Reclassification of Amycolicicoccus subflavus as Hoyosella subflava comb. nov. and emended descriptions of the genus Hoyosella and Hoyosella altamirensis.

16S rRNA gene sequences of two type strains belonging to different genera within the suborder Corynebacterineae, namely Hoyosella altamirensis and Amycolicicoccus subflavus, show a similarity of 99.8 %. Therefore, in order to clarify their taxonomic relationship, a polyphasic recharacterization under the same conditions was carried out. The peptidoglycan of H. altamirensis NBRC 109631T and A. subflavus NBRC 109087T was of A1γ type with meso-diaminopimelic acid as their diagnostic diamino acid. Both strains contained MK-8 as the only detected menaquinone, C16 : 0 and C18 : 1ω9c as the major fatty acids, and diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol as the principal polar lipids. The coincidences of these chemotaxonomic features suggested that H. altamirensis and A. subflavus should be assigned to the same genus. Meanwhile, the average nucleotide identity value between both strains and the results of physiological and biochemical tests indicated that H. altamirensis and A. subflavus should be affiliated to different species. Therefore, according to Rules 38 and 41a of the Bacteriological Code, it is proposed that Amycolicicoccus subflavus Wang et al. 2010 be reclassified as Hoyosella subflava comb. nov. (type strain DQS3-9A1T=CGMCC 4.3532T=DSM 45089T=JCM 17490T=NBRC 109087T) and the descriptions of the genus HoyosellaJurado et al. 2009 and Hoyosella altamirensisJurado et al. 2009 are emended accordingly.

A genome sequence-based approach to taxonomy of the genus Nocardia.

The genus Nocardia includes both pathogens and producers of useful secondary metabolites. Although 16S rRNA analysis is required to accurately discriminate among phylogenetic relationships of the Nocardia species, most branches of 16S rRNA-based phylogenetic trees are not reliable. In this study, we performed in silico analyses of the genome sequences of Nocardia species in order to understand their diversity and classification for their identification and applications. Draft genome sequences of 26 Nocardia strains were determined. Phylogenetic trees were prepared on the basis of multilocus sequence analysis of the concatenated sequences of 12 genes (atpD-dnaJ-groL1-groL2-gyrB-recA-rpoA-secA-secY-sodA-trpB-ychF) and a bidirectional best hit. To elucidate the evolutionary relationships of these genes, the genome-to-genome distance was investigated on the basis of the average nucleotide identity, DNA maximal unique matches index, and genome-to-genome distance calculator. The topologies of all phylogenetic trees were found to be essentially similar to each other. Furthermore, whole genome-derived and multiple gene-derived relationships were found to be suitable for extensive intra-genus assessment of the genus Nocardia.

Complete genome sequence of Oscillibacter valericigenes Sjm18-20(T) (=NBRC 101213(T)).

Oscillibacter valericigenes is a mesophilic, strictly anaerobic bacterium belonging to the clostridial cluster IV. Strain Sjm18-20(T) (=NBRC 101213(T) =DSM 18026(T)) is the type strain of the species and represents the genus Oscillibacter Iino et al. 2007. It was isolated from the alimentary canal of a Japanese corbicula clam (Corbicula japonica) collected on a seacoast in Shimane Prefecture in Japan. Phylogenetically, strain Sjm18-20(T) is closest to uncultured bacteria in digestive tracts, including the enriched cells thought to represent Oscillospira guilliermondii Chatton and Perard 1913. The isolated phylogenetic position and some distinct characteristics prompted us to determine the complete genome sequence. The 4,410,036 bp chromosome and the 60,586 bp plasmid were predicted to encode a total of 4,723 protein-coding genes.