Production of inulooligosaccharides from chicory extract by endoinulinase from Xanthomonas oryzae No. 5

Inulooligosaccharides (IOS) production from chicory extract was carried out using endoinulinase obtained from a new isolate, Xanthomonas oryzae No. 5. The IOS production from chicory extract was maximum when 50 g/liter of chi cory extract was utilized as the substrate. As the substrate concentration increased, the IOS production accordingly decreased probably due to substra te inhibition. For a comparative study, enzyme reactions were carried out f rom pure inulin as substrate. Though total IOS contents indicated higher IO S yield with pure inulin compared to that of chicory extract, the distribut ion of inulooligosaccharide components between pure inulin and chicory extr act was not significantly different; i.e. DP5 and higher oligosaccharides a re major products in case of both chicory extract and pure inulin as substr ate. A considerable amount of oligofructose (about 30%, w/w), which were or iginally present in chicory extract, resulted in the change of the enzyme k inetics. A reaction pH 7 was found to be most suitable for enzyme reaction. The initial reaction rates increased with increasing enzyme dosage, althou gh the relative composition of the IOS produced remain unchanged. (C) 2001 Elsevier Science Inc. All rights reserved.