Energy generation and the sulfur-carbon cycle. Progress report

Technical Report · Thu Jan 01 04:00:00 EST 1981

OSTI ID:6052320

Laboratory studies demonstrated that a variety of anaerobic bacterial species actively reduced dimethylsulfoxide as an electron acceptor while oxidizing organic substrates as electron donors during growth. The microbial decomposition of methionine in anaerobic Lake Mendota sediments, methanethiol and dimethylsulfide were detected as intermediates; whereas, methane, carbon dioxide, and hydrogen sulfide were the final end products of anaerobic decomposition. Dimethylsulfide and methylmercaptan were immediate methane precursors in Lake Mendota sediments. The oxidation of methane by anaerobic bacteria and characterization of an acetate fermenting methanogenic bacterium were studied. Cultures of methanogenic bacteria demonstrated that methanogens converted /sup 14/CH/sub 4/ to /sup 14/CO/sub 2/ by a pathway that involved different cellular intermediates than those involved in methane production. The general physiological properties of an acetate fermenting methanogen isolated from sewage sludge was characterized. Most notably, this species would not grow on H/sub 2/ + CO/sub 2/. Studies on the influence of sulfate metabolism on carbon turnover in Lake Mendota suggested that approximately 50% of the reduced endogenous carbon was mineralized via sulfate reduction and 50% via methanogenesis. Most of the endogenous carbon mineralized via sulfate reduction occurred in the surface sediments. Sulfate reduction was not limited by in situ sulfate concentration in surface sediments. Studies on biopolymer decomposition showed in situ turnover rate constants for /sup 14/C-pectin of 0.11 h/sup -1/ in Lake Mendota sediments and 0.004 h/sup -1/ in Knaack Lake. The number of anaerobic pectin degrading bacteria in the sediments of both lakes varied with seasons. (ERB)

• Research Organization: Wisconsin Univ., Madison (USA). Dept. of Bacteriology
• DOE Contract Number: AS02-76EV02161
• OSTI ID: 6052320
• Report Number(s): DOE/EV/02161-T1; ON: DE81030949
• Country of Publication: United States
• Language: English

Related Subjects

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10 SYNTHETIC FUELS
520100 -- Environment
Aquatic-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
550200 -- Biochemistry
550500 -- Metabolism
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
ACETATES
ALKANES
AMINO ACIDS
ANAEROBIC CONDITIONS
BACTERIA
BIOCHEMICAL REACTION KINETICS
BIOCONVERSION
BIOLOGICAL PATHWAYS
BLOOD SUBSTITUTES
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON CYCLE
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CORRELATIONS
DECOMPOSITION
DMSO
DRUGS
ENZYME ACTIVITY
FERMENTATION
GREAT SALT LAKE
HEMATOLOGIC AGENTS
HYDROCARBONS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LAKES
LIPOTROPIC FACTORS
METABOLISM
METHANE
METHANOGENIC BACTERIA
METHIONINE
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDATION
OXYGEN COMPOUNDS
PECTINS
POLYSACCHARIDES
REACTION KINETICS
REDUCTION
SACCHARIDES
SEASONAL VARIATIONS
SEDIMENTS
SULFATES
SULFOXIDES
SULFUR COMPOUNDS
SURFACE WATERS
TRACER TECHNIQUES
VARIATIONS