Arsenicibacter rosenii gen. nov., sp. nov., an efficient arsenic methylating and volatilizing bacterium isolated from an arsenic-contaminated paddy soil.

A novel bacterium with strong arsenic (As) methylation and volatilization abilities, designated strain SM-1T, was isolated from an As-contaminated paddy soil. SM-1T is strictly aerobic, rod-shaped, non-motile, Gram-negative and orange-coloured. Phylogenetic analysis revealed that strain SM-1T showed low 16S rRNA gene sequence similarities (≤88 %) to members of established genera in the family Cytophagaceae. Growth of this strain was observed at 15-45 °C (optimum, 37 °C), pH 6.0-8.0 (optimum, 7.0) and 0-0.5 % (w/v) NaCl. The major cellular fatty acids were C16 : 1ω5c and iso-C15 : 0. The respiratory quinone was MK-7, and the predominant polar lipids were phosphatidylethanolamine, an unidentified lipid (L), and an unidentified aminolipid (AL2). The DNA G+C content was 51.5 mol%. On the basis of phenotypic, phylogenetic and chemotaxonomic properties, strain SM-1T represents a novel species in a new genus within the family Cytophagaceae, for which the name Arsenicibacter rosenii gen. nov., sp. nov. is proposed. The type strain of Arsenicibacter rosenii is SM-1T (=CCTCC AB 2017086T=KCTC 52624T).