【作者】 张玉霞；

【导师】 赵继华； 沈伟国；

【作者基本信息】 兰州大学 ， 物理化学， 2007， 硕士

【摘要】 本论文用紫外-可见分光光度计，通过测定蓖麻油的水解产物-脂肪酸与铜离子形成的络合物在710 nm处的吸光度变化，研究了AOT/TritonX-100混合微乳液体系和单一的AOT微乳液体系中，TritonX-100占总表面活性剂的摩尔分数（x（％））、水与总体表面活性剂的摩尔比（ω₀）、水相pH值、反应温度（T）、酶浓度([E]_wp4-24mg·mL^-1)、底物浓度([s]0.04-0.32mol·L^-1)等因素对假丝酵母脂肪酶催化蓖麻油水解反应的影响。研究发现，保持总体表面活性剂浓度不变，向AOT微乳液体系中引入非离子型表面活性剂TritonX-100能够明显提高假丝酵母脂肪酶的酶活性，且在0≤x≤20％的范围内，酶活性随着x的增大而迅速增大。研究结果表明，单一AOT微乳液体系中，当反应温度为307.15-311.15K、水相pH=6.8、ω₀=6-7时酶活力最高；而AOT/TritonX-100混合微乳液体系（x=20％）中，当反应温度为307.15K，水相pH=7.0，ω₀=5-6时酶活力最高。应用Arrhenius方程求得了两个体系中该反应的活化能，根据米氏方程求得了表观米氏常数(K_m，a)，最大反应速率(v_max)以及酶的催化常数(K_cat)。发现向AOT微乳液体系中引入非离子型表面活性剂TritonX-100，并不改变反应活化能；但是在AOT/TritonX-100混合微乳液体系中v_max和K_cat均为单一AOT微乳液体系中的两倍，而K_m则略有增大。并对酶在两种不同体系中的稳定性进行了讨论。更多还原

【Abstract】 The hydrolysis activity of Candida rugosa lipase by using castor oil as the substrate were studied in simple AOT reverse microemulsion system and in AOT/Triton X-100 mixed reverse microemulsion system. The effects of molar fraction of TritonX-100 to total surfactants（x）, molar ratio of water to total surfactants（ω₀）, reaction temperature, pH and the concentration of enzyme in "water pool" and substrate on enzymatic activity were investigated. It is found that the activity of Candida rugosa lipase increases rapidly with x up to 20%. Maximum enzyme activity appears at 307.15-311.15 K, pH=6.8 andω₀=6-7 in simple AOT reverse microemulsion system and at 307.15 K, pH=7.0,ω₀=5-6 in AOT/TritonX-100 mixed reverse microemulsion system （x=20%）, respectively.The activation energy, the Michaelis constant K_m,a ,the maximum enzyme activity(v_max) and the catalytic rate constant(K_cat) of the reaction were calculated in both reaction systems. It is seen that the activation energy of the reaction in reverse microemulsions with and without Triton X-100 is almost identical,whereas v_max and K_cat increase significantly and K_m,a increases appreciably in the AOT/TritonX-100 mixed reverse microemulsions system. The stabilities of the enzyme in microemulsions were also determined and discussed.更多还原