Production of beta-mannanase and beta-mannosidase from Aspergillus awamori K4 and their properties

Abstract

beta-Mannanase and beta-mannosidase from Aspergillus awamori K4 was produced by solid culture with coffee waste and wheat bran. The optimum composition for enzyme production was 40% coffee waste-60% wheat bran. Two enzymes were partially purified. Optimum pH was about 5 for both enzymes, and optimum temperature was around 80 degrees C for beta-mannanase and 60-70 degrees C for beta-mannosidase. These enzymes produced some oligosaccharides from glucomannan and galactomannan by their hydrolyzing and transferring activities. beta-Mannanase hydrolyzed konjak and locust bean gum 39.1% and 15.8%, respectively. Oligosaccharides of various molecular size were released from glucomannan of konjak, but on the addition of cellulase, mannobiose was released selectively. In locust bean gum, tetra-, tri-, and disaccharides (mannobiose) were mainly released by K4 beta-mannanase. Tetra- and trisaccharides were heterooligosaccharides consisting of galactose and mannose residues. K4 beta-mannosidase had a transglycosylation action, transferring mannose residue to alcohols and sugars like fructose.