Process Biochemistry, Vol.34, No.2, 181-186, 1999
Recovery of pectolytic enzymes produced by solid state culture of Aspergillus niger
Pectinases are enzymes with a wide range of applications in the food and drink industries. In the present work, the extraction of pectinases produced by Aspergillus niger in a solid state fermentation system was investigated. The purpose was to reduce enzyme losses in the fermented solids and at the same time obtain a crude extract as concentrated as possible. Initially the performances of stirred tank and fixed bed extractors were compared. Polygalacturonase activity and viscosity reducing capacity obtained in the stirred tank system were 105% and 15% superior, respectively. Repeated extractions and multiple stage countercurrent extraction were studied, employing stirred tanks. It was possible to observe that three stages were enough for total recovery of the enzymes contained in the solids. The final enzyme extract obtained by counter-current extraction with three stages showed a polygalacturonase activity 81% higher than the one obtained by one-stage extraction.