Arthrobacter cavernae sp. nov., a novel actinobacterium isolated from sediment of karst cave

A novel, Gram-stain-positive, aerobic, non-endospore-forming, non-motile and rod-shaped bacterium designated PO-11T was isolated from sediment of karst cave collected in Libo county, Guizhou Province, PR China. The isolate grew optimally on R2A agar at 25 degrees C, pH 8.0 and with 0.5% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that PO-11(T) belonged to the genus Arthrobacter and was most closely related to Arthrobacter methylotrophus TGA(T) (98.3% sequence similarity), Arthrobacter alkaliphilus LC6(T) (97.7 %) and Arthrobacter ramosus CCM1646(T) (97.1%). Genome sequencing revealed a genome size of 4073119 bp and the genomic DNA G+C content was 66.16mol%. Its DNA-DNA relatedness values with A. methylotrophus TGA(T), A. alkaliphilus LC6(T) and A. ramosus CCM1646(T) were 23.0, 22.9 and 23.2 %, respectively. The main fatty acids were anteiso-C 15 :0, anteiso-C-17:0 and iso-C-16:0. The major respiratory quinone was MK-9(H-2). The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, glycolipid, phosphatidylethanolamine, phosphatidylinositol and unidentified lipids. Thus, based on phylogenetic and phenotypic and chemotaxonomic data, strain PO-11(T) represents a novel species of the genus Arthrobacter, for which the name Arthrobacter cavernae sp. nov. is proposed. The type strain is strain PO-11(T) (=CCTCC AB 2021070(T)=LMG 32459(T)).