Production of chitooligosaccharides using an ultrafiltration membrane reactor and their antibacterial activity

To increase the solubility of chitosan in an aqueous solution and to facilitate its utilization, the enzymatic production of chitooligosaccharides with a high degree of polymerization (DP) was carried out using an ultrafiltration (UF) membrane reactor system. 80% of the oligosaccharides produced were in the range DP3¯6. Compared with a batch reactor, in the UF membrane reactor system, at least 11 batches of substrate could be hydrolysed for the same quantity of chitosanuse. Oligosaccharides obtained using the reactor system showed antibacterial activity and a 0.5% concentration completely inhibited the growth of Escherichia coli.