School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China.
Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-Product Safety and Quality, Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China.
J Microbiol. 2023 May;61(5):525-542. doi: 10.1007/s12275-023-00046-4. Epub 2023 May 2.
The Fusarium graminearum species complex (FGSC) can produce various mycotoxins and is a major concern for food quantity and quality worldwide. In this study, we determined the effects of water activity (a), temperature, incubation time and their interactions on mycotoxin accumulation and the expression levels of biosynthetic genes in FGSC strains from maize samples in China. The highest deoxynivalenol (DON), 3-acetyldeoxynivalenol(3ADON) and 15-acetyldeoxynivalenol (15ADON) levels of the F. boothii and F. graminearum strains were observed at 0.98 a/30 °C or 0.99 a/25 °C. F. asiaticum and F. meridionale reached maximum nivalenol (NIV) and 4-acetylnivalenol (4ANIV) contents at 0.99 a and 30 °C. With the extension of the incubation time, the concentrations of DON and NIV gradually increased, while those of their derivatives decreased. F. boothii, F. meridionale and one F. asiaticum strain had the highest zearalenone (ZEN) values at 0.95 a and 25 °C, while the optimum conditions for the other F. asiaticum strain and F. graminearum were 0.99 a and 30 °C. Four genes associated with trichothecene and zearalenone synthesis were significantly induced under higher water stress in the early stage of production. The results indicated independence of mycotoxin production and gene expression, as maximum amounts of these toxic metabolites were observed at higher a in most cases. This study provides useful information for the monitoring and prevention of such toxins entering the maize production chain.
镰刀菌禾谷种复合体（FGSC）能够产生各种真菌毒素，是全世界关注的粮食数量和质量的主要问题。本研究测定了水分活度（a）、温度、培养时间及其相互作用对来自中国玉米样品的 FGSC 菌株产毒和生物合成基因表达水平的影响。在 0.98 a/30°C 或 0.99 a/25°C 时，F. boothii 和 F. graminearum 菌株的脱氧雪腐镰刀菌烯醇（DON）、3-乙酰脱氧雪腐镰刀菌烯醇（3ADON）和 15-乙酰脱氧雪腐镰刀菌烯醇（15ADON）含量最高。F. asiaticum 和 F. meridionale 在 0.99 a 和 30°C 时达到最高的玉米赤霉烯酮（ZEN）和 4-乙酰玉米赤霉烯醇（4ANIV）含量。随着培养时间的延长，DON 和 ZEN 的浓度逐渐增加，而其衍生物的浓度则降低。F. boothii、F. meridionale 和一株 F. asiaticum 菌株在 0.95 a 和 25°C 时具有最高的玉米赤霉烯酮（ZEN）值，而另一株 F. asiaticum 菌株和 F. graminearum 的最佳条件为 0.99 a 和 30°C。在产毒早期，与单端孢霉烯族化合物和玉米赤霉烯酮合成相关的 4 个基因在较高的水分胁迫下显著诱导。结果表明，产毒和基因表达之间具有独立性，因为在大多数情况下，在较高的 a 条件下观察到这些有毒代谢物的最大含量。本研究为监测和预防此类毒素进入玉米生产链提供了有用信息。
