Hydrogenophaga soli sp. nov., isolated from rice field soil.

Abstract

A novel Gram-stain-negative bacterial strain, designated strain S10T, was isolated from soil collected in a rice field in Goyang, South Korea. Cells of strain S10T were strictly aerobic, motile and rod-shaped. Colonies were round, convex, smooth and white. The strain grew optimally at 37 °C, pH 7.0 and 0 % (w/v) NaCl. Phylogenetic analysis of the 16S rRNA gene sequence of strain S10T revealed that the bacterium belongs to the family Comamonadaceae and is related to members of the genus Hydrogenophaga, with Hydrogenophaga caeni EMB71T being its closest relative (97.9 % sequence similarity). The DNA G+C content of strain S10T was 68.2 mol%. Strain S10T contained phosphatidylethanolamine and diphosphatidylglycerol as the major polar lipids. The major fatty acids were C16 : 0 and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The predominant respiratory quinone was ubiquinone Q-8. DNA-DNA hybridization values of strain S10T with Hydrogenophaga caeni KCTC 12613T, Hydrogenophaga atypica DSM 15342T and Hydrogenophaga defluvii DSM 15341T were 16.1±4.8, 49.0±3.2 and 21.9±8.8 %, respectively. Based on phylogenetic distinctiveness, DNA-DNA hybridization and specific physiological and biochemical characteristics, strain S10T (=KCTC 52520T=JCM 31711T) is classified as a novel species of the genus Hydrogenophaga, for which the name Hydrogenophagasoli sp. nov. is proposed.