Methylated sulfur compounds in microbial mats: in situ concentrations and metabolism by a colorless sulfur bacterium.

摘要: The concentrations of the volatile organic sulfur compounds methanethiol, dimethyl disulfide, and sulfide (DMS) viable population capable DMS utilization in laminated microbial ecosystems were evaluated. Significant levels disulfide (maximum 220 24 nmol cm3 sediment-1, respectively) could be detected only at top 20 mm mat, whereas methanethiol was found depth horizons from to 50 concentration 42 sediment-1). surface layer doubled after cold hydrolysis its precursor, dimethylsulfoniopropionate. Most-probable-number counts revealed 2.2 x 10(5) cells 0- 5-mm horizon, growth on as sole source energy. An obligately chemolithoautotrophic bacillus designated strain T5 isolated marine sediment. Continuous culture studies which growth-limiting substrate a maximum specific rate 0.10 h-1 saturation constant 90 mumol liter-1 for aerobic this substrate.