ABSTRACT Volatile organic compounds (VOCs) from a biocontrol bacterium Paenibacillus polymyxa CF05 were evaluated for antifungal effects against Rhizopus stolonifer, an important pathogen causing postharvest fruit rot. The aerial mycelial growth and sporangia production of R. stolonifer was inhibited after exposure to the bacterial VOCs. Moreover, bacterial VOCs exhibited effective inhibition on Rhizopus rots of cherry, mango and nectarine, resulting 75.88%, 60.64% and 73.13% of suppression ratios at 96 h postinoculation (hpi), respectively. However, the suppression ratios were lower than chemical fungicide imazalil. The main volatile compounds from CF05 were analysed by solid-phase microextraction-gas chromatography tandem mass spectrometry (SPME-GC-MS) and 14 compounds were predominately identified. Among them, the volatile compounds benzothiazole and butylated hydroxytoluene exhibited the highest inhibitory effects on R. stolonifer, resulting 0.03 μL mL −1 headspace and 0.04 μL mL −1 headspace of 50% effective concentrations (EC50), respectively. Furthermore, the antagonistic effects of bacterial VOCs were dependent on the cultivation medium, which might be attributed to their various amounts and compositions. In conclusion, the antifungal VOCs from strain CF05 could be a promising agent in the integrated management of Rhizopus fruit rot.

中文翻译：

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多粘类芽孢杆菌CF05产生的挥发性有机物对根霉果实腐烂的抑制作用

摘要 评估了来自生物防治细菌多粘类芽孢杆菌 CF05 的挥发性有机化合物 (VOC) 对根茎根霉的抗真菌作用，根霉是导致采后果实腐烂的重要病原体。R. stolonifer 的气生菌丝生长和孢子囊产生在暴露于细菌 VOC 后受到抑制。此外，细菌 VOC 对樱桃、芒果和油桃的根霉腐烂具有有效的抑制作用，在接种后 96 小时 (hpi) 的抑制率分别为 75.88%、60.64% 和 73.13%。然而，抑制率低于化学杀菌剂抑霉唑。采用固相微萃取-气相色谱串联质谱（SPME-GC-MS）分析CF05中的主要挥发性化合物，主要鉴定出14种化合物。他们之中，挥发性化合物苯并噻唑和丁基化羟基甲苯对R. stolonifer 表现出最高的抑制作用，分别产生0.03 μL mL -1 顶空和0.04 μL mL -1 顶空的50% 有效浓度（EC50）。此外，细菌 VOC 的拮抗作用取决于培养基，这可能归因于它们的不同数量和组成。总之，来自CF05菌株的抗真菌VOCs可能是根霉果实腐烂综合治理的有前途的药剂。这可能归因于它们的不同数量和组成。总之，来自CF05菌株的抗真菌VOCs可能是根霉果实腐烂综合治理的有前途的药剂。这可能归因于它们的不同数量和组成。总之，来自CF05菌株的抗真菌VOCs可能是根霉果实腐烂综合治理的有前途的药剂。