Jackson Lauren W, Pryor Barry M
School of Plant Sciences, University of Arizona, 1140 E South Campus Drive, P. O. Box 210036, Tucson, AZ, 85721, USA.
Department of Plant Pathology, University of Minnesota, 1991 Upper Buford Circle, St. Paul, MN, 55108, USA.
AMB Express. 2017 Dec;7(1):110. doi: 10.1186/s13568-017-0415-0. Epub 2017 Jun 2.
Aflatoxins are highly carcinogenic secondary metabolites that can contaminate approximately 25% of crops and that cause or exacerbate multiple adverse health conditions, especially in Sub-Saharan Africa and South and Southeast Asia. Regulation and decontamination of aflatoxins in high exposure areas is lacking. Biological detoxification methods are promising because they are assumed to be cheaper and more environmentally friendly compared to chemical alternatives. White-rot fungi produce non-specific enzymes that are known to degrade aflatoxin in in situ and ex situ experiments. The aims of this study were to (1) decontaminate aflatoxin B (AFB) in naturally contaminated maize with the edible, white-rot fungus Pleurotus ostreatus (oyster mushroom) using a solid-state fermentation system that followed standard cultivation techniques, and to (2) and to assess the risk of mutagenicity in the resulting breakdown products and mushrooms. Vegetative growth and yield characteristics of P. ostreatus were not inhibited by the presence of AFB. AFB was degraded by up to 94% by the Blue strain. No aflatoxin could be detected in P. ostreatus mushrooms produced from AFB-contaminated maize. Moreover, the mutagenicity of breakdown products from the maize substrate, and reversion of breakdown products to the parent compound, were minimal. These results suggest that P. ostreatus significantly degrades AFB in naturally contaminated maize under standard cultivation techniques to levels that are acceptable for some livestock fodder, and that using P. ostreatus to bioconvert crops into mushrooms can reduce AFB-related losses.
黄曲霉毒素是具有高度致癌性的次生代谢产物，可污染约25%的农作物，并导致或加剧多种不良健康状况，尤其是在撒哈拉以南非洲以及南亚和东南亚地区。高暴露地区缺乏对黄曲霉毒素的监管和去污措施。生物解毒方法很有前景，因为与化学方法相比，它们被认为成本更低且更环保。白腐真菌会产生非特异性酶，在原位和异位实验中均已知其能降解黄曲霉毒素。本研究的目的是：（1）使用遵循标准培养技术的固态发酵系统，用可食用的白腐真菌平菇对天然污染玉米中的黄曲霉毒素B（AFB）进行去污；（2）评估所得分解产物和蘑菇的致突变风险。AFB的存在并未抑制平菇的营养生长和产量特性。蓝色菌株可将AFB降解高达94%。在由受AFB污染的玉米培育出的平菇中未检测到黄曲霉毒素。此外，玉米基质分解产物的致突变性以及分解产物向母体化合物的逆转作用极小。这些结果表明，在标准培养技术下，平菇能将天然污染玉米中的AFB显著降解至某些牲畜饲料可接受的水平，并且利用平菇将作物转化为蘑菇可减少与AFB相关的损失。
