The contamination of Aspergillus carbonarius causes decreases and great decay of agricultural products, and threatens the human and animal health by producing mycotoxins, especially ochratoxin A. Bacillus subtilis has been proved to efficiently inhibit the growth of A. carbonarius. Revealing the major active compound and the mechanisms for the antifungal of B. subtilis are essential to enhance its antifungal activity and control the quality of antifungal products made of it. In this study, we determined that iturin A is the major compound that inhibits Aspergillus carbonarius, a widespread fungal pathogen of grape and other fruits. Iturin A significantly inhibited growth and ochratoxin A production of A. carbonarius with minimal inhibitory concentrations (MICs) of 10 μg/mL and 0.312 μg/mL, respectively. Morphological observations revealed that iturin A caused swelling of the fungal cells and thinning of the cell wall and membrane at 1/2 MIC, whereas it inhibited fungal spore germination and caused mitochondrial swelling at higher concentrations. A differential transcriptomic analysis indicated that the mechanisms used by iturin A to inhibit A. carbonarius were to downregulate the expression of genes related to cell membrane, transport, osmotic pressure, oxidation-reduction processes, and energy metabolism. Among the down-regulated genes, those related to the transport capacity were most significantly influenced, including the increase of energy-related transport pathways and decrease of other pathways. Notably, the genes related to taurine and hypotaurine metabolism were also decreased, indicating iturin A potentially cause the occurrence of osmotic imbalance in A. carbonarius, which may be the intrinsic cause for the swelling of fungal cells and mitochondria. Overall, iturin A produced by B. subtilis played important roles to inhibit A. carbonarius via changing the fungal cell structure and causing perturbations to energy, transport and osmotic pressure metabolisms in fungi. The results indicated a new direction for researches on the mechanisms for lipopeptides and provided useful information to develop more efficient antifungal agents, which are important to agriculture and biomedicine.

的污染黑炭黑原因降低，农产品的大衰退，并通过产生霉菌毒素威胁着人类和动物的健康，特别是赭曲霉毒素A.枯草芽孢杆菌已被证明能够有效地抑制其生长炭黑曲霉。揭示枯草芽孢杆菌的主要活性化合物和抗真菌机制对于增强其抗真菌活性和控制由其制成的抗真菌产品的质量至关重要。在这项研究中，我们确定了伊图灵A是抑制葡萄和其他水果中广泛的真菌病原体碳曲霉的主要化合物。Iturin A显着抑制鱼的生长和to曲霉A的产生A. carbonarius的最小抑菌浓度（MIC）分别为10μg/ mL和0.312μg/ mL。形态学观察表明，在1/2 MIC时，伊图灵A引起真菌细胞肿胀和细胞壁和膜变薄，而在较高浓度下它抑制真菌孢子萌发并引起线粒体肿胀。差分转录分析表明，所使用的伊枯草菌素甲抑制机制炭黑曲霉下调与细胞膜，转运，渗透压，氧化还原过程和能量代谢有关的基因的表达。在下调的基因中，与运输能力有关的基因受到的影响最大，包括与能量有关的运输途径的增加和其他途径的减少。值得注意的是，相关的牛磺酸和亚牛磺酸代谢的基因也被减少，表明伊枯草菌素甲潜在地引起渗透压不平衡的发生炭黑曲霉，其可以是用于真菌细胞和线粒体的肿胀的内在原因。总体而言，枯草芽孢杆菌产生的iturin A在抑制A. carbonarius方面起着重要作用。改变真菌的细胞结构，并对真菌的能量，转运和渗透压代谢产生干扰。该结果为脂肽作用机理的研究指明了新的方向，并为开发更有效的抗真菌剂提供了有用的信息，这对农业和生物医学具有重要意义。