Abstract:Antagonistic actinomycetes are the important microbes for development of efficient and safe biological food preservatives. In this study, a total of 190 actinomycete strains were separated using the plate dilution method for soil samples collected from Guangzhou and its surrounding areas, and then preliminary screening and rescreening were conducted using the agar disc and Oxford cylinder diffusion methods, respectively. Strain PY-C-21 was identified by 16S rDNA sequence analysis, morphological and cultural characteristics, and physiological and biochemical characteristics. The active ingredients of the fermentation products from PY-C-21 were extracted using the solvent extraction method, and then the crude extracts of the PY-C-21 fermentation products were purified by silica gel column chromatography. The pure compounds were obtained by high-performance liquid chromatography, thin layer chromatography, and preparative chromatography, and monomeric compounds with antibacterial effects were analyzed by gas chromatography mass spectrometry, and high resolution mass spectrometry. The results showed that PY-C-21 possessed a stable and broad-spectrum antimicrobial activity, and was identified as Streptomyces toxytricini. The main active products in the fermentation products were identified as dibutyl phthalate, benzoic acid, phenol, 2,2?-methylenebis(6-tert-butyl-4-methylphenol), and bis(2-ethylhexyl) phthalate.
