Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, 362 001, Gujarat, India.
Arch Microbiol. 2022 May 10;204(6):311. doi: 10.1007/s00203-022-02917-7.
The Beauveria spp. were isolated from soil and insect cadavers and confirmed as Beauveria bassiana by molecular identification using a specific primer. The bioefficacy of 14 B. bassiana against whiteflies indicated the highest percent mortality in JAU2, followed by JAU1. The LC and LC values were found to be 0.043 × 10 and 0.05 × 10 conidia.ml, respectively, in JAU2. Extracellular metabolites of B.bassiana are derived and used for the green synthesis of silver nanoparticles (AgNPs). The synthesized green AgNPs were characterized for size (24.8 nm), shape (scanning electron microscopy), stability (200 mV zeta), and purity (energy-dispersive X-ray spectroscopy, 3 keV). A total of 63 extracellular metabolites were identified using LC-MS/QTOF in potent JAU2 with recognition of alcohols, phenols, carboxylic acids, amines, alkynes, and amides as functional groups. The functional groups of green AgNPs were also confirmed in Fourier transforms infrared spectroscopy (FTIR) with the specific spectra in the electromagnetic spectrum. The relationship between identified metabolites of antagonist and the FTIR spectrum of the functional group indicated the involvement of extracellular novel compounds, viz., homoisocitrate, aconitine, phodexin A, capillone, solanocapsine, and anethole in the synthesis of green AgNPs. The efficacy of green AgNPs on whiteflies suggested that corrected percent mortality was observed at 60 µg Ag.ml at 120 h, which corresponds to the LC value (66.42 µg Ag.ml). Results were interpreted to show that green AgNPs synthesized from extracellular metabolites of B.bassiana JAU2 gave better insecticidal activity at LC as compared to live antagonist JAU2.
从土壤和昆虫尸体中分离出球孢白僵菌，并通过使用特定引物的分子鉴定确认为球孢白僵菌。14 株球孢白僵菌对粉虱的生物活性表明，JAU2 的死亡率最高，其次是 JAU1。在 JAU2 中，LC 和 LC 值分别为 0.043×10 和 0.05×10 个孢子/ml。球孢白僵菌的胞外代谢产物被衍生并用于绿色合成银纳米粒子（AgNPs）。合成的绿色 AgNPs 的大小（24.8nm）、形状（扫描电子显微镜）、稳定性（200mV zeta）和纯度（能量色散 X 射线能谱，3keV）进行了表征。在具有识别醇、酚、羧酸、胺、炔烃和酰胺等功能基团的强效 JAU2 中，使用 LC-MS/QTOF 共鉴定出 63 种胞外代谢产物。在傅里叶变换红外光谱（FTIR）中也确认了绿色 AgNPs 的功能基团，其在电磁光谱中具有特定的光谱。拮抗物的鉴定代谢产物与功能基团的 FTIR 光谱之间的关系表明，在绿色 AgNPs 的合成中涉及到了新型的胞外化合物，即，异柠檬酸、乌头碱、phodexin A、capillone、solanocapsine 和茴香脑。绿色 AgNPs 对粉虱的功效表明，在 120 小时时，60µg Ag.ml 处观察到校正死亡率为 66.42µg Ag.ml，这对应于 LC 值。结果表明，与活的拮抗物 JAU2 相比，从 B.bassiana JAU2 的胞外代谢产物合成的绿色 AgNPs 在 LC 下具有更好的杀虫活性。
