Application of the Taguchi method to optimize the process conditions in the production of lipase by Pseudomonas aeroginosa B-3556

Pseudomonas aeoroginosa B-3556 was grown on soy flour based semi-solid media for lipase production. The effect of different factors including medium composition, pH, temperature, mixing intensity and substrate particle size on lipase productivity was analyzed using the Taguchi method in three steps. Based on these analyses the optimum concentrations of soy flour, (NH4)2HPO4, K2HPO4 and MgS04.7H2O were found to be 3%, 3%, 0.5% and 0.21% respectively. Furthermore, optimum values for temperature, pH and the shaking speed were determined as 30 °C, 7.1 and 150 rpm. As for the substrate particle size, the best result was achieved when the soy flour had a mesh size cut of 60-70. The influence of the trace elements on lipase production was studied and it was shown that their addition to the medium was not necessary. Maximum lipase activity under optimum conditions was obtained as 44.8 unit/ml after 48 hrs of cell cultivation.