摘要
[目的]利用黄曲霉固态发酵麻疯树饼粕产蛋白酶,研究产酶工艺条件及其酶学性质。[方法]将黄曲霉接种含麻疯树饼粕的固体发酵培养基,采用福林法测定在不同湿度条件、不同碳源或氮源条件以及不同培养时间下所产蛋白酶的活力。饱和硫酸铵法纯化蛋白酶,并测定其在不同催化温度、不同pH条件和不同有机溶剂处理下的活力,分析其催化动力学。[结果]控制相对湿度为50%,向培养基中添加0.10g/ml乳糖和0.02g/ml蛋白胨,30℃下发酵5d,蛋白酶活力最高。蛋白酶的最适催化温度为45℃,最适作用pH值为6.0,最大催化速度Vmax为3333.33μg/min,Km为31.25mg/ml,有机溶剂可以适当提高蛋白酶活力。[结论]利用黄曲霉固态发酵产蛋白酶是利用麻疯树饼粕的有效途径。
[Objective]To determine the optimal conditions for production of protease through solid-state fermentation of deoiled Jatropha curcas seed cake by Aspergillus flavus and to explore the enzymatic properties of the protease.[Method]After Aspergillus flavus was inoculated into the solid fermentation medium containing Jatropha curcas seed cake,protease activity was determined by the Folin method under the conditions of different humidity,carbon or nitrogen sources and incubation time.Then the protease was purified by saturated ammonium sulfate,and its activity was measured under the conditions of different catalyst temperatures,pH values and organic solvents.Its catalytic kinetics was also analyzed.[Result]The protease activity peaked,when the relative humidity was 50%,lactose and peptone was supplemented respectively at the final concentrations of 0.10 g/ml and 0.02 g/ml,and the seed cake was fermented at 30 ℃ for 5 d.For protease,the optimum catalytic temperature was 45 ℃,the optimum pH value was 6.0,the maximum catalytic velocity（Vmax） was 3 333.33 μg/min,and the Km was 31.25 mg/ml.Organic solvents appropriately enhanced protease activity.[Conclusion]Production of protease by Aspergillus flavus under solid state fermentation is a viable approach to utilize Jatropha curcas seed cake.
出处
《安徽农业科学》
CAS
北大核心
2010年第4期1681-1683,1686,共4页
Journal of Anhui Agricultural Sciences
基金
教育部"春晖"计划(Z2007-1-52017)
贵州省科学技术基金项目(黔科合J字[2007]2035号)
国家大学生创新性实验计划(贵大国创字2008017号)
贵州大学大学生创新性实验计划
关键词
麻疯树饼粕
固态发酵
蛋白酶
Jatropha curcas seed cake
Aspergillus flavus
Protease
