Arthrobacter nanjingensis sp. nov., a mineral-weathering bacterium isolated from forest soil

A Gram-stain-positive, non-motile, rod- or coccoid-shaped actinobacterium, designated strain A33(T), was isolated from a forest soil sample from Nanjing, Jiangsu Province, PR China. The strain grew optimally at 30 °C, pH 7.0 and with 3 % NaCl (w/v). Phylogenetic analysis of the strain, based on 16S rRNA gene sequences, showed that it was most closely related to Arthrobacter woluwensis (98.4 % sequence similarity), Arthrobacter humicola (97.5 %), Arthrobacter globiformis (97.4 %), Arthrobacter oryzae (97.3 %) and Arthrobacter cupressi (97.0 %). The major cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C15 : 0; MK-9(H2) was the predominant respiratory quinone. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and three glycolipids. Cell-wall analysis revealed that the peptidoglycan type was A3α, based on l-lysine-l-alanine; the cell-wall sugars were galactose and mannose. The genomic G+C content of strain A33(T) was 66.8 mol%. The low DNA-DNA relatedness values between strain A33(T) and recognized species of the genus Arthrobacter and many phenotypic properties supported the classification of strain A33(T) as a representative of a novel species of the genus Arthrobacter, for which the name Arthrobacter nanjingensis sp. nov. is proposed. The type strain is A33(T) ( = CCTCC AB 2014069(T) = DSM 28237(T)).