sergey bulat * russian-french gdri consortium

Searching for tiny life in extreme environments relevant to Jovian’s Europa: Lessons from subglacial ice studies at Lake Vostok (East

Antarctica)

Sergey Bulat* Russian-French GDRI consortium

GDRI consortium • PNPI FSBI, St Petersburg, RU

– Sergey Bulat - PI• AARI FSBI, St Petersburg, RU

– Vladimir Lipenkov - PI– Valery Lukin

• VNIIOceangeologia, St Petersburg, RU– German Leitchenkov

• LGGE CNRS-UJF, Grenoble, FR– Jean Robert Petit - PI – Michel Legrand (DOC)

• Université de Bretagne Occidentale, Brest, FR – Mohamed Jebbar

• Station Biologique de Roscoff, Roscoff, FR – Dominique Marie

• Ecologie Microbienne UCB-Lyon I, Lyon, FR – Philippe Normand

Bulat 11 oct-13 2MS3-IKI RAN, Moscow

Main BIO

Culturing

Cell counts

RepetitionCulturing

Working on Earth-known microbial DNA

4 primary [nucleo]bases: cytosine, guanine, adenine and

thymine - C, G, A, T GenBank sequence database

Clean (dust-free) room 10,000Laminar flow hood 100 DNA/RNA BioCap hood 100

Vostok ice for Biology

• Comprehensive Biological controls

– Sham/mock DNA extraction– Negative PCR– Ice core wash water – Lab Environment (dust)– Vostok drill fluid – Outer-core (optionally)

REQUIREMENTS:

211 seqs July 2011

Contaminant databasesBulat 11 oct-13 2MS3-IKI RAN, Moscow

Vostok ice for Biology

• Authentication of findings by ecology (environmental conditions)

REQUIREMENTS:

“Everything is everywhere, but, the environment selects” – Baas Becking, 1934


A framework for biological

studies adopted for Lake Vostok

DNA extractionPrimary PCR

No PCR products

Bulat 11 oct-13

Absolute minimum -89.2°CAverage ann. Temp. -55.1°C

RADARSAT, CSA

Vostok station (+3488m) (since 1957)

Lake Vostok (-3663m)

1260 km from the coast

(78°S, 106°E)

Bulat 11 oct-13

Vostok vs. Europa SURFACE

SNOW

Bulat 11 oct-13

Very clean ‘life-hostile’ environ

• Low accumulation – 2.1-2.4g /cm2/a• Low Aeolian dust input

– 2 μm mode; 10-15 ppb (summer time)• Harsh irradiation (UV-C etc.) (‘ozone hole’ – Aug-Nov)

– + Water-Oxygen free radicals– Oxidized organics (photochemical reactions at ice-air interface)

• Low freezing temperatures – below -36oC (-55.1oC ann.)

Vostok Surface snow (0 – 130m up to 4 Kyr)

(6-6.5 cm/a – snow / needles!)

Below 3m the snow is pristine

NO FREE (only BOUND) WATER!

2MS3-IKI RAN, Moscow

Vostok MEGA-snow 2010


V500S10 (Vostok500kmSnow2010

(RAE 55)

Vostok MEGA-snow – SURFACE – 500km toward Vostok


Vostok MEGA-snow – SURFACE – 3.0 km SW away

VMS10 (VostokMeteoricSnow2010

(RAE 55)

Vostok MEGA-snow 2010


RESULTS

Vostok Contaminant LibraryHuman Normal Microbiome

Vostok MEGA- et Colossal-snow 2011

Vostok MEGA-snow 2011• 216km from coastal Progress – PMS11-1

– Crate 23L 5-8L melt• 29km from coastal Progress – PMS11-2

– Crate 23L 5-8L melt


Sergey Popob

PMS11-1 7034.925S, 8124.103E H 2376m

PMS11-2 6941.081S, 7633.621E H 865m

Bulat 11 oct-13 2MS3-IKI RAN, MoscowVostok Colossal-snow 2011

220L

CS11 78,4722S, 106,7796E(VostokCollossalSnow2011 (RAE 56)

Vostok MEGA- et Colossal-snow 2011 - RESULTS


Cell counts

Sample Bacteria / ml

Roscoff sea water 30961PMS11-1 - 216 km Progress 45PMS11-2 - 29 km Progress 0CS11-15 Vostok - 2.8-3.0 m deep 0


PCR - phylotypes

Vostok MEGA- et Colossal-snow 2011 - RESULTS

Sample Bacteria / ml

PMS11-1 - 216 km Progress 45

V4-v8 16S rDNA amplicon sequencing HA-Pseudomonas sp (alpha-proteo) - 80%

99% Ewingella americana (gamma-proteo, Enterobact.)Bradyrhizobium sp(elkani) (alpha-proteo)

Vostok Contaminant LibraryHuman Normal Microbiome

Clinical specimens including wound, sputum, urine, stool, blood etc. Sources of infection – domestic air conditioning units, ice baths etc.

Pre CONCLUSION

• Vostok [et 29km from coast!] SURFACE snow contains a few cells / ml - NO CELL populations [lifeless]


Background contamination?

Vostok vs. Europa ICE CORE

Towards the Lake Vostok

SALE Subglacial Antarctic Lake Environments - >386

Siegert et al., 2005AGU Chapman conf 2010


Friendly environment?

• Deeply ice buried (in dark) – 4 km• High pressure – 337-377 bar• Permanently BUT not very cold – -2.65°C • Likely oxygen supersaturated - >70 mg/L

up to 700-1300 mg/L

Lake Vostok known since 1994

FREE (LIQUID) WATER!

RADARSAT, CSA

Published in Nature (Kapitsa et al., 1996)


No life

May host life

ISOLATED


Lake Vostok settings • Huge subglacial lake (Masolov et al., SCAR OSC2008)

– 275 x 65 km in size; 15 500 km2 area; 6 100 km3 water– Two main basins with the ridge between 150-200 m deep – Average depth - 300 m; max depth – ~1650 m (south basin) – Water renewal – 80-100 Kyr

• Buried beneath 2.0-0.8 Myr old 3750-4200 m thick ice sheet

• Isolated from surface biota for >14 Ma – Age of water (melted ice) - ~1 Ma

• No hydrological links to other lakes

RADARSAT, CSA

2.0-0.8 Ma years old


Vostok ice core

Ледниковы й лед

Озерны й лед

Вода

Фундамент

Уровень моря

4200 м 3750 м

FMВ ост о к

05 01 0 01 5 02 0 02 5 0Р а с с т оя н и е , к м

3623 м

5Г

3 0 0

Melting zoneAccretion

North South

Meteoric ice

Lake water body

Accretion (lake) iceAccr. rate – <10 mm/a

0.8 Ma 2.0 Ma – 3538m

Gases 680m

(78°S, 106°E)19.02.1990

3650m


3720 m - Jan 21, 2011

Bulat 11 oct-13 2MS3-IKI RAN, Moscow 30m left!

Bulat 11 oct-13

AccretionICE

GAS contents*

DOC (ppbC)

Majorions*

TYPE 1 Sediments

Low (10-2)

CO2, CH4, O2

10 ± 9 Mg2+ Ca2+ SO4

2- (S2-)

(no NH4+, nitrate)

TYPE 2 Very clean

Very low

(10-3)(no O2, CH4)

5.6 ± 4.6 -(no NH4

+, nitrate)

Conditions

Low aerobicAnaerobic

Ultra-Oligotrophic

No heterotrophs

No e-donors?(Hydrogen?)

Accretion ice BIO featuresNO GAS NO DOC

Many oligotrophic lakes have DOC's in the range of 100 to 500 ppb


Bulat 11 oct-13

Bacterial metabolic pathways Accretion ice type

1E-donor E-acceptor Carbon Process Microbes

H2 SO42- CO2 Sulfate reduction

(H2S)Sulfate-reducers

H2 O2 (in mineralinclusions)

CO2 Hydrogen-oxidation

Hydrogen-oxidizers

H2 CO2 CO2 Methanogenesis (CH4)

Methanogenic archaea

S2-

S0

O2 (NO3-) CO2 Sulfur oxidation (SO4

2- - acidic)Sulfur-oxidizers

In mineral inclusions

RECALL: Gas content is very low - 0.001 vs. 0.1 g/cm3


Life prospective in lake ice 1Anaerobic

chemolithoautotrophic piezophilic psychrophiles

Type1 Type2

?

Given a limiting life temperature threshold - -20°C (Astrobiology, 2006, 6, 677-732)

RESULTS

Bacteria in [deep] lake ice

3608BK - Big ‘Kamina’

6 x 8.5 x 15 (mm)

3608m

Mono-crystalline ice


Bulat 11 oct-13

5G2-3608 et 5G2-3646


Big Kamina-2?

Vostok cells / phylotypes - update 2010


Glacier flour

Cells DOC Phylotypes Vostok ice core

Ice Type Sample (m) DOC (ppbC)

Cells / ml (% similarity, GenBank) Phylotype

Snow (50 yr) 4.0-4.3 0-0.02 Glacier 122 5.4 ± 1.1 1.9

4.5-760 kyr 2005 6.4 ± 0.7 2.4 2054 4.4 ± 0.7 3-24 3489 ND 0

Accretion I 3561 ND 4-9 (99%) Hydrogenophilus thermoluteolus

30-40 kyr 3607 12.5 ± 0.3 ND (100%) H. thermoluteolus (β-Proteo)(91%) Uncult bacterium (OP11 div.)

36083608BK

NDND

0-19 ND (94%) Ilumatobacter luminis (Actino)

Accretion II 3613 3.0 – 7.0 3 20-30 kyr 3621 3.2 – 20.4 2

3622 2.5 ± 0.7 0.6 3635 4.0 – 9.0 4.7 3650 9.0 – 15.0 3.1 thoroughly treated 3650 ND 4777 untreated surface 3659 ND 12

Sulfate-reducing bacteriaHydrogen-oxidizing bacteriaMethanogenic archaea Sulfur-oxidizing bacteria

Both UNCLASSIFIED!


General CONCLUSION•Vostok [et 29km from coast!] SURFACE snow - NO CELL populations [lifeless]

•DEEP lake Vostok ICE contains NO CELL populations [lifeless]?


With no cracks!

Astrobiology implications

In searching for [tiny] life indices on icy worlds like Jovian Europa

Lake Vostok [ice] is a unique TEST area

BioLESSONS from Vostok•Work on youngest the least processed at the surface of Europa material (i.e. ocean water ice) flashed out veins or faults (within ridges?) in a radiation shadow


Work guide for ice samples delivered to Earth

• applying stringent ice sample (and tools to work on) decontamination procedures in clean conditions to meet trace chemistry and Ancient DNA analysis standards

• certification of the various environments in contact with the ice samples for biological content (establishment of contaminant library)

• implementation of appropriate methods to obtain a signal at as low as possible a detection level

• verification of findings through their possible metabolic profiles as deduced from physical/chemical features of the environment under consideration

• replication of findings at an independent laboratory (or experiment) within the framework of specialized laboratories


sergey bulat * russian-french gdri consortium

Documents

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