Croceibacterium selenioxidans sp. nov., isolated from seleniferous soil

A Gram-negative, aerobic bacterial strain, designated LX-88^T, was isolated from seleniferous soil in Enshi, Hubei Province, PR China. Strain LX-88^Toxidized elemental selenium to selenite, and produced carotenoids but not bacteriochlorophyll. The isolate grew optimally at 28 °C, pH 8.0 and with 0.5 % (w/v) NaCl. Phylogenetic analysies of the organism's 16S rRNA and bacterial core gene set sequences indicated that LX-88^T belongs to the genus Croceibacterium, and has the highest degree of 16S rRNA gene sequence similarity to Croceibacterium soli MN-1^T (97.4 %). The LX-88^T genome was 3.4 Mbp and had a G+C content of 63.6 mol%. The average nucleotide identity and digital DNA-DNA hybridization values showed low relatedness (below 95 and 70 %, respectively) between strain LX-88^T and other strains in the genus Croceibacterium. Ubiquinone-10 was the predominant quinone. The polar lipid profile was dominated by diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, an unidentified aminolipid, an unidentified phospholipid and an unidentified lipid. The major fatty acid was summed feature 8 (C_{18 : 1} ω7c and/or C_{18 : 1} ω6c). These physiological and biochemical tests facilitated the differentiation of strain LX-88^T from other members of the genus Croceibacterium. The results of this multifaceted taxonomic study indicate that strain LX-88^T represents a novel species in the genus Croceibacterium, for which the name Croceibacterium selenioxidans sp. nov. is proposed. The type strain is LX-88^T (=MCCC 1K08007^T=LMG 32570^T).