Streptomyces taklimakanensis sp. nov., an actinomycete isolated from the Taklimakan desert.

Abstract

A novel Streptomyces strain, designated TRM43335T, was isolated from the Taklimakan desert in Alar City, Xinjiang, north-west China. The strain was found to exhibit an inhibitory effect on biofilm formation by Candida albicans and Staphylococcus epidermidis. A polyphasic approach was used to determine its taxonomic status. The strain was observed to form abundant aerial mycelium, occasionally twisted and which differentiated into spiral spore chains. Spores of TRM43335T were observed to be oval-shaped, with a smooth surface. Strain TRM43335T was found to grow optimally at 37°C, pH 8 and in the presence of 1% (w/v) NaCl. The major sugars were identified as ribose, xylose, glucose, mannose and galactose, and the principal phospholipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannoside and phosphatidylinositol. The diagnostic cell wall amino acid was identified as LL-diaminopimelic acid. The predominant menaquinone was found to be MK-9(H6). The major cellular fatty acids were identified as iso-C16:1 H, anteiso-C15:0, iso-C16:0, anteiso-C17:0, anteiso-C17:1 w9c and iso-C15:0. Analysis of the 16S rRNA sequence showed that strain TRM43335T exhibits high sequence similarity to Streptomyces desertarenae SYSU D8023T 98.69%. A multilocus sequence analysis of five house-keeping genes (atpD, gyrB, rpoB, recA and trpB) also illustrated that strain TRM43335T should be assigned to the genus Streptomyces. The DNA G + C content of the strain was determined to be 72.8mol%. The average nucleotide identity relatedness between strain TRM43335T and the phylogenetically related strain S. desertarenae SYSU D8023T was found to be 89.23%, and the in silico DNA-DNA hybridization value to be 36.70%. Therefore, it is concluded that strain TRM43335T represents a novel species of the genus Streptomyces, for which the name Streptomyces taklimakanensis sp. nov is proposed. The type strain is TRM43335T (CCTCC AA 2018052T = KCTC 49254T).