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Title: Oxidation of dimethyl sulfide to dimethyl sulfoxide by phototrophic purple bacteria

Enrichment cultures of phototrophic purple bacteria rapidly oxidized up to 10 mM dimethyl sulfide (DMS) to dimethyl sulfoxide (DMSO). DMSO was qualitatively identified by proton nuclear magnetic resonance. By using a biological assay, DMSO was always quantitatively recovered from the culture media. DMS oxidation was not detected in cultures incubated in the dark, and it was slow in cultures exposed to full daylight. Under optimal conditions, the second-order rate constant for DMS oxidation was 6 day/sup -1/ mg of protein/sup -1/ ml/sup -1/. The rate constant was reduced in the presence of high concentration of sulfide (>1 mM), but was not affected by the addition of acetate. DMS was also oxidized to DMSO by a pure strain (tentatively identified as a Thiocystis sp.) isolated from the enrichment cultures. DMS supported growth of the enrichment cultures and of the pure strain by serving as an electron source for photosynthesis. A determination of the amount of protein produced in the cultures and an estimation of the electron balance suggested that the two electrons liberated during the oxidation of DMS to DMSO were quantitatively used to reduce carbon dioxide to biomass. The oxidation of DMS by phototrophic purple bacteria may be an importantmore » source of DMSO detected in anaerobic ponds and marshes.« less
Authors:
; ; ;
Publication Date:
OSTI Identifier:
5927073
Resource Type:
Journal Article
Resource Relation:
Journal Name: Appl. Environ. Microbiol.; (United States); Journal Volume: 53:9
Research Org:
Swiss Federal Institute for Water Resources and Water Pollution Control (EAWAG), Kastanienbaum
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; DMSO; BIOSYNTHESIS; PHOTOSYNTHETIC BACTERIA; GROWTH; SULFIDES; BIODEGRADATION; ELECTRONS; METABOLISM; NUCLEAR MAGNETIC RESONANCE; PHOTOSYNTHESIS; VISIBLE RADIATION; CHALCOGENIDES; CHEMICAL REACTIONS; DECOMPOSITION; ELECTROMAGNETIC RADIATION; ELEMENTARY PARTICLES; FERMIONS; LEPTONS; MAGNETIC RESONANCE; ORGANIC COMPOUNDS; ORGANIC SULFUR COMPOUNDS; PHOTOCHEMICAL REACTIONS; RADIATIONS; RESONANCE; SULFOXIDES; SULFUR COMPOUNDS; SYNTHESIS 560300* -- Chemicals Metabolism & Toxicology