Production of inulooligosaccharides from inulin by a dual endoinulinase system

Inulooligosaccharide (IOS) production from pure inulin was carried out usin g a dual endoinulinase system originated from Xanthomonas sp. and Pseudomon as sp. A statistical experimental design was employed to obtain the best po ssible combination of pH, temperature, enzyme dosage ratio and substrate co ncentration for maximum inulooligosaccharide production based on the initia l reaction rate of the dual enzyme system. The optimum reaction conditions were as follows: pH, 5.8; temperature, 50 degreesC; substrate concentration , 50 g/liter. The maximum conversion yield was 92% when 50 g/liter of pure inulin was incubated with the dual enzyme system containing Xanthomonas enz yme to Pseudomonas enzyme in the ratio of 4:1 for 110 h. Substrate inhibiti on was not detected for a prolonged reaction period of 110 h up to 150 g/li ter of inulin with an enzyme dosage of 460 U/g substrate. By use of the dua l enzyme system, higher conversion yield of IOS and even product compositio n were achieved. (C) 2001 Elsevier Science Inc. All rights reserved.