In order to understand the antifungal properties of the fermentation broth of Streptomyces albidoflavus G-1 and its optimal fermentation conditions,the methods of flat panel confrontation and growth rate were used to study the antifungal properties,and the single factor experiment,RDA analysis and response surface CCD design were applied to study the key limiting factors for the production of antifungal substances and the optimal combination of fermentation conditions. The results showed that fermentation broth of S. albidoflavus G-1 not only had more than 70% of inhibitory rate against Alternaria solani,Fusarium oxysporum f. sp. niveum,Fusarium graminerum,Fusarium oxysporum f. sp. capsicum,Phytophthora melonis and Monilinia fructicola,but also still maintained > 70% inhibitory rate at ≤80℃,UV irradiation 24 h,pH 3-13,and diluted 100 times. In addition,based on RDA analysis,it was found that initial pH value,temperature,maltose and potato were the key limiting factors for producing antifungal substances from strain G-1. The optimal culture condition was 8% maltose and 16.5% potato,initial pH value 6.5,temperature 30° C,speed 160 r / min,and fermentation time 5 d. Moreover,the antifungal rate increased by 14.46% at optimized fermentation condition. Therefore it is concluded that the fermentation broth of strain G-1 not only has fine antifungal stability,but also may largely produce antifungal compaounds with a lower cost and short time at optimized fermentation conditions,which may provide theoretical foundation for the field of large-scale fermentation and field application.
