中文摘要：

采用经高碘酸钠活化的葡聚糖修饰米根霉脂肪酶,以获得具有较高酸解催化活性的脂肪酶。研究反应时间、反应p H值、还原剂浓度及葡聚糖质量分数对化学修饰效果的影响,并利用Box-Behnken设计法及响应面优化法对米根霉脂肪酶的化学修饰条件进行优化,当反应p H值为7.63、反应时间为15.53 h、还原剂浓度为0.20 mol/L、葡聚糖质量分数为0.3%时,脂肪酶酸解率可达到最高值37.28%。在40℃最适温度条件下,修饰酶的活性是原酶的2.2倍,且经化学修饰后脂肪酶的稳定性有显著提高。

英文摘要：

In order to obtain a high activity of acidolysis,Rhizopus oryzae lipase（ROL） was modified with Na IO4-oxidized dextran.The effects of reaction time,reaction p H,reductant concentration and dextran concentration on modification efficiency were studied.Box-Behnken experimental design and response surface methodology were used to optimize the modification conditions as follows：p H 7.63;reaction time,15.53 h;reductant concentration,0.20 mol/L;and dextran concentration,0.3%.Under these conditions,the maximum predicted acidolysis rate of lipase of 37.28% was obtained,which was basically consistent with the experimental value.The effect of the above four factors on the acidolysis rate of lipase was in the decreasing order of reaction time,reaction p H,dextran concentration and reductant concentration.After chemical modification,ROL had obvious changes in absorption characteristics in the ultraviolet region.The maximum absorption wavelength was obviously different.At the optimum temperature of 40 ℃,the activity of dextran-ROL was increased 2.2 times compared to ROL,and the stability of dextran-ROL was also improved significantly.