橡胶树炭疽病生防链霉菌DL5C发酵培养基筛选及发酵条件优化研究

Screening of Biocontrol Streptomyces DL5C Fermentation Medium and Optimization of Fermentation Conditions for Anthracnose of Rubber Tree

研发环保的生防菌剂是当前绿色安全的一种方法,优化强拮抗放线菌的发酵培养基及发酵条件,筛选最优配比,可为研制新型、环境友好型的生物杀菌剂提供前期基础。本实验以初始固体培养基为基础,采用单因素试验,以抑菌率和发酵培养基中菌体数量作为测定指标,筛选出最适的碳源、氮源;在确定碳氮源的基础上进行正交试验,确定培养基中各成分的最佳配比,最终得到最佳培养基。确定合适的碳氮源之后,对种子液接种量、料水比、起始pH、温度、发酵终点等条件进行优化,最终实验发现链霉菌DL5C固体发酵培养基为麦麸50%、玉米粉8%、花生粉饼5%、米糠10%、稻壳26.7%、CaCO_(3)0.3%,最佳接种量20%,最佳料水比1∶1,最适pH 5,最适温度32℃,最佳发酵时间是10 d,发酵活菌数达到2.20×10^(10)CFU/g,抑菌率为92.22%。

Optimal fermentation medium and conditions of strong antagonistic actinomycetes and optimal proportion screen-ing provides the preliminary basis for the development of new and environmentally friendly biological fungicides.A single factor test was conducted based on the initial solid medium,and the appropriate carbon and nitrogen sources were screened by inhibiting rates and the number of mycelium in fermentation medium.Further orthogonal experiments are carried out aimed at obtaining the optimum ratio of each component in medium.Then the fermentation conditions,including inoculum size of seed solution,the ratio of feed and water,the initial pH,the temperature and the end point of fermentation were optimized.The results showed the optimum fermentation composition for streptomyces DL5C were 50%wheat bran,8%corn flour,5%peanut powder cake,10%rice bran,T27%rice husk and 0.3%CaCO_(3).The optimum inoculum was 20%and the optimum ratio of material water was 1∶1.The optimum pH was 5.The optimum temperature was 32℃ and the optimum fermentation period was 10 days and the number of live bacteria is 2.20×10^(10)cfu/g,the bacteriostatic rate was 92.22%.