Botrytis cinerea, the causal agent of gray mold is one of the major devastating fungal pathogens that occurs in strawberry cultivation and leads to massive losses. Due to the rapid emergence of resistant strains in recent years, an ecofriendly disease management strategy needs to be developed to control this aggressive pathogen. Bacillus velezensis CE 100 exhibited strong antagonistic activity with 53.05% against B. cinerea by dual culture method. In the present study, 50% of culture filtrate supplemented into PDA medium absolutely inhibited mycelial growth of B. cinerea whereas the highest concentration (960 mg/L) of different crude extracts including ethyl acetate, chloroform, and n-butanol crude extracts of B. velezensis CE 100, strongly inhibited mycelial growth of B. cinerea with the highest inhibition of 79.26%, 70.21% and 69.59% respectively, resulting in severe damage to hyphal structures with bulging and swellings. Hence, the antifungal compound responsible was progressively separated from ethyl acetate crude extract using medium pressure liquid chromatography. The purified compound was identified as methyl hippurate by nuclear magnetic resonance and mass spectrometry. The inhibitory effect of methyl hippurate on both spore germination and mycelial growth of B. cinerea was revealed by its dose-dependent pattern. The spore germination rate was completely restricted at a concentration of 3 mg/mL of methyl hippurate whereas no mycelial growth was observed in agar medium supplemented with 4 mg/mL and 6 mg/mL of methyl hippurate by poisoned food method. Microscopic imaging revealed that the morphologies of spores were severely altered by long-time exposure to methyl hippurate at concentrations of 1 mg/mL, 2 mg/mL and 3 mg/mL and hyphae of B. cinerea were severely deformed by exposure to methyl hippurate at concentrations of 2 mg/mL, 4 mg/mL and 6 mg/mL. No significant inhibition on tomato seed germination was observed in treatments with methyl hippurate (2 mg/mL) for both 6 h and 12 h soaking period as compared to the controls. Based on these results, B. velezensis CE 100 could be considered a potential agent for development of environmentally friendly disease control strategies as a consequence of the synergetic interactions of diverse crude metabolites and methyl hippurate.

Botrytis cinerea，灰霉病的病原体，是草莓种植中发生的主要破坏性真菌病原体之一，会导致大量损失。由于近年来耐药菌株的迅速出现，需要制定生态友好的疾病管理策略来控制这种侵袭性病原体。Bacillus velezensis CE 100通过双培养法对B. cinerea表现出53.05% 的强拮抗活性。在本研究中，50% 的培养滤液补充到 PDA 培养基中绝对抑制了B. cinerea 的菌丝体生长，而不同粗提物（包括乙酸乙酯、氯仿和正丁醇粗提物）的最高浓度 (960 mg/L)B. velezensis CE 100 对B. cinerea 的菌丝生长有强烈抑制作用，抑制率最高，分别为 79.26%、70.21% 和 69.59%，导致菌丝结构严重受损，出现鼓胀现象。因此，使用中压液相色谱从乙酸乙酯粗提取物中逐渐分离出负责的抗真菌化合物。纯化的化合物通过核磁共振和质谱鉴定为马尿酸甲酯。马尿酸甲酯对灰霉病孢子萌发和菌丝生长的抑制作用其剂量依赖性模式揭示了这一点。孢子萌发率在 3 mg/mL 的马尿酸甲酯浓度下完全受到限制，而在添加 4 mg/mL 和 6 mg/mL 马尿酸甲酯的琼脂培养基中通过毒食法未观察到菌丝体生长。显微成像显示，长期暴露于浓度为 1 mg/mL、2 mg/mL 和 3 mg/mL 的马尿酸甲酯会严重改变孢子的形态，暴露于马尿酸甲酯后，灰霉病菌的菌丝严重变形浓度为 2 mg/mL、4 mg/mL 和 6 mg/mL。与对照组相比，马尿酸甲酯 (2 mg/mL) 浸泡 6 小时和 12 小时均未观察到对番茄种子萌发的显着抑制。基于这些结果，B. velezensis 由于多种粗代谢物和马尿酸甲酯的协同相互作用，CE 100 可被视为开发环境友好型疾病控制策略的潜在试剂。