Streptomyces zagrosensis sp. nov., isolated from soil.

Abstract

The taxonomic position of a novel actinomycete isolated from soil in Fars Province (Iran) was determined using a polyphasic approach. Phenotypic characterization and 16S rRNA gene sequence analysis of the isolate matched those described for members of the genus Streptomyces. On ISP2 medium, strain HM 1154(T) produced a dark cream, branched substrate mycelium and Retinaculiaperti aerial hyphae that in some images also appeared spiral and that developed into greyish-white spore chains with a smooth surface. The isolate showed optimal growth at 28 °C and pH 6-9 with 0-4% (w/v) NaCl. Whole-cell hydrolysates contained ll-diaminopimelic acid as diagnostic diamino acid, ribose and glucose. The main phospholipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol, three unknown phospholipids and an unknown aminophospholipid; MK-9(H4) and MK-9(H2) were the predominant menaquinones. The major cellular fatty acids were the branched saturated iso-C16:0 and anteiso-C15:0. Strain HM 1154(T) exhibited the highest 16S rRNA gene sequence similarities to Streptomyces coerulescens DSM 40146(T) (99.4%), Streptomyces varsoviensis DSM 40346(T) (99.3%), Streptomyces youssoufiensis DSM 41920(T) (99.2%), Streptomyces abikoensis DSM 40831(T) (99.2%), Streptomyces rimosus subsp. rimosus DSM 40260(T) (99.1%), Streptomyces luteireticuli DSM 40509(T) (99.1%), Streptomyces thioluteus DSM 40027(T) (99.1%), Streptomyces blastmyceticus DSM 40029(T) (99.0%) and Streptomyces hiroshimensis DSM 40037(T) (99.0%). DNA-DNA hybridization studies showed relatedness values of 11.0-35.8% with the closest related species. Based on these results, strain HM 1154(T) is considered to represent a novel species within the genus Streptomyces, for which the name Streptomyces zagrosensis sp. nov. is proposed. The type strain is HM 1154(T) ( = DSM 42018(T) = UTMC 1154(T) = CECT 8305(T)).