Antimicrobial activity and identification of endophytic actinomycetes strain 13-85 isolated from Acanthopanax senticosus / 中草药

ABSTRACT

Objective: To studies the antimicrobial activity and stability of fermentation extracts produced by endophytic actinomycete strain 13-85 from Acanthopanax senticosus; Secondary metabolite biosynthesis genes were detected. Meanwhile, the strain was identified. Methods: Paper disc diffusion method was used to test the antimicrobial activity and stability of strain 13-85, the biosynthesis genes (PKS I, PKS II, NRPS, Halo, and CYP) were obtained by PCR, and sequences were analyzed. The strain was identified by phenotypic characteristics and molecular characteristics. Results: The fermentation broth of the strain showed broad-spectrum, strong activity, and stability against pathogenic microbes. The strain contains PKS II gene and NRPS gene. The PKS II sequence had 89% homology compared with Streptomyces fradiae PKS gene (Accession Number AFO70128.1). The NRPS gene sequence had 95% homology with S. virginiae NRPS gene (Accession Number WP_033225509.1). The sequence of 16S rRNA of the strain had 99.85% homology with S. amritsarensis (Accession Number GQ906975). Conclusion: Metabolites of the actinomycete strain 13-85 with broad-spectrum antibacterial activity and better stability, have a value for development and application. The strain 13-85 was identified as Streptomyces amritsarensis, a valid species of genus Streptomyces.