Arthrobacter rhombi sp. nov., isolated from Greenland halibut (Reinhardtius hippoglossoides)

Two strains of a hitherto undescribed Gram-positive coryneform bacterium isolated from Greenland halibut (Reinhardtius hippoglossoides) were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains constitute a new line within the genus Arthrobacter. The nearest relatives of the bacterium from fish were members of the Arthrobacter nicotianael Arthrobacter sulfureus group. The unknown bacterium was readily distinguished from these species by phenotypic methods. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Arthrobacter rhombi sp. nov. The type strain of Arthrobacter rhombi is CCUG 38813T.