Streptomyces plumbidurans sp. nov., a Pb 2+ -tolerant actinomycete.

A novel actinobacterium, designated KC 17012 ^T , was isolated from lead zinc tailings collected from Lanping, Yunnan, PR China. Comparative 16S rRNA gene sequencing showed that KC 17012 ^T belonged to the genus Streptomyces and was most closely related to the type strains of Streptomyces neyagawaensis (98.34%), Streptomyces panaciradicis (98.34%) and Streptomyces heilongjiangensis (98.27%). Phylogenetic tree analysis revealed strain KC 17012 ^T formed a distinct clade. The genome size was 8.64 Mbp with a DNA G+C content of 70.8%. Digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain KC 17012 ^T and those of S. neyagawaensis JCM 4796 ^T (25.3 and 81.5 %) and S. panaciradicis NBRC 109811 ^T (30.1 and 85.7 %) were below the thresholds of 70 and 96% for prokaryotic conspecific assignation. The strain formed long straight aerial hyphae which generated regular short rod spores with spiny surfaces. Growth occurred at 10-45 °C, pH 6-8 and with 0-9 % NaCl (w/v). Strain KC 17012 ^T contained ll-diaminopimelic acid and the major whole-cell hydrolysates included glucose, mannose and ribose. The menaquinones were MK-9(H ₄ ), MK-9(H ₆ ) and MK-9(H ₈ ). The major cellular fatty acids were iso-C _15 : 0 , anteiso-C _15 : 0 , iso-C _16 : 0 and anteiso-C _17 : 0 . The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, one unidentified lipid and one unidentified phospholipid. On the basis of the results of a polyphasic taxonomic study, it is concluded that KC 17012 ^T represents a novel species of the genus Streptomyces , for which the name Streptomyces plumbidurans sp. nov., is proposed. The type strain is KC 17012 ^T (CGMCC 4.7704 ^T =JCM 35204 ^T ).