Sphingobium cupriresistens sp. nov., a copper-resistant bacterium isolated from copper mine soil, and emended description of the genus Sphingobium.

A gram-negative, aerobic, copper-resistant bacterium, designated strain CU4(T), was isolated from copper mine soil in Daye, China. Phylogenetic analysis based on 16S rRNA gene sequences showed highest similarity to Sphingobium rhizovicinum CC-FH12-1(T) (98.4 %), followed by Sphingobium francense Sp+(T) (97.2 %), Sphingobium japonicum UT26(T) (97.1 %), Sphingobium abikonense NBRC 16140(T) (97.0 %), Sphingobium xenophagum DSM 6383(T) (96.9 %) and Sphingobium yanoikuyae DSM 7462(T) (95.5 %). The major fatty acids (>5 %) were summed feature 7 (C(18 : 1)ω7c, C(18 : 1)ω9t and/or C(18 : 1)ω12t), summed feature 4 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH), C(16 : 0) and C(14 : 0) 2-OH, and the predominant quinone was ubiquinone Q-10. Spermidine was the major polyamine component. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, phosphatidyldimethylethanolamine and phosphatidylcholine. The genomic DNA G+C content of strain CU4(T) was 64.9 mol%. Comparison of DNA-DNA hybridization, phenotypic and chemotaxonomic characteristics between strain CU4(T) and phylogenetically related strains revealed that the new isolate represents a novel species of the genus Sphingobium, for which the name Sphingobium cupriresistens sp. nov. is proposed. The type strain is CU4(T) ( = KCTC 23865(T) = CCTCC AB 2011146(T)). An emended description of the genus Sphingobium is also proposed.