施氏假单胞菌F4产黄曲霉毒素B_1降解酶条件的优化

Optimization of Fermentation Conditions for AFB_1-degrading Enzyme Production by Pseudomonas stutzeri F4

在前期工作中分离到可高效降解黄曲霉毒素B1(AFB1)的施氏假单胞菌F4,本实验对其产AFB1降解酶的发酵条件进行考察和优化,选择与产酶相关的种龄、接种量、起始pH值、发酵时间以及发酵温度5个因素,以AFB1降解酶酶活力为评价指标,在单因素试验的基础上,通过三因素三水平的Box-Behnken响应面分析法优化施氏假单胞菌发酵产AFB1降解酶的条件。结果表明,在接种量和起始pH值分别为3%和6.5时,最优发酵条件为种龄10.47h、发酵时间42.52h、发酵温度30.28℃,在此发酵条件下,酶活力可达到2768.7U,比优化前提高了28.99%。

Pseudomonas stutzeri F4 with high degradation activity of AFB1 was isolated and identified previously.In this study,the fermentation conditions for AFB1-degrading enzyme（ADE） production by this strain were optimized.The effects of inoculum age,inoculum size,initial pH,fermentation time and temperature on ADE activity were tested by single factor tests.Based on the results of single factor tests,the fermentation conditions were then optimized using response surface methodology.When inoculum size and initial pH were 3% and 6.5,the optimum fermentation condition was inoculum age of 10.47 h,fermentation time of 42.52 h and fermentation temperature of 30.28 ℃.The ADE activity in the fermented broth reached 2768.7 U under the optimized conditions,which was 28.99% higher than before optimization.