Cultivation and in situ detection of a thermophilic bacterium capable of oxidizing propionate in syntrophic association with hydrogenotrophic methanogens in a thermophilic methanogenic granular sludge

H. Imachi, Y. Sekiguchi, Y. Kamagata, A. Ohashi, H. Harada

研究成果: Article査読

92 被引用数 (Scopus)

抄録

The thermophilic, anaerobic, propionate-oxidizing bacterial populations present in the methanogenic granular sludge in a thermophilic (55°C) upflow anaerobic sludge blanket reactor were studied by cultivation and in situ hybridization analysis. For isolation of propionate-degrading microbes, primary enrichment was made with propionate as the sole energy source at 55°C. After several attempts to purify the microbes, a thermophilic, syntrophic, propionate-oxidizing bacterium, designated strain SI, was isolated in both pure culture and coculture with Methanobacterium thermoautotrophicum. Under thermophilic (55°C) conditions, strain SI oxidized propionate, ethanol, and lactate in coculture with M. thermoautotrophicum. In pure culture, the isolate was found to ferment pyruvate. 16S ribosomal DNA sequence analysis revealed that the strain was relatively close to members of the genus Desulfotomaculum, but it was only distantly related to any known species. To elucidate the abundance and spatial distribution of organisms of the strain SI type within the sludge granules, a 16S rRNA-targeted oligonucleotide probe specific for strain SI was developed and applied to thin sections of the granules. Fluorescence in situ hybridization combined with confocal laser scanning microscopy revealed that a number of rod-shaped cells were present in the middle and inner layers of the thermophilic granule sections and that they formed close associations with hydrogenotrophic methanogens. They accounted for approximately 1.1% of the total cells in the sludge. these results demonstrated that strain SI was one of the significant populations in the granular sludge and that it was responsible for propionate oxidation in the methanogenic granular sludge in the reactor.

本文言語English
ページ(範囲)3608-3615
ページ数8
ジャーナルApplied and environmental microbiology
66
8
DOI
出版ステータスPublished - 2000

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Applied Microbiology and Biotechnology
  • Ecology

フィンガープリント 「Cultivation and in situ detection of a thermophilic bacterium capable of oxidizing propionate in syntrophic association with hydrogenotrophic methanogens in a thermophilic methanogenic granular sludge」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル