Insights on Heterologous Expression of Fungal Cellulases in Pichia pastoris

Cellulosic biomass, the most remarkable renewable source of fuels and other compounds of potential importance, needs highly complex mixture of various enzymes for its degradation. For sustainable and economical bioprocess, the availability of these enzymes in high quantities and at a low price is much warranted. The advancements in discovery of new strains, highly valuable techniques and molecular biotechnological tools have led to Pichia pastoris gaining a recognized organism status both at industrial as well as laboratory level. With numerous beneficial characteristics on its credit P. pastoris has emerged a promising host for most of heterologous proteins production. Thus, the production of fungal cellulytic enzymes is of worth to be comprehensively illustrated. There are some activators including promoters used in the expression host to increase the utility of expression system. This review summarizes the heterologous expression of fungal cellulases ( Exo-glucanases , endo-glucanases (EGs) and beta-glucosidases ( BGLs )) and advocates the various kinds of promoters used in P. Pastoris for expression of these enzymes and proteins. Further, concluding remarks will provide insights revealing the scope of P. pastoris as a potential expression system tool in today's modern direction of research.