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 SSE 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 degrees C, respectively. The enzyme also exhibited 80 % of its initial activity in neutral and mildly acid media and at temperatures between 20 and 30 degrees C for a period of 24 hours.