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[Music]

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[Applause]

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and my intent was to start with the

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acknowledgments upfront in case I don't

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get there later and that is to say that

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this is sort of an integrated effort

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from part of the rocket-powered life

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team and we thank the NASA Astrobiology

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Institute for funding and my goal today

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is going to be to integrate data that's

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come from several different students

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that have been working on various

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aspects of the system so you'll see me

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refer to them but this is taking just

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some of the snapshots of current

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information from a variety of different

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studies looking at both the geochemistry

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and integrated microbiology derive from

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each of these students and postdocs

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right now so the system that I'm going

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to talk about today is derived from just

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one of the sites that we work on in our

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pl I'm specifically going to look at the

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OMA know feel light and the reason here

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is that I'm trying to look into the

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subsurface of a system where we have an

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enormous volumetric amount of peridotite

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that's not dramatically impacted by

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other lithology surrounding it and so

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what we're able to do is to look into a

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subsurface environment where the

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peridotite is an aquifer that's active

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it's storing fluids and those fluids are

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in the 30 to 50 degrees C range and they

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have abundant hydrogen so I'm not going

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to be talking about the generation of

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that hydrogen today but rather to say

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everywhere we look we have anywhere from

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micro molar 2 milli molar concentrations

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of hydrogen and that is being modulated

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again by not only the geochemical

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dynamics but the microbial activity

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within the subsurface and in terms of

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linking this to some of the systems that

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I think this information is going to be

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relevant for I wanted to put up both of

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these slides today so when we talk about

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looking at subsurface life in a pretty

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tight in let's say in icy world's

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context most the time at least for what

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we're working on in in the Oman system

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we're not discussing really the ocean

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and the possible biological activity in

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the ocean system or the under surface of

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the ice although serpentinization the

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process we're studying is well known to

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modulate potentially the ocean chemistry

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rather we're interested in imagining

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what may occur in the

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rakh hosted environment and what those

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habitable niches are as you have fluid

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ingress and circulation at temperatures

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that are non hydrothermal so we're

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looking at what would be represented by

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large volumes of rock again but it away

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from a high heat source when we talk

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about Mars which is something that I

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refer to really briefly in part of the

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plenary yesterday in this particular

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case we're interested in our system in

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the more static component of the

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subsurface environment and I'll

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differentiate that today and these are

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areas where we're really not having

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aggressive fluid circulation or exchange

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it's relatively sealed system but we

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would like to know if you're again you

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had a subsurface aquifer on Mars and you

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had hydrogen stored or generated in that

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condition what is it required to allow

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biological activity to persist over long

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periods of time and if that should

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happen what would be both the signals of

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that extant life or again if it was to

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be preserved or fossilized what would we

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expect to see is those signals so

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contextually again I just keep coming

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back to where water rock interaction but

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under highly rock dominated conditions

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but trying to understand the microbial

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activity and preservation under that

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state so if I'm lucky now its own maybe

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almost about 2:30 and I could just talk

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okay so Oman system in cartoon format

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when I show this type of a picture of

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the surface environment of peridotite

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that would sort of be here looking at a

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mountain landscape what we're interested

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in is looking then again at the

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hydrology in the rock system in the

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steeper subsurface and we've been really

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fortunate to have access to the

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subsurface through pre-existing Legacy

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boreholes and that's a way that we're

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able to pull fluids out of the

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subsurface over a diverse array of

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conditions as well as targeted drilling

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in the last year in 2018 that has

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allowed us to pull and recover core over

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many hundreds of meters in multiple

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locations and those bore holes are again

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the cored rocks they're penetrating

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different parts of a hydrological regime

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so there's a shallow flow system shorter

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residence time residence time fluids

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moving through a fracture network in

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habitable conditions generated here and

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James long gave a great talk earlier

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this week about some of the geochemical

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states of that system but we're also

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really interested in the ability of life

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to persist and be

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and thrive and be active and preserved

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in the deeper parts here which I'm going

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to call the more closed system it's more

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hyper alkaline and highly reducing from

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having pulled a lot of fluids out year

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after year and across the different

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parts of the system we do know a lot

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about who the dominant organisms at

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least are biologically so kitty Rumford

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published a paper and following on from

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Hannah Miller really identifying for

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example a CEO thermia affirmative self

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of ibrahim athena bacterium several

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different organisms is some of the

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dominant like an methane sita genic

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sulfur cycling and nitrogen cycling taxa

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that are present now they're

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differentially distributed and more

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still trying to probe them the activity

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of different organisms in different

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states of the system to understand that

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role if we take one environment we're

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really profiling as a function of depth

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and we look at the different geochemical

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states of the system this is where we're

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in a sub oxic moderately reducing

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environment that we can find often in

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the shallower parts that upper tens of

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meters in the fractured aquifer but as

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soon as we get into a part of the system

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that again has a lot less fluid transfer

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that's occurring through it's more

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static and closed we rapidly drive down

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to the lower stability of lot water

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limit of water and are held there and so

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we actually have a huge amount of data

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that sits right down here but we can

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span these conditions when we pump

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fluids sorry about that

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and when we pump fluids we're pumping

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all of this up together and integrating

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it into that community so a lot of our

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goals at the moment have been to

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actually as a function of depth and in

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geochemical environments to separate

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this out better but if we're in the

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surface environment where there's a lot

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of fluid mixing going on

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nitrate it's our most dominant electron

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acceptor and so kitty our efforts been

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trying to trace the prevalence of

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nitrate and then we have full conversion

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to ammonia so this becomes a highly

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reducing system high ammonia fluids and

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the look at the differential gene

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abundance for nitrogen cycling the idea

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here would be although we have nitrate

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and some of these sort of more shallow

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mixing systems it's really not playing a

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role deeper down

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we do have sulfate throughout we often

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have sulfate in excess that's not being

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fully consumed we do lose our di si but

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we do have partially carbonated rocks

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and each of these set a state of the

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system that's

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interesting to probe biologically and

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some work published this year by Libby

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phones one of the things that were able

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to see is that no matter where we've

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been pulling fluids from in this more

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integrated fashion

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we're often sitting at about 10 to the 5

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cells per mil this is actually a

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surprisingly robust microbial population

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that we're seeing in the fluid system

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throughout and it's true even when we're

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in these more hyper alkaline fluids

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meaning once we're above pH of 10 and in

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the same study one of the things that

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Libby was working on was trying to probe

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both the reduction of co2 into through a

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variety of different pathways and it's

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assimilation into biomass in this

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particular assay what she was doing was

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trying to take 14 labeled bicarbonate

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and look at its conversion to methane to

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detect active Nathanael Genesis again

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what she can see is that there's active

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magenta thany Genesis through all the

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different pH and water chemistry's of

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the system although you know leave it

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there for right now so this was

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promising to us we also see methanogens

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distributed throughout the system

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however when we come in and we start to

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look at the geochemistry of the fluids

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and just the methane alone it's often

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quite confounding in terms of how to

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interpret the data so this is some work

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from Dan no chaffed and in this

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particular case what he's plotting is

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the Delta 13c of methane against c1 over

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c2 plus c3 alkanes in our surface

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fractured shallow mixed water kind of

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aquifers we get pulses of methane out

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and they're easily recognized as

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microbial we also get these higher rates

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of microbial methanogenesis there

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there's really no question however when

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we move to the closed system hyper

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alkaline part we have this enormous flip

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in terms of the Delta 13c of methane

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we're often sitting right around zero or

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per mil and it's very enigmatic to

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interpret it in terms of its origin and

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source but one of the things that's

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notable is when you look at c1 over they

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see two plus c3 work 10 to the 2 to 10

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to the 5 in terms of enrichment and it

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again points to this potential for a

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microbial source but we need to have

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other ways to assess and discriminate

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that and it would be surprising to be

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surprising to have methane with

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compositions as heavy as this that may

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be generated through by

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logical activity particularly because

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this is the state of the fluids also in

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which we're looking and trying to probe

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the activity of methanogens sitting at

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the lower stability limit of water

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sitting across these alkaline to hyper

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alkaline pH in very limited di C but

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these are in rocks that have undergone

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significant water rock reaction and are

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carbonated even though it's a low level

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of carbonation throughout so coming back

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to the geochemical parameters one of the

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things that dan did is he worked with

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both Shuhei owners lab and then with ed

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young ed young's lab trying to look at

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the clumped isotope systematics of the

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methane when we started this project the

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only parameter available to us here was

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looking at the cap 13 CH 3 d component

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and we're just looking at this case at

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different systems at what would be an

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isotopic equilibrium and in this case we

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have again significant bond disorder and

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it in a partitioning methane here that

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looks like it's microbial in nature this

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year we were able to get an extra lens

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into this through the cap 12 ch2 D 2 as

277
00:10:03,900 --> 00:10:02,170
well as in this kinds of systems and in

278
00:10:05,609 --> 00:10:03,910
this case this would be an array for

279
00:10:07,679 --> 00:10:05,619
both low to high temperature isotope

280
00:10:09,569 --> 00:10:07,689
equilibrium but when we're looking at

281
00:10:11,819 --> 00:10:09,579
these two rare mouse 18 isotopologues

282
00:10:14,340 --> 00:10:11,829
this would be for example data from Kidd

283
00:10:16,319 --> 00:10:14,350
Creek but this is the microbial array in

284
00:10:19,799 --> 00:10:16,329
a Mons plotting squarely within that as

285
00:10:21,239 --> 00:10:19,809
well from this lens so coming back to

286
00:10:23,909 --> 00:10:21,249
then trying to probe these systems in

287
00:10:25,829 --> 00:10:23,919
terms of the active biology Emily Krause

288
00:10:28,319 --> 00:10:25,839
gave a talk here earlier this week on

289
00:10:30,449 --> 00:10:28,329
Tuesday where she's going in and pulling

290
00:10:33,329 --> 00:10:30,459
DNA and out of these highly reduced

291
00:10:36,119 --> 00:10:33,339
hyper alkaline fluids and in sequencing

292
00:10:38,639 --> 00:10:36,129
in in this particular set of samples

293
00:10:40,499 --> 00:10:38,649
that we've had recently the remember

294
00:10:42,479 --> 00:10:40,509
again I had 10 to the 5 cells per mil as

295
00:10:44,999 --> 00:10:42,489
an average number across the system and

296
00:10:46,859 --> 00:10:45,009
now we have 10 to almost 20% of the

297
00:10:49,079 --> 00:10:46,869
total 16s reads are from methane a

298
00:10:51,419 --> 00:10:49,089
bacterium that's present that's a pretty

299
00:10:53,159 --> 00:10:51,429
abundant methanogenic population and

300
00:10:55,199 --> 00:10:53,169
these hyper alkaline reduced fluids and

301
00:10:56,699 --> 00:10:55,209
then in this other axis here what she's

302
00:10:59,280 --> 00:10:56,709
looking at is that is the number of

303
00:11:01,499 --> 00:10:59,290
transcripts and so the methanogens are

304
00:11:03,720 --> 00:11:01,509
by far the active population under this

305
00:11:05,519 --> 00:11:03,730
condition so we are getting a number of

306
00:11:06,960 --> 00:11:05,529
metrics that are telling us they're here

307
00:11:08,369 --> 00:11:06,970
and they're busy and they are making

308
00:11:09,749 --> 00:11:08,379
methane and we're capturing and

309
00:11:11,970 --> 00:11:09,759
collecting that with a pretty strong

310
00:11:15,330 --> 00:11:11,980
signal from both the geochemical by

311
00:11:17,640 --> 00:11:15,340
illogical space we have been very

312
00:11:19,470 --> 00:11:17,650
fortunate working here that him we had

313
00:11:21,780 --> 00:11:19,480
done targeted culturing that started a

314
00:11:24,480 --> 00:11:21,790
few years ago going after within

315
00:11:26,280 --> 00:11:24,490
methanogenesis and we do have one of the

316
00:11:27,900 --> 00:11:26,290
mechana bacterium in culture that's

317
00:11:29,640 --> 00:11:27,910
present in the system so Dan Coleman is

318
00:11:31,320 --> 00:11:29,650
actually mapping out the differential

319
00:11:33,540 --> 00:11:31,330
distribution of methane a bacterium

320
00:11:35,700 --> 00:11:33,550
across the system this is one of the

321
00:11:37,710 --> 00:11:35,710
math in a bacterium that we see and

322
00:11:40,050 --> 00:11:37,720
Hannah Miller was able to then start to

323
00:11:41,910 --> 00:11:40,060
grow it in the laboratory where she was

324
00:11:43,590 --> 00:11:41,920
providing it with a variety of carbon

325
00:11:45,930 --> 00:11:43,600
sources including trying to grow it on

326
00:11:48,270 --> 00:11:45,940
calcium carbonate and the idea here is

327
00:11:50,520 --> 00:11:48,280
with this particular isolate she's able

328
00:11:52,740 --> 00:11:50,530
to grow it much more easily in these

329
00:11:55,020 --> 00:11:52,750
more alkaline pH high D icy conditions

330
00:11:56,520 --> 00:11:55,030
but she can push it to higher pH and

331
00:11:58,680 --> 00:11:56,530
slower growth rates but still get

332
00:12:01,200 --> 00:11:58,690
persistent methane formation and see a

333
00:12:03,750 --> 00:12:01,210
huge shift in the Delta 13c of methane

334
00:12:05,850 --> 00:12:03,760
that's that increases by over 50 per mil

335
00:12:07,740 --> 00:12:05,860
and that's just a simple function of

336
00:12:08,910 --> 00:12:07,750
carbon limitation and availability in

337
00:12:10,830 --> 00:12:08,920
that system but it's such a strong

338
00:12:13,730 --> 00:12:10,840
switch that's flipping us in terms of

339
00:12:16,410 --> 00:12:13,740
what that bulk isotope characteristic is

340
00:12:18,570 --> 00:12:16,420
so to give an image of that order

341
00:12:19,830 --> 00:12:18,580
visioning is that back in the field site

342
00:12:21,210 --> 00:12:19,840
type of system is that when we're

343
00:12:23,190 --> 00:12:21,220
looking in areas where there's been this

344
00:12:24,840 --> 00:12:23,200
prior carbonation even though there's

345
00:12:27,090 --> 00:12:24,850
very little di C and we're sitting in

346
00:12:29,130 --> 00:12:27,100
hyper alkaline pH the rate and soluble

347
00:12:31,950 --> 00:12:29,140
ization of calcium carbonates very low

348
00:12:33,870 --> 00:12:31,960
but we must have a coupled acquisition

349
00:12:35,820 --> 00:12:33,880
system here which is allowing there to

350
00:12:38,100 --> 00:12:35,830
be the solubilization up taken almost

351
00:12:39,960 --> 00:12:38,110
quantitative conversion of that co2 into

352
00:12:41,460 --> 00:12:39,970
methane and that's something that we're

353
00:12:44,700 --> 00:12:41,470
now trying to probe and get at the rates

354
00:12:46,410 --> 00:12:44,710
for and just listening to san jose talk

355
00:12:48,480 --> 00:12:46,420
earlier today because it is fun to try

356
00:12:49,590 --> 00:12:48,490
and integrate through the week it's been

357
00:12:52,560 --> 00:12:49,600
really interesting to have these

358
00:12:55,080 --> 00:12:52,570
discussions about the km for the fan of

359
00:12:57,210 --> 00:12:55,090
genesis for this step for co2

360
00:12:59,010 --> 00:12:57,220
acquisition and to think about whether

361
00:13:00,900 --> 00:12:59,020
or not this organism or some of the ones

362
00:13:03,180 --> 00:13:00,910
that are adapted in here maybe do have a

363
00:13:04,560 --> 00:13:03,190
different km that affects some of the

364
00:13:07,800 --> 00:13:04,570
energetics and that's something that

365
00:13:09,660 --> 00:13:07,810
hasn't been directly tested or probed so

366
00:13:12,480 --> 00:13:09,670
just a the last part of this talk and

367
00:13:13,380 --> 00:13:12,490
just have a slider to to also connect to

368
00:13:15,360 --> 00:13:13,390
some of the work we've been doing

369
00:13:17,700 --> 00:13:15,370
looking at sulfate reduction so this is

370
00:13:19,560 --> 00:13:17,710
with Clemens Columbia who is an NP P

371
00:13:22,090 --> 00:13:19,570
postdoc in Torrey holers lab at NASA

372
00:13:24,490 --> 00:13:22,100
Ames and

373
00:13:26,499 --> 00:13:24,500
is another incredibly Astra biologically

374
00:13:28,629 --> 00:13:26,509
irrelevant metabolism for these systems

375
00:13:30,639 --> 00:13:28,639
looking at sulfate as the dominant

376
00:13:32,290 --> 00:13:30,649
electron acceptor not only with hydrogen

377
00:13:34,090 --> 00:13:32,300
but also with the micro molar

378
00:13:35,860 --> 00:13:34,100
concentrations of organic acids we

379
00:13:38,499 --> 00:13:35,870
detect in these systems as well as with

380
00:13:40,569 --> 00:13:38,509
the abundant methane and so clemens

381
00:13:42,370 --> 00:13:40,579
systematically started probing the fluid

382
00:13:44,110 --> 00:13:42,380
system to start with a 35 labelled

383
00:13:45,910 --> 00:13:44,120
sulfate to try and probe the

384
00:13:49,870 --> 00:13:45,920
distribution of sulfate reduction

385
00:13:51,970 --> 00:13:49,880
activity and in general he has very low

386
00:13:54,220 --> 00:13:51,980
rates so pica moles per mils per day

387
00:13:56,379 --> 00:13:54,230
he's worked in deep sea sediments in

388
00:13:58,240 --> 00:13:56,389
different parts of the globe and these

389
00:14:00,249 --> 00:13:58,250
are exceedingly low rates but he has

390
00:14:02,710 --> 00:14:00,259
been able to see them persistent but

391
00:14:04,720 --> 00:14:02,720
they are really diminished in the hyper

392
00:14:06,340 --> 00:14:04,730
alpha state of the system so unlike

393
00:14:07,689 --> 00:14:06,350
methane agenesis sulfate reduction is

394
00:14:09,639 --> 00:14:07,699
actually the one heating up against a

395
00:14:14,350 --> 00:14:09,649
wall in ways we don't understand

396
00:14:15,819 --> 00:14:14,360
once we get above pH of 10 now that

397
00:14:17,470 --> 00:14:15,829
we've done the drilling into the deep

398
00:14:19,150 --> 00:14:17,480
and we are starting to look as a

399
00:14:21,069 --> 00:14:19,160
function of depth and and again

400
00:14:23,920 --> 00:14:21,079
geochemical states of the system and the

401
00:14:25,600 --> 00:14:23,930
subsurface Clemens has again been

402
00:14:27,670 --> 00:14:25,610
probing these cores to look at the

403
00:14:29,829 --> 00:14:27,680
differential distribution of sulfate

404
00:14:31,509 --> 00:14:29,839
reduction activity so in just one of the

405
00:14:34,269 --> 00:14:31,519
course that we've been starting to work

406
00:14:36,129 --> 00:14:34,279
on and this this would be go from zero

407
00:14:38,530 --> 00:14:36,139
to 400 meters of depth or at least this

408
00:14:39,840 --> 00:14:38,540
core does he probed a series of

409
00:14:41,740 --> 00:14:39,850
different depths and has a clear

410
00:14:44,379 --> 00:14:41,750
localization of where sulfate reduction

411
00:14:46,420 --> 00:14:44,389
is occurring we have down whole logs

412
00:14:49,960 --> 00:14:46,430
that allow us to look at the pH and the

413
00:14:51,610 --> 00:14:49,970
redox h of these fluids and what we're

414
00:14:53,620 --> 00:14:51,620
really finding is that once that's a

415
00:14:56,110 --> 00:14:53,630
reducing condition but we dropped down

416
00:14:58,210 --> 00:14:56,120
below pH 10 or 10 and a half we can see

417
00:14:59,740 --> 00:14:58,220
the sulfate reduction kick in and it's

418
00:15:02,110 --> 00:14:59,750
being suppressed elsewhere in this

419
00:15:03,670 --> 00:15:02,120
course so this is giving us some

420
00:15:05,559 --> 00:15:03,680
guideposts now and other work that's

421
00:15:06,879 --> 00:15:05,569
ongoing such as KT REM fritz talked

422
00:15:09,129 --> 00:15:06,889
earlier this week where she's been

423
00:15:10,749 --> 00:15:09,139
looking at the intact polar lipid

424
00:15:12,220 --> 00:15:10,759
distribution in these samples this has

425
00:15:14,530 --> 00:15:12,230
been a great place for her to work to

426
00:15:16,990 --> 00:15:14,540
prove that she can really extract and

427
00:15:19,360 --> 00:15:17,000
start to characterize IPL's from these

428
00:15:21,670 --> 00:15:19,370
kinds of cores and detect them well in a

429
00:15:26,129 --> 00:15:21,680
but in excess of any contamination in

430
00:15:28,580 --> 00:15:26,139
these kinds of systems so to conclude

431
00:15:30,830 --> 00:15:28,590
we're at the beginning

432
00:15:32,990 --> 00:15:30,840
and we're really feeling like we've now

433
00:15:35,660 --> 00:15:33,000
starting to understand components of how

434
00:15:39,320 --> 00:15:35,670
the system is set up that we can begin

435
00:15:41,300 --> 00:15:39,330
to really aggressively delineate where

436
00:15:43,370 --> 00:15:41,310
different microbial metabolisms are

437
00:15:44,690 --> 00:15:43,380
functionally active and start working on

438
00:15:46,940 --> 00:15:44,700
pulling out and exploring the

439
00:15:48,950 --> 00:15:46,950
physiological adaptations to hyper

440
00:15:50,630 --> 00:15:48,960
alkaline pH and thus extreme carbon

441
00:15:54,530 --> 00:15:50,640
limitation and the differential

442
00:15:56,780 --> 00:15:54,540
abundance and activity of populations we

443
00:15:58,280 --> 00:15:56,790
are very interested in both the total

444
00:15:59,840 --> 00:15:58,290
community but the active microbial

445
00:16:01,670 --> 00:15:59,850
community in these very differences

446
00:16:03,680 --> 00:16:01,680
parts of the system that more Open Mixed

447
00:16:05,870 --> 00:16:03,690
chemical environment and then what's

448
00:16:07,850 --> 00:16:05,880
sealed in to the more static aspect of

449
00:16:09,950 --> 00:16:07,860
the system but is able to slowly persist

450
00:16:11,480 --> 00:16:09,960
and all of those of course are going to

451
00:16:13,610 --> 00:16:11,490
lend themselves to trying to identify

452
00:16:15,740 --> 00:16:13,620
the bio markers and the bio signatures

453
00:16:17,180 --> 00:16:15,750
of that activity we have to keep nesting

454
00:16:19,340 --> 00:16:17,190
in at these different scales to come

455
00:16:20,570 --> 00:16:19,350
find that but our search strategy for

456
00:16:22,790 --> 00:16:20,580
life and actually trying to represent

457
00:16:25,040 --> 00:16:22,800
the chemical and the biological measures

458
00:16:34,730 --> 00:16:25,050
of that life activity is looking really

459
00:16:36,140 --> 00:16:34,740
promising so thank you very much Lexus

460
00:16:39,860 --> 00:16:36,150
we have time for a few questions for

461
00:16:41,780 --> 00:16:39,870
Alexis you mentioned kick Creek in the

462
00:16:44,890 --> 00:16:41,790
clumped isotopes and then with the

463
00:16:49,970 --> 00:16:44,900
sulfate reduction you also sure that

464
00:16:52,400 --> 00:16:49,980
methane goes to bicarbonate he's there a

465
00:16:55,550 --> 00:16:52,410
carbon cycling there that I mean how

466
00:16:57,710 --> 00:16:55,560
does that fit into the I forget exactly

467
00:17:00,140 --> 00:16:57,720
what you said in reference to the where

468
00:17:04,310 --> 00:17:00,150
your data fit into the Kid Greek but are

469
00:17:06,080 --> 00:17:04,320
there McDonald robes you know coupled to

470
00:17:10,190 --> 00:17:06,090
suffered silver that affect the club

471
00:17:11,780 --> 00:17:10,200
Ascalon yeah I mean it's in the overall

472
00:17:14,510 --> 00:17:11,790
question of what you're asking

473
00:17:16,070 --> 00:17:14,520
we have a really complex carbon cycle

474
00:17:16,970 --> 00:17:16,080
occurring here and we're just feeling

475
00:17:19,370 --> 00:17:16,980
like we're starting to have the right

476
00:17:21,110 --> 00:17:19,380
data to tease it out so especially in

477
00:17:23,090 --> 00:17:21,120
places where there's no measurable di C

478
00:17:24,890 --> 00:17:23,100
there's a lot of questions about what's

479
00:17:26,990 --> 00:17:24,900
the real form of carbon being taken up

480
00:17:28,880 --> 00:17:27,000
by cells and being used so co2 is one

481
00:17:31,220 --> 00:17:28,890
option we have this discussion about the

482
00:17:35,090 --> 00:17:31,230
km but we're really looking at formate

483
00:17:37,010 --> 00:17:35,100
and co availability and its role and a

484
00:17:39,310 --> 00:17:37,020
potentially for example of the math and

485
00:17:40,980 --> 00:17:39,320
Genesis or in sulfate-reducing

486
00:17:43,169 --> 00:17:40,990
populations

487
00:17:44,789 --> 00:17:43,179
but um we have to start to really trace

488
00:17:47,100 --> 00:17:44,799
that elegantly and we've had to know

489
00:17:48,720 --> 00:17:47,110
where and how to do that so I think

490
00:17:50,370 --> 00:17:48,730
we're tip of the iceberg and trying to

491
00:17:52,350 --> 00:17:50,380
really understand the balance of how

492
00:17:54,690 --> 00:17:52,360
we're both producing and REE consuming

493
00:17:56,310 --> 00:17:54,700
co2 and where these different

494
00:17:58,019 --> 00:17:56,320
populations are active it's weird that

495
00:17:59,970 --> 00:17:58,029
we can shut the sulfate reduction down

496
00:18:02,010 --> 00:17:59,980
above pH 10 and really not be able to

497
00:18:04,130 --> 00:18:02,020
detect it that allows us to separate

498
00:18:06,810 --> 00:18:04,140
sulfate reduction in the methanogens

499
00:18:08,460 --> 00:18:06,820
activity at the higher ph conditions and

500
00:18:13,850 --> 00:18:08,470
we put them back together in the

501
00:18:16,649 --> 00:18:13,860
moderate moderate pH 10 9 can it realm

502
00:18:23,460 --> 00:18:16,659
no time for another question Alexis

503
00:18:26,909 --> 00:18:23,470
there are others thanks for the great

504
00:18:28,470 --> 00:18:26,919
talk I have a related question but maybe

505
00:18:32,039 --> 00:18:28,480
it's too specific but I'm curious about

506
00:18:33,750 --> 00:18:32,049
it if you have any insights as to the

507
00:18:36,630 --> 00:18:33,760
membrane bioenergetics of these

508
00:18:39,000 --> 00:18:36,640
organisms because one of the persistent

509
00:18:42,000 --> 00:18:39,010
questions is the PMF or is it a sodium

510
00:18:44,190 --> 00:18:42,010
motive force or do you guys have any new

511
00:18:46,409 --> 00:18:44,200
data about that we don't have new data

512
00:18:48,539 --> 00:18:46,419
about that what we are doing is actually

513
00:18:50,190 --> 00:18:48,549
using data from some of the work Dan

514
00:18:53,010 --> 00:18:50,200
Coleman's been doing which isn't shown

515
00:18:55,560 --> 00:18:53,020
here trying to come back in and actually

516
00:18:57,659 --> 00:18:55,570
we retarget the isolation of the meth

517
00:18:59,370 --> 00:18:57,669
ana bacterium that is functioning well

518
00:19:00,360 --> 00:18:59,380
in the hyper alkaline component of the

519
00:19:01,919 --> 00:19:00,370
systems the one that's really

520
00:19:03,240 --> 00:19:01,929
differentially distributed there and

521
00:19:05,220 --> 00:19:03,250
that one want to be a more appropriate

522
00:19:06,299 --> 00:19:05,230
one to do this I'm also really

523
00:19:09,060 --> 00:19:06,309
interested generally with the

524
00:19:09,960 --> 00:19:09,070
methanogens what the Delta pH is between

525
00:19:11,549 --> 00:19:09,970
the external and the internal

526
00:19:12,960 --> 00:19:11,559
environment and I think we really need a

527
00:19:15,570 --> 00:19:12,970
good measure of what is that

528
00:19:17,310 --> 00:19:15,580
intracellular pH which is also a part of

529
00:19:19,200 --> 00:19:17,320
them that is membrane bioenergetics so

530
00:19:20,940 --> 00:19:19,210
we're thinking about that but how to do

531
00:19:23,010 --> 00:19:20,950
this well and we really would like to

532
00:19:24,779 --> 00:19:23,020
move beyond the with antigen with an

533
00:19:26,279 --> 00:19:24,789
effect you and we have in culture and go

534
00:19:30,720 --> 00:19:26,289
after the one that we think is more

535
00:19:31,850 --> 00:19:30,730
physiologically adapted right thank you

536
00:19:33,810 --> 00:19:31,860
all XS