Regulation and Improvement of Cellulase Production: Recent Advances

Abstract

Cellulases and hemicellulases are the main industrial sources from different microorganisms used to depolymerise plant biomass to simple sugars that are converted to chemical intermediates and biofuels, such as ethanol. Cellulases are formed adaptively, and several positive (xyr1, Ace2, HAP2/3/5) and negative (Ace1, Cre1) components involved in this regulation are now known. In this review, we summarise current knowledge about how cellulase biosynthesis is regulated, and outline recent approaches and suitable strategies for facilitating the targeted improvement of cel-lulase production by genetic engineering. Trichoderma reesei is the preferred organism for pro-ducing industrial cellulases. However, a more efficient heterologous expression system for en-zymes from different organism is needed to further improve its cellulase mixture. In addition those optimizations of the promoter and linker for hybrid genes can dramatically improve the ef-ficiency of heterologous expression of cellulase genes.