Characterization of Micrococcus antarcticus sp nov., a psychrophilic bacterium from Antarctica

A Gram-positive, cold-adapted, aerobic, spherical actinobacterium (strain T 2(T)) with a quite low cardinal growth temperature was isolated from Chines e Great-Wall station in Antarctica. Sequence comparisons of the 16S rDNA in dicated the isolate to be a phylogenetic member of the genus Micrococcus. f amily Micrococcaceae, in which it represents a novel lineage. The phylogene tic distinctness of the isolate with respect to the type strains Micrococcu s luteus and Micrococcus lylae was supported by DNA-DNA similarity values o f less than 40%. Chemotaxonomic properties supported the placement of the i solate in the genus Micrococcus. The diagnostic diamino acid of the cell-wa ll peptidoglycan is lysine. The predominant menaquinones are MK-8 and MK-8( H-2). The G+C content of the DNA of the isolate is 66.4 mol%. Genotypic. mo rphological and physiological characteristics were used to describe a new s pecies of Micrococcus, for which the name Micrococcus antarcticus is propos ed. The type strain is T2(T) (= AS 1.2372(T)).