Syntrophomonas erecta sp. nov., a novel anaerobe that syntrophically degrades short-chain fatty acids

Publisher Website
Google Scholar
Abstract
Two novel anaerobes, strains GB4-38T and SB9-1, were isolated from an upflow anaerobic sludge blanket reactor for treating bean-curd farm wastewater and lotus field mud, respectively. The strains degraded straight-chain fatty acids with 4–8 carbon atoms in syntrophic association with methanogens and converted 1 mol butyrate into about 2 mol acetate and presumably 2 mol H2. None of the branched-chain fatty acids tested could be degraded. Benzoate was not degraded. Fumarate, sulfate, thiosulfate, sulfur and nitrate did not serve as electron acceptors for butyrate degradation. In the absence of a methanogen partner, strain GB4-38T grew on crotonate in pure culture; the generation time was about 5 h at 37 °C. However, strain SB9-1 grew on butyrate plus pentenoate, but not crotonate, in pure culture and the generation time was 18 h at 37 °C. Cells of GB4-38T and SB9-1 were straight rods and stained Gram-negative. The major cellular fatty acids of GB4-38T were C14 : 0 (29·74 %), C16 : 0 (17·00 %), C16 : 1 ω5c (16·63 %) and isoC17 : 1 I (15·34 %). ll-Diaminopimelic acid existed in the cellular peptidoglycan. The genomic DNA G+C content of strain GB4-38T was 43·2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences supported clustering of the two strains with syntrophic bacterial species of the genus Syntrophomonas (89·6–92·4 % sequence similarity), but phenotypic, chemotaxonomic and genetic characters differentiated the two strains from members of this genus. Therefore, it is proposed that the two strains are representatives of a novel species, Syntrophomonas erecta sp. nov. The type strain is GB4-38T (=CGMCC 1.5013T=DSM 16215T).

This publication has 23 references indexed in Scilit: