FUNCTIONAL IMPROVEMNET OF CELLULASES AIMED FOR ENZYMATIC DEGRADATION AND SACCHARIFICATION OF CELLULOSIC BIOMASS

We performed to improve the·-glucosidase 1 which was the most useful enzyme among cellulase components produced by a filamentous fungus，Aspergillus aculeatus，for the saccharification of cellulosic biomass.Firstly，the activity against insoluble cellulose of relatively high molecular mass was raised by adding the cellulose-biding domain。Secondary，a mutantenzyme with drastically lowered product inhibition by glucose was successfully isolated after the screening of a random mutagenesis library on amino acid residues around the substrate-binding site.

We performed to improve the ・-glucosidase 1 which was the most useful enzyme among cellulase components produced by a filamentous fungus, Aspergillus aculeatus, for the saccharification of cellulosic biomass. Firstly, the activity against insoluble cellulose of relatively high molecular mass was raised by adding the cellulose-biding domain. Secondary, a mutantenzyme with drastically lowered product inhibition by glucose was successfully isolated after the screening of a random mutagenesis library on amino acid residues around the substrate-binding site.