Polaribacter septentrionalilitoris sp. nov., isolated from the biofilm of a stone from the North Sea

A new member of the family Flavobacteriaceae was isolated from the biofilm of a stone at Nordstrand, a peninsula at the German North Sea shore. Phylogenetic analysis of the 16S rRNA gene sequence showed that strain ANORD1(T) was most closely related to the validly described type strains Polaribacter porphyrae LNM-20(T) (97.0 %) and Polaribacter reichenbachii KMM 6386(T) (96.9 % 16S rRNA gene sequence similarity) and clustered with Polaribacter gangjinensis K17-16(T) (96.0 %). Strain ANORD1(T) was determined to be mesophilic, Gram-negative, non-motile and strictly aerobic. Optimal growth was observed at 20-30 degrees C, within a salinity range of 2-7 % sea salt and from pH 7-10. Like other type strains of the genus Polaribacter, ANORD1(T) was tested negative for flexirubin-type pigments, while carotenoid-type pigments were detected. The DNA G+C content of strain ANORD1(T) was 30.6 mol%. The sole respiratory quinone detected was menaquinone 6 (MK-6). The major fatty acids identified were C-15:0, iso-C-15:0, C-15:1 omega 6c and iso-C-15:0 3-OH. Based on the polyphasic approach, strain ANORD1(T) represents a novel species in the genus Polaribacter, with the name Polaribacter septentrionalilitoris sp. nov. being proposed. The type strain is ANORD1(T) (=DSM 110039(T)=NCIMB 15081(T)=MTCC 12685(T)).