Methanogenesis in big soda lake, nevada: an alkaline, moderately hypersaline desert lake.
Incubated sediment slurries from Big Soda Lake, Nevada, produced significant levels of CH(4), and production was inhibited by 2-bromoethanesulfonic acid and by autoclaving. Methane production was stimulated by methanol, trimethylamine, and, to a lesser extent, methionine. Surprisingly, hydrogen, acetate, and formate amendments provided only slight or no stimulation of methanogenesis. Methane production by sediment slurries had a pH optimum of 9.7. A methanol-grown enrichment culture containing a small, epifluorescent coccus as the predominant organism was recovered from sediments. The enrichment grew best when FeS or autoclaved sediment particles were included in the media, had a pH optimum of 9.7, and produced CH(4) from CH(3)OH. The methane formed by methanolgrown enrichment cultures was depleted in C by 72 to 77 per thousand relative to the methanol.
Oremland
R S
RS
U.S. Geological Survey, Menlo Park, California 94025, and Ames Research Center, National Aeronautics and Space Administration, Moffett Field, California 94035.
Marsh
L
L
Desmarais
D J
DJ