ULTRAFILTRATION PREPARATION OF PECTINOLYTIC ENZYMES FROM CITRIC-ACID FERMENTATION BROTH

The introduction of ultrafiltration to the classical scheme of citric acid production allows the combination of two technological cycles: ci tric acid production and the recovery of pectinolytic enzymes from the fermentation broth. Both products are partially purified and concentr ated. The investigation was carried out using a tubular ultrafiltratio n module with polyacrylonitrile membranes with adequate transport-sepa ration properties. The ultrafiltration process was optimized and the c oncentration of fermentation broth was carried out after primary diafi ltration. The retentate obtained was also concentrated by means of a t hermal method and permeate containing citric acid was then concentrate d using a reverse osmosis DDS plate-frame module (De Danske Sukkerfabr ikker, Denmark).