Terminal processes in the anaerobic degradation of an algal-bacterial mat in a high-sulfate hot spring
The algal-bacterial mat of a high-sulfate hot spring (Bath Lake) provided an environment in which to compare terminal processes involved in anaerobic decomposition. Sulfate reduction was found to dominate methane production, as indicated by comparison of initial electron flow through the two processes, rapid conversion of (2-/sup 14/C)acetate to /sup 14/CO/sub 2/ and not to /sup 14/CH/sub 4/, and the lack of rapid reduction of NaH/sup 14/CO/sub 3/ to /sup 14/CH/sub 4/. Sulfate reduction was the dominant process at all depth intervals, but a marked decrease of sulfate reduction and sulfate-reducing bacteria was observed with depth. Concurrent methanogenesis was indicated by the presence of viable methanogenic bacteria and very low but detectable rates of methane production. A marked increase in methane production was observed after sulfate depletion despite high concentrations of sulfide (>1.25 mM), indicating that methanogenesis was not inhibited by sulfide in the natural environment. Although a sulfate minimum and sulfide maximum occurred in the region of maximal sulfate reduction, the absence of sulfate depletion in interstitial water suggests that methanogenesis is always severely limited in Bath Lake sediments. Low initial methanogenesis was not due to anaerobic methane oxidation.
- Research Organization:
- Montana State Univ., Bozeman
- OSTI ID:
- 7001706
- Journal Information:
- Appl. Environ. Microbiol.; (United States), Vol. 40:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALGAE
BIOLOGICAL EFFECTS
METHANOGENIC BACTERIA
ANAEROBIC CONDITIONS
BIODEGRADATION
ELECTRON TRANSFER
EXPERIMENTAL DATA
HOT SPRINGS
METHANE
MONTANA
OXIDATION
SULFATES
ALKANES
BACTERIA
CHEMICAL REACTIONS
DATA
DECOMPOSITION
HYDROCARBONS
INFORMATION
MICROORGANISMS
NORTH AMERICA
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PLANTS
ROCKY MOUNTAIN REGION
SULFUR COMPOUNDS
THERMAL SPRINGS
USA
WATER SPRINGS
510200* - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)