Ecophysiology of terminal carbon metabolizing bacteria in anoxic sedimentary environments
Chemical, radiotracer, and microbiological experiments were used to understand the transformation of simple carbon compounds by anaerobic bacteria in diverse aquatic sediments and laboratory cultures. The mildly acidic sediments of Knack Lake (pH 6.2), displayed low rates of organic decomposition, and methane formation occurred almost exclusively from acetate. Low pH inhibited methanogenesis and organic decomposition. Fall turnover in Lake Mendota sediments was associated with dramatic changes in environmental parameters including: elevated concentrations of sulfate and carbon metabolites, increased rates of sulfate reduction, decreased levels of methanogenesis, increased ratio (by viable counts) of sulfate reducing to methanogenic bacteria, and higher /sup 14/CO/sub 2///sup 14/C/sub 4/ + /sup 14/CO/sub 2/ gas ratios produced during the biodegradation of /sup 14/C-carbon substrates (e.g., acetate and methanol). Hydrogen consumption by sulfate reducers in Lake Mendota sediments and in co-cultures of Desulfovibrio vulgaris and Methanosarcina barkeri led to an alteration in the carbon and electron flow pathway resulting in increased CO/sub 2/, sulfide production, and decreased methanogenesis. These data agreed with the environmental observations in Lake Mendota that high sulfate concentrations resulted in higher ratios of CO/sub 2//CH/sub 4/ produced from the degradation of organic matter. A new glycine-metabolizing acetogenic species was isolated and characterized from Knaack Lake which further extended the known diversity of anaerobic bacteria in nature.
- Research Organization:
- Wisconsin Univ., Madison (USA)
- OSTI ID:
- 5006743
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBON 14 COMPOUNDS
BIODEGRADATION
METABOLISM
DESULFOVIBRIO
PHYSIOLOGY
ACETATES
ANOXIA
CARBON DIOXIDE
LAKES
METHANOL
PH VALUE
SEDIMENTS
ALCOHOLS
BACTERIA
CARBON COMPOUNDS
CARBON OXIDES
CARBOXYLIC ACID SALTS
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
HYDROXY COMPOUNDS
LABELLED COMPOUNDS
MICROORGANISMS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SULFATE-REDUCING BACTERIA
SURFACE WATERS
550701* - Microbiology- Tracer Techniques