Siimmary
I n this paper we studied the conditions for the production of @-glucosidase from T. reesei QM9414 in batch cultures using milled and sieved wheat straw as sole carbon source. High 8-glucosidase production in the presence of wheat straw, a more realistic substrate than commercial cellulose, was obtained. The influence of particle size of wheat straw on p-glucosidase production in cell-free, cell and cellwall extracts w a s studied. The particle size of wheat straw notably influenced enzyme production in cell and extrnmycelial extracts but i t was less important with respect to the cell wall bound enzyme. p-Glucosidase production was studied along of the fermentation. The results suggest a close relation between B-glucosidase from cell extract and extramycelial broth; geneticin levels of inhibition of 8-glucosidase biosynthesis in both fractions were similar, a fact that suggests a common origin for the enzyme.
Kinetic parameters for b-glucosidase from cell free and cell extracts were V,,, = 0.28 pmol/min/ mg, K M = 0.91 mM and V,,,, = 0.095 pmol/min/mg, K , = 0.39 mM respectively. Kinetic parameters for B-glucosidase from cell-wall could not be calculated because experimental data did not fit the different monosubstrate equations.