Streptomyces iranensis sp. nov., isolated from soil

A novel streptomycete, designated strain HM 35(T), was isolated from soil in Isfahan city, Iran. Strain HM 35(T) produced a branched substrate mycelium and aerial hyphae that developed into short, compact, spiral spore chains with grey rugose spores at the tips of the aerial hyphae. On some media, these spirals coalesced into dark masses of spores with age. Whole-cell hydrolysates of strain HM 35(T) contained LL-diaminopimelic acid, glucose and ribose. Phospholipids detected were phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, phosphatidylinositol mannosides, hydroxy-phosphatidylethanolamine, lyso-phosphatidylethanolamine and hydroxy-lyso-phosphatidylethanolamine. MK-9(H(4)), MK-9(H(6)) and MK-9(H(8)) were the predominant menaquinones. The major fatty acids were iso- and anteiso-branched components. The chemotaxonomic characteristics of the novel isolate matched those described for members of the genus Streptomyces. Based on 16S rRNA gene sequence analysis, strain HM 35(T) showed highest similarity to Streptomyces rapamycinicus NRRL 5491(T) (99.2 %), Streptomyces violaceusniger DSM 40563(T) (99.1 %), Streptomyces javensis DSM 41764(T) (99.1 %) and Streptomyces yogyakartensis DSM 41766(T) (99.1 %). The novel strain formed a distinct monophyletic line within the 16S rRNA gene sequence tree. The level of DNA-DNA relatedness between strain HM 35(T) and the type strain of S. rapamycinicus was 72.7 %. Strain HM 35(T) showed the typical morphology found among members of the S. violaceusniger/Streptomyces hygroscopicus group but could be clearly differentiated from closely related species based on other phenotypic markers. Phenotypic and genotypic data thus indicate that strain HM 35(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces iranensis is proposed. The type strain is HM 35(T) (=DSM 41954(T)=CCUG 57623(T)).