Cereal Chem 64:8-15   |  VIEW ARTICLE

Detection and Assay of (1-4)-Beta-D-Glucanase, (1-3)-Beta-D-Glucanase, (1-3)(1-4)-Beta-D- Glucanase, and Xylanase Based on Complex Formation of Substrate with Congo Red.

P. J. Wood and J. Weisz. Copyright 1987 by the American Association of Cereal Chemists, Inc. 

The dye binding of Congo red by cereal (1-3)(1-4)-beta-D-glucans, substituted celluloses, O- (carboxymethyl) pachyman, and larchwood xylan may be used to detect and estimate (1-3)(1-4)-beta-D- glucanase, (1-4)-beta-D-glucanase, (1-3)-beta-D-glucanase, and xylanase activities, respectively. Oligosaccharide reaction products, resulting from enzyme activity on these polysaccharides, do not bind Congo red. This can be monitored in solution and was exploited in a gel-diffusion assay system in which radial diffusion of enzyme into a substrate-bearing gel slab was detected by Congo red staining. The diameter of the reaction zone was proportional to the logarithm of the enzyme concentration. Gel diffusion measurements of (1-3)-beta-D-glucanase activity in germinating barley corresponded well to viscometrically determined values. The method was applied to survey commercial amylolytic enzymes for beta-D-glucanase and xylanase contamination.