Cellulase production by new fungal strains from Brazil

Ethanol is one of the most important renewable fuels due to the economic and environmental benefits of its use. Currently, ethanol is produced commercially from conventional feedstocks such as sugarcane and cornstarch. However, agro-industrial residues can be converted into ethanol. Besides being cheap, agro-industrial residues would reduce considerably the competition for use of land for food production. The transformation of these materials into ethanol is mediated by enzymatic mixtures that include cellulases. In this work we screened two fungal collections for cellulase activities. One from Cerrado (a Brazilian biome) soil and other collection from fungal strains associated to sugarcane plants. For this, a qualitative test for presence of cellulases was performed on plates containing carboxymethylcellulose and Avicel. We selected 39 strains. These 39 fungal strains were tested for cellulase production in submerged fermentation using sugarcane bagasse as a carbon source. After 168 h of fermentation, enzymatic activities were measured on the supernatant and the 11 best cellulase producers were selected and cultivated in a richer culture medium. Based on the results obtained, the 3 best fungi were selected: 147, 66 and CBF-13. Fungus strain 147 showed activities of 308, 201 and 1.300 mU/mL respectively, for FPase, b-glucosidase and endoglucanase. Fungus strain 66 showed activities of 310, 180 and 673 mU/mL, respectively. And fungus strain CBF-13 showed activities of 79, 361 and 441 mU/mL respectively. Cellulase production by these strains is being optimized and results will be presented.