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

A pink-coloured bacterium (strain KR32 T ) was isolated from cheese and assigned to the ‘ Arthrobacter agilis group’. Members of the ‘pink Arthrobacter agilis group’ form a stable clade (100 % bootstrap value) and contain the species Arthrobacter agilis , Arthrobacter ruber and Arthrobacter echini , which share ≥99.0 % 16S rRNA gene sequence similarity. Isolate KR32 T showed highest 16S rRNA gene sequence similarity (99.9 %) to A. agilis DSM 20550 T . Additional multilocus sequence comparison confirmed the assignment of strain KR32 T to the clade ‘pink A. agilis group’. Average nucleotide identity and digital DNA–DNA hybridization values between isolate KR32 T and A. agilis DSM 20550 T were 82.85 and 26.30 %, respectively. The G+C content of the genomic DNA of isolate KR32 T was 69.14 mol%. Chemotaxonomic analysis determined anteiso-C 15 : 0 as the predominant fatty acid and MK-9(H 2 ) 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 T grew with increased concentrations of bacterioruberin and production of unsaturated fatty acids. Strain KR32 T 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 A. agilis group’. Therefore, strain KR32 T represents a novel species for which the name Arthrobacter bussei sp. nov. is proposed. The type strain is KR32 T (=DSM 109896 T =LMG 31480 T =NCCB 100733 T ).