Pelosinus defluvii sp. nov., isolated from chlorinated solvent-contaminated groundwater, emended description of the genus Pelosinus and transfer of Sporotalea propionica to Pelosinus propionicus comb. nov.

Abstract

Two anaerobic bacterial strains, designated SHI-1Tand SHI-2, were isolated from chlorinated solvent-contaminated groundwater. They were found to be identical in phenotypic properties and shared high (98.5–99.8 %) pairwise 16S rRNA gene sequence similarity. Multiple 16S rRNA genes were found to be present in the isolates as well asPelosinus fermentansDSM 17108TandSporotalea propionicaDSM 13327T. Strains SHI-1Tand SHI-2 could be differentiated from their closest phylogenetic relatives,P. fermentansDSM 17108TandS. propionicaDSM 13327T, on the basis of their phenotypic and phylogenetic properties. The isolates were Gram-negative, spore-forming, motile rods with peritrichous flagella. Growth occurred at 10–42 °C and pH 5.5–8.5. Fermentative growth was observed on Casamino acids, fructose, fumarate, glucose, glycerol, pyruvate and yeast extract. The major organic acids produced from glucose and glycerol fermentation were propionate and acetate. The major organic acids produced from fermentation of fumarate were propionate, acetate and succinate. The major cellular fatty acids were summed feature 4 (consisting of C15 : 1ω8cand/or C15 : 2), summed feature 8 (consisting of C17 : 1ω8cand/or C17 : 2) and C14 : 0dimethyl aldehyde. The polar lipids comprised aminophospholipids, including phosphatidylethanolamine and phosphatidylserine, and an unknown phospholipid. The genomic DNA G+C content was 39.2 mol%. We propose that strains SHI-1Tand SHI-2 are assigned to a novel species of the genusPelosinus, with the namePelosinusdefluviisp. nov. (type strain SHI-1T = NRRL Y-59407T = LMG 25549T). The description of the genusPelosinusis emended. We also propose the transfer ofS. propionicato the genusPelosinusasPelosinuspropionicuscomb. nov. (type strain TmPN3T = DSM 13327T = ATCC BAA-626T), on the basis of phylogenetic, chemotaxonomic and phenotypic properties.