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: citric acid production and the recovery of pectinolytic enzymes from the fermentation broth. Both products are partially purified and concentrated. The investigation was carried out using a tubular ultrafiltration module with polyacrylonitrile membranes with adequate transport-separation properties. The ultrafiltration process was optimized and the concentration of fermentation broth was carried out after primary diafiltration. The retentate obtained was also concentrated by means of a thermal method and permeate containing citric acid was then concentrated using a reverse osmosis DDS plate-frame module (De Danske Sukkerfabrikker, Denmark).