Statistical Optimization of Extracellular Thermo-Alkaline Lipase Production from Aeromonas caviae LipT51 with Response Surface Methodology

Extracellular thermo-alkaline lipase production from Aeromonas caviae LipT51 was statistically optimized by response surface methodology (RSM). First, the one factor at a time approach was implemented to screen the sources of carbon (olive oil, tributyrin, sunflower oil, waste frying oil, glycerol, Tween 80, Tween 20, palm oil, and Triton X100) and nitrogen (peptone, yeast extract, tryptone, whey, urea, NaNO2, NH4NO3) for the highest lipase production. Then, optimum values for waste frying oil selected as carbon source, tryptone selected as nitrogen source and initial pH of the medium were determined by RSM using Box-Behnken design (BBD). The quadratic model of BBD for lipase production was statistically significant and reliable (p < 0.0001, R2 = 0.9881). The validated optimal conditions for maximum lipase production (1.6 U mL-1) were determined as 1.13% waste frying oil, 1.5% tryptone and pH 7.9. For the first time in this study, optimization of lipase production from an A. caviae strain was carried out and under optimized culture conditions using cheap waste material. The production efficiency of lipase enzyme, which is known to be valuable with its detergent activity, increased 2.7 times compared to non-optimized conditions.