METHOD OF ENHANCING ENZYME ACTIVITY

Described are methods and means for enhancing enzyme activity toward insoluble substrates. This is achieved by means of in vitro compartmentalization in which an insoluble microparticle functions both as the enzyme substrate and as a structure for negative selection. Enhanced enzymes expressed from a microparticle-linked polynucleotide library preferentially degrade the microparticle releasing specific gene variants into solution. Gene variants encoding less active enzyme variants remain linked to the microparticle and may be removed through centrifugation, thus enriching the polynucleotide library for more active enzyme variants. These methods may be used to enhance cellulase and ligninase activity toward insoluble cellulosic biomass.