Paenibacillus polymyxa JSa-9发酵培养基优化及其在黄瓜枯萎病中的应用研究

Optimization of fermentation medium and application in cucumber Fusarium wilt of Paenibacillus polymyxa JSa-9

[目的]本文旨在提高菌株Paenibacillus polymyxa JSa-9的芽孢产量并研究其芽孢液对黄瓜枯萎病的生物防治作用。[方法]采用单因素试验方法筛选最适于P.polymyxa JSa-9产芽孢的碳源、氮源和无机盐,在此基础上采用Taguchi试验方法优化各组分的最佳配比;通过田间试验研究P.polymyxa JSa-9芽孢液与其他药剂对黄瓜枯萎病的相对防效及对黄瓜幼苗生长的作用。[结果]P.polymyxa JSa-9产芽孢各组分的最优配比为麦芽浸粉15 g·L^(-1)、玉米浆15 g·L^(-1)、Ca CO_35 g·L^(-1)、Mg Cl_2·6H_2O 0.5 g·L^(-1),此条件下预测得到的芽孢产量可达到7.44×10~9CFU·m L^(-1),此时培养基的信噪比为60.13;田间试验中P.polymyxa JSa-9芽孢液相对防效达69.02%,优于发酵上清液,经芽孢液处理的幼苗植株高度为7.61 cm,单株叶片数为4.79,能显著促进黄瓜幼苗生长(P<0.05)。[结论]采用单因素试验与Taguchi试验相结合的方法优化培养基,效果显著,得到的P.polymyxa JSa-9芽孢液对黄瓜枯萎病有良好的防治效果,且具有一定促生长作用。

[Objectives] The objective of this study is to increase the yield of spore and explore the suppressing effect on cucumber Fusarium wilt of Paenibacillus polymyxa JSa-9.[Methods] Single factor experiment was used to value the effect of different carbon sources,nitrogen sources and inorganic ions on spore formation,subsequently,Taguchi method was applied to get the optimum composition of above factors;the field experiment was explored to assess the function of different agents including the spore solution of P.polymyxa JSa-9 on cucumber Fusarium wilt and growth of cucumber in seedling stage.[Results] The optimum composition for spore formation of P.polymyxa JSa-9 was 15 g·L^-1 malt extract,15 g·L^-1 corn steep liquor,5 g·L^-1 CaCO3,0.5 g·L^-1 MgCl2·6H2O. The spore production increased to 7.44×10^9 CFU·mL^-1,and the S/N was 60.13. The relative biocontrol efficacy of the spore solution was 69.02%,which was better than fermentation supernatant. The height of cucumber plant and the number of leaves per plant of cucumber treated with spore solution were 7.61 cm and 4.79,respectively,which indicated that the spore solution of P.polymyxa JSa-9 can promote cucumber growth significantly（P〈0.05）.[Conclusions] Single factor experiment and Taguchi method were simultaneously used in the optimization of the fermentation of P.polymyxa JSa-9 for spore formation,which was proved to be effective. The spore solution was capable of suppressing plant diseases and promoting plant growth.