Continuous production of chitooligosaccharides using a dual reactor system

The continuous production of chitooligosaccharides from chitosan was achiev ed with a dual reactor system which consisted of an ultrafiltration (UF) me mbrane reactor and a column reactor packed with an immobilized enzyme. The production of the oligosaccharides was performed by two steps, the first, t he preparation of the partially hydrolyzed chitosan (PHC) from viscose chit osan in the column reactor packed with an enzyme and the second, the produc tion of the oligosaccharides from PHC in the UF membrane reactor. Three kin ds of PHCs were obtained from three different outflow rates (3, 5, and 9 ml /min) in the column reactor and were supplied to a substrate feed tank of t he following UF reactor in order to identify the influence of the feed on m embrane fouling. The PHC obtained with a 5 ml/min overflow rate was the mos t suitable substrate for alleviation of membrane fouling and efficient hydr olysis under the operating conditions of the dual reactor system. In additi on, chitooligosaccharides produced using the dual reactor system were readi ly fractionated by a proper selection of membranes. Therefore, it was shown that this dual reactor system was adequate for continuous production of ch itooligosaccharides from chitosan by enzymic hydrolysis. (C) 2000 Elsevier Science Ltd. All rights reserved.