PRODUCTION OF HEMICELLULOSE-DEGRADING AND CELLULOSE-DEGRADING ENZYMESBY VARIOUS STRAINS OF SCLEROTIUM-ROLFSII

A number of wild-type isolates of Sclerotium rolfsii were screened for their capacity to produce lignocellulolytic enzymes when grown on a c ellulose-based medium. S. rolfsii proved to be an efficient producer o f hemicellulolytic enzymes under the conditions selected for this scre ening, although there was a great variability in enzyme activities for med by the different isolates. In addition to xylanase and mannanase, which were produced in remarkably high levels, a number of accessory e nzymes, which are important for the complete degradation of substitute d hemicelluloses and include alpha-arabinosidase, acetyl esterase, and alpha-galactosidase, are formed by S. rolfsii. Efficient production o f xylanase and mannanase was achieved when cellulose-based media were used for growth. Under these conditions, enhanced levels of endoglucan ase were formed as well. Formation of xylanase and mannanase could be more specifically induced when using xylan or mannan as growth substra tes, although the enzyme activities thus obtained were significantly l ower compared to cultivations on cellulose as main inducing substrate.