洋葱假单胞菌(Pseudomonas cepacia)PCL-3产脂肪酶发酵条件研究

Optimization of Fermentation Conditions of Lipase Produced by Pseudomonas cepacia PCL-3

研究了洋葱假单胞菌(Pseudomonas cepacia)PCL-3发酵产碱性脂肪酶培养条件的优化。采用单因子试验筛选出糊精为最适碳源,蛋白胨和尿素为复合氮源。通过Plackett-Burman设计试验,对影响产酶条件的8个相关因子进行评估并筛选出具有显著效应的3个因子:尿素、接种量以及初始pH值。用最陡爬坡实验逼近显著因子的最大响应区域后,采用响应面分析法,确定尿素、接种量以及初始pH值最优值分别为0.15%,3.05%和8.59。优化后液体发酵培养基中脂肪酶活力提高到48.88U/ml,比初始酶活25.37U/ml提高了1.93倍。10L的发酵罐中,脂肪酶活力在52h达到最大,为47.69U/ml。

The fermentation conditions of alkaline lipase producing by Pseudomonas cepacia PCL-3 were optimized. Based on the analysis of single factorial experiments, dextrin was the most suitable carbon source, peptone and urea were the suitable compound nitrogen sources among the examined materials. Three significant factors （urea, inoculum and initial pH） were selected from the eight factors related to lipase production by Plaekett-Burman method, and were further optimized with response surface analysis. And then, steepest ascent procedures were applied to define the optimal response region of the three factors. The obtained optimal conditions were urea 0. 15% , inoculum 3.05% and initial pH 8.38, Under which conditions, the enzyme activity was improved from 25.37 U/ml to 48.88 U/ml, enhanced 1.93 folds. Starting from the flask conditions, the highest lipase activity of 47.69U/ml was achieved by batch fermentation in a 10 L fermentor after 52 h of the cultivation.