Plant growth promoting rhizobacteria offer an effective and eco-sustainable solution to protect crops against phytopathogens. In the present study, Bacillus safensis STJP (NAIMCC-B-02323) from the rhizospheric soil of Stevia rebaudiana showed strong biocontrol activity against phytopathogen, Alternaria alternata. B. safensis STJP produced antifungal volatile organic compounds (AVOC). In the presence of AVOC, there was no conidia germination, mycelium growth was inhibited, and hyphae ruptured as observed by scanning electron microscopy. When mycelium of the fungus from bacterial treated plate was transferred into fresh potato dextrose agar plate, A. alternata could not grow. Extracted AVOC from B. safensis STJP were identified by thin-layer chromatography (TLC), Fourier-transform-infrared (FTIR) spectroscopy and gas-chromatography–mass spectrometry (GC–MS). In total 25 bacterial metabolites were identified by GC–MS analysis having alcohol, alkane, phenol, alkyl halide and aromatic compounds. Five of these (phenol, 2,4-bis (1,1-dimethylethyl)-, 3-hexadecanol, pyrrolo(1,2-a)pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl)-, 5,10-diethoxy-2,3,7,8-tetrahydro-1H,6H-dipyrrolo(1,2-a:1′,2′-d)pyrazine and hexadecanoic acid) inhibited the mycelium growth, controlling spore formation and conidia germination of A. alternata. This study concluded that AVOC producing B. safensis can be used as a green-fungicide against A. alternata. Bacterial metabolites could pave the way for the development of next generation biopesticides. This can be a reliable technology to enhance the quality and reliability of biopesticides.

促进植物生长的根际细菌提供了一种有效且生态可持续的解决方案，以保护作物免受植物病原体的侵害。在本研究中，来自甜叶菊根际土壤的安全芽孢杆菌 STJP (NAIMCC-B-02323)对植物病原体Alternaria alternata显示出很强的生物防治活性。B. safensis STJP 产生抗真菌挥发性有机化合物 (AVOC)。在AVOC存在下，没有分生孢子萌发，菌丝生长受到抑制，扫描电镜观察菌丝破裂。将细菌处理板的真菌菌丝体转移到新鲜马铃薯葡萄糖琼脂平板上时，A.alternata不能生长。提取的 AVOCB. safensis STJP 通过薄层色谱 (TLC)、傅里叶变换红外 (FTIR) 光谱和气相色谱-质谱 (GC-MS) 进行鉴定。通过 GC-MS 分析共鉴定了 25 种细菌代谢物，包括醇、烷烃、苯酚、卤代烷和芳香族化合物。其中五种（苯酚、2,4-双（1,1-二甲基乙基）-、3-十六醇、吡咯并（1,2-a）吡嗪-1,4-二酮、六氢-3-（2-甲基丙基）- , 5,10-diethoxy-2,3,7,8-tetrahydro-1H,6H-dipyrrolo(1,2-a:1',2'-d)pyrazine and hexadecanoic acid) 抑制菌丝体生长，控制孢子形成和A. alternata的分生孢子萌发。该研究得出的结论是，产生 AVOC 的B. safensis可用作对抗A. alternata的绿色杀菌剂. 细菌代谢物可以为下一代生物农药的开发铺平道路。这可以成为提高生物农药质量和可靠性的可靠技术。