Abstract:
A novel coccoid-shaped strain, AS/ASP6 (II)(T), was isolated from a sample taken from Plakortis simplex (Schulze), a marine sponge, collected at a depth of 30 m from the Bay of Bengal. This strain was identified by using a polyphasic taxonomic approach. The results of 16S rRNA gene sequence analysis showed that strain AS/ASP6 (II)(T) should be assigned to the genus Planococcus. Chemotaxonomic data (A4 alpha-type peptidoglycan; MK-6, MK-7 and MK-8 menaquinones; mainly branched cellular fatty acids; and phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol as cellular phospholipids) supported taxonomic placement in the genus Planococcus. Phylogenetic analysis of the 16S rRNA gene sequence showed that strain AS/ASP6 (II)(T) belonged to the genus Planococcus and was closely related to the type strains of Planococcus maritimus (99.1%) followed by Planococcus rifietoensis (98.6 %), Planococcus maitriensis (98.5%), Planococcus citreus (98.3%), Planococcus salinarum (98.1 %), Planococcus columbae (97.9 %), Planococcus donghaensis (97.8 %) and Planococcus antarcticus (97.7 %); DNA-DNA hybridization values obtained were well below the threshold that is required for the proposal of a novel species. The G+C content of the genomic DNA was 51.0 mol%. The phenotypic and genotypic data showed that strain AS/ASP6 (II)(T) merits recognition as a representative of a novel species of the genus Planococcus, for which the name Planococcus plakortidis sp. nov. is proposed; the type strain is AS/ASP6 (II)(T) (=MTCC 8491(T) =DSM 23997(T)).