Serrano Paloma, Hermelink Antje, Lasch Peter, de Vera Jean-Pierre, König Nicole, Burckhardt Oliver, Wagner Dirk
GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam, Section Geomicrobiology, Telegrafenberg, 14473 Potsdam, Germany Alfred Wegener Institute Helmholz Centre for Polar and Marine Research, Telegrafenberg A45 14473 Potsdam, Germany.
Robert Koch Institute, Centre for Biological Threats and Special Pathogens, Nordufer 20 13353 Berlin, Germany.
FEMS Microbiol Ecol. 2015 Dec;91(12). doi: 10.1093/femsec/fiv126. Epub 2015 Oct 22.
Methanogenic archaea are widespread anaerobic microorganisms responsible for the production of biogenic methane. Several new species of psychrotolerant methanogenic archaea were recently isolated from a permafrost-affected soil in the Lena Delta (Siberia, Russia), showing an exceptional resistance against desiccation, osmotic stress, low temperatures, starvation, UV and ionizing radiation when compared to methanogens from non-permafrost environments. To gain a deeper insight into the differences observed in their resistance, we described the chemical composition of methanogenic strains from permafrost and non-permafrost environments using confocal Raman microspectroscopy (CRM). CRM is a powerful tool for microbial identification and provides fingerprint-like information about the chemical composition of the cells. Our results show that the chemical composition of methanogens from permafrost-affected soils presents a high homology and is remarkably different from strains inhabiting non-permafrost environments. In addition, we performed a phylogenetic reconstruction of the studied strains based on the functional gene mcrA to prove the different evolutionary relationship of the permafrost strains. We conclude that the permafrost methanogenic strains show a convergent chemical composition regardless of their genotype. This fact is likely to be the consequence of a complex adaptive process to the Siberian permafrost environment and might be the reason underlying their resistant nature.
产甲烷古菌是广泛存在的厌氧微生物，负责生物成因甲烷的产生。最近，从勒拿河三角洲（俄罗斯西伯利亚）受永久冻土影响的土壤中分离出几种新的耐冷产甲烷古菌，与非永久冻土环境中的产甲烷菌相比，它们对干燥、渗透胁迫、低温、饥饿、紫外线和电离辐射具有极强的抵抗力。为了更深入地了解它们在抗性方面的差异，我们使用共聚焦拉曼显微光谱（CRM）描述了来自永久冻土和非永久冻土环境的产甲烷菌株的化学成分。CRM是一种用于微生物鉴定的强大工具，可提供有关细胞化学成分的指纹状信息。我们的结果表明，来自受永久冻土影响土壤的产甲烷菌的化学成分具有高度同源性，与栖息于非永久冻土环境的菌株明显不同。此外，我们基于功能基因mcrA对所研究的菌株进行了系统发育重建，以证明永久冻土菌株的不同进化关系。我们得出结论，无论其基因型如何，永久冻土产甲烷菌株都呈现出趋同的化学成分。这一事实可能是对西伯利亚永久冻土环境复杂适应过程的结果，也可能是它们具有抗性的潜在原因。
