Microbial community structure in methane hydrate-bearing sediments of freshwater Lake Baikal

Methane hydrates, typically found in marine sediments, have been discovered in the freshwater sediments of Lake Baikal, the world's largest freshwater basin. A study by Kadnikov et al. (2011) reveals that these hydrates are biologically formed, with microbial communities playing a significant role. The research used pyrosequencing of 16S rRNA genes to analyze microbial communities in the water column and sediments at a hydrate-bearing site. Aerobic methanotrophic bacteria dominated the lake floor water sample, while shallow sediments were rich in Archaea, particularly methanogens from Methanomicrobiales and Methanosarcinales orders. Deeper sediments near the hydrate were predominantly Bacteria, including Chloroflexi, candidate division JS1, and Caldiserica. The study suggests that methane hydrates in Lake Baikal are formed through methanogenesis rather than anaerobic oxidation of methane.

Kadnikov, V. V., Mardanov, A. V., Beletsky, A. V., Shubenkova, O. V., Pogodaeva, T. V., Zemskaya, T. I., Ravin, N. V., & Skryabin, K. G. (2011). Microbial community structure in methane hydrate-bearing sediments of freshwater Lake Baikal. FEMS Microbiology Ecology, 79(2), 348–358. https://doi.org/10.1111/j.1574-6941.2011.01221.x