Purification of pectinases from Aspergillus niger ATCC 9642 by ethanol precipitation

The present work aimed to study the recovery and preconcentration of pectinases (exo-polygalacturonase - exo-PG, pectinmethylesterase - PME, pectin lyase - PMGL) produced by Aspergillus niger ATCC 9642, by the precipitation with ethanol. The effects of the concentration of ethanol and the rate of addition of ethanol to the crude extract on the purification yield and purification factor were assessed. Purification factors (PF) of 1.3, 2.3 and 4.8-fold were obtained for exo-PG, PME and PMGL, respectively. Precipitation allowed fractionation of exo-PG and caused an activation of PMGL. The precipitation method using ethanol was proven to be effective in the recovery and fractionation of pectinases.