Energy generation and the sulfur-carbon cycle. Progress report
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
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Related Subjects
54 ENVIRONMENTAL SCIENCES
59 BASIC BIOLOGICAL SCIENCES
DMSO
REDUCTION
METHANOGENIC BACTERIA
METABOLISM
ACETATES
FERMENTATION
METHANE
OXIDATION
LAKES
CARBON CYCLE
PECTINS
DECOMPOSITION
CARBON COMPOUNDS
CARBON 14 COMPOUNDS
TRACER TECHNIQUES
ANAEROBIC CONDITIONS
METHIONINE
BACTERIA
BIOLOGICAL PATHWAYS
BIOCHEMICAL REACTION KINETICS
CORRELATIONS
SEDIMENTS
SULFATES
ENZYME ACTIVITY
SEASONAL VARIATIONS
GREAT SALT LAKE
ALKANES
AMINO ACIDS
BIOCONVERSION
BLOOD SUBSTITUTES
CARBOHYDRATES
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DRUGS
HEMATOLOGIC AGENTS
HYDROCARBONS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPOTROPIC FACTORS
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
POLYSACCHARIDES
REACTION KINETICS
SACCHARIDES
SULFOXIDES
SULFUR COMPOUNDS
SURFACE WATERS
VARIATIONS
090100* - Hydrocarbon Fuels- (-1989)
520100 - Environment
Aquatic- Basic Studies- (-1989)
550700 - Microbiology
550500 - Metabolism
550200 - Biochemistry