College of Food Science and Technology, Guangdong Ocean University, Zhanjiang, China.
Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Zhanjiang, China.
Microbiol Spectr. 2022 Dec 21;10(6):e0368222. doi: 10.1128/spectrum.03682-22. Epub 2022 Oct 31.
Fusarium oxysporum is ubiquitous and can easily contaminate food during processing and storage, potentially producing T-2 toxin, which can pose a severe health risk to public health. Previous research on the presence of T-2 has focused on starch-rich foods, while protein- and amino acid-rich foods have received relatively little attention. In this study, the effects of amino acids on the growth of F. oxysporum and its T-2 production were investigated by gene deletion and complementation experiments. The results showed that amino acids, including aspartic acid, methionine, isoleucine, serine, phenylalanine, and cysteine, significantly inhibited the growth of F. oxysporum, while promoting T-2 synthesis, with cysteine having the most pronounced effect. The target of rapamycin complex 1 (TORC1) is a key pathway in response to a variety of amino acids, including cysteine. and were found to be negative regulators of T-2 synthesis. The study highlights the elevated risk of T-2 production by F. oxysporum in cysteine-rich foods and the need to take appropriate measures to prevent and control the potential harm that such foods may present to public health. F. oxysporum and its T-2 contamination of food not only leads to food wastage but also poses a major food safety challenge to humans. The growth and T-2 production characteristics of F. oxysporum in high-protein substrates are considerably different from those in grains. Here, we show that the abundant free amino acids in a protein-rich food matrix are a key regulatory factor for the growth of, and toxin production by, F. oxysporum. Cysteine has the most pronounced effect on inhibiting mycelial growth and promoting T-2 synthesis through the TORC1 pathway. This implies that consumers tend to overlook T-2 contamination due to the poor growth of F. oxysporum in food rich in protein and amino acids, especially cysteine. Therefore, particular attention should be paid to the protection of those products.
镰刀菌（Fusarium oxysporum）无处不在，在加工和储存过程中很容易污染食物，可能会产生 T-2 毒素，这对公众健康构成严重威胁。以前关于 T-2 存在的研究主要集中在富含淀粉的食物上，而富含蛋白质和氨基酸的食物则相对较少受到关注。在这项研究中，通过基因缺失和互补实验研究了氨基酸对 F. oxysporum 生长及其 T-2 产生的影响。结果表明，包括天冬氨酸、蛋氨酸、异亮氨酸、丝氨酸、苯丙氨酸和半胱氨酸在内的氨基酸显著抑制 F. oxysporum 的生长，同时促进 T-2 的合成，其中半胱氨酸的效果最为显著。雷帕霉素靶蛋白复合物 1（TORC1）是一种对包括半胱氨酸在内的多种氨基酸做出反应的关键途径。发现和是 T-2 合成的负调节剂。该研究强调了 F. oxysporum 在富含半胱氨酸的食物中产生 T-2 的风险升高，需要采取适当措施预防和控制此类食物可能对公众健康造成的潜在危害。F. oxysporum 及其 T-2 对食物的污染不仅导致食物浪费，而且对人类的食品安全构成重大挑战。F. oxysporum 在高蛋白基质中的生长和 T-2 产生特性与谷物中的生长特性有很大不同。在这里，我们表明，富含蛋白质的食物基质中的丰富游离氨基酸是 F. oxysporum 生长和毒素产生的关键调节因素。半胱氨酸通过 TORC1 途径对抑制菌丝生长和促进 T-2 合成的作用最为显著。这意味着消费者往往会忽略由于富含蛋白质和氨基酸的食物中 F. oxysporum 生长不良而导致的 T-2 污染，尤其是半胱氨酸。因此，应特别注意保护这些产品。
