An anaerobic, thermophilic, filamentous (0.45 × >100 µm) bacterium, designated D1-25-10-4T, was isolated from a deep hot aquifer in France. Cells were non-motile and Gram-negative. Growth was observed at 43–65 °C (optimum 55 °C), at pH 6.8–7.8 (optimum pH 7.0) and with 0–5 g NaCl l−1 (optimum 0 g NaCl l−1). Strain D1-25-10-4T was a chemo-organotroph and fermented ribose, maltose, glucose, galactose, arabinose, fructose, mannose, sucrose, raffinose, xylose, glycerol, fumarate, peptone, starch and xylan. Yeast extract was required for growth. Sulfate, thiosulfate, sulfite, elemental sulfur, nitrate, nitrite and fumarate were not used as terminal electron acceptors. The G+C content of the DNA was 61.9 mol%. The major cellular fatty acids of strain D1-25-10-4T were C17 : 0, C18 : 0, C16 : 0 and iso-C17 : 0. The closest phylogenetic relative of strain D1-25-10-4T was Caldilinea aerophila STL-6-O1T (97.9 % 16S rRNA gene sequence similarity). DNA–DNA relatedness between strain D1-25-10-4T and Caldilinea aerophila DSM 14535T was 8.7±1 %. On the basis of phylogenetic, genotypic and phenotypic characteristics, strain D1-25-10-4T represents a novel species within the genus Caldilinea, class Caldilineae, phylum Chloroflexi, for which the name Caldilinea tarbellica sp. nov. is proposed. The type strain is D1-25-10-4T ( = DSM 22659T = JCM 16120T).
Four gamma- and UV-radiation-resistant bacterial strains, designated TDMA-24T, TDMA-24-2, TDMA-24-3 and TDMA-24-4, were isolated from a fresh-water sample collected at Misasa, Tottori, Japan. Cells of these strains were Gram-reaction-positive, non-motile, non-spore-forming, rod-shaped and formed red colonies. The genomic DNA G+C contents ranged from 70.5 to 70.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolates belong to the genus Deinococcus, the highest sequence similarities being with Deinococcus aquaticus PB314T (98 %) and Deinococcus caeni Ho-08T (97 %). The polar lipid profile of strain TDMA-24T comprised three unidentified phosphoglycolipids, five unidentified glycolipids and seven unidentified polar lipids. MK-8 was the predominant respiratory quinone. Major fatty acids were iso-C15 : 0, C15 : 1ω6c, C15 : 0, C16 : 0 and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c). On the basis of their phylogenetic positions and chemotaxonomic and phenotypic characteristics, the novel isolates represent a novel species of the genus Deinococcus, for which the name Deinococcus depolymerans sp. nov. is proposed. The type strain is TDMA-24T ( = JCM 14369T = NBRC 102115T = CCUG 53609T).