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

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. , 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 6C 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 C 15 : 1 v8c and/or C 15 : 2 ), summed feature 8 (consisting of C 17 : 1 v8c and/ or C 17 : 2 ) and C 14 : 0 dimethyl 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-1 T and SHI-2 are assigned to a novel species of the genus Pelosinus, with the name Pelosinus defluvii sp. nov. The genus Pelosinus was described by Shelobolina et al. (2007) to accommodate a bacterium belonging to the Sporomusa-Pectinatus-Selenomonas group of the phylum Firmicutes (Strömpl et al., 1999). This group is a heterogeneous assemblage of organisms with Gram-negative cell walls and is also referred to as clostridial cluster IX (Collins et al., 1994) and the family Veillonellaceae (Rogosa, 1971). At present, the genus Pelosinus is represented by a single species, Pelosinus fermentans, the type strain of which was first isolated from a subsurface kaolin deposit in Russia (Shelobolina et al., 2007). The genus Sporotalea contains the single species Sporotalea propionica and was described by Boga et al. (2007) to accommodate a propionigenic bacterium isolated from the intestinal tract of the soilfeeding termite Thoracotermes macrothorax. At the time of initial publication, the closest phylogenetic relative reported for both P. fermentans R7 T (Shelobolina et al., A supplementary figure is available with the online version of this paper.

Novel Firmicutes Group Implicated in the Dechlorination of Two Chlorinated Xanthones, Analogues of Natural Organochlorines

“…Eight targeted bands were also closely related to bacteria from both dechlorinating and nondechlorinating cultures (Tilden-4, Palos Verdes-1, Pine Barrens II-2, Pine Barrens II-4, the sequences closely related to Pine Barrens II-3 and Tilden-1, Pine Barrens II-1, and Leech Lake-1). Interestingly, sequences corresponding to band Pine Barrens II-1 are closely associated with the genera Pelosinus; two Pelosinus species were recently isolated from chlorinated-solvent-contaminated aquifers but, upon isolation, were not capable of dechlorinating selected solvents (48). A third Pelosinus isolate from a dechlorinating culture (strain BXM) was deposited in GenBank but has not yet been described, and a Pelosinus isolate was identified to be a dominant strain in a trichloroethene-dechlorinating enrichment culture containing Dehalococcoides (49).…”

Microbial Community Succession during Lactate Amendment and Electron Acceptor Limitation Reveals a Predominance of Metal-Reducing Pelosinus spp

“…The second species, P. defluvii, cannot utilize lactate but can reduce Fe(III) although not sulfate (35), while P. fermentans strain UFO1, isolated from Oak Ridge sediments, can consume lactate and reduce Fe(III) as well as U(VI) (39). While Fe(III) and U(VI) reduction have been observed in Pelosinus isolates, no isolates have been shown to reduce Cr.…”

Genomic and Physiological Characterization of the Chromate-Reducing, Aquifer-Derived Firmicute Pelosinus sp. Strain HCF1

“…Members of the Veillonellaceae, and particularly Pelosinus spp., have recently been reported to be among the more abundant bacterial taxa in chromate-reducing systems inoculated with material from the chromium-contaminated aquifer at the U.S. Department of Energy (DOE) Hanford 100H site in Washington State (1,2) and in other contaminated aquifers (3)(4)(5). Chromate-reducing bacteria are of interest because in situ reductive immobilization is favored as one of the more cost-effective approaches to remediation of aquifers contaminated with Cr(VI), a potent toxicant, mutagen, and carcinogen (6,7).…”