sp. nov., isolated from freshwater sediment.

A Gram stain-positive, non-spore-forming, non-motile and rod-shaped actinomycete, strain 5221, was isolated from the sediment of a river collected at Ronggui in the Pearl River Delta, PR China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain formed a distinct lineage within the genus and had the highest sequence similarity to Tp12 (96.7 %), followed by 2C6-41 (96.5 %), SST-8 (96.0 %) and 20 (95.9 %). The results of chemotaxonomic analyses, including detecting anteiso-C, anteiso-C, and C as the major cellular fatty acids, diphosphatidylglycerol, phosphatidylglycerol and three phosphoglycolipids as the polar lipids, MK-8(H) as the major menaquinone, and a DNA G+C content of 72.4 mol%, supported that strain 5221 is a member of the genus . Furthermore, low sequence similarities of 16S rRNA gene sequences, differences in fatty acid compositions and differential physiological characteristics such as enzyme activity and carbon sources utilization ability distinguished the isolate from its close relatives. Therefore, strain 5221 represents a novel species of the genus , for which the name sp. nov. is proposed, with the type strain 5221 (=GDMCC 1.1766=KACC 21700).