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.