A novel endophytic actinomycete with antagonistic activity against various phytopathogenic fungi, designated strain p1417T, was isolated from the root of cattail (Typha angustifolia L.) collected from Yunnan Province, Southwest China. A polyphasic taxonomic study was carried out to establish the taxonomic status of this strain. Strain p1417T was found to have morphological and chemotaxonomic characteristics typical of the genus Streptomyces. The diamino acid present in the cell wall was LL-diaminopimelic acid. Xylose and arabinose occurred in whole cell hydrolysates. The menaquinones were identified as MK-9(H8), MK-9(H6) and MK-9(H4). The polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were found to be iso-C16:0, anteiso-C15:0, iso-C15:0 and C16:0. The genomic DNA G + C content of strain p1417T based on the genome sequence was 72.0 mol%. Based on 16 S rRNA gene, five housekeeping genes and whole genome sequences analysis, strain p1417T was most closely related to Streptomyces flavofungini JCM 4753T (99.4% 16 S rRNA gene sequence similarity), Streptomyces alboflavus JCM 4615T (98.8%) and Streptomyces aureoverticillatus JCM 4347T (98.2%). However, the average nucleotide identity values, the digital DNA-DNA hybridization values and the multilocus sequence analysis evolutionary distances between this strain and its closely related strains showed that it belonged to one distinct species. In addition, these results were also supported by differences in the phenotypic and chemotaxonomic characteristics between strain p1417T and three closely related type strains. Therefore, it is concluded that strain p1417T represents a novel species of the genus of Streptomyces, for which the name Streptomyces typhae sp. nov. is proposed. The type strain is p1417T (= CCTCC AA 2019091T = DSM 110636T).
Keywords: Antifungal activity; Endophyte; Genome; Polyphasic taxonomy; Streptomyces.