BACKGROUNDRhopalosiphum padi is a major infection affecting cereal crops in the boundary area. However, continuous use of chemical pesticides has increased cases of drug resistance in its field population. Therefore, we aimed to verify the insecticidal properties of Bacillus amyloliquefaciens YJNbs21.10 against aphids, isolated to determine the bioactivity of its metabolite Macrolactin A against aphids for the first time.RESULTSThe results of activity tracking showed that the fermentation broth of YJNbs21.10 had the best inhibitory efficacy against R. padi, and the corrected efficiency reached 95.57% after 24 h. With the continuous separation and test, the efficiency of the active components decreased: Macrolactin A, as the most active substance, had a control activity against aphids under 500 mg L−1 of 74.64% at 72 h, (which was significantly lower than that of fermentation broth, indicating a synergistic effect between the active substances of each part of the strain. In addition, the result of the stereomicroscope showed that Macrolactin A damaged the body wall of aphids. The toxicity of Macrolactin A to R. padi was confirmed through the gradient test.CONCLUSIONIn this study, Bacillus amyloliquefaciens YJNbs21.10 exhibited comparable inhibitory ability to chemical pesticides suggesting its potential to provide effective biological control on aphids. The biological activity of Macrolactin A against aphids was also verified for the first time, in this experiment, the EC50 of this substance against aphids was 169.02 mg L−1 (24 h), which provided strong evidence that YJNbs21.10 may act as an effective agent for the prevention of aphid. © 2024 Society of Chemical Industry.

中文翻译：

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从一种新的解淀粉芽孢杆菌中分离素 A 及其对 Rhopalosiphum padi 的杀蚜活性


背景 Rhopalosiphum padi 是影响边界地区谷类作物的主要感染。然而，化学杀虫剂的持续使用增加了其田间人群的耐药病例。因此，我们旨在验证解淀粉芽孢杆菌 YJNbs21.10 对蚜虫的杀虫特性，分离以首次确定其代谢物素 A 对蚜虫的生物活性。结果活性追踪结果显示，YJNbs21.10 发酵液对 R. padi 的抑制效果最好，24 h后校正效率达到95.57%。随着连续分离和测试，活性成分的效率降低：素 A 作为最活跃的物质，在 72 h 时对 500 mg L-1 下的蚜虫的防治活性为 74.64%（显著低于发酵液，表明菌株各部分的活性物质之间存在协同作用。此外，体视显微镜的结果表明，素 A 破坏了蚜虫的体壁。通过梯度测试证实了素 A 对 R. padi 的毒性。结论在本研究中，解淀粉芽孢杆菌 YJNbs21.10 表现出与化学农药相当的抑制能力，表明其对蚜虫提供有效生物防治的潜力。素 A 对蚜虫的生物活性也首次得到验证，在本实验中，该物质对蚜虫的 EC50 为 169.02 mg L-1 （24 h），这提供了强有力的证据，证明 YJNbs21.10 可能是预防蚜虫的有效剂。© 2024 化工学会.