Confocal Raman microspectroscopy reveals a convergence of the chemical composition in methanogenic archaea from a Siberian permafrost-affected soil

• Published in: FEMS Microbiology Ecology
• Main Authors: Serrano, P., Hermelink, A., Lasch, P., de Vera, Jean Pierre Paul, König, N., Burckhardt, O., Wagner, D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Federation of European Microbiological Societies, Published by Blackwell Publishing Ltd. 2015
• Subjects: Leitungsbereich PF; lena delta; permafrost; Siberia
• Online Access: https://elib.dlr.de/98843/; https://elib.dlr.de/98843/1/femsec.fiv126.full.pdf

Methanogenic archaea are widespread anaerobic microorganisms responsible for the 25 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 33 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.