Optimization of lipase production from organic solid waste by anaerobic digestion and its application in biodiesel production

Lipases are particularly important due to the fact that they specifically hydrolyze the acylglycerols into free fatty acids and glycerol, which is of greater interest for biodiesel production. In this study, garbage lipase was produced from organic waste (Pomegranate (P), Orange (O) and Pineapple (PA) peels) by optimization the organic waste composition, ultrasonic pre-treatment time and process parameters. Optimization of process parameters using RSM and ANN modelling was performed with the composition of 35(P): 20(O): 35(PA) and 15 min (pre-treatment). The maximum lipase activity of 57.43 U/mL was obtained at pH (6), temperature (33 °C), agitation (210 rpm) and time (4 days). The effects of pH, temperature, organic solvents on the stability of partially purified lipase (PPL) and enzyme kinetic parameters were also investigated. PPL yielded 88.63% conversion of palm oil into biodiesel. Hence, garbage lipase would be a potential biocatalyst for biodiesel conversion and other industrial catalytic processes.