Purification and Characterization of a β-1，3-1，4-Glucanase from Aspergillus awamori and Its Application in Preparation of Glucooligosaccharides

Abstract:

A β-1，3-1，4-glucanase（AaBglu29） from Aspergillus awamori was purified and its application in glucooligosaccharides production from oat bran was studied. The β-1，3-1，4-glucanase was purified to homogeneity by ammonium precipitation and anion-exchange chromatography. The molecular mass of AaBglu29 was estimated to be 30.7×103 and 27.6×103 by SDS-PAGE and gel filtration，respectively. The AaBglu29 was most active at pH 5.0 and 55 ℃. The enzyme displayed strict substrate specificity towards barely β-glucan（9，500 U/mg），oat β-glucan（7 950 U/mg） and lichenan（5 980 U/mg）. In addition，the enzyme was suitable for production of glucooligosaccharides（GOS） from oat bran. The highest GOS yield of 90%（based on β-1，3-1，4-glucan in oat bran） was achieved from 5% oat bran after 4 h of enzymatic hydrolysis（100 U/g） at 50 ℃ and pH 5.0. The properties indicated that AaBglu29 is a promising candidate for application in food and feed fields.