Agrivida is developing transgenic biomass optimized for cellulosic ethanol production. We are creating intein modified hydrolytic enzymes such as xylanases and endoglucanases with heat inducible activity. Because presence of the intein disrupts enzymes activity, plants can produce these intein-modified enzymes without having a deleterious effect on phenotype. After harvesting the plants,  inteins can be thermally induced to undergo splicing, reconstituting active cell wall degrading enzymes within the biomass. Specific enzymes are selected based on literature and in-house results for versatility and robust activity on target biomass. Inteins are then inserted into a variety of positions within the wild type enzymes. Intein-modified enzymes that display heat-inducible activity in initial assays are then further modified via random and site directed mutagenesis and evaluated with high throughput screening. Subsequent rounds of mutagenesis and splicing condition optimization can further enhance controlled enzyme activity. Once intein modified enzymes are selected from our high throughput host system they are transferred to plants.