Streptomyces phytophilus sp. nov., an endophytic actinobacterium with biosynthesis potential as an antibiotic producer

An endophytic actinobacterium, strain PIP175^T, was isolated from the root sample of a native apricot tree (Pittosporum angus-tifolium) growing on the Bedford Park campus of Flinders University, Adelaide, South Australia. This strain is a Gram stain-positive, aerobic actinobacterium with well-developed substrate mycelia. Aerial mycelia rarely produce spores and the spore chain is spiral. Strain PIP175^T showed the highest 16S rRNA gene sequence similarity to Streptomyces aculeolatus DSM 41644^T (99.4 %). Other closely related phylogenetic representatives include Streptomyces synnematoformans DSM 41902^T (98.3 %), Streptomyces albospinus NBRC 13846^T (97.6 %), Streptomyces cacaoi subsp. cacaoi NRRL B-1220^T (97.5 %) and Streptomyces ruber NBRC 14600^T (97.4 %). The major cellular fatty acid of this strain was iso-C_{16: 0} and the major menaquinone was MK-9(H₆ ). The whole-cell sugar contained galactose, glucose and mannose. Chemotaxonomic data confirmed that strain PIP175^T belonged to the genus Streptomyces. Digital DNA–DNA hybridization, average nucleotide identity based on blast and OrthoANIu results between strain PIP175^T and S. aculeolatus DSM 41644^T were 60.0, 94.1 and 94.9 %, respectively. Genotypic and phenotypic data and genome analysis results allowed the differentiation of strain PIP175^T from its closest species with validly published names. Strain PIP175^T showed good activity against methicillin-resistant Staphylococcus aureus 03120385. Genome mining of strain PIP175^T revealed biosynthetic genes encoding proteins relating to antibiotic production, plant growth promo-tion and biodegradation enzymes. The name proposed for the new species is Streptomyces phytophilus sp. nov. The type strain is PIP175^T (=DSM 103379^T=TBRC 6026^T).