Abstract: It is aimed to optimize the fermentation conditions and detergent performance of lipase-producing Pseudomonas stutzeri PS59. The single-factor experiments and response surface analysis were adopted to select the best carbon and nitrogen sources. The impacts of enzyme dosage,time,temperature,pH,and adding dose of surface active agent on lipase detergent performance was also primarily evaluated for determining the optimal value of each factor. The results showed that the optimal carbon and nitrogen sources for producing lipase in laboratory culturing P. stutzeri for producing lipase were sucrose and soybean peptone. The optimal fermentation medium formula（g/L）were：soy peptone 22.39 g,sucrose10 g,K₂HPO₄·3H₂O 1 g,MgSO₄·7H₂O 0.5g,anhydrous CaCl₂ 0.05 g,olive oil 8.1 g,pH 8.1,temperature 30℃,and fermentation time 36 h,the average enzyme yield reached 36.12±1.32 U/mL,comparing with the original yield 15.65±4.81 U/mL,it increased by 1.3 times. To achieve the best washing effect,the optimal enzyme dosage was 100 U,the optimal washing time and temperature were 25 min and 25℃,respectively. Washing pH had little effect on the detergent performance. Under the optimal washing conditions,the washing performance while adding enzyme improved by 30%-40%.

Key words: Pseudomonas stutzeri, lipase, optimization of fermentation conditions, optimization of washing performance