In addition to Trichoderma reesei, Penicillium echinulatum is among the microorganisms that show great potential of cellulase secretion for enzymatically converting biomass into ethanol. For instance, mutants of P. echinulatum are able to secrete cellulases with filter paper activity (FPA) higher than 2IUml−1 when grown in media containing1% cellulose as carbon source[14,15].They also produce high yields of cellulases in solid-state fermentation using sugar-cane bagasse (SCB) that reach more than 30FPUg−1 of SCB [28]. Moreover, the FPA and -glucosidases of P. echinulatum are of interest for cellulose hydrolysis because they show good thermal stability at 50◦C and 55◦C, respectively [29], and its cellulase complex presents a good proportion of FPA and -glucosidase for efficiently hydrolyzing cellulose, when compared to the cellulases of T. reesei [30].