Aflatoxin B1 inhibition in Aspergillus flavus by Aspergillus niger through down-regulating expression of major biosynthetic genes and AFB1 degradation by atoxigenic A. flavus
Aflatoxin B1 inhibition in Aspergillus flavus by Aspergillus niger through down-regulating expression of major biosynthetic genes and AFB1 degradation by atoxigenic A. flavus
复制标题
黑曲霉通过下调主要生物合成基因的表达和产毒黄曲霉降解 AFB1 抑制黄曲霉中的黄曲霉毒素 B1
DOI：
10.1016/j.ijfoodmicro.2017.05.013
复制
发表时间：
2017
影响因子：
5.4
通讯作者：
Yang Liu
中科院分区：
文献类型：
--
作者：
Fuguo Xing;Limin Wang;Xiao Liu;Jonathan Nimal Selvaraj;Yan Wang;Yueju Zhao;Yang Liu
从花生中分离到20株尼日尔曲霉菌株，其中14株菌株能完全抑制黄曲霉毒素B1的产生。利用Spin-X离心系统，证实了在黄曲霉生长的最初24 h内，虽然在黄曲霉对抑制敏感的阶段，可溶性信号分子或抗生素并不存在，但它们参与了黑曲霉的抑制作用。在黄曲霉中，20个黄曲霉毒素生物合成基因中有19个被黑曲霉下调。重要的是，aflS的表达显著下调，导致AflS/AflR比率降低。结果表明，黑曲霉可能通过降低AFB 1受体mRNA的丰度而直接抑制AFB 1的合成。有趣的是，atoxigenicA.flavusJZ2和GZ 15有效地降解黄曲霉毒素B1。发现了两个新的代谢产物，其关键的内酯环和呋喃环均被破坏和氢化，这意味着内酯酶和还原酶可能参与了降解过程。
Twenty Aspergillus niger strains were isolated from peanuts and 14 strains were able to completely inhibit AFB1production with co-cultivation. By using a Spin-X centrifuge system, it was confirmed that there are some soluble signal molecules or antibiotics involved in the inhibition byA.niger, although they are absent during the initial 24 h ofA.flavusgrowth when it is sensitive to inhibition. InA.flavus, 19 of 20 aflatoxin biosynthetic genes were down-regulated byA.niger. Importantly, the expression ofaflSwas significantly down-regulated, resulting in a reduction of AflS/AflR ratio. The results suggest thatA.nigercould directly inhibit AFB1biosynthesis through reducing the abundance ofaflStoaflRmRNAs. Interestingly, atoxigenicA.flavusJZ2 and GZ15 effectively degrade AFB1. Two new metabolites were identified and the key toxic lactone and furofuran rings both were destroyed and hydrogenated, meaning that lactonase and reductase might be involved in the degradation process.