Arthrobacter bussei sp. nov., a pink-coloured organism isolated from cheese made of cow's milk

A pink-coloured bacterium (strain KR32 ) was isolated from cheese and assigned to the ' group'. Members of the 'pink group' form a stable clade (100 % bootstrap value) and contain the species , and , which share ≥99.0 % 16S rRNA gene sequence similarity. Isolate KR32 showed highest 16S rRNA gene sequence similarity (99.9 %) to DSM 20550 . Additional multilocus sequence comparison confirmed the assignment of strain KR32 to the clade 'pink group'. Average nucleotide identity and digital DNA-DNA hybridization values between isolate KR32 and DSM 20550 were 82.85 and 26.30 %, respectively. The G+C content of the genomic DNA of isolate KR32 was 69.14 mol%. Chemotaxonomic analysis determined anteiso-C as the predominant fatty acid and MK-9(H ) as the predominant menaquinone. Polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and monoacyldimannosyl-monoacylglycerol. The peptidoglycan type of the isolate was A3α. The carotenoid bacterioruberin was detected as the major pigment. At 10 °C, strain KR32 grew with increased concentrations of bacterioruberin and production of unsaturated fatty acids. Strain KR32 was a Gram-stain-positive, catalase-positive, oxidase-positive and coccus-shaped bacterium with optimal growth at 27-30 °C and pH 8. The results of phylogenetic and phenotypic analyses enabled the differentiation of the isolate from other closely related species of the 'pink group'. Therefore, strain KR32 represents a novel species for which the name sp. nov. is proposed. The type strain is KR32 (=DSM 109896 =LMG 31480 =NCCB 100733 ).