淡紫拟青霉E7菌株固体放大发酵产孢培养基和工艺条件研究

Medium and Culture Conditions for Sporulation in Solid State Scale-up Fermentation of Paecilomyces lilacinus E7 Strain

为探讨淡紫拟青霉E7菌株固体放大发酵因子间的关系以获得大量孢子用于田间试验,通过正交试验设计优化固体发酵培养基成分和培养条件组合,并测定外加碳源、氮源、无机盐和装料方式对产孢量的影响。结果表明:以玉米粉+甘蔗渣+麸皮+壳聚糖组成的正交2号配方为最佳复合培养基质,分生孢子产量达7.13×109个/g,以发酵液pH+液相发酵终点+温度+初始含水量组成的正交4号配方为优适培养条件,分生孢子产量达8.97×109个/g;该菌株在优化后的培养基配方中添加0.4%蔗糖、0.2%蛋白胨、0.002%硫酸锰,以双层纱布袋装料按优化后的培养条件放大培养,产孢量最高可达到8.22×1010个/g。优化后的E7菌株发酵产孢培养基基质用量少,发酵成本低,适合于固体放大发酵生产淡紫拟青霉孢子。

In order to improve the production of the spore yield of Paecilomyces lilacinus E7 strain in solid state scale-up fermentation and to provide enough spores for field tests,optimal combinations of medium composition and culture conditions were determined by orthogonal design,and the impact of external carbon,nitrogen source,inorganic salts and charging method on sporulation were also determined.Results indicated that the best compound culture medium was the second orthogonal formula which was composed by corn flour,sugarcane bagasse,bran and chitosan,and the highest couidia production was up to 7.13×109/g.The best culture condition was the fourth orthogonal formula which contained fermentative liquid pH,liquid fermentation time,temperature and initial moisture content,and the highest conidia production was up to 8.97×109/g.The conidia production could reach 8.22×1010/g when E7 strain was incubated in double layers of gauze bag and was added 0.4％ sucrose,0.2％ peptone and 0.002％ manganese sulfate extrally and fermented in culture conditions.With the least fermentation substrates usage and reduced cost,the optimized medium and culture conditions were suitable for the conidia production of E7 strain in solid state scale-up fermentation.