TY - JOUR

T1 - Survival of halophiles of Altai lakes under extreme environmental conditions

T2 - Implications for the search for Martian life

AU - Bryanskaya, Alla V.

AU - Berezhnoy, Alexey A.

AU - Rozanov, Alexey S.

AU - Serdyukov, Danil S.

AU - Malup, Tatyana K.

AU - Peltek, Sergey E.

PY - 2020/2

Y1 - 2020/2

N2 - Mars is considered to be one of the most favourable places in the Solar System to search for past and present life. In the past Mars was warmer and wetter, so terrestrial halophiles can be regarded as analogues of hypothetical ancient Martian halophiles. In this study we used microorganisms from unique Altai region (Russia) to estimate the capability of terrestrial bacteria and archaea to survive at low temperatures and high concentration of salts and metals, similar to the Martian environment. The current report demonstrates that both halophilic archaea and halotolerant bacteria from saline lakes of the Altai region may be considered as analogues of ancient Martian organisms, since they are able to withstand conditions that hypothetically existed in subsurface layers of the early Mars (low temperatures, salt solutions with a high content of NaCl) with only slight decrease in viability. We also found that the studied microorganisms can use some organic substances found in meteorites. We consider that transfer of unicellular halophiles from Earth to Mars was possible, and, moreover, they could successfully survive and grow on early Mars. Adjusting our growth media to the chemical composition of the lakes, from which the studied strains were isolated, resulted in significant increase in survival and growth rates. Certain strains could survive several freeze-thaw cycles at -70 °C typical for Martian nights.

AB - Mars is considered to be one of the most favourable places in the Solar System to search for past and present life. In the past Mars was warmer and wetter, so terrestrial halophiles can be regarded as analogues of hypothetical ancient Martian halophiles. In this study we used microorganisms from unique Altai region (Russia) to estimate the capability of terrestrial bacteria and archaea to survive at low temperatures and high concentration of salts and metals, similar to the Martian environment. The current report demonstrates that both halophilic archaea and halotolerant bacteria from saline lakes of the Altai region may be considered as analogues of ancient Martian organisms, since they are able to withstand conditions that hypothetically existed in subsurface layers of the early Mars (low temperatures, salt solutions with a high content of NaCl) with only slight decrease in viability. We also found that the studied microorganisms can use some organic substances found in meteorites. We consider that transfer of unicellular halophiles from Earth to Mars was possible, and, moreover, they could successfully survive and grow on early Mars. Adjusting our growth media to the chemical composition of the lakes, from which the studied strains were isolated, resulted in significant increase in survival and growth rates. Certain strains could survive several freeze-thaw cycles at -70 °C typical for Martian nights.

KW - Archaea

KW - bacteria

KW - extremophiles

KW - halophiles

KW - Mars

KW - surviving

KW - PERCHLORATE

KW - BACTERIAL-GROWTH

KW - SALTS

KW - SP-NOV.

KW - ARCHAEA

KW - TEMPERATURES

KW - MARS

KW - KULUNDA STEPPE ALTAI

KW - ORGANIC-COMPOUNDS

KW - CHEMISTRY

UR - http://www.scopus.com/inward/record.url?scp=85065989544&partnerID=8YFLogxK

U2 - 10.1017/S1473550419000077

DO - 10.1017/S1473550419000077

M3 - Article

AN - SCOPUS:85065989544

VL - 19

SP - 1

EP - 15

JO - International Journal of Astrobiology

JF - International Journal of Astrobiology

SN - 1473-5504

IS - 1

ER -