Pannonibacter indica sp. nov., a highly arsenate-tolerant bacterium isolated from a hot spring in India.

A novel aerobic bacterium, strain HT23(T), able to grow on 500 mM sodium arsenate was isolated from a hot-spring sediment sample collected from Athamallik, Orissa, India. Cells of this isolate were Gram negative. Heterotrophic growth was observed at pH 6.0-11.0 and 20-45 °C. Optimum growth was observed at 37 °C and pH 7.0-10.0. The major polar lipids are diphosphatidyl glycerol, phosphatidyl glycerol, phosphatidyl ethanolamine, phosphatidyl choline and phosphatidyl monomethyl ethanolamine. The major isoprenoid quinone was Q-10. 16S rRNA gene sequence analysis indicated that the bacterium clustered with the genus Pannonibacter and showed 98.9 % similarity with Pannonibacter phragmitetus C6-19(T) (DSM 14782(T)) and 98 % with the P. phragmitetus group B and P. phragmitetus group E strains. Levels of DNA-DNA relatedness between the strain HT23(T) and P. phragmitetus C6-19(T) (DSM 14782(T)) and other strains of P. phragmitetus group B and group E strains were below 55 %. On the basis of phenotypic and chemotaxonomic characteristics, 16S rRNA gene sequence analysis and DNA-DNA hybridization data, strain HT23(T) is considered to represent a novel species of the genus Pannonibacter, for which the name Pannonibacter indica sp. nov. is proposed. The type strain is HT23(T) (=JCM 16851(T) = DSM 23407(T) = LMG 25769(T)).