Porticoccus litoralis gen. nov., sp. nov., a gammaproteobacterium isolated from the Yellow Sea.

Abstract

A marine bacterium, designated IMCC2115(T), was isolated from coastal seawater (Yellow Sea, Korea) using a high throughput cultivation method based on dilution-to-extinction, and taxonomically investigated. Cells of the strain formed tiny, beige to off-white colonies and were Gram-stain-negative, obligately aerobic, chemoheterotrophic, non-motile cocci. Based on 16S rRNA gene sequence comparisons, the strain was most closely related to the genera Marinimicrobium (92.0-92.4 %) and Microbulbifer (91.6-92.8 %), but phylogenetic trees showed that the strain formed a distinct phyletic line in the class Gammaproteobacteria adjacent to the OM60 and SAR92 clades. The DNA G+C content of the strain was 47.8 mol% and the predominant cellular fatty acids were anteiso-C(15 : 0) (67.6 %), anteiso-C(17 : 0) (14.4 %) and C(16 : 0) (6.9 %). The 16S rRNA gene sequence analyses and phenotypic and chemotaxonomic tests allowed the differentiation of IMCC2115(T) from other related genera in the class Gammaproteobacteria. Therefore, strain IMCC2115(T) (=KCCM 42369(T) =NBRC 102686(T)) is proposed as the representative of a new genus and species, for which the name Porticoccus litoralis gen. nov., sp. nov. is proposed.