Lomans, B. P.. Dept. of Microbiology, Faculty of Science, University of Nijmegen, bartl@sci.kun.nl
Pol, A. P.. Dept. of Microbiology, Faculty of Science, University of Nijmegen, arjan@sci.kun.nl
Op den Camp, H. J. M.. Dept. of Microbiology, Faculty of Science, University of Nijmegen, huubcamp@sci.kun.nl
Drift, C. van der. Dept. of Microbiology, Faculty of Science, University of Nijmegen, chrisvdd@sci.kun.nl

 
METHANOGENESIS FROM DIMETHYL SULFIDE AND METHANETHIOL IN ANOXIC FRESHWATER SEDIMENTS
 
Production and degradation of volatile organic sulfur compounds (VOSC) were studied in 32 sediment slurries collected from various freshwater systems in The Netherlands. In these ecosystems there appeared to be a correlation between methanethiol (MT) + dimethyl sulfide (DMS) concentrations and the amount of sulfide present. Production of VOSC in slurry incubations was low. However, a strong accumulation of MT was observed in sediment slurries supplemented with bromoethanesulfonate. This indicates that endogenous MT and DMS production is relatively well balanced with its degradation by methanogenic bacteria, resulting in low steady state concentrations. We investigated the role of methanogens in the degradation of MT and DMS in freshwater sediments. A methanogen was isolated from a sediment through enrichment on DMS. Physiological and molecular characterization indicated that it was new species most closely related to Methanococcoides burtonii. The isolate had a low salt tolerance and was able to use methanol, methylated amines and methylated sulfides as carbon and energy source. From the analysis of the 16S rRNA it became evident that this strain possessed a unique restriction site. This site was used to detect the presence of similar methanogens in several other freshwater sediments. All sediments tested showed the unique band characteristic of our isolate.
 
Day: Friday, Feb. 5
Time: 10:30 - 10:45am
Location: Sweeney Center
 
Code: SS37FR1030S