Arthrobacter gangotriensis sp. nov. and Arthrobacter kerguelensis sp. nov. from Antarctica.

Two coryneform bacteria were isolated from a penguin rookery soil sample collected in Antarctica, near the Indian station Dakshin Gangotri (strain Lz1y(T)), and from sea water from Kerguelen island, Antarctica (strain KGN15(T)). They have morphological and chemotaxonomic properties (peptidoglycan A4alpha type; major menaquinones MK-8, MK-9 and MK-10; predominant fatty acids anteiso-C(15 : 0) and anteiso-C(17 : 0)) that are characteristic of members of the genus Arthrobacter. The isolates shared 97.8 % 16S rRNA gene sequence similarity to each other and were most closely related to Arthrobacter sulfureus (about 98.5 % sequence similarity). DNA-DNA hybridization experiments revealed 50 % relatedness between the isolates, while the levels of DNA-DNA relatedness between strains Lz1y(T) and KGN15 (T) and their phylogenetic relative, A. sulfureus, were respectively 54 and 12 %. Based on the above data and distinct phenotypic differences between the isolates and A. sulfureus, two novel species are proposed, Arthrobacter gangotriensis sp. nov. (type strain Lz1y(T)=DSM 15796(T)=JCM 12166(T)) and Arthrobacter kerguelensis sp. nov. (type strain KGN15(T)=DSM 15797(T)=JCM 12165(T)).