KNO_(3)提高苏云金芽胞杆菌Bt-8发酵液杀虫活性的作用分析  

The effect of adding KNO_(3) on insecticidal activity of Bacillus thuringiensis Bt-8 fermentation broth

作　　者：祁建杭[1,2] 刘琴 刘雪梅[2] 夏杨 蔡扬生 李传明 徐健[1] 韩光杰[1,2] QI Jianhang;LIU Qin;LIU Xuemei;XIA Yang;CAI Yangsheng;LI Chuanming;XU Jian;HAN Guangjie(Jiangsu Lixiahe District Institute of Agricultural Sciences/National Agricultural Experimental Station for Agricultural Microbiology in Yangzhou,Yangzhou 225007,China;Yangzhou Luyuan Bio-Chemical Company Limited,Yangzhou 225008,China)

机构地区：[1]江苏里下河地区农业科学研究所/国家农业微生物扬州观测实验站,江苏扬州225007 [2]扬州绿源生物化工有限公司,江苏扬州225008

出　　处：《扬州大学学报（农业与生命科学版）》2022年第5期136-141,共6页Journal of Yangzhou University：Agricultural and Life Science Edition

基　　金：江苏省农业科技自主创新资金项目[CX(2020)1004];江苏省国际合作项目(BZ2020039);扬州市科技攻关项目(YZ2021034);江苏里下河地区农业科学研究所科研项目(SJ[21]202)。

摘　　要：为明确KNO_(3)对苏云金芽胞杆菌(Bacillus thuringiensis,Bt)Bt-8发酵液杀虫活性的增强作用,试验设计不同无机氮源和钾素的发酵配方,测定其发酵液杀虫活性并定量分析毒素蛋白含量。结果表明:添加0.1%KNO_(3)培养的Bt-8发酵液对小菜蛾3龄幼虫48 h的校正死亡率较对照提高16.7%(P=0.0402)。添加0.1%不同无机氮培养的Bt-8发酵液对小菜蛾的致死中量LD50与对照无显著差异,且NH_(4)^(+)的添加显著降低Bt-8发酵液杀虫活性。而添加0.1%KCl或KH_(2)PO_(4)后,Bt-8发酵液杀虫活性显著上升,LD_(50)分别为0.756和0.732 mL·L^(-1)。在对照配方中添加不同比例的KH_(2)PO_(4),其发酵液杀虫活性随钾素浓度的增加而增大,0.4%KH_(2)PO_(4)培养的Bt-8发酵稀释液对小菜蛾的校正死亡率为100%。进一步分析发酵液中毒素蛋白Cry1Ac含量发现,毒素蛋白产量与发酵液杀虫活性呈正相关。综上,KNO_(3)中钾素可提高苏云金芽胞杆菌Bt-8发酵液毒素蛋白产量并增强其杀虫活性,这为苏云金芽胞杆菌Bt-8菌株工业化发酵提供了理论参考。To clarify the enhancement effect of KNO_(3) on the insecticidal activity of Bacillus thuringiensis(Bt)Bt-8 fermentation broth,the different fermentation formulas with inorganic nitrogen or potassium were designed.The insecticidal activity of different fermentation broth was determined by bioassay,and the content of toxin protein Cry1 Ac was quantitatively analyzed.The results indicated that the 48 h corrected mortality of Bt-8 fermentation broth to third instar larvae of Plutella xylostella increased by 16.7%(P=0.0402)after adding 0.1%KNO_(3) compared to the control.The LD_(50) of Bt-8 fermentation broth cultured with 0.1% different inorganic nitrogen to P.xylostella had no significant difference from the control,and the addition of NH_(4)^(+) significantly reduced the insecticidal activity of Bt-8 fermentation broth.However,the insecticidal activity of Bt-8 fermentation broth increased significantly after adding 0.1% KCl or KH_(2)PO_(4),and the LD_(50) were 0.756 and 0.732 mL·L^(-1),respectively.Different proportions of KH_(2)PO_(4) were added into the control formula,the insecticidal activity of the fermentation broth increased with the increase of potassium concentration.The corrected mortality of Bt-8 fermentation broth cultured with 0.4% KH_(2)PO_(4) to P.xylostella was 100%.Further,the contents of toxin protein Cry1Ac in these fermentation broths were analyzed.The production of toxin protein was positively correlated with the insecticidal activity of the fermentation broth.Hence,the potassium in KNO_(3)added to the fermentation broth of Bt-8enhanced the insecticidal activity by increasing the production of toxin protein.The results provide a theoretical reference for the industrial fermentation of Bt-8strain.

关 键 词：苏云金芽胞杆菌 发酵培养 钾离子 毒素蛋白 杀虫活性 

分 类 号：S433.4[农业科学—农业昆虫与害虫防治]