Pseudaminobacter arsenicus sp. nov., an arsenic-resistant bacterium isolated from arsenic-rich aquifers.

An arsenic-resistant strain, CB3T, was isolated from arsenic-rich aquifers at the Jianghan Plain in Hubei, China. Phylogenetic and biochemical analysis suggested that it should represent a new species of the genus Pseudaminobacter in the family Phyllobacteriaceae. The 16S rRNA gene of CB3T shared the highest sequence similarities to those of the type strains Pseudaminobacter defluvii THI 051T (97.8 % identity) and Pseudaminobacter salicylatoxidans BN12T (97.4 %). The DNA-DNA relatedness values of CB3T with respect to strains belonging to the genus Pseudaminobacter were less than 70 %. The fatty acid profile of CB3T consisted of C16 : 0, cyclo-C19 : 0ω8c and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) as major components. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine and diphosphatidylglycerol. The DNA G+C content was 61.4 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain CB3T was distinct from previously described Pseudaminobacter species. Therefore, we propose that strain CB3T represents a novel species of the genus Pseudaminobacter, Pseudaminobacterarsenicus sp. nov., strain CB3T (=CCTCC AB2016116T=KCTC 52625T) is designated as the type strain.