Preliminary evidence that degradation of aflatoxin B1 by Flavobacterium aurantiacum is enzymatic
Preliminary evidence that degradation of aflatoxin B1 by Flavobacterium aurantiacum is enzymatic
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DOI：
10.4315/0362-028x-63.3.415
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发表时间：
2000-03-01
影响因子：
2
通讯作者：
Draughon, FA
中科院分区：
文献类型：
--
作者：
Smiley, RD;Draughon, FA
研究了橙黄杆菌粗蛋白提取物对水溶液中黄曲霉毒素B-1(AB(1))的降解能力。粗蛋白提取物(800mUg/mI)对溶液中AB(1)的降解率为74.5%。AB(1)经加热处理的粗蛋白提取物(每英里总蛋白800mU)孵育后，平均回收率为94.5%。DNase I处理的粗蛋白提取物对溶液中ABI的降解率为80.5%，这表明橙色假单胞菌对黄曲霉毒素的去除不是由于与细菌基因组DNA的非特异性结合。蛋白酶K处理的粗蛋白提取物降解了AB(1)的34.5%，这提供了黄曲霉毒素的降解与一种可能是一种酶的蛋白质有关的证据。溶液pH影响粗蛋白提取物在24 h后对AB(1)的降解量，最大降解量出现在pH 7(pH分别为5、6、7和8)，部分AB(1)的降解发生在低至5和高至8的pH水平。酸性pH比碱性pH更不利于粗蛋白对AB(1)的降解能力。研究结果表明，橙花假单胞菌对AB(1)的降解可能是酶促作用。
The ability of crude protein extracts from Flavobacterium aurantiacum to degrade aflatoxin B-1 (AB(1)) in aqueous solution was evaluated. Crude protein extracts (800 mu g of total protein per mi) degraded 74.5% of AB(1) in solution. An average of 94.5% of AB(1) was recovered after incubation with heat-treated crude protein extracts (800 mu g of total protein per mi). DNase I-treated crude protein extracts degraded 80.5% of ABI in solution, suggesting that removal of aflatoxin by F. aurantiacum is not due to nonspecific binding with the bacterium's genomic DNA. Proteinase K-treated crude protein extracts degraded 34.5% of AB(1), providing evidence that degradation of aflatoxin is linked to a protein that is possibly an enzyme. Solution pH affected the amount of AB I degraded by crude protein extracts after 24 h. Maximum degradation was observed at pH 7 (pH levels tested: 5, 6, 7, and 8), with some AB(1) degradation occurring at pH levels as low as 5 and as high as 8. Acidic pH levels were more detrimental to the ability of crude protein extracts to degrade AB(1) than was basic pH. The results of this work indicate that the degradation of AB(1) by F. aurantiacum may be enzymatic.