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[Music]

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Hello I'm from Honda I'm a PhD student

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from University of Sao Paulo in Brazil

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and I'll talk about my work

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microbial mediated carbon mineralization

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from agove Brazil

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so uh the motivation for this works the

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importance of studying the evolution of

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life on Earth as we know that the first

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signs of Life are eliminations and

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fossils of microorganisms and within

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this we have the investigation of

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potential evidence of life such as

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microbial forces and stromatolites then

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we need to differentiate from my medic

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form of an

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inorganic mineral so therefore it's

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necessary to investigate the biogenicity

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that is that if if that was actually

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formed by life or not and also we have

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the Dolomite problem that is a major

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question the scientists have been

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are one of the most important records of

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from the past and even if with the

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several studies related to development

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formation uh the results are still

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controversial maybe to the the little

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understanding uh that exists and the

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difficulty of obtaining this mineral in

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laboratory conditions like uh below 50

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degrees Celsius so given this we have

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the so-called Dolomite problem uh which

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has been much debated over uh the last

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few years however it is possible to find

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a few current dollar my precipitation

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events in hyper saline lakes and

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alkaline environments such as this

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region of Lago of Emira and but I should

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do this thing that is next to each other

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and

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um so these are one of the few places in

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the world that has Dolomite

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precipitation uh today so in these

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places there are microorganisms

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responsible for mediating the Carbonite

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precipitation uh which can serve as a

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nucleation centers for for the mineral

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uh within their biofilm their EPS

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exopolymeric extracellular substance

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and this photo was taken during my field

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collection and it shows their uh a thick

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layer of of dolomite of dolomite

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sediment below and uh above we can see

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like a microbial match with a biofilm in

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the

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so talking briefly about right

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precipitation by microorganisms in

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nature environmental conditions modulate

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the communities and within that a lot of

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microorganisms uh they are known for

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their ability to precipitate minerals so

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these minerals can be precipitated by

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physical methods in which the microbial

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Community serves as a nucleation of a

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nucleation site for the deformation of

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carbonate or it can be in a chemical way

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or an inorganic as an inorganic mineral

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so this precipitation occurs mainly due

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to changes in the pH the amount of

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organic carbon dissolves in the medium

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or the environment

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and the availability of calcium and

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magnesium ions so in the case of

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dolomite and the availability of

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nucleation sites for Crystal formation

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that can be the exopolymeric substances

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present in the in the biofilms of

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bacteria

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thank you

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so some microorganisms have the ability

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to produce biofumes formed by these

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these extracellular polymeric substances

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which are mainly composed of

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exopolysaccharides acidic residues uh

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sugars they have a negative charge and

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and can bind to different ions such as

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calcium magnesium so the role of DPS in

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the precipitation of carbonate occurs in

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two fronts initially the EPS can reduce

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precipitation by sequestering metallic

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ions but during the degradation of the

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EPS by some sulfur reducing bacteria uh

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the resulting High concentration of of

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calcium calcium magnesium ions can favor

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precipitation and in addition The

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Continuous supply of ions added to a

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more alkaline environment due to micro

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the micro environmental generated micro

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environment generated by the EPS May

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favor the bioprecipitation of of these

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minerals

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so now moving to the Azure biological

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importance it's interesting to know that

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the environmental condition of Mars in

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the nwakian Hesperian period

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why similar to why similar to work so at

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that time it was a much it has it had a

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much denser atmosphere a higher

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temperatures than the possible presence

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of liquid water on the surface which

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indicates the potential of of the planet

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to have supported microbial life

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so in the face of this some geological

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studies of g0 crater on Mars have

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demonstrated a large carbonate deposits

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in the west region of the crater and on

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on Earth regions of hypersonic shallow

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Lakes are closely related to the

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biological deposition of carbonates

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indicating great potential for

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identifier identifying preserved by a

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signature in these regions

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uh so I I would just specifically uh for

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a

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through these objectives so my

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objectives are testing a Carbonite

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mineral precipitation using allophiedic

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bacteria from Lego Batman

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and uh do structural morphological and

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optic investigation of Carbonite

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minerals like x-ray diffraction remain

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spectroscopy synchrosomite techniques

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um

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and uh they're established by viable

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protocols for biosignature

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identification

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so uh briefly uh you can see more in my

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poster for the precipitation experiment

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the methodology of montanale uh that is

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a reference that studies this uh this

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region was used to test if metabolically

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inactivated cells within biofilm could

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precipitate minerals only with the

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biofilm so the experiment was carried

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out in a controlled environment at 30

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degrees and was divided into these

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conditions that we had a DPS treatment

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that we let the bacteria growing for 15

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days then we added the antibiotics to

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inactivate the cells with the biofin

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form then we had the bacteria growing

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normally then we had a treatment with

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antibiotics being added from the

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beginning and we had the control without

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victory so we did this experiment to

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test if this was possible to form uh

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precipitates only with the biofilm but

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we said we said we saw that uh it's uh

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we we've we found a viable sales after

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after some time of of experiment uh

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within this biofilm so I think that it's

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really hard to inactivate cells in this

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way so we are trying other protocols and

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uh here here is only my preliminary

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results just giving a brief about this

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oh I'll talk to my poster after

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obtaining these precipitates we analyze

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the X-ray diffraction to identify the

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mineral phases present in the sample of

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the bacteria idiomarina the string

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called uh here in the right we took a

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scanning electron microscopy

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of the the precipitates from the same

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bacteria and we can see the difference

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different morphologies such as dumbbells

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shapes and rounded shapes of calcium

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carbonates and this morphology are

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usually associated with biogenic

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minerals so we still need to analyze EDS

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spectrums for a conform conform more

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exactly which mineral each morphology

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relates to and finding my minor shifts

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in the the fraterograms and the the

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Raman spectrums for establishing viable

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protocols so this is my poster session

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uh 22 and that's it thank you so much