- Volume 64, Issue Pt_12, 2014

A group of strains representing species of the genus Leptospira, isolated from patients with leptospirosis in Mayotte (Indian Ocean), were previously found to be considerably divergent from other known species of the genus Leptospira . This was inferred from sequence analysis of rrs (16S rRNA) and other genetic loci and suggests that they belong to a novel species. Two strains from each serogroup currently identified within this novel species were studied. Spirochaete, aerobic, motile, helix-shaped strains grew well at 30–37 °C, but not at 13 °C or in the presence of 8-azaguanine. Draft genomes of the strains were also analysed to study the DNA relatedness with other species of the genus Leptospira . The new isolates formed a distinct clade, which was most closely related to Leptospira borgpetersenii , in multilocus sequence analysis using concatenated sequences of the genes rpoB, recA, fusA, gyrB, leuS and sucA. Analysis of average nucleotide identity and genome-to-genome distances, which have recently been proposed as reliable substitutes for classical DNA–DNA hybridization, further confirmed that these isolates should be classified as representatives of a novel species. The G+C content of the genomic DNA was 39.5 mol%. These isolates are considered to represent a novel species, for which the name Leptospira mayottensis sp. nov. is proposed, with 200901116T ( = CIP 110703T = DSM 28999T) as the type strain.

A Gram-stain-positive, strictly aerobic, non-motile, coccoid bacterium, designated NCCP-154T, was isolated from citrus leaf canker lesions and was subjected to a polyphasic taxonomic study. Strain NCCP-154T grew at 10–37 °C (optimum 30 °C) and at pH 7.0–8.0 (optimum pH 7.0). The novel strain exhibited tolerance of UV irradiation (>1000 J m−2). Based on 16S rRNA gene sequence analysis, strain NCCP-154T showed the highest similarity to Deinococcus gobiensis CGMCC 1.7299T (98.8 %), and less than 94 % similarity to other closely related taxa. The chemotaxonomic data [major menaquinone, MK-8; cell-wall peptidoglycan type, A3β (Orn–Gly2); major fatty acids, summed feature 3 (C16 : 1ω7c/iso-C15 : 0 2-OH; 35.3 %) followed by C16 : 0 (12.7 %), iso-C17 : 1ω9c (9.2 %), C17 : 1ω8c (7.4 %) and iso-C17 : 0 (6.9 %); major polar lipids made up of several unidentified phosphoglycolipids and glycolipids and an aminophospholipid, and mannose as the predominant whole-cell sugar] also supported the affiliation of strain NCCP-154T to the genus Deinococcus . The level of DNA–DNA relatedness between strain NCCP-154T and D. gobiensis JCM 16679T was 63.3±3.7 %. The DNA G+C content of strain NCCP-154T was 70.0 mol%. Based on the phylogenetic analyses, DNA–DNA hybridization and physiological and biochemical characteristics, strain NCCP-154T can be differentiated from species with validly published names. Therefore, it represents a novel species of the genus Deinococcus . The name Deinococcus citri sp. nov. is proposed, with the type strain NCCP-154T ( = JCM 19024T = DSM 24791T = KCTC 13793T).

An anaerobic, psychrophilic bacterium, strain MO-SPC2T, was isolated from a methanogenic microbial community in a continuous-flow bioreactor that was established from subseafloor sediments collected from off the Shimokita Peninsula of Japan in the north-western Pacific Ocean. Cells were pleomorphic: spherical, annular, curved rod, helical and coccoid cell morphologies were observed. Motility only occurred in helical cells. Strain MO-SPC2T grew at 0–17 °C (optimally at 9 °C), at pH 6.0–8.0 (optimally at pH 6.8–7.2) and in 20–40 g NaCl l−1 (optimally at 20–30 NaCl l−1). The strain grew chemo-organotrophically with mono-, di- and polysaccharides. The major end products of glucose fermentation were acetate, ethanol, hydrogen and carbon dioxide. The abundant polar lipids of strain MO-SPC2T were phosphatidylglycolipids, phospholipids and glycolipids. The major cellular fatty acids were C14 : 0, C16 : 0 and C16 : 1ω9. Isoprenoid quinones were not detected. The G+C content of the DNA was 32.3 mol%. 16S rRNA gene-based phylogenetic analysis showed that strain MO-SPC2T was affiliated with the genus Sphaerochaeta within the phylum Spirochaetes , and its closest relatives were Sphaerochaeta pleomorpha GrapesT (88.4 % sequence identity), Sphaerochaeta globosa BuddyT (86.7 %) and Sphaerochaeta coccoides SPN1T (85.4 %). Based on phenotypic characteristics and phylogenetic traits, strain MO-SPC2T is considered to represent a novel species of the genus Sphaerochaeta , for which the name Sphaerochaeta multiformis sp. nov. is proposed. The type strain is MO-SPC2T ( = JCM 17281T = DSM 23952T). An emended description of the genus Sphaerochaeta is also proposed.