Flexivirga caeni sp. nov., isolated from activated sludge

A Gram-stain-positive, strictly aerobic, non-motile, non-spore-forming and oval-shaped bacterium, designated strain BO-16 was isolated from activated sludge. In this study, we describe the taxonomic characterization and classification of this bacterium by using the polyphasic approach. Growth of BO-16 was observed at 10-40 °C (optimum, 25-37 °C) and at pH 5.0-10.0 (optimum, pH 7.0) on R2A agar. The major fatty acids it contained were -C , -C and -C and the major polar lipids were diphosphatidylglycerol, phosphatidylinositol and phosphatidylethanolamine. This isoprenoid quinones included MK-8 (H ) and MK-8 (H ). The peptidoglycan contained lysine, serine, alanine, glycine and glutamic acid and represented the peptidoglycan type A4 . On the basis of 16S rRNA gene sequence similarity, BO-16 was shown to represent a member of the genus and to be related to KACC 18597 (98.4 % sequence similarity), KCTC 39536 (97.5 %), DSM 24460 (97.4 %) and KCTC 39625 (97.3 %). The G+C content of the genomic DNA was 68.0 mol%. The DNA-DNA relatedness values between BO-16 and its closest phylogenetic neighbours were much lower than 70 %. BO-16 could be differentiated phylogenetically and phenotypically from the species of the genus with validly published names. Therefore the isolate represents a novel species, for which the name sp. nov. is proposed, with the type strain BO-16 (=KACC 19647 =LMG 30859 ).