解淀粉芽胞杆菌MH71摇瓶发酵培养基及发酵条件优化

Optimization of Fermentation Medium Components and Cultural Conditions for Bacillus amyloliquefaciens MH71 in Flask

从黑龙江省漠河多年永冻土层采集的冻土样品中分离的拮抗菌解淀粉芽胞杆菌Bacillus amyloliquefaciens MH71,对多种植物病原真菌和细菌具有较强的拮抗作用。本研究主要以无菌滤液对番茄灰霉病菌的抑菌活性为检测指标,采用单因素试验筛选菌株MH71的最佳产抗菌物质培养基及最佳碳源、氮源和无机盐,运用Minitab软件,通过Box-Benhnken试验及响应面分析相结合的方法对该菌株产抗菌物质的发酵培养基配方和摇瓶发酵条件进行了优化。结果表明,菌株MH71产抗菌物质最佳培养基组成为玉米粉36.6 g/L、牛肉膏3.2 g/L、Na Cl 1.33 g/L、葡萄糖14 g/L、蛋白胨7 g/L、Mg SO40.4 g/L、K2HPO4 0.8 g/L、Ca CO3 8 g/L。最适发酵条件为培养温度30℃、摇床转速200 r/min、发酵起始p H 7.0、接种量3%、装液量100 m L/500 m L、发酵时间为72 h。在最佳培养基和培养条件下,菌株MH71的活菌数达到了2.1×109 CFU/m L,芽孢数为1.2×109 CFU/m L,同时对番茄灰霉病菌的抑菌能力较优化前提高了37.4%。

Bacillus amyloliquefaciens MH71, originally isolated from the permafrost soil samples collected from Mohe, Heilongjiang Province, showed strong biocontrol activities against a large number of phytopathogenic fungi and bacteria. The optimal carbon source, nitrogen source and inorganic salt for the production of antimicrobial substance against Botrytis cinerea by strain MH71 were tested. The medium composition and fermentation conditions were optimized by Box-Benhnken test and response surface method. Data were analyzed by Minitab statistical software. The results showed that the best medium were(g/L): corn flour 36.6, beef extract 3.2, Na Cl 1.33, glucose 14, peptone 7, Mg SO4 0.4, K2HPO4 0.8, Ca CO3 8. The optimal fermentation conditions were: culture temperature 30 ℃, rotation speed 200 r/min, initial p H value 7.0, inoculation 3%, liquid volume of 100 m L/500 m L, and fermentation for 72 h. Under the optimal medium and culture conditions, the number of viable bacteria reached 2.1×109 CFU/m L, spore number was 1.2×109 CFU/m L, and antimicrobial activity against B. cinerea is increased by 37.4%, compared with that before optimization.