Sphaerisporangium fuscum sp. nov., Isolated from Sediment of Anmucuo Lake in Tibet Autonomous Region of China.

A novel actinomycete strain, designated H8589T, was isolated from a lake sediment sample, and a polyphasic approach was employed to determine its taxonomic position. Phylogenetic analysis based on 16S rRNA gene indicated that strain H8589T formed a monophyletic clade within the genus Sphaerisporangium and was most closely related to Sphaerisporangium siamense DSM 45784 T (97.9% similarity) and Sphaerisporangium rufum DSM 46862 T (97.7% similarity). The draft genome had a length of 10,134,050 bp with a G + C content of 71.2%. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between strain H8589T and its closely related Sphaerisporangium species were 80.6 ~ 83.2%, 73.9 ~ 78.4% and 24.5 ~ 29.0%, respectively, which were significantly lower than the widely accepted species-defined threshold. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. Whole-cell sugars were glucose, ribose and madurose. The menaquinones were MK-9(H4), MK-9(H2), MK-9(H6) and MK-9. The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, unidentified phospholipids and unidentified aminophospholipids. The major fatty acids were identified as iso-C16:0, 10-methyl-C17:0 and C17:0. The results of phenotypic properties, genotypic distinctiveness and chemotaxonomic features indicated that strain H8589T should represent a novel species within the genus Sphaerisporangium, Sphaerisporangium fuscum sp.nov. The type strain is H8589T (= JCM 34848 T = CICC 25115 T).