Purification and Properties of a Fructooligosaccharide-producing β-Fructofuranosidase from Aspergillus niger ATCC 20611

Abstract

A fructooligosaccharide-producing β-fructoturanosidase was purified from cells of Aspergillus niger ATCC 20611. The molecular weight was 340, 000 by gel filtration. The optimum pH of the enzyme was 5.0-6.0 and the optimum temperature was 50-60°C. The enzyme was rendered inactive by 1 HIM Hg²⁺ and the Km value for sucrose was 0.29 M. The enzyme catalyzed an almost exclusively fructosyl transfer reaction in a 50% sucrose solution to produce a mixture of fructooligosaccharides and glucose, but both fructosyl transfer and hydrolytic action were observed in a 0.5 % solution. The β-fructofuranosidase showed a high regiospecificity to transfer the fructosyl moiety for the 1-OH group of terminal fructofuranosides.