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.