Effect of sulfate on carbon and electron flow during microbial methanogenesis in freshwater sediments

Journal Article · Tue Feb 01 04:00:00 EST 1977 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6551762

Winfrey, M R; Zeikus, J G

The effect of sulfate on methane production in Lake Mendota sediments was investigated to clarify the mechanism of sulfate inhibition of methanogenesis. Methanogenesis was shown to be inhibited by the addition of as little as 0.2 mM sulfate. Sulfate inhibition was reversed by the addition of either H/sub 2/ or acetate. Methane evolved when inhibition was reversed by H/sub 2/ additions was derived from /sup 11/CO/sub 2/. Conversely, when acetate was added to overcome sulfate inhibition, the evolved methane was derived from (2-/sup 14/C) acetate. A competition for available H/sub 2/ and acetate was proposed as the mechanism by which sulfate inhibited methanogenesis. Acetate was shown to be metabolized even in the absence of methanogenic activity. In the presence of sulfate, the methyl position of acetate was converted to CO/sub 2/. The addition of sulfate to sediments did not result in the accumulation of significant amounts of sulfide in the pore water. Sulfate additions did not inhibit methanogenesis unless greater than 100 ..mu..g of free sulfide per ml was present in the pore water. These results indicate that carbon and electron flow are altered when sulfate is added to sediments. Sulfate-reducing organisms appear to assume the role of methanogenic bacteria in sulfate-containing sediments by utilizing methanogenic precursors.

• Research Organization: Univ. of Wisconsin, Madison
• OSTI ID: 6551762
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 33:2; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090122* -- Hydrocarbon Fuels-- Preparation from Wastes or Biomass-- (1976-1989)
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
ALKANES
BACTERIA
BIOSYNTHESIS
CRYOGENIC FLUIDS
ELECTRON TRANSFER
FLUIDS
FRESH WATER
HYDROCARBONS
HYDROGEN COMPOUNDS
INHIBITION
MATERIAL BALANCE
METHANE
MICROORGANISMS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
SEDIMENTS
SULFATES
SULFUR COMPOUNDS
SYNTHESIS
WATER