生防链霉菌HS1发酵工艺优化

Optimization for fermentation process of strain HS1 of Streptomyces scopuliridis

为进一步提高链霉菌Streptomyces scopuliridis对杨树溃疡病的防治效果,采用单因子和正交试验相结合的方法对菌株HS1的发酵培养基和发酵条件进行优化,测定发酵液理化性质,并初步探索完善5~50 L二级发酵工艺。结果表明:拮抗菌株HS1最佳发酵培养基配方(质量体积比)为可溶性淀粉8%、花生饼粉3.5%、硝酸钾0.2%、氯化钠0.4%、碳酸钙0.4%,最佳发酵条件为发酵温度28℃、初始pH 7.0、菌株种龄4 d、接种量(菌种和培养基体积百分比)6%、发酵4 d。二级发酵工艺中,种子罐采用高氏一号培养基,发酵温度28℃、转速150 r/min、通气量3.0 L/min、发酵4 d、初始pH 7.0;发酵罐培养基组分按优化后配方,转速250 r/min、通气量10.0 L/min、发酵6 d、初始pH 7.0;发酵液中性时抑菌效果最好,光和热稳定性良好、耐贮性高。拮抗菌株HS1可为开发防治杨树溃疡病的生物农药提供新的原材料,发酵液抑菌效果良好、稳定易保存,可为进一步研制生防菌剂奠定基础。

In order to improve control effect of Streptomyces scopuliridis against poplar canker,the basic fermentation medium and fermentation conditions of the strain HS1 were optimized based on single factor and orthogonal experiment,and physicochemical properties of the fermentation broth were determined.The secondary fermentation process of 5-50 L was preliminarily explored and improved.The results showed that the optimal fermentation medium formula for antagonistic strain HS1 mass-to-volume ratio was soluble starch 8%,peanut meal 3.5%,potassium nitrate 0.2%,sodium chloride 0.4%and calcium carbonate 0.4%.The optimum fermentation conditions were fermentation temperature 28℃,initial pH 7.0,age of the HS1 four days,inoculation amount(volume fraction)6%,fermenting for four days.In the secondary fermentation process,seeding tank adopt Gauze’s medium,and fermentation conditions were temperature 28℃,rotation speed 150 r/min,aeration rate 3.0 L/min,fermenting for four days,initial pH 7.0.The components of medium in fermentation tank adopted optimized formula,rotation speed 250 r/min,aeration rate 10.0 L/min,fermenting time six days and initial pH 7.0.Stability determination showed that neutral fermentation broth had the best antibacterial effect,light and heat stability and high storage stability.The antagonistic strain HS1 could be developed to provide new raw materials for biological pesticides against poplar canker.The fermentation broth had good antibacterial effect,and was stable and easy to preserve,which could lay a foundation for further subsequent research and development.