Streptomyces venetus sp. nov., an actinomycete with a blue aerial mycelium

A Gram-positive bacterium, designated CMU-AB225^T, was isolated from rhizosphere soil of an oil palm (Elaeis guineensis). The strain exhibited a blue aerial spore mass and a light cream to moderate yellow substrate mycelium and formed chains of spiny spores. Whole-cell hydrolysates consisted of ll-diaminopimelic acid, glucose, ribose, mannose and galactose. The predominant menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The polar lipids profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol-mannoside, four unidentified lipids, two unidentified aminolipids and an unidentified glycolipid. The major cellular fatty acids (>10 %) were iso-C16 : 0, C16 : 0, anteiso-C15 : 0 and iso-C15 : 0. The G+C content of genomic DNA was 69.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CMU-AB225^T was a member of the genus Streptomyces and formed a distinct phyletic line which was most closely related to Streptomyces koyangensis JCM 14915^T, Streptomyces misionensis JCM 4497^T and Streptomyces aurantiogriseus JCM 4346^T. Multilocus sequence analysis (MLSA) using five housekeeping genes (atpD, gyrB, recA, rpoB and trpB) showed that the MLSA distances of strain CMU-AB225^T to phylogenetically related species were greater than the 0.007 threshold. Moreover, the low values of DNA-DNA relatedness and phenotypic differences, especially a blue aerial mycelium, enabled strain CMU-AB225^T to be distinguished from its closely related species. It is thus proposed that strain CMU-AB225^T represents a novel species, namely Streptomyces venetus sp. nov. The type strain is CMU-AB225^T (=JCM 31290^T=TBRC 2001^T).