RAPID SCREENING FOR ENDO-BETA-1,4-GLUCANASE AND ENDO-BETA-1,4-MANNANASE ACTIVITIES AND SPECIFIC MEASUREMENT USING SOLUBLE DYE-LABELED SUBSTRATES

Soluble dye-labelled substrates were prepared for the specific and rap id screening and the measurement of endo-beta-1,4-glucanase and endo-b eta-1,4-mannanase activities. Soluble carboxy-methylcellulose and locu st bean galactomannan were dyed with Remazol Brilliant Blue R. A speci fic screening procedure was developed to isolate genes coding for cell ulolytic and hemicellulolytic enzymes from a Cellulomonas sp. CelB7 li brary. The assay is advantageous for the simple, rapid and direct dete ction of cellulase and hemicellulase activities in a large number of c lones as found in gene libraries without replica plating or blotting t echniques. The prepared dye-labelled substrates can also be used for t he quantitative measurement of specific endo activities of cellulolyti c and hemicellulolytic enzymes because the undigested substrate can be precipitated and the amount of soluble dye, determined spectrophotome trically, is proportional to enzyme activity. (C) 1997 Elsevier Scienc e B.V.