WHOLE BROTH CELLULASE PRODUCTION FOR USE IN SIMULTANEOUS SACCHARIFICATION AND FERMENTATION

Cellulase, an enzyme that catalyzes the breakdown of cellulose into glucose, is produced inside fungal cells and secreted into the surrounding media. However, the cells retain significant amounts of β-glucosidase, and this extra enzyme could improve the performance of a simultaneous saccharification and fermentation (SSF) process. To test the possible contribution of mycelia-bound enzyme to SSF performance with modern fungal cellulase producers, the performance of SSF using whole culture broth (with cells) was compared to SSF performance using culture filtrate. Cellulase broth was produced using the advanced Trichoderma reesei mutant L27. Measurements of cellulase activities showed that the broth had more activity than the filtrate. Subsequent SSF experiments were conducted at 37°C in shake flasks with Saccharomyces cerevisiae, and the broth produced 8-25% higher ethanol yields than the cellulase filtrate produced. © 1990 Humana Press Inc.