Screening and identification of a streptomyces sp.with antifungal activity

[Objective] Screening and identification of a marine-derived actinomycetes with antifugal activity, and then to determine the optimum fermentation conditions. [Method] Candida albicans was used as indicator bacteria to screen active strains. Strain H74-21 was identified based on its morphological, cultural, physiological and sequence analysis of 16S rDNA. HPLC-MS was used to determine the optimal media by analyzing the secondary metabolites. [Results] Strain H74-21 was identified to be a Streptomyces antibioticus strain. The optimum conditions were: 8.0% sucrose, 4.0% yeast extract, calcium carbonate 0.5%, 1L H2O, pH7.0~7.4, 28~30°C, fermentation for 5 days. [Conclusion] A antifungal Streptomyces strain H74-21 was successfully isolated and identified. The optimization of fermentation conditions improved the diversity and total amount of secondary metabolites. This result would be an important reference for further exploring the antifugal secondary metabolites.