Purification, Characterization, Expression and Application of Microbial Glucanases and Xylanases - Fatma Elgharbi - Bog

β-glucans, are consisting of linear β-D-glucosyl residues linked through β-1,3 and/or β-1,4 glycosidic bonds. The degradation of β-glucans in nature is catalyzed by β-glucanases. These enzymes constitute an important biotechnological aid in reducing the amount of chlorine required for bleaching in pulp and paper industry, the bioconversion of lignocellulosic materials into fermentative products, the improvement of digestibility of animal feedstock and the clarification of juices.
β-1,4-Xylans are consisting of a homopolymeric backbone of β-1,4-linked D-xylopyranose units and short side chains. β-1,4-Xylanases are the key enzymes that hydrolyze the backbone structure of β-1,4-xylans to initiate degradation of the complex polysaccharides by microorganisms.These enzymes have attached considerable research interest due to their worldwide commercial applications (textile, paper and pulp, foodstuff, animal feed, pharmaceutical and biofuel production), both alone and in combination with other enzymes.
Due to their limited properties, the currently marketed commercial enzymes may not be ideally suitable for industrial applications. Accordingly, there are continuing efforts to search for new sources for the production of enzymes with interesting properties that can be produced in high yields. In recent years, heterologous expression is becoming one of the main tools for the production of industrial enzymes.
In this work, microbial glucanases and xylanases were purified, characterized and overexpressed in heterologous systems. The 3D models of some enzymes were generated and discussed. These enzymes have been also tested for their effectiveness in various industrial applications.