Proposal of a new halobacterial genus Natrinema gen. nov., with two species Natrinema pellirubrum nom. nov. and Natrinema pallidum nom. nov.

Abstract

A phylogenetic analysis of 69 halobacterial 16S rRNA gene sequences has been carried out, integrating data from new isolates, previously described halobacteria and cloned sequences from uncultivated halobacteria. Halobacterium halobium NCIMB 777, Halobacterium trapanicum NCIMB 784 and Halobacterium salinarium NCIMB 786, together with several other strains (strains T5.7, L11 and Halobacterium trapanicum NCIMB 767) constitute a distinct lineage with at least 98.2% sequence similarity. These strains have been incorrectly assigned to the genus Halobacterium. Therefore, based on a variety of taxonomic criteria, it is proposed that Halobacterium salinarium NCIMB 786 is renamed as Natrinema pellirubrum nom. nov., the type species of the new genus Natrinema gen. nov., and that Halobacterium halobium NCIMB 777 and Halobacterium trapanicum NCIMB 784 are renamed as a single species, Natrinema pallidum nom. nov. It was notable that halobacteria closely related to the proposed new genus have been isolated from relatively low-salt environments.