Xie Yanli, Wang Wei, Zhang Shujie
School of Food Science and Technology, Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, Henan University of Technology, Zhengzhou, Henan 450001, People's Republic of China.
College of Life Sciences, Henan Normal University, Xinxiang, Henan 453007, People's Republic of China.
Toxicon. 2019 Jan;157:35-42. doi: 10.1016/j.toxicon.2018.11.290. Epub 2018 Nov 15.
Aflatoxin B (AFB) is a secondary metabolite produced by Aspergillus flavus and other fungi. Soil, crops, food, feed, etc. were susceptible to aflatoxin B contamination, which caused adverse economic and health consequences. It is necessary to search for microorganisms or microbial enzymes that can degrade AFB. The degradation activity of AFB by cell-free supernatant (68.30%) of isolate Pantoea sp. T6 was significantly higher (P < 0.05) than viable bacterial cells (4.87%) and intracellular cell extracts (3.68%). The supernatant's AFB degradation activity was reduced from 68.30% to 5.33% in treatment with protease K and sodium dodecyl sulphate (SDS). An extracellular enzyme from the supernatant was secreted by Pantoea sp. T6 and was named as Pantoea aflatoxin degradation enzyme (PADE), which was obtained using Diethylaminoethanol (DEAE)-Sepharose chromatography. PADE was further purified by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The PADE, outer membrane protein A, was identified by mass spectrometry and molecular mass was 38180.1Da. The optimum temperature and pH for the reaction of PADE with AFB were 40 °C and 7.0, respectively. These finding showing that the PADE, which was isolated from the supernatant of Pantoea sp. T6, has the ability to degrade AFB, and may have potential application for aflatoxin B reduction in the food and feed industry.
黄曲霉毒素B（AFB）是黄曲霉和其他真菌产生的次生代谢产物。土壤、农作物、食品、饲料等易受黄曲霉毒素B污染，会造成不良的经济和健康后果。有必要寻找能够降解AFB的微生物或微生物酶。分离出的泛菌属菌株T6的无细胞上清液对AFB的降解活性（68.30%）显著高于活细菌细胞（4.87%）和细胞内提取物（3.68%）（P<0.05）。用蛋白酶K和十二烷基硫酸钠（SDS）处理后，上清液的AFB降解活性从68.30%降至5.33%。泛菌属菌株T6分泌了一种来自上清液的细胞外酶，命名为泛菌黄曲霉毒素降解酶（PADE），该酶通过二乙氨基乙醇（DEAE）-琼脂糖凝胶柱层析获得。PADE通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）进一步纯化。通过质谱鉴定出PADE为外膜蛋白A，分子量为38180.1Da。PADE与AFB反应的最佳温度和pH分别为40℃和7.0。这些发现表明，从泛菌属菌株T6上清液中分离出的PADE具有降解AFB的能力，可能在食品和饲料工业中具有降低黄曲霉毒素B的潜在应用价值。
