Two recently reported bacterial strains that are able to reductively dehalogenate polychlorinated aliphatic alkanes, including 1,2,3-trichloropropane, 1,2-dichloropropane, 1,1,2,2-tetrachloroethane, 1,1,2-trichloroethane and 1,2-dichloroethane, were further characterized to clarify their taxonomic position. The two strains, designated BL-DC-8 and BL-DC-9T, were mesophilic, non-spore-forming, non-motile, Gram-negative staining and strictly anaerobic. Cells were irregular cocci, 0.3–0.6 μm in diameter. The two strains were resistant to ampicillin and vancomycin. Hydrogen was utilized as an electron donor. The genomic DNA G+C content of strains BL-DC-8 and BL-DC-9T was 54.0 and 53.8 mol%, respectively. The major cellular fatty acids were C18 : 1 ω9c, C16 : 1 ω9c, C16 : 0 and C14 : 0. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the strains cluster within the phylum Chloroflexi, but are related only distantly to all recognized taxa in the phylum. Morphological, physiological and chemotaxonomic traits as well as phylogenetic analysis support the conclusion that these two strains represent a novel species of a new genus in the phylum Chloroflexi, for which the name Dehalogenimonas lykanthroporepellens gen. nov., sp. nov. is proposed. The type strain of Dehalogenimonas lykanthroporepellens is BL-DC-9T (=ATCC BAA-1523T =JCM 15061T).
A radiation-resistant, Gram-stain-positive, non-motile, non-sporulating, aerobic, coccoid bacterium, strain 3axT, was isolated from a marine fish (black pomfret, Parastromateus niger), with radiation as a selective pressure. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 3axT exhibited highest similarity (97.9 %) with Deinococcus proteolyticus DSM 20540T. The ΔT m for DNA–DNA hybridization of D. proteolyticus DSM 20540T and strain 3axT was 15.3 °C, indicating that the novel strain was distinct from D. proteolyticus DSM 20540T. The predominant respiratory quinone was MK-8. Strain 3axT could grow at 20–42 °C; the optimum temperature for growth was 35 °C. The strain grew well at pH 6–9, with optimum growth at pH 7. The cell wall contained ornithine. The major fatty acids were 16 : 0, 16 : 1ω7c, 16 : 1ω9c and 18 : 1ω9c. Three phosphoglycolipids and one aminophospholipid were the major polar lipids. Based on the genotypic, phenotypic and chemotaxonomic characteristics, strain 3axT was significantly different from D. proteolyticus DSM 20540T and, therefore, it was identified as representing a novel species of the genus Deinococcus, for which the name Deinococcus piscis sp. nov. is proposed. The type strain is 3axT (=MTCC9123T =DSM 19767T).
An anaerobic, thermophilic, thiosulfate-reducing bacterium, strain AZM16c01T, isolated from a hot spring in Japan [Mori, K., Sunamura, M., Yanagawa, K., Ishibashi, J., Miyoshi, Y., Iino, T., Suzuki, K. & Urabe, T. (2008). Appl Environ Microbiol 74, 6223–6229] was characterized in detail. The 16S rRNA gene sequence analysis had revealed that strain AZM16c01T was the first cultivated representative of the candidate phylum OP5. The cells were multicellular filaments with a single polar flagellum. The strain contained iso-C17 : 0 as the major fatty acid and menaquinone-8(H6), menaquinone-8(H8) and menaquinone-8(H10) as the respiratory quinones. The G+C content of the genomic DNA of strain AZM16c01T was 34.6 mol%. Optimum growth was obtained at 65 °C, pH 6.5 and in the absence of NaCl, with a doubling time of 10.6 h. On the basis of the results of phylogenetic analysis based on the 16S rRNA gene sequence and the characterization of the strain in this study, we propose the name Caldisericum exile gen. nov., sp. nov. for strain AZM16c01T (=NBRC 104410T=DSM 21853T). In addition, we propose the new phylum name Caldiserica phyl. nov. for the candidate phylum OP5 represented by C. exile gen. nov., sp. nov., and Caldisericaceae fam. nov., Caldisericales ord. nov. and Caldisericia classis nov.