In order to examine the potential survivability of life in the Martian deep subsurface, we have investigated the effects of temperature (45°C, 55°C and 65°C) and pressure (1, 400, 800 and 1200 atm) on the growth, carbon isotopic data and morphology of chemolithoautotrophic anaerobic methanogenic archaea, Methanothermobacter wolfeii. The growth and survivability of this methanogen were determined by measuring the methane concentration in headspace gas samples after the cells were returned to their conventional growth conditions. Interestingly, this methanogen survived at all the temperatures and pressures tested. M. wolfeii demonstrated the highest methane concentration following exposure to pressure of 800 atm and a temperature of 65°C. We found that the stable carbon isotopic fractionation of methane, δ13C(CH4), was slightly more enriched in 12C at 1 atm and 55°C than the carbon isotopic data obtained in other temperature and pressure conditions. A comparison of the images of the cells before and after the exposure to different temperatures and pressures did not show any obvious alteration in the morphology of M. wolfeii. The research reported here suggests that at least one methanogen, M. wolfeii, may be able to survive under hypothetical Martian subsurface conditions with respect to temperature and pressure.

中文翻译：

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温度和高压对产甲烷菌的生长和生存能力以及稳定碳同位素分馏的影响：对火星深层地下生命的影响

为了检查火星深层地下生命的潜在生存能力，我们研究了温度（45°C、55°C 和 65°C）和压力（1、400、800 和 1200 atm）对生长的影响，化学自养厌氧产甲烷古菌的碳同位素数据和形态，沃尔夫甲烷热杆菌. 这种产甲烷菌的生长和生存能力是通过在细胞恢复到其常规生长条件后测量顶空气体样品中的甲烷浓度来确定的。有趣的是，这种产甲烷菌在所有测试的温度和压力下都存活了下来。M. wolfeii在暴露于 800 atm 的压力和 65°C 的温度后，显示出最高的甲烷浓度。我们发现甲烷的稳定碳同位素分馏，δ13C(CH4), 稍微丰富一些121 atm 和 55°C 下的 C 比在其他温度和压力条件下获得的碳同位素数据。细胞在不同温度和压力暴露前后的图像比较未显示细胞形态有任何明显变化。M. wolfeii. 这里报告的研究表明，至少有一种产甲烷菌，M. wolfeii，可能能够在假设的火星地下条件下与温度和压力有关。