Production of Extracellular Lipase from Aspergillus niger by Solid-State Fermentation

Lipase production in Aspergillus niger J-1 was tested using both submerged fermentation (SmF) and solid-state fermentation (SSF) on a mineral culture medium and wheat bran, respectively. The optimization of the culture medium was carried out for both SmF and SSF. The maximum lipase activity, 1.46 IU/mL, was obtained during the submerged fermentation in a medium containing glucose at 2% and olive oil at 2% under conditions of 1 vvm and 450 m-1. However, 9.14 IU/g of dry solid substrate equivalent to 4.8 IU/mL of lipase activity was reached using solid-state fermentation process with a medium containing 0.75% of ammonium sulphate and 0.34% of urea. The optimum pH and temperature for enzymatic activity were pH=6 and 40°C, respectively. The enzyme also exhibited 80% of its initial activity in neutral and mildly acid media and at temperatures between 20 and 30°C for a period of 24 hours.