College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Key Laboratory of Advanced Processing of Aquatic Products of Guangdong Higher Education Institution, Zhanjiang 524088, China.
Department of Clinical Laboratory, Affiliated Hospital of Guangdong Medical University, Zhanjiang 524001, China.
J Hazard Mater. 2023 Oct 5;459:132218. doi: 10.1016/j.jhazmat.2023.132218. Epub 2023 Aug 3.
Aflatoxin B1 (AFB) is the most potent known naturally occurring carcinogen and pose an immense threat to food safety and human health. L-Cysteine hydrochloride (L-CH) is a food additive often used as a fruit and vegetable preservative and also to approved bread consistency. In this study, we investigated the effects and mechanisms of L-CH as an antimicrobial on the growth of Aspergillus flavus (A. flavus) and AFB biosynthesis. L-CH significantly inhibited A. flavus mycelial growth, affected mycelial morphology and AFB synthesis. Furthermore, L-CH induced glutathione (GSH) synthesis which scavenged intracellular reactive oxygen species (ROS). RNA-Seq indicated that L-CH inhibited hyphal branching, and spore and sclerotia formation by controlling cell wall and spore development-related genes. Activation of the GSH metabolic pathway eliminated intracellular ROS, leading to hyphal dwarfing. L-CH treatment downregulated most of the Aflatoxin (AF) cluster genes and aflS, aflR, AFLA_091090 transcription factors. This study provides new insights into the molecular mechanism of L-CH control of A. flavus and AFB foundation. We believe that L-CH could be used as a food additive to control AFB in foods and also in the environment.
黄曲霉毒素 B1（AFB）是已知最具致癌性的天然存在的致癌物，对食品安全和人类健康构成巨大威胁。L-半胱氨酸盐酸盐（L-CH）是一种食品添加剂，常用于水果和蔬菜的防腐剂，也用于批准的面包稠度。在这项研究中，我们研究了 L-CH 作为一种抗菌剂对黄曲霉（A. flavus）生长和 AFB 生物合成的影响和作用机制。L-CH 显著抑制了黄曲霉的菌丝生长，影响了菌丝形态和 AFB 的合成。此外，L-CH 诱导了谷胱甘肽（GSH）的合成，从而清除了细胞内的活性氧（ROS）。RNA-Seq 表明，L-CH 通过控制细胞壁和孢子发育相关基因，抑制菌丝分枝、孢子和菌核形成。GSH 代谢途径的激活消除了细胞内的 ROS，导致菌丝矮小。L-CH 处理下调了大多数黄曲霉毒素（AF）簇基因和 aflS、aflR、AFLA_091090 转录因子。这项研究为 L-CH 控制黄曲霉和 AFB 基础的分子机制提供了新的见解。我们相信，L-CH 可以用作食品添加剂来控制食品和环境中的 AFB。
