Enzymatic Degradation of Cell Wall and Related Plant Polysaccharides

Abstract

Polysaccharides such as starch, cellulose and other glucans, pectins, xylans, mannans, and fructans are present as major structural and storage materials in plants. These constituents may be degraded and modified by endogenous enzymes during plant growth and development. In plant pathogenesis by microorganisms, extracellular enzymes secreted by infected strains play a major role in plant tissue degradation and invasion of the host. Many of these polysaccharide-degrading enzymes are also produced by microorganisms widely used in industrial enzyme production. Most commerical enzyme preparations contain an array of secondary activities in addition to the one or two principal components which have standardized activities. In the processing of unpurified carbohydrate materials such as cereals, fruits, and tubers, these secondary enzyme activities offer major potential for improving process efficiency. Use of more defined combinations of industrial polysaccharases should allow final control of existing enzyme processes and should also lead to the development of novel enzymatic applications.

Biotechnological Production of Xylitol from Agro-Industrial Wastes

“…Although fermentable D-glucose could be produced from cellulose through the action of either acid or enzymes breaking the β-(1,4)-glycosidic linkages (Kumar et al, 2009), the structure of cellulose along with the intermolecular hydrogen bonds gives cellulose high tensile strength, makes it insoluble in most solvents and is partly responsible for the resistance of cellulose against microbial degradation (Ward & Moo-Young 1989). On the contrary, hemicelluloses, because of their branched, amorphous nature, are relatively easy to hydrolyze (Hamelinck et al, 2005), particularly, in contrast to cellulose, the polymers present in hemicelluloses are easily hydrolyzable (Kumar et al, 2009).…”

Characterization of the active site and thermostability regions of endoxylanase from Thermoanaerobacterium saccharolyticum B6A-RI

“…After cellulose, xylan is the most abundant renewable polysaccharide in nature, accounting for 20 to 30% of the dry weight of woody tissue (46).…”

Microbial Pectic Enzymes in the Food and Wine Industry

“…(Lang & Dornenburg, 2000;Whitaker, 1990). In plants, pectic enzymes are very important since they play a role in elongation and cellular growth as well as in fruit ripening (Sakai, 1992;Ward & Moo-Young, 1989;Whitaker, 1990). Pectolytic activity of microorganisms plays a significant role, firstly, in the pathogenesis of plants since these enzymes are the first to attack the tissue (Collmer & Keen, 1986;Whitaker, 1990).…”