The action of mould enzymes on sucrose

Abstract

Extracts were prepared from Penicillium spinulosum. Aspergillus oryzae and A. niger by autolysis under toluene and by crushing frozen mycelium and spores. The action of these extracts on sucrose was followed by paper chromatography. The breakdown of sucrose by molds is not a simple hydrolysis. An initially rapid disappearance of substrate is accompanied by the formation of 4 non-reducing fructose-containing oligosaccharides and the liberation of glucose. Hydrolysis of these oligosaccharides proceeds slowly, fructose being liberated at an almost constant rate throughout the reaction. The formation of the oligosaccharides was not observed when mold extracts were incubated with other sugars singly, or with a mixture of glucose and fructose. The effects of pH, substrate concn. and partial heat inactivation were investigated. The ratio of oligosaccharide formation to fructose liberation was the same with all P. spinulosum extracts examined, but was smaller and more variable with extracts of Aspergillus spp. The breakdown of sucrose by mold extracts is discussed and attributed to the transference of fructose residues to suitable acceptors by a beta-fructofuranosidase, considered to be the only enzyme responsible for the hydrolysis of sucrose by P. spinulosum extracts.