低温耐热脂肪酶的筛选、纯化及特性研究  

Screening,Purification and Characteristics of A Cold-adapted Lipase

作　　者：施文芳[1] 胡长浩[1] 沈麟[1] 林琳[1] 

机构地区：[1]福建师范大学生命科学学院,福建福州350108

出　　处：《生物技术》2009年第2期20-23,共4页Biotechnology

基　　金：福建省科技平台项目(2006H0085);国家自然科学基金项目(30270033);福建省自然科学基金项目(No.B0120001;C0410009)资助

摘　　要：目的:对一株低温耐热脂肪酶产生菌Pseudomonas RT-7进行产酶、纯化和特性研究。方法和结果:该菌的发酵液经50%硫铵沉淀、DEAE-Sepharose及SephacrylS-100分离获得了纯化的脂肪酶(PL-7)。SDS-PAGE电泳估算其表观分子量为44kDa,对底物特异性、作用温度、作用pH和耐热性的研究表明该酶为碱性脂肪酶,最适温度在15～20℃。该酶对C≤12链长的甘油三酯有较好的水解能力。该酶具有在低温和高温下稳定而在中温下不稳定的特点:表现为该酶经60℃30min处理后残余酶活高达93.33%,90℃处理30min后残余酶活仍有35.19%,而在40℃处理30min酶活仅残余28.23%。结论:该酶为低温碱性脂肪酶并在高温条件下具有很好的耐热性。Objective：An extracellular cold-adapted lipase producing strain Pseudomonas RT-7 was studied on the enzyme production,purification and characteristics. Method and Result：The lipase secreted by the strain （Pseudomonas RT-7 lipase, PL-7） was purified to homogeneity by ammonium sulfate precipitation,DEAE-Sepharose ion-exchange and Sephacryl S-100 gel filtration. The molecular mass of the lipase is around 44kDa when estimated by SDS-PAGE. The lipase has highest activity at alkaline conditions of pH 9 and shows high activity at low temperature conditions with the optimum temperature at 15-20℃. PL-7 can catalyze triglyceride with C≤12 and shows special thermostability： the enzyme is stable at low temperature （below 20℃） and very stable at high temperature （60-80℃）, but not stable at mild temperature （40℃）： It retained 93.3% of its original activity after incubation at 60℃ for 30min and 35.2% activity after incubation at 90℃ for 30min. However, it only retained 28.2% activity after 40℃, 30min incubation. Conclusion：The extracellular cold-adapted lipase has high thermostability at the high temperature.

关 键 词：假单胞菌 低温脂肪酶 耐高温 

分 类 号：Q93[生物学—微生物学] Q814.1