Characterization and catalytic activity of free and immobilized lipase from Aspergillus niger: a comparative study

Aspergillus niger lipase was immobilized by deposition on Celite and the hydrolytic and esterification activities, stability and enantioselectivity of both free and immobilized enzyme were compared. Both the free and immobilized preparations showed similar biochemical properties, with maximum activity at pH 6.0 and a temperature of 30-40 ºC. The most important effects observed when the lipase was immobilized were thermal stability and an improved esterification activity during the reaction of (R,S)-ibuprofen with 1-propanol in isooctane. Moreover, immobilized Aspergillus niger lipase maintained an esterification activity of at least 73% after 5 days of storage at 40 ºC and can be recycled and reused at least 6 times.