中国生物工程杂志

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