菌株TLB15发酵培养基的优化及其发酵液的杀虫活性

Optimum Fermentation Medium for Insecticidal Active Substances from Strain TLB15

采用正交试验对菌株TLB15的摇瓶发酵培养基进行了优化,结果表明:优化后的培养基为玉米粉3%、豆粉2%、蔗糖1%、硫酸铵0.1%、磷酸氢二钾0.3%、磷酸二氢钾0.2%、七水硫酸镁0.04%。采用10L小型发酵罐发酵48h后活菌数达4.52×109 cfu·mL-1,产芽孢率为90%。室内生物测定结果表明,菌株TLB15发酵液在药后72h对小菜蛾2龄幼虫和甜菜夜蛾2龄幼虫的校正死亡率为66.93%和69.07%。

The optimum fermentation culture medium of strain TLB15 was modified through an orthogonal experiment L18 （37 ） . The results showed that the optimum fermentation culture medium contained 3.0% corm meal ,2.0% soybean powder , 1.0% sugar , 0.1% ammonium sulfate , 0.3% potassium hydrogen phosphate trihydrate ,0.2% potassium dihydrogen phosphate ,and 0.04% magnesium sulfate heptahydrate .The number of viable cells was 4.52 × 109 cfu · mL -1 and the rate of spore formation was 90% after 48hs′fermentation .The 72-h adjusted mortality of TLB15 strain fermentation liquid on the larvae of Plutella xylostella and Spodoptera exigua w ere 66.93% and 69.07% ,respectively .