Showing papers on "Methanogen published in 1980"
TL;DR: A new genus and species of a nonmotile gram-negative rod, Syntrophobacter wolinii, is the first bacterium described which degrades propionate only in coculture with an H(2)-using organism and in the absence of light or exogenous electron acceptors such as O(2), sulfate, or nitrate.
Abstract: A new genus and species of a nonmotile gram-negative rod, Syntrophobacter wolinii, is the first bacterium described which degrades propionate only in coculture with an H(2)-using organism and in the absence of light or exogenous electron acceptors such as O(2), sulfate, or nitrate. It was isolated from methanogenic enrichments from an anaerobic municipal sewage digestor, using anaerobic roll tubes containing a medium with propionate as the energy source in association with an H(2)-using, sulfate-reducing Desulfovibrio sp. which cannot utilize fatty acids other than formate. S. wolinii produced acetate and, presumably, CO(2) and H(2) (or formate) from propionate. In media without sulfate and with Methanospirillum hungatei, a methanogen that uses only H(2)-CO(2) or formate as an energy source, acetate, methane, and, presumably, CO(2) were produced from propionate and only small amounts of Desulfovibrio sp. were present. Isolation in coculture with the methanogen was not successful. S. wolinii does not use other saturated fatty acids as energy sources.
552 citations
TL;DR: Microbial methanogenesis was examined in thermal waters, muds, and decomposing algal-bacterial mats associated with volcanic activity in Yellowstone National Park and revealed that the microbial population was predominantly rod shaped and asporogenous.
Abstract: Microbial methanogenesis was examined in thermal waters, muds, and decomposing algal-bacterial mats associated with volcanic activity in Yellowstone National Park. Radioactive tracer studies with [(14)C]glucose, acetate, or carbonate and enrichment culture techniques demonstrated that methanogenesis occurred at temperatures near 70 degrees C but below 80 degrees C and correlated with hydrogen production from either geothermal processes or microbial fermentation. Three Methanobacterium thermoautotrophicum strains (YT1, YTA, and YTC) isolated from diverse volcanic habitats differed from the neotype sewage strain DeltaH in deoxyribonucleic acid guanosine-plus-cytosine content and immunological properties. Microbial methanogenesis was characterized in more detail at a 65 degrees C site in the Octopus Spring algal-bacterial mat ecosystem. Here methanogenesis was active, was associated with anaerobic microbial decomposition of biomass, occurred concomitantly with detectable microbial hydrogen formation, and displayed a temperature activity optimum near 65 degrees C. Enumeration studies estimated more than 10(9) chemoorganotrophic hydrolytic bacteria and 10(6) chemolithotrophic methanogenic bacteria per g (dry weight) of algal-bacterial mat. Enumeration, enrichment, and isolation studies revealed that the microbial population was predominantly rod shaped and asporogenous. A prevalent chemoorganotrophic organism in the mat that was isolated from an end dilution tube was a taxonomically undescribed gram-negative obligate anaerobe (strain HTB2), whereas a prevalent chemolithotrophic methanogen isolated from an end dilution tube was identified as M. thermoautotrophicum (strain YTB). Taxonomically recognizable obligate anaerobes that were isolated from glucose and xylose enrichment cultures included Thermoanaerobium brockii strain HTB and Clostridium thermohydrosulfuricum strain 39E. The nutritional properties, growth temperature optima, growth rates, and fermentation products of thermophilic bacterial strains 39E, HTB2, and YTB were determined.
193 citations