Method for preparing gentio-oligosaccharide by using immobilized beta-glucosidase

Abstract

The invention discloses a method for preparing gentio-oligosaccharide by using immobilized beta-glucosidase. The method for preparing the gentio-oligosaccharide by using the immobilized beta-glucosidase comprises the following steps of: 1) preparing beta-glucosidase through solid-state fermentation of Aspergillus niger; 2) immobilizing the beta-glucosidase by a crosslinking-embedding method; and 3) producing the gentio-oligosaccharide by transforming glucose by using the immobilized beta-glucosidase. The recovery rate of enzyme activity of an immobilized enzyme prepared by the method is up to 60 percent, and the conversion rate of a substrate, namely the glucose converted by the immobilized enzyme is 45 percent; and the stability and pH tolerance of the immobilized enzyme are remarkably improved, the mechanical strength is high, the immobilized enzyme can be continuously and repeatedly used for 4 to 6 bathes, and the enzyme activity is kept unchanged. The utilization rate of the gentio-oligosaccharide produced by an enzyme method is improved, the production cost and difficulty in separation and purification of the gentio-oligosaccharide are reduced, and the method is suitable for large-scale continuous production and has a great significance for improving the technical level of the production of the gentio-oligosaccharide in China.

Description

technical field

[0001] The invention relates to the technical field of enzyme engineering, in particular to a method for preparing gentian oligosaccharides by using immobilized β-glucosidase. Background technique

[0002] Gentian oligosaccharides are a class of oligosaccharides bound by glucose with β-1,6 glycosidic bonds. It is not easy to digest, low calorific value; relatively stable to pH and heat, has the functions of regulating the environment of intestinal flora, proliferating intestinal beneficial flora, and improving the effect of laxative, etc. It can produce good results in products such as ice cream and ice cream, so it is widely used in health food and other fields.

[0003] At present, there are many methods for preparing gentian oligosaccharides. The first ones were extracted from the stems and roots of Gentiana. Due to the limitation of raw materials, it is difficult to mass-produce them. In recent years, with the rise of enzymatic preparation of oligosacch...