Substrate Specificity of Methanogenic Communities from Lake Baikal Bottom Sediments Associated with Hydrocarbon Gas Discharge

摘要

Methane production by microbial communities from Lake Baikal bottom sediments with different chemical composition of pore water was studied. Methane production was more active in the media supplemented with H~(2): CO~(2)and H~(2)+ CH~(3)COONa, rather than on media with acetate as the sole source of carbon and energy. Addition of methanol stimulated methane production only in the case of microbial communities from upper silts. Ability of the communities to produce methane correlated reliably with the concentrations of the NO_(3–), SO~(4)_(2?), Cl_(–), and CH~(3)COO_(–)ions in the pore water of the relevant sediments. Cultivation of communities from the mud volcano sediments resulted in development of methanogenic archaea of the family Methanocellaсеае in the media supplemented with H~(2): CO~(2)and H~(2)+ CH~(3)COONa, while methanogenic archaea in the communities cultivated without additional substrates belonged to the genera Methanoregula , Methanobacterium , and Methanosaeta .