Streptomyces luozhongensis sp. nov., a novel actinomycete with antifungal activity and antibacterial activity

Abstract

A novel actinomycete strain, designated TRM 49605T, was isolated from a desert soil sample from Lop Nur, Xinjiang, north-west China, and characterised using a polyphasic taxonomic approach. The strain exhibited antifungal activity against the following strains: Saccharomyces cerevisiae, Curvularia lunata, Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, Penicillium citrinum, Candida albicans and Candida tropicalis; Antibacterial activity against Bacillus subtilis, Staphylococcus epidermidis and Micrococcus luteus; and no antibacterial activity against Escherichia coli. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain TRM 49605T to the genus Streptomyces. Strain TRM 49605T shows high sequence similarities to Streptomyces roseolilacinus NBRC 12815T (98.62%), Streptomyces flavovariabilis NRRL B-16367T (98.45%) and Streptomyces variegatus NRRL B-16380T (98.45%). Whole cell hydrolysates of strain TRM 49605T were found to contain LL-diaminopimelic acid as the diagnostic diamino acid and galactose, glucose, xylose and mannose as the major whole cell sugars. The major fatty acids in strain TRM 49605T were identified as iso C16:0, anteiso C15:0, C16:0 and Summed Feature 5 as defined by MIDI. The main menaquinones were identified as MK-9(H4), MK-9(H6), MK-9(H8) and MK-10(H6). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and phosphatidylinositol mannoside. The G+C content of the genomic DNA was determined to be 71.2%. The DNA-DNA relatedness between strain TRM 49605T and the phylogenetically related strain S. roseolilacinus NBRC 12815T was 60.12±0.06%, which is lower than the 70% threshold value for delineation of genomic prokaryotic species. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain TRM 49605T (=CCTCC AA2015026T=KCTC 39666T) should be designated as the type strain of a novel species of the genus Streptomyces, for which the name Streptomyces luozhongensis sp. nov. is proposed.