Granulosicoccus marinus sp. nov., isolated from Antarctic seawater, and emended description of the genus Granulosicoccus.

A Gram-staining-negative, motile by flagella, non-pigmented, poly-β-hydroxybutyrate-producing, strictly aerobic and sphere-shaped bacterium, IMCC3490(T), was isolated from a coastal seawater sample from the Antarctic Peninsula. Optimal growth of strain IMCC3490(T) was observed at 20 °C, pH 8.0 and in the presence of 2 % (w/v) NaCl. Phylogenetic analysis using 16S rRNA gene sequences indicated that strain IMCC3490(T) belonged to the genus Granulosicoccus in the family Granulosicoccaceae. The strain was closely related to Granulosicoccus antarcticus IMCC3135(T) (98.8 % 16S rRNA gene sequence similarity) and Granulosicoccus coccoides Z 271(T) (98.5 %). The DNA-DNA relatedness values between IMCC3490(T) and type strains of the two species of the genus were far lower than 70 %, which indicated strain IMCC3490(T) is a novel genomic species of the genus Granulosicoccus. The major fatty acids of strain IMCC3490(T) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The isoprenoid quinone detected was ubiquinone-8 (Q-8) and predominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 61.0 mol%. On the basis of phylogenetic analyses, DNA-DNA relatedness values and phenotypic data, it is suggested that strain IMCC3490(T) represents a novel species of the genus Granulosicoccus, for which the name Granulosicoccus marinus sp. nov. is proposed. The type strain is IMCC3490(T) ( = KACC 17483(T) = NBRC 109704(T)). An emended description of the genus Granulosicoccus is also provided.