MODES OF ACTION OF BETA-MANNANASE ENZYMES OF DIVERSE ORIGIN ON LEGUME SEED GALACTOMANNANS

.beta.-Mannase (EC-3.2.1.78) activities in the commercial enzyme preparations Driselase [Basidiomycetes sp.] and Cellulase [Aspergillus niger], in culture solutions of Bacillus subtilis (TX1), in commercial snail gut (Helix pomatia) preparations and in germinated seeds of lucerne, Leucaena leucocephala and honey locust, were purified by substrate affinity chromatography on glucomannan-AH-Sepharose. On isoelectric focusing, multiple protein bands were found, all of which had .beta.-mannanase activity. Each preparation appeared as a single major band on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzymes varied in their final specific activities, Km values, optimal pH, isoelectric points and pH and temperature stabilities but had similar MW. The enzymes have different abilities to hydrolyze galactomannans which are highly substituted with galactose. Driselase and Cellulase contain .beta.-mannanases which can attack highly substituted galactomannans at points of single unsubstituted D-mannosyl residues if the D-galactose residues in the vicinity of the bond to be hydrolyzed are all on 1 side of the main chain.