A novel aerobic, obligately mixotrophic, moderately thermophilic, thiosulfate-oxidizing bacterium, S10 T , was isolated from hot-spring sediment samples collected from Atri, Bhubaneswar, India. The cells of this isolate stained Gram-negative and were strictly aerobic, non-sporulating, rodshaped and motile with a single polar flagellum. Strain S10 T was positive for oxidase and catalase activities. It was capable of utilizing thiosulfate under mixotrophic growth conditions. Mixotrophic growth was observed at pH 6.0-8.5 and 25-45 6C; optimum growth occurred at pH 7.5-8.0 and 30-37 6C. The major cellular fatty acids were C 12 : 0 3-OH, C 16 : 1 v7c, C 16 : 0 , C 17 : 0 cyclo, C 18 : 1 v7c and C 19 : 0 cyclo v8c. The DNA G+C content of strain S10 T was 64.8 mol%. 16S rRNA gene sequence analysis indicated that the bacterium clustered within the radiation of the genus Thiomonas and showed 98.0 % similarity with Thiomonas perometabolis ATCC 23370 T and Thiomonas intermedia ATCC 15466 T . However, DNA-DNA reassociation values of strain S10 T with Thiomonas perometabolis JCM 20426 T and Thiomonas intermedia JCM 20425 T , its nearest phylogenetic relatives, were 46 and 39 %, respectively. On the basis of phenotypic, physiological and chemotaxonomic properties, 16S rRNA gene sequence analysis and DNA-DNA reassociation studies, it is proposed that strain S10 T represents a novel species of the genus Thiomonas, Thiomonas bhubaneswarensis sp. nov.; the type strain is S10 T (5DSM 18181 T 5JCM 14806 T ).

A novel bacterium, designated strain HT27T , was isolated from a sulfur spring sample collected from Athamallik, Orissa, India, and was characterized by using a polyphasic approach. Cells were Gram-negative, strictly aerobic, rod-shaped and motile by means of a single polar flagellum. Strain HT27 T was oxidase-and catalase-positive. Growth was observed at pH 5.0-11.0 and at 15-45 6C; the highest growth yield was observed at pH 7.5-8.0 and 30-37 6C. The G+C content of the genomic DNA of strain HT27 T was 63 mol%. The major cellular fatty acids were