Arthrobacter ruber sp. nov., isolated from glacier ice.

A Gram-stain-positive strain designated MDB1-42 was isolated from ice collected from Midui glacier in Tibet, PR China. Strain MDB1-42 was catalase-positive, oxidase-negative and grew optimally at 25-28 °C and pH 7.0. Phylogenetic analysis based on 16S rRNA gene sequences revealed that MDB1-42 represented a member of the genus Arthrobacter. The highest level of 16S rRNA gene sequence similarity (99.86 %) was found with Arthrobacter agilis NBRC 15319. Multilocus sequence analysis revealed low similarity of 91.93 % between MDB1-42 and Arthrobacter agilis NBRC 15319. Average nucleotide identity and digital DNA-DNA hybridization values between MDB1-42 and the most closely related strain, Arthrobacter agilis DSM 20550, were 81.36 and 24.5 %, respectively. The genomic DNA G+C content was 69.0 mol%. The major cellular fatty acids of MDB1-42 were anteiso-C15 : 0 and anteiso-C17:0. The polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, one unidentified glycolipid and one unidentified lipid. The predominant menaquinone was MK-9(H2). On the basis of results obtained using a polyphasic approach, a novel species Arthrobacter ruber sp. nov. is proposed, with MDB1-42 (=CGMCC 1.9772=NBRC 113088) as the type strain.