Production of Recombinant Cellobiohydrolase II in a New Expression System Based on .

Cellulase is a family of at least three groups of enzymes that participate in the sequential hydrolysis of cellulose. Recombinant expression of cellulases might allow reducing their production times and increasing the low proteins concentrations obtained with filamentous fungi. In this study, we describe the production of cellobiohydrolase II (CBHII) in a native strain of . Recombinant CBHII was expressed in 54-A reaching enzyme activity values of up to 14.5 U L. The enzyme extract showed optimum pH and temperature of 5.0-6.0 and 40°C, respectively. Enzyme kinetic parameters ( of 2.73 mM and max of 23.1 M min) were between the ranges of values reported for other CBHII enzymes. Finally, the results showed that an enzymatic extract of 54-A carrying the recombinant CBHII allows production of reducing sugars similar to that of a crude extract from cellulolytic fungi. These results show the first report on the use of as a host to produce recombinant proteins. In addition, recombinant CBHII enzyme could potentially be used in the degradation of lignocellulosic residues to produce bioethanol, based on its pH and temperature activity profile.