**Abstract**

Cellulases are important enzymes in cellulose degradation that occurs in nature, this degradation involves a system of extracellular multienzymes and have wide application. The construction of a high-quality system for the production of these enzymes is important for its application in the process of saccharification of biomass involved in the biofuel production process. Several species of fungi are capable of synthesizing and secreting high amounts of cellulase, most studies with fungal species use linearized plasmid, since these are encompassed to chromosomal DNA, improving its stability and expression efficiency. Advances in the production of recombinant enzymes focus on the search for industrially viable microorganisms capable of producing enzymes under various conditions, expressing them in a highly efficient manner, aiming at the synthesis of several copies of genes and a strong promoter. To resay these restrictions, molecular biology combined with recombinant DNA technology is a viable tool in enzymatic production. In subsequent topics, the production of endoglucanases, exoglucanases and β-glucosidase of fungi cloned in *Escherichia coli*, *Pichia pastoris* and other different expression systems will be addressed.

**Keywords:** recombinants cellulases, fungal cellulases, lignocellulosic biomass, cellulose degradation, heterologous systems, CRISPR/Cas9
