College of Biological Engineering, Henan University of Technology, 100 Lianhua Street, Zhengzhou, 450001, People's Republic of China.
Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou, 450001, People's Republic of China.
Appl Microbiol Biotechnol. 2021 Oct;105(20):7871-7888. doi: 10.1007/s00253-021-11581-8. Epub 2021 Sep 22.
Chemical control of fungal spoilage of postharvest cereal grains is an important strategy for the management of grain storage. Here, the potential antifungal activity of 1-nonanol, a main component of cereal volatiles, against Aspergillus flavus was studied. The growth of A. flavus was completely inhibited by 0.11 and 0.20 μL/mL 1-nonanol at vapor and liquid contact phases, respectively. Metabolomic analysis identified 135 metabolites whose expression was significantly different between 1-nonanol-treated and untreated A. flavus. These metabolites were involved in the tricarboxylic acid cycle, amino acid biosynthesis, protein degradation and absorption, aminoacyl-tRNA biosynthesis, mineral absorption, and in interactions with ABC transporters. Biochemical validation confirmed the disruptive effect of 1-nonanol on A. flavus growth, as indicated by the leakage of intracellular electrolytes, decreased succinate dehydrogenase, mitochondrial dehydrogenase, and ATPase activity, and the accumulation of reactive oxygen species. We speculated that 1-nonanol could disrupt cell membrane integrity and mitochondrial function and might induce apoptosis of A. flavus mycelia. Simulated grain storage experiments showed that 1-nonanol vapor, at a concentration of 264 μL/L, completely inhibited A. flavus growth in wheat, corn, and paddy grain with an 18% moisture content. This study provides new insights into the antifungal mechanism of 1-nonanol against A. flavus, indicating that it has a promising potential as a bio-preservative to prevent fungal spoilage of postharvest grains. KEY POINTS: • 1-Nonanol showed higher antifungal activity against A. flavus. • The antifungal mechanisms of 1-nonanol against A. flavus were revealed. • 1-Nonanol could damage cell membrane integrity and mitochondrial function.
化学防治法是控制收获后谷物真菌腐败的重要策略。本研究探讨了谷物挥发物主要成分之一 1-壬醇对黄曲霉的潜在抑菌活性。在气相和液相接触阶段，0.11 和 0.20 μL/mL 的 1-壬醇完全抑制了黄曲霉的生长。代谢组学分析鉴定出 135 种代谢物，它们在 1-壬醇处理和未处理的黄曲霉之间的表达有显著差异。这些代谢物参与三羧酸循环、氨基酸生物合成、蛋白质降解和吸收、氨酰-tRNA 生物合成、矿物质吸收以及与 ABC 转运蛋白的相互作用。生化验证证实了 1-壬醇对黄曲霉生长的破坏作用，如细胞内电解质泄漏、琥珀酸脱氢酶、线粒体脱氢酶和 ATP 酶活性降低以及活性氧的积累。我们推测 1-壬醇可能破坏细胞膜完整性和线粒体功能，并可能诱导黄曲霉菌丝凋亡。模拟谷物储存实验表明，浓度为 264 μL/L 的 1-壬醇蒸气完全抑制了含水量为 18%的小麦、玉米和稻谷中黄曲霉的生长。本研究为 1-壬醇对黄曲霉的抑菌机制提供了新的见解，表明其作为一种生物防腐剂具有防止收获后谷物真菌腐败的潜在应用价值。
