:43:23,119
but this is the sort of thing you

1122
00:43:27,750 --> 00:43:24,960
encounter

1123
00:43:29,190 --> 00:43:27,760
and interestingly enough after that none

1124
00:43:30,710 --> 00:43:29,200
of the tube strokes

1125
00:43:31,589 --> 00:43:30,720
and the organisms were continuing to

1126
00:43:33,910 --> 00:43:31,599
grow

1127
00:43:36,150 --> 00:43:33,920
so we think the eps that these bacteria

1128
00:43:38,630 --> 00:43:36,160
produce may have something to do

1129
00:43:41,030 --> 00:43:38,640
with lowering the freezing point of the

1130
00:43:44,309 --> 00:43:41,040
water but we're not uh positive about

1131
00:43:46,069 --> 00:43:44,319
that yet to be easily tested though

1132
00:43:49,270 --> 00:43:46,079
uh so anyway this is a growth curve we

1133
00:43:50,230 --> 00:43:49,280
got the generation time here was 240

1134
00:43:52,870 --> 00:43:50,240
hours

1135
00:43:55,349 --> 00:43:52,880
or 10 days for a generation time so it's

1136
00:43:57,990 --> 00:43:55,359
pretty slow growing

1137
00:43:59,670 --> 00:43:58,000
but it is growing nonetheless

1138
00:44:02,550 --> 00:43:59,680
so here are the features of the genome

1139
00:44:07,430 --> 00:44:05,030
first of all i think what's interesting

1140
00:44:10,150 --> 00:44:07,440
perhaps maybe the most interesting thing

1141
00:44:13,589 --> 00:44:10,160
is that the cell membrane proteins

1142
00:44:16,150 --> 00:44:13,599
are not as hydrophobic as typical cell

1143
00:44:17,829 --> 00:44:16,160
membrane proteins of bacteria

1144
00:44:20,870 --> 00:44:17,839
they're more hydrophilic

1145
00:44:22,870 --> 00:44:20,880
and this would give the bacterium

1146
00:44:23,670 --> 00:44:22,880
more fluidity in the cell membrane and

1147
00:44:24,470 --> 00:44:23,680
this is

1148
00:44:26,710 --> 00:44:24,480
uh

1149
00:44:28,069 --> 00:44:26,720
what what normally happens is the it's

1150
00:44:30,630 --> 00:44:28,079
thought that the cell membrane sort of

1151
00:44:32,309 --> 00:44:30,640
freezes up or rigidifies and then you

1152
00:44:34,470 --> 00:44:32,319
lose your ability to

1153
00:44:35,750 --> 00:44:34,480
uh to grow and transport nutrients and

1154
00:44:37,910 --> 00:44:35,760
so forth

1155
00:44:39,349 --> 00:44:37,920
and we found six different classes of

1156
00:44:41,750 --> 00:44:39,359
proteins here

1157
00:44:43,990 --> 00:44:41,760
a typical bacterium has four classes

1158
00:44:45,430 --> 00:44:44,000
there's one bacterium that has five

1159
00:44:47,630 --> 00:44:45,440
classes

1160
00:44:50,470 --> 00:44:47,640
and that's also psychophile called

1161
00:44:52,390 --> 00:44:50,480
pseudoalteromonas haloplanctus

1162
00:44:54,550 --> 00:44:52,400
this organism has actually six classes

1163
00:44:56,470 --> 00:44:54,560
of proteins so it's quite unusual

1164
00:44:59,109 --> 00:44:56,480
in that regard and this is based upon

1165
00:45:00,870 --> 00:44:59,119
correspondence analysis

1166
00:45:03,430 --> 00:45:00,880
one of these classes has many unique

1167
00:45:05,109 --> 00:45:03,440
orphan genes that may be related to low

1168
00:45:06,550 --> 00:45:05,119
temperature growth

1169
00:45:08,790 --> 00:45:06,560
and we don't know what these are are

1170
00:45:10,550 --> 00:45:08,800
doing but again express arrays would be

1171
00:45:13,910 --> 00:45:10,560
very interesting to try

1172
00:45:15,349 --> 00:45:13,920
uh to see what is perhaps going on here

1173
00:45:17,109 --> 00:45:15,359
which ones are expressed under low

1174
00:45:18,630 --> 00:45:17,119
temperatures

1175
00:45:21,510 --> 00:45:18,640
there's another interesting feature here

1176
00:45:24,390 --> 00:45:21,520
and that is that these organisms have

1177
00:45:26,150 --> 00:45:24,400
quite a bit of asparagine

1178
00:45:27,589 --> 00:45:26,160
this is amino acid that they have in

1179
00:45:29,829 --> 00:45:27,599
their proteins

1180
00:45:31,829 --> 00:45:29,839
now asparagine is interesting in that at

1181
00:45:33,430 --> 00:45:31,839
higher temperatures it breaks down to

1182
00:45:35,910 --> 00:45:33,440
aspartic acid

1183
00:45:38,230 --> 00:45:35,920
so you don't see so much in mesophiles

1184
00:45:40,870 --> 00:45:38,240
and certainly thermophiles but in this

1185
00:45:42,550 --> 00:45:40,880
psychophile you see a lot of it

1186
00:45:45,510 --> 00:45:42,560
and there's less of things like

1187
00:45:48,630 --> 00:45:45,520
methionine cysteine and histamine

1188
00:45:50,309 --> 00:45:48,640
and these are sensitive to oxygen and at

1189
00:45:52,550 --> 00:45:50,319
low temperatures of course the

1190
00:45:54,550 --> 00:45:52,560
environment is going to have a lot more

1191
00:45:55,829 --> 00:45:54,560
oxygen in it

1192
00:45:58,150 --> 00:45:55,839
so we think these things may be

1193
00:45:58,829 --> 00:45:58,160
important whoops

1194
00:46:07,510 --> 00:45:58,839
to

1195
00:46:08,710 --> 00:46:07,520
there we go

1196
00:46:10,870 --> 00:46:08,720
uh so

1197
00:46:12,870 --> 00:46:10,880
this is the correspondence analysis

1198
00:46:14,790 --> 00:46:12,880
plotting against the most informative

1199
00:46:17,030 --> 00:46:14,800
axes that they found

1200
00:46:18,790 --> 00:46:17,040
one is the asparagine concentration and

1201
00:46:20,390 --> 00:46:18,800
you can see they have generally quite a

1202
00:46:22,790 --> 00:46:20,400
bit of asparagine they're the six

1203
00:46:25,190 --> 00:46:22,800
different classes of protein illustrated

1204
00:46:29,270 --> 00:46:26,790
aromaticity

1205
00:46:30,870 --> 00:46:29,280
they don't have so many aromatic amino

1206
00:46:33,349 --> 00:46:30,880
acids in them

1207
00:46:36,390 --> 00:46:33,359
and hydrophobicity they have a low

1208
00:46:38,150 --> 00:46:36,400
hydrophobicity in the proteins so we

1209
00:46:40,150 --> 00:46:38,160
think these are probably important

1210
00:46:42,069 --> 00:46:40,160
aspects of low temperature growth this

1211
00:46:44,309 --> 00:46:42,079
is just the amino acid composition of

1212
00:46:46,870 --> 00:46:44,319
total proteins and i want to just point

1213
00:46:48,390 --> 00:46:46,880
out here is the asparagine here you can

1214
00:46:51,190 --> 00:46:48,400
see it's quite a bit higher than you

1215
00:46:53,030 --> 00:46:51,200
have an e coli shoe and alanine denses

1216
00:46:54,309 --> 00:46:53,040
and vibrio cholera

1217
00:46:55,670 --> 00:46:54,319
so there's something going on here at

1218
00:46:57,349 --> 00:46:55,680
low temperature that's consistent with

1219
00:47:01,510 --> 00:46:57,359
that

1220
00:47:03,030 --> 00:47:01,520
methionine here compared to these other

1221
00:47:05,270 --> 00:47:03,040
bacteria

1222
00:47:07,030 --> 00:47:05,280
less of the histidine

1223
00:47:09,349 --> 00:47:07,040
and less of the

1224
00:47:10,950 --> 00:47:09,359
arginine and there are other features

1225
00:47:13,109 --> 00:47:10,960
i'm not going to point out here but the

1226
00:47:16,550 --> 00:47:13,119
proteins are somewhat different in terms

1227
00:47:19,030 --> 00:47:16,560
of their amino acid composition

1228
00:47:21,990 --> 00:47:19,040
so to summarize

1229
00:47:25,109 --> 00:47:22,000
uh we have a large number of cyclic gdp

1230
00:47:25,119 --> 00:47:27,510
that

1231
00:47:34,069 --> 00:47:31,349
are important in eps production

1232
00:47:35,589 --> 00:47:34,079
there are also chaperones and stress

1233
00:47:37,990 --> 00:47:35,599
proteins that we think are very

1234
00:47:40,390 --> 00:47:38,000
important in in terms of low temperature

1235
00:47:42,309 --> 00:47:40,400
growth refolding proteins so that

1236
00:47:44,630 --> 00:47:42,319
they're more able to

1237
00:47:46,069 --> 00:47:44,640
work at lower temperatures

1238
00:47:49,510 --> 00:47:46,079
there's also

1239
00:47:52,870 --> 00:47:49,520
uh betaine choline and betaine choline

1240
00:47:54,950 --> 00:47:52,880
is an osmolite as the

1241
00:47:56,950 --> 00:47:54,960
salt concentrations in brine pockets

1242
00:47:59,750 --> 00:47:56,960
increases this osmo light would be

1243
00:48:02,870 --> 00:47:59,760
produced by the cell inside the cell to

1244
00:48:03,910 --> 00:48:02,880
counterbalance the external osmotic

1245
00:48:04,870 --> 00:48:03,920
pressure

1246
00:48:07,109 --> 00:48:04,880
from the

1247
00:48:09,190 --> 00:48:07,119
salt

1248
00:48:11,430 --> 00:48:09,200
and then it has these two different gas

1249
00:48:13,030 --> 00:48:11,440
vessel proteins inside the genome as

1250
00:48:14,470 --> 00:48:13,040
well

1251
00:48:16,470 --> 00:48:14,480
curiously

1252
00:48:17,589 --> 00:48:16,480
the most closely related organism to

1253
00:48:19,589 --> 00:48:17,599
this

1254
00:48:22,390 --> 00:48:19,599
is is not of

1255
00:48:25,109 --> 00:48:22,400
these others that were in the same group

1256
00:48:27,270 --> 00:48:25,119
uh on the basis of proteins it's vibrio

1257
00:48:28,790 --> 00:48:27,280
cholera now vibrio cholera

1258
00:48:30,790 --> 00:48:28,800
is um

1259
00:48:32,870 --> 00:48:30,800
not only a pathogen but it's in a

1260
00:48:35,270 --> 00:48:32,880
different family and it's in fact in a

1261
00:48:37,430 --> 00:48:35,280
different order of the bacteria

1262
00:48:38,790 --> 00:48:37,440
so this was really quite a surprise to

1263
00:48:39,670 --> 00:48:38,800
us

1264
00:48:41,589 --> 00:48:39,680
but

1265
00:48:42,710 --> 00:48:41,599
in looking at the types of proteins that

1266
00:48:44,950 --> 00:48:42,720
are similar

1267
00:48:47,430 --> 00:48:44,960
it turns out it's basic

1268
00:48:51,109 --> 00:48:47,440
core metabolism proteins

1269
00:48:53,910 --> 00:48:51,119
things that give the organism energy

1270
00:48:55,349 --> 00:48:53,920
they have a glycolytic system which they

1271
00:48:58,470 --> 00:48:55,359
share in common

1272
00:49:00,950 --> 00:48:58,480
they have the tca cycle for example

1273
00:49:03,109 --> 00:49:00,960
they carry out fermentation so these

1274
00:49:06,309 --> 00:49:03,119
genes are the ones that are shared

1275
00:49:08,069 --> 00:49:06,319
uh with these uh with the vibrio cholera

1276
00:49:10,870 --> 00:49:08,079
and then these are the other organisms

1277
00:49:13,670 --> 00:49:10,880
uh here that we've showed shown and

1278
00:49:15,910 --> 00:49:13,680
psycho psycho three here is is not as

1279
00:49:18,630 --> 00:49:15,920
similar as chunella yes it's kind of

1280
00:49:20,309 --> 00:49:18,640
fascinating there are these differences

1281
00:49:22,390 --> 00:49:20,319
on this

1282
00:49:23,109 --> 00:49:22,400
comparison with other bacteria

1283
00:49:23,990 --> 00:49:23,119
so

1284
00:49:25,910 --> 00:49:24,000
the

1285
00:49:27,430 --> 00:49:25,920
vibrio cholera thing as i mentioned it's

1286
00:49:29,670 --> 00:49:27,440
surprising

1287
00:49:31,430 --> 00:49:29,680
we don't think it's a horizontal gene

1288
00:49:33,430 --> 00:49:31,440
transfer julia talked about lateral gene

1289
00:49:35,270 --> 00:49:33,440
transfer horizontal gene transfer is the

1290
00:49:37,270 --> 00:49:35,280
same thing a different word for it where

1291
00:49:39,270 --> 00:49:37,280
you're getting transfer perhaps of the

1292
00:49:42,950 --> 00:49:39,280
16s gene

1293
00:49:44,549 --> 00:49:42,960
into an unrelated group namely the

1294
00:49:46,309 --> 00:49:44,559
psychomonas group we don't think that

1295
00:49:48,790 --> 00:49:46,319
that's the case because it's just these

1296
00:49:50,630 --> 00:49:48,800
poor metabolic genes we think that is

1297
00:49:52,710 --> 00:49:50,640
they share an evolutionary history with

1298
00:49:56,549 --> 00:49:52,720
vibrio but that's an ancient history and

1299
00:50:02,069 --> 00:49:59,190
they also uh we in comparing with

1300
00:50:04,549 --> 00:50:02,079
psychoarithmetic uh secretary's minus 12

1301
00:50:06,790 --> 00:50:04,559
to 19 degree bug idiom arena is not

1302
00:50:08,630 --> 00:50:06,800
really a psychophile uh but this is

1303
00:50:11,109 --> 00:50:08,640
another organization comparison as i

1304
00:50:14,390 --> 00:50:11,119
said it was quite closely related but it

1305
00:50:17,030 --> 00:50:14,400
grows from 4 degrees to 46 degrees

1306
00:50:18,790 --> 00:50:17,040
at somewhat higher growth temperatures

1307
00:50:20,549 --> 00:50:18,800
nonetheless they share

1308
00:50:22,309 --> 00:50:20,559
many proteins in common these close

1309
00:50:24,630 --> 00:50:22,319
relatives and these proteins are

1310
00:50:26,710 --> 00:50:24,640
probably the most important ones for low

1311
00:50:28,790 --> 00:50:26,720
temperature growth they include things

1312
00:50:30,710 --> 00:50:28,800
involved with rna

1313
00:50:32,790 --> 00:50:30,720
and dna uh

1314
00:50:34,309 --> 00:50:32,800
synthesis and so your dna polymerase is

1315
00:50:36,790 --> 00:50:34,319
one for example

1316
00:50:38,950 --> 00:50:36,800
rna helicases and so forth so we think

1317
00:50:41,109 --> 00:50:38,960
these are the types of enzymes that are

1318
00:50:44,710 --> 00:50:41,119
really important for

1319
00:50:46,950 --> 00:50:44,720
cyclophilic bacterial growth

1320
00:50:49,430 --> 00:50:46,960
summary here

1321
00:50:51,589 --> 00:50:49,440
gas vacuole bacteria are indigenous to

1322
00:50:55,109 --> 00:50:51,599
the sea ice community

1323
00:50:57,109 --> 00:50:55,119
sea ice bacteria are superb psychophiles

1324
00:50:59,510 --> 00:50:57,119
psychomonas ingrahamian grows at minus

1325
00:51:01,270 --> 00:50:59,520
12 or lower

1326
00:51:03,910 --> 00:51:01,280
genomic peaches that are adventurous

1327
00:51:05,990 --> 00:51:03,920
unusual membranes ludicry six glasses of

1328
00:51:09,270 --> 00:51:06,000
protein very high asparagine

1329
00:51:11,670 --> 00:51:09,280
concentrations production of eps

1330
00:51:13,030 --> 00:51:11,680
and the two types of gas festivals that

1331
00:51:15,829 --> 00:51:13,040
they have

1332
00:51:17,589 --> 00:51:15,839
so i will leave it at that and uh

1333
00:51:19,510 --> 00:51:17,599
well i should mention i wanted is

1334
00:51:21,589 --> 00:51:19,520
especially mentioned only graduate

1335
00:51:24,470 --> 00:51:21,599
students and so forth from the lab

1336
00:51:26,790 --> 00:51:24,480
monica riley she was the

1337
00:51:28,309 --> 00:51:26,800
the power behind the genome sequence and

1338
00:51:29,910 --> 00:51:28,319
i have to give her special credit here

1339
00:51:31,910 --> 00:51:29,920
because i've talked a lot about that

1340
00:51:34,230 --> 00:51:31,920
work

1341
00:51:36,069 --> 00:51:34,240
okay i guess jody are we ready for

1342
00:51:38,470 --> 00:51:36,079
questions or what's the procedure at

1343
00:51:39,829 --> 00:51:38,480
this point

1344
00:51:41,750 --> 00:51:39,839
well the first

1345
00:51:48,710 --> 00:51:41,760
thing is for all of us to thank our

1346
00:51:54,710 --> 00:51:52,630
yeah the process here is for folks with

1347
00:51:57,349 --> 00:51:54,720
questions out there to raise their hands

1348
00:52:00,150 --> 00:51:57,359
on webex is the preferred way although

1349
00:52:02,069 --> 00:52:00,160
folks can also jump in uh while you're

1350
00:52:04,470 --> 00:52:02,079
raising your hands on webex let me just

1351
00:52:07,349 --> 00:52:04,480
put in a plug for the next director

1352
00:52:09,349 --> 00:52:07,359
seminar which is four weeks from today

1353
00:52:11,510 --> 00:52:09,359
by steve benner

1354
00:52:12,950 --> 00:52:11,520
so i hope you'll all tune in then and

1355
00:52:15,270 --> 00:52:12,960
maybe i'll

1356
00:52:17,910 --> 00:52:15,280
take the chair's prerogative here to ask

1357
00:52:19,670 --> 00:52:17,920
a question which may actually be more

1358
00:52:21,750 --> 00:52:19,680
appropriately directed to somebody in

1359
00:52:24,309 --> 00:52:21,760
the audience because it's not so much

1360
00:52:26,790 --> 00:52:24,319
directly on on what you talked about but

1361
00:52:29,190 --> 00:52:26,800
on the application of what you've talked

1362
00:52:30,870 --> 00:52:29,200
about particularly to europa and jody

1363
00:52:32,710 --> 00:52:30,880
i'm thinking of

1364
00:52:34,390 --> 00:52:32,720
your discussion of the microphysics of

1365
00:52:37,030 --> 00:52:34,400
the ice and i'm just wondering if

1366
00:52:39,670 --> 00:52:37,040
anybody has done modeling

1367
00:52:42,870 --> 00:52:39,680
that you know of of the

1368
00:52:45,190 --> 00:52:42,880
frozen ice above the european ocean to

1369
00:52:46,710 --> 00:52:45,200
understand at the bottom of that ice

1370
00:52:48,470 --> 00:52:46,720
where the ice in the ocean are in

1371
00:52:50,390 --> 00:52:48,480
contact

1372
00:52:53,109 --> 00:52:50,400
what kind of thickness

1373
00:52:54,710 --> 00:52:53,119
of ice might have the kind of

1374
00:52:57,829 --> 00:52:54,720
microstructure

1375
00:52:58,870 --> 00:52:57,839
with interconnected brine pores that you

1376
00:53:02,069 --> 00:52:58,880
find

1377
00:53:03,910 --> 00:53:02,079
in the sea ice that you're looking at

1378
00:53:06,230 --> 00:53:03,920
and just you know how might that

1379
00:53:10,630 --> 00:53:06,240
microphysics be reproduced

1380
00:53:12,069 --> 00:53:10,640
at the bottom of a european ice layer

1381
00:53:13,670 --> 00:53:12,079
well i don't think anybody's done that

1382
00:53:15,750 --> 00:53:13,680
modeling work yet i think they're still

1383
00:53:19,030 --> 00:53:15,760
debating how thick the ice cover is if

1384
00:53:20,549 --> 00:53:19,040
there is a an ocean what its salinity is

1385
00:53:22,309 --> 00:53:20,559
but there's plenty of modeling work

1386
00:53:24,870 --> 00:53:22,319
that's been done with regards to earth

1387
00:53:27,190 --> 00:53:24,880
sea ice and we know that temperature and

1388
00:53:30,630 --> 00:53:27,200
the salt concentration of the source

1389
00:53:32,870 --> 00:53:30,640
liquid control the final product of the

1390
00:53:34,069 --> 00:53:32,880
ice and its interconnectivity of pore

1391
00:53:37,030 --> 00:53:34,079
space

1392
00:53:37,990 --> 00:53:37,040
so if we knew the salinity of a europan

1393
00:53:40,630 --> 00:53:38,000
ocean

1394
00:53:42,309 --> 00:53:40,640
and if we knew the temperature gradient

1395
00:53:43,910 --> 00:53:42,319
then we have ways to immediately

1396
00:53:46,069 --> 00:53:43,920
calculate and model

1397
00:53:48,710 --> 00:53:46,079
where you could expect to find enough

1398
00:53:50,710 --> 00:53:48,720
liquid porosity to support

1399
00:53:52,870 --> 00:53:50,720
microbes

1400
00:53:54,790 --> 00:53:52,880
well if there are some european modelers

1401
00:53:57,349 --> 00:53:54,800
out there i hope you take that as

1402
00:54:00,150 --> 00:53:57,359
something of a challenge from jody and

1403
00:54:02,470 --> 00:54:00,160
try to take a crack at that

1404
00:54:04,390 --> 00:54:02,480
so uh let's see do we have any hands

1405
00:54:06,549 --> 00:54:04,400
raised marco there are no hands raised

1406
00:54:08,870 --> 00:54:06,559
yet in webex so let me encourage you to

1407
00:54:11,030 --> 00:54:08,880
do so if you can otherwise if somebody

1408
00:54:13,829 --> 00:54:11,040
has a question out there or a comment

1409
00:54:16,549 --> 00:54:13,839
please just jump in at this point

1410
00:54:21,990 --> 00:54:19,190
this is gene brentley at penn state

1411
00:54:23,190 --> 00:54:22,000
and can you hear me yes we sure can

1412
00:54:25,750 --> 00:54:23,200
go ahead gene

1413
00:54:28,150 --> 00:54:25,760
apparently you couldn't see us

1414
00:54:30,549 --> 00:54:28,160
anyway i wanted to ask jim staley

1415
00:54:32,870 --> 00:54:30,559
towards the end of his talk he was

1416
00:54:35,270 --> 00:54:32,880
mentioning protein similarities with

1417
00:54:37,109 --> 00:54:35,280
other organisms and unfortunately we got

1418
00:54:38,510 --> 00:54:37,119
disconnected but i was trying to figure

1419
00:54:41,589 --> 00:54:38,520
out did you mean that it was

1420
00:54:43,910 --> 00:54:41,599
phylogenetically related by rna to

1421
00:54:47,030 --> 00:54:43,920
vibrio calorie or were those just

1422
00:54:49,349 --> 00:54:47,040
protein homologies that were related

1423
00:54:51,589 --> 00:54:49,359
yeah it was protein homologies it was

1424
00:54:54,230 --> 00:54:51,599
surprising because it's not so closely

1425
00:54:56,230 --> 00:54:54,240
related on the basis of 16s phylogeny

1426
00:54:58,710 --> 00:54:56,240
and that's sort of the disparity there

1427
00:55:00,870 --> 00:54:58,720
how does one explain it but i i would

1428
00:55:05,030 --> 00:55:00,880
argue that since we're talking about

1429
00:55:07,670 --> 00:55:05,040
core metabolic genes of being in common

1430
00:55:09,750 --> 00:55:07,680
between vibrio and cyclone synchromei

1431
00:55:12,069 --> 00:55:09,760
that that's what they share

1432
00:55:14,230 --> 00:55:12,079
and those genes one wouldn't expect to

1433
00:55:15,829 --> 00:55:14,240
necessarily be involved in this sort of

1434
00:55:18,069 --> 00:55:15,839
peripheral activity that has to do with

1435
00:55:19,589 --> 00:55:18,079
cyclophilic so i think the 16s is

1436
00:55:21,670 --> 00:55:19,599
actually true here i don't think that's

1437
00:55:22,630 --> 00:55:21,680
a 16 s transfer that's happened that

1438
00:55:23,589 --> 00:55:22,640
would be my

1439
00:55:26,150 --> 00:55:23,599
argument

1440
00:55:32,069 --> 00:55:28,069
that makes sense

1441
00:55:36,069 --> 00:55:34,230
i think somebody else was also trying to

1442
00:55:38,630 --> 00:55:36,079
break in perhaps just about the same

1443
00:55:39,510 --> 00:55:38,640
time as jeans so if uh you were please

1444
00:55:41,349 --> 00:55:39,520
go ahead

1445
00:55:45,510 --> 00:55:41,359
the vicky meadows i think yeah it was

1446
00:55:50,630 --> 00:55:48,150
jim actually about um you talk about the

1447
00:55:52,630 --> 00:55:50,640
buoyancy control for these microbes does

1448
00:55:54,630 --> 00:55:52,640
anybody know or is anybody speculated as

1449
00:55:55,829 --> 00:55:54,640
to why they might need disbuoyancy

1450
00:55:58,309 --> 00:55:55,839
control are they trying to get to

1451
00:56:00,069 --> 00:55:58,319
optimum temperatures or insulation

1452
00:56:01,750 --> 00:56:00,079
that's a very good question

1453
00:56:03,510 --> 00:56:01,760
and i didn't have time to tell you but

1454
00:56:05,190 --> 00:56:03,520
these gas vacuoles are found on all

1455
00:56:07,670 --> 00:56:05,200
sorts of bacteria especially freshwater

1456
00:56:09,750 --> 00:56:07,680
bacteria so the cyanobacteria have them

1457
00:56:11,109 --> 00:56:09,760
they want to be up to the top where the

1458
00:56:13,430 --> 00:56:11,119
wall the light is coming in for

1459
00:56:15,190 --> 00:56:13,440
photosynthesis but you also have

1460
00:56:17,109 --> 00:56:15,200
photosynthetic bacteria that are in

1461
00:56:19,430 --> 00:56:17,119
oxygenic photosynthetic bacteria that

1462
00:56:20,950 --> 00:56:19,440
grow in the anaerobic zone of these very

1463
00:56:21,829 --> 00:56:20,960
same lakes where the cyanobacteria are

1464
00:56:23,430 --> 00:56:21,839
so they're

1465
00:56:25,270 --> 00:56:23,440
trying to fight beneath that there are

1466
00:56:27,270 --> 00:56:25,280
even some methanogens that produce gas

1467
00:56:28,630 --> 00:56:27,280
fractals in the archaea the same

1468
00:56:30,309 --> 00:56:28,640
structure

1469
00:56:33,270 --> 00:56:30,319
and they would be found in the sediments

1470
00:56:34,870 --> 00:56:33,280
or near to the sediments in lakes so

1471
00:56:36,230 --> 00:56:34,880
more or less depending upon the need of

1472
00:56:38,390 --> 00:56:36,240
the organism

1473
00:56:40,950 --> 00:56:38,400
any habitat that has a vertical gradient

1474
00:56:43,270 --> 00:56:40,960
like this could have gas vacuum so a

1475
00:56:44,950 --> 00:56:43,280
place like europa that would be a simple

1476
00:56:47,750 --> 00:56:44,960
organelle motility that might have

1477
00:56:52,950 --> 00:56:47,760
evolved early on and could be there yet

1478
00:56:52,960 --> 00:56:57,270
we have a question from ames

1479
00:57:01,349 --> 00:56:59,670
oh hi carl this is orlando santos over

1480
00:57:03,190 --> 00:57:01,359
in 239 and i had a question that was

1481
00:57:05,430 --> 00:57:03,200
similar to yours

1482
00:57:08,309 --> 00:57:05,440
about the physical structure of the ice

1483
00:57:10,309 --> 00:57:08,319
that contains microbes and what i'm

1484
00:57:12,870 --> 00:57:10,319
thinking about that is using it as a bio

1485
00:57:14,309 --> 00:57:12,880
signature so i'm wondering if anybody's

1486
00:57:17,270 --> 00:57:14,319
looked to see

1487
00:57:19,109 --> 00:57:17,280
how that structure changes like for

1488
00:57:22,069 --> 00:57:19,119
example say the

1489
00:57:24,390 --> 00:57:22,079
electrical conductivity of the ice or

1490
00:57:26,630 --> 00:57:24,400
the conductivity of the ice to radar for

1491
00:57:28,630 --> 00:57:26,640
example and if that could be used to

1492
00:57:29,750 --> 00:57:28,640
look to see if that structure exists on

1493
00:57:33,190 --> 00:57:29,760
europa

1494
00:57:35,589 --> 00:57:33,200
and then kind of a related question is

1495
00:57:37,190 --> 00:57:35,599
how does that structure develop under

1496
00:57:40,309 --> 00:57:37,200
different gravity conditions does

1497
00:57:42,230 --> 00:57:40,319
anybody look to see if if for example

1498
00:57:45,270 --> 00:57:42,240
hyper gravity conditions affects that

1499
00:57:50,710 --> 00:57:48,230
well those are excellent questions

1500
00:57:52,950 --> 00:57:50,720
as far as i know only proposals have

1501
00:57:55,750 --> 00:57:52,960
been written to do that sort of work

1502
00:57:58,230 --> 00:57:55,760
no work has gone forward with that

1503
00:58:01,589 --> 00:57:58,240
it keep in mind that it's fairly new

1504
00:58:03,030 --> 00:58:01,599
information that exopolymers alter the

1505
00:58:04,950 --> 00:58:03,040
physics of ice

1506
00:58:06,309 --> 00:58:04,960
so we're

1507
00:58:08,150 --> 00:58:06,319
like i said we've written a couple of

1508
00:58:10,470 --> 00:58:08,160
proposals with no success yet but we'd

1509
00:58:12,470 --> 00:58:10,480
love to look at the concept of

1510
00:58:14,470 --> 00:58:12,480
altered physics of ice as a bio

1511
00:58:17,430 --> 00:58:14,480
signature i think the problem is going

1512
00:58:19,670 --> 00:58:17,440
to be one of scale we can all already

1513
00:58:22,630 --> 00:58:19,680
recognize on a small scale that you you

1514
00:58:25,190 --> 00:58:22,640
could detect these differences both

1515
00:58:27,030 --> 00:58:25,200
visually and by the mechanical strength

1516
00:58:29,030 --> 00:58:27,040
of the ice the more porous and

1517
00:58:29,750 --> 00:58:29,040
liquid-filled it is the less strong it

1518
00:58:32,549 --> 00:58:29,760
is

1519
00:58:34,870 --> 00:58:32,559
but to detect a biosignature remotely

1520
00:58:37,670 --> 00:58:34,880
with a spacecraft you're talking about a

1521
00:58:39,910 --> 00:58:37,680
different scale of evaluating the ice

1522
00:58:42,309 --> 00:58:39,920
with lots of different issues to deal

1523
00:58:44,150 --> 00:58:42,319
with so i think that's a big challenge i

1524
00:58:47,510 --> 00:58:44,160
think conceptually we've got a

1525
00:58:49,349 --> 00:58:47,520
biosignature but to translate that into

1526
00:58:51,589 --> 00:58:49,359
one that we can use in the search for

1527
00:58:55,990 --> 00:58:51,599
life that's

1528
00:59:07,829 --> 00:58:57,829
okay we have a question from montana

1529
00:59:23,750 --> 00:59:10,150
montana state montana i think your

1530
00:59:23,760 --> 00:59:33,030
so

1531
00:59:38,309 --> 00:59:34,630
well while we're waiting for montana

1532
00:59:41,829 --> 00:59:38,319
state to unmute their microphone uh

1533
00:59:45,230 --> 00:59:41,839
i'd i'd love to hear more discussion of

1534
00:59:48,390 --> 00:59:45,240
uh this potential for using the

1535
00:59:50,309 --> 00:59:48,400
microstructure of ice as a biosignature

1536
00:59:52,150 --> 00:59:50,319
that really was striking i thought this

1537
00:59:54,549 --> 00:59:52,160
discussion that you just had with

1538
00:59:57,510 --> 00:59:54,559
orlando

1539
01:00:00,870 --> 00:59:57,520
was was very much to the point

1540
01:00:03,270 --> 01:00:00,880
uh are there

1541
01:00:06,230 --> 01:00:03,280
well what what do you think is the next

1542
01:00:08,470 --> 01:00:06,240
step you spoke about writing proposals

1543
01:00:09,589 --> 01:00:08,480
and without asking you to reveal what

1544
01:00:16,230 --> 01:00:09,599
you're writing

1545
01:00:20,230 --> 01:00:18,309
excuse me i overspoke you just at the

1546
01:00:21,990 --> 01:00:20,240
end what was your final question well

1547
01:00:25,910 --> 01:00:22,000
what what do you think are the next

1548
01:00:26,829 --> 01:00:25,920
steps in developing the ability to use

1549
01:00:29,109 --> 01:00:26,839
the

1550
01:00:32,710 --> 01:00:29,119
microstructure alterations that you're

1551
01:00:35,109 --> 01:00:32,720
seeing in ice as a result of the eps

1552
01:00:37,030 --> 01:00:35,119
the next steps in developing the ability

1553
01:00:39,910 --> 01:00:37,040
to use that as a biosignature well

1554
01:00:41,349 --> 01:00:39,920
perhaps the next baby step if you will

1555
01:00:43,990 --> 01:00:41,359
would be to

1556
01:00:46,390 --> 01:00:44,000
advance to a different scale from

1557
01:00:47,829 --> 01:00:46,400
we've gone from the millimeter down to

1558
01:00:50,069 --> 01:00:47,839
the micrometer and back up to the

1559
01:00:53,190 --> 01:00:50,079
millimeter scale let's get to the meter

1560
01:00:55,190 --> 01:00:53,200
scale which we could test in our arctic

1561
01:00:58,789 --> 01:00:55,200
develop some instrumentation that would

1562
01:01:00,309 --> 01:00:58,799
look down on arctic sea ice and look and

1563
01:01:02,870 --> 01:01:00,319
i don't know what the sensor would be

1564
01:01:04,870 --> 01:01:02,880
that would have to be worked out

1565
01:01:06,549 --> 01:01:04,880
the proposal i'm thinking of was not my

1566
01:01:08,630 --> 01:01:06,559
own

1567
01:01:09,589 --> 01:01:08,640
so i certainly won't elaborate further

1568
01:01:11,829 --> 01:01:09,599
on it

1569
01:01:14,150 --> 01:01:11,839
but there should be ways to take the

1570
01:01:15,670 --> 01:01:14,160
next step forward on the meter scale see

1571
01:01:16,630 --> 01:01:15,680
what different types of ice we can

1572
01:01:19,910 --> 01:01:16,640
detect

1573
01:01:21,190 --> 01:01:19,920
remotely at a distance of several meters

1574
01:01:23,670 --> 01:01:21,200
and you could even begin in the

1575
01:01:26,630 --> 01:01:23,680
laboratory with that process and and

1576
01:01:28,789 --> 01:01:26,640
eventually take it to the field

1577
01:01:32,710 --> 01:01:28,799
great thank you montana state do you

1578
01:01:35,670 --> 01:01:34,309
on the chat

1579
01:01:39,910 --> 01:01:35,680
ah

1580
01:01:41,990 --> 01:01:39,920
there a potential to isolate ancient

1581
01:01:43,670 --> 01:01:42,000
organisms from these brine channels in

1582
01:01:47,910 --> 01:01:43,680
an analogous fashion to what has been

1583
01:01:52,230 --> 01:01:49,270
um

1584
01:01:54,950 --> 01:01:52,240
so sea ice itself the oldest sea ice

1585
01:01:56,870 --> 01:01:54,960
that we used to have was 10 years

1586
01:01:58,789 --> 01:01:56,880
because of climate change today we're

1587
01:02:00,950 --> 01:01:58,799
losing that ice and we're losing the

1588
01:02:02,069 --> 01:02:00,960
multi-year ice so that our chances of

1589
01:02:04,630 --> 01:02:02,079
even getting

1590
01:02:06,470 --> 01:02:04,640
one or two-year-old ices is slim but

1591
01:02:09,109 --> 01:02:06,480
that certainly is not ancient

1592
01:02:11,030 --> 01:02:09,119
our best shot i think for getting

1593
01:02:13,190 --> 01:02:11,040
ancient microbes

1594
01:02:14,150 --> 01:02:13,200
analogous to the salt work that was

1595
01:02:16,870 --> 01:02:14,160
mentioned

1596
01:02:19,270 --> 01:02:16,880
is to work in permafrost and the deeper

1597
01:02:21,990 --> 01:02:19,280
in permafrost the older that material is

1598
01:02:25,349 --> 01:02:22,000
and that's why i showed you that

1599
01:02:27,430 --> 01:02:25,359
quick slide of cryo pegs these lenses of

1600
01:02:30,069 --> 01:02:27,440
liquid salt that are buried deeply in

1601
01:02:31,990 --> 01:02:30,079
permafrost they are beginning to be of a

1602
01:02:34,549 --> 01:02:32,000
geologic age

1603
01:02:36,230 --> 01:02:34,559
the russians have reported ages of up to

1604
01:02:38,470 --> 01:02:36,240
three million years

1605
01:02:41,349 --> 01:02:38,480
uh the ones that the cryo pegs we have

1606
01:02:42,870 --> 01:02:41,359
access to in alaska for example are more

1607
01:02:45,109 --> 01:02:42,880
on the order of one to two hundred

1608
01:02:48,710 --> 01:02:45,119
thousand years but that's getting us

1609
01:02:51,430 --> 01:02:48,720
there but the difference will be that

1610
01:02:54,870 --> 01:02:51,440
microbes in those cryo pegs they're in a

1611
01:02:57,109 --> 01:02:54,880
liquid uh habitat bathed by all sorts of

1612
01:02:58,230 --> 01:02:57,119
interesting things and i don't expect

1613
01:03:00,470 --> 01:02:58,240
them to be

1614
01:03:02,549 --> 01:03:00,480
preserved there but rather actively

1615
01:03:04,069 --> 01:03:02,559
evolving

1616
01:03:14,630 --> 01:03:04,079
so that's a slightly different question

1617
01:03:19,750 --> 01:03:16,390
ames your hand is still raised do you

1618
01:03:25,990 --> 01:03:22,309
oh sorry we must must have left it up

1619
01:03:31,670 --> 01:03:27,829
further questions from anyone you can

1620
01:03:37,430 --> 01:03:33,190
this is gene brenchley again since

1621
01:03:42,630 --> 01:03:39,990
i appreciated both of the talks by jody

1622
01:03:46,069 --> 01:03:42,640
and jim i did have one other thought for

1623
01:03:48,390 --> 01:03:46,079
jim he mentioned that he thought one

1624
01:03:52,549 --> 01:03:48,400
aspect of a psychophile would be that it

1625
01:03:54,789 --> 01:03:52,559
would have low gc content in the dna

1626
01:03:57,349 --> 01:03:54,799
and i can understand your reasoning and

1627
01:03:59,109 --> 01:03:57,359
thinking of terms of replication but

1628
01:04:01,270 --> 01:03:59,119
wouldn't there be so many replication

1629
01:04:04,950 --> 01:04:01,280
proteins and things to help replication

1630
01:04:07,349 --> 01:04:04,960
that maybe the gc content would be not

1631
01:04:10,150 --> 01:04:07,359
that important

1632
01:04:12,309 --> 01:04:10,160
you're quite likely right on that gene i

1633
01:04:13,109 --> 01:04:12,319
mean this is just sort of thrown out as

1634
01:05:21,829 --> 01:04:13,119
a

1635
01:05:23,750 --> 01:05:21,839
four weeks from now when steve benner

1636
01:05:26,549 --> 01:05:23,760
will be talking with us about a theory

1637
01:05:27,750 --> 01:05:26,559
of life so should be interesting okay