Table_2_Aflatoxin contamination of maize and groundnut in Burundi: Distribution of contamination, identification of causal agents and potential biocontrol genotypes of Aspergillus flavus.pdf

Aflatoxin contamination of the staples maize and groundnut is a concern for health and economic impacts across sub-Saharan Africa. The current study (i) determined aflatoxin levels in maize and groundnut collected at harvest in Burundi, (ii) characterized populations of Aspergillus section Flavi associated with the two crops, and (iii) assessed aflatoxin-producing potentials among the recovered fungi. A total of 120 groundnut and 380 maize samples were collected at harvest from eight and 16 provinces, respectively. Most of the groundnut (93%) and maize (87%) contained aflatoxin below the European Union threshold, 4 μg/kg. Morphological characterization of the recovered Aspergillus section Flavi fungi revealed that the L-morphotype of A. flavus was the predominant species. Aflatoxin production potentials of the L-morphotype isolates were evaluated in maize fermentations. Some isolates produced over 137,000 μg/kg aflatoxin B1. Thus, despite the relatively low aflatoxin levels at harvest, the association of both crops with highly toxigenic fungi poses significant risk of post-harvest aflatoxin contamination and suggests measures to mitigate aflatoxin contamination in Burundi should be developed. Over 55% of the L-morphotype A. flavus did not produce aflatoxins. These atoxigenic L-morphotype fungi were characterized using molecular markers. Several atoxigenic genotypes were detected across the country and could be used as biocontrol agents. The results from the current study hold promise for developing aflatoxin management strategies centered on biocontrol for use in Burundi to reduce aflatoxin contamination throughout the value chain.

黄曲霉毒素对主食玉米和大豆的污染，对撒哈拉以南非洲地区的公共卫生和经济影响构成了担忧。本研究旨在：（一）测定在布隆迪收获时采集的玉米和大豆中的黄曲霉毒素含量；（二）表征与两种作物相关的曲霉属Flavi节段种群；（三）评估回收真菌中的黄曲霉毒素产生潜力。共收集了120份花生和380份玉米样品，分别来自8个和16个省份。大部分花生（93%）和玉米（87%）中的黄曲霉毒素含量低于欧盟标准，即4 μg/kg。对回收的曲霉属Flavi节段真菌的形态学特征分析表明，A. flavus的L-形态型是优势物种。L-形态型分离株在玉米发酵中的黄曲霉毒素产生潜力得到评估。一些分离株产生了超过137,000 μg/kg的黄曲霉毒素B1。因此，尽管收获时的黄曲霉毒素含量相对较低，但两种作物与高毒性真菌的关联仍对收获后黄曲霉毒素污染构成重大风险，并暗示应在布隆迪制定减轻黄曲霉毒素污染的措施。（二）在55%以上的L-形态型A. flavus中未检测到黄曲霉毒素的产生。这些非产毒的L-形态型真菌通过分子标记进行了表征。在全国范围内检测到多种非产毒基因型，可作为生物防治剂。本研究的结果为在布隆迪开发以生物防治为中心的黄曲霉毒素管理策略提供了希望，旨在在整个产业链中降低黄曲霉毒素的污染。