Sulfurovum denitrificans sp. nov., an obligately chemolithoautotrophic sulfur-oxidizing epsilonproteobacterium isolated from a hydrothermal field

Abstract

A novel marine sulfur-oxidizing bacterium, designated strain eps51^T, was isolated from a surface rock sample collected from the hydrothermal field of Suiyo Seamount on the Izu-Bonin Arc in the Western Pacific Ocean. This bacterium was Gram-staining-negative, non-motile and rod-shaped. Strain eps51^T grew chemolithoautotrophically, by sulfur-oxidizing respiration with elemental sulfur and thiosulfate as electron donors and used only carbon dioxide as a carbon source. Oxygen and nitrate were used as its electron acceptors. The isolate grew optimally at 30 °C, at pH 7.0 and with 3 % NaCl. The predominant fatty acids were C16 : 1ω7c, C18 : 1ω7c and C16 : 0. The respiratory quinone was menaquinone-6 and the genomic DNA G+C content was 40.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequence revealed that eps51^T represented a member of the genus Sulfurovum and the closest relative was Sulfurovum aggregans (96.7 %). Based on its phylogenetic position along with its physiological and chemotaxonomic characteristics, the name Sulfurovum denitrificans sp. nov. is proposed, with the type strain eps51^T (=NBRC 102602^T=DSM 19611^T).