Exiguobacterium indicum sp. nov., a psychrophilic bacterium from the Hamta glacier of the Himalayan mountain ranges of India

Abstract

Strain HHS 31T, a Gram-positive, motile, rod-shaped, non-spore-forming, alkaliphilic bacterium, was isolated from the melt water of a glacier. Phenotypic and chemotaxonomic characteristics indicate that strain HHS 31T is related to species of the genus Exiguobacterium. The 16S rRNA gene sequence similarities between HHS 31T and strains of known species confirm that it is closely related to members of the genus Exiguobacterium (93–99 %) and that it exhibits >97 % similarity with Exiguobacterium acetylicum DSM 20416T (98.9 %), Exiguobacterium antarcticum DSM 14480T (98.0 %), Exiguobacterium oxidotolerans JCM 12280T (97.9 %) and Exiguobacterium undae DSM 14481T (97.4 %). Phylogenetic analysis based on the 16S rRNA gene sequence further confirms the affiliation of HHS 31T with the genus Exiguobacterium. However, the levels of DNA–DNA relatedness between HHS 31T and E. oxidotolerans JCM 12280T, E. acetylicum DSM 20416T, E. undae DSM 14481T and E. antarcticum DSM 14480T are 50, 63, 67 and 28 %, respectively. Strain HHS 31T also differs from these four closely related species in terms of a number of phenotypic traits. The phenotypic, chemotaxonomic and phylogenetic data suggest that HHS 31T merits the status of a novel species, for which the name Exiguobacterium indicum sp. nov. is proposed. The type strain is HHS 31T (=LMG 23471T=IAM 15368T).