aeration basin of an activated sludge process, was clarified by phenotypic, chemotaxonomic and phylogenetic analyses. The strain possesses wall chemotype IV, MK-9(H_0 ), as the major menaquinone, and contains saturated, monounsaturated and 10-methyl branched fatty acids. The G+C content of its DNA is 68.1 mol%. Phenotypic data and DNA relatedness to known species indicate that the strain SCNU5^T represents a new species within the genus Tsukamurella, for which we propose the name Tsukamurella sunchonensis sp. nov. The type strain of T. sunchonensis is SCNU5^T (=KCTC 9827^T ).