Production of glucooligosaccharides by an acceptor reaction using two types of glucansucrase from Streptococcus sobrinus

Abstract

Glucooligosaccharides (GOS) were produced by using an acceptor reaction with two types of glucansucrase (GTF-S and GTF-I) from Streptococcus sobrinus. Acceptor reactions of GTF-S with maltose acceptor, gave a great number of GOS ranging from DP (degree of polymerization) 2 to DP15. At the both acceptor reactions with GTF-S or GTF-I, as the sucrose/maltose ratio was decreased, the amount of dextran and DP of oligosaccharides was decreased. A maximum GOS yield of 69% was achieved at the acceptor reaction with GTF-I and when the molar ratio of sucrose/maltose is 2:1, in which GOS of DP6 ~ DP9 were major oligosaccharides and 17% of dextran. The polymeric size of GOS could be controlled by varying the ratio of sucrose to the acceptor (maltose in this work).