Optimization of Lipases Production byBacillus licheniformis F11.4 using Response Surface Methodology

Lipase is a lipids hydrolyze enzyme which are widely used in various industries such as chemical, pharmaceutical, food industries, and detergents. Bacillus licheniformis F11.4 is one of the bacteria with potential source of lipase. This study aimed to obtain optimum production of lipase from B. licheniformis F11.4 by optimizing the composition of media and pH values with fish flour as a replacement for peptone and yeast extract based medium. Selection of the significant factors used a 2-level factorial design. The upper limit and lower limit of the selected factors was optimized using Central Composite Design (CCD) and the data analysis was performed using the Response Surface Methodology (RSM). Fermentation was carried out in erlenmeyer at initial pH 8 and a temperature of 37 °C, using a shaker incubator at 150 rpm. A fermentation system for lipases production is considered optimal when its desirability value closes to 1. By using numerical optimization, an optimal medium could be obtained, i.e. consisting of OO:CPO 0.14 % (w/v) and fish flour 2% (w/v), at pH 8 and 150 rpm, which produced lipase with enzyme activity of 1.563 U mL-1 and protein level of 0.08 mg mL-1.Furthermore, the results are verified in the Erlenmeyer, working volume of 50 mL, pH = 8, T = 37 °C, agitation 150 rpm, t=18 hours, the activity of lipase and protein levels are 1.568 ± 0.014 U mL-1 and 0.072 ± 0.006 mg mL-1 respectively.The results showed that the optimum condition lipase activity was 1.568 U mL-1 so that the increase in the activity of only 75% compared to before optimization.