Monday, May 2, 2011
Grand Ballroom C-D, 2nd fl (Sheraton Seattle)
The successful strategy to reduce cellulase enzymes costs includes both microorganism selection and improved fermentation process conditions. The Amazon biome is the world’s largest reserve of biological diversity, presenting special soil and climate characteristics ideal for microorganism growth. Enzymes production using low cost and easily available agricultural residues as substrates can contribute to cost reduction. This work addresses both cellulase cost reduction approaches (microorganism selection and improvement of fermentation process) by describing the isolation, screening and selection of biomass-degrading fungi species from the Amazon forest and analyzing the enzymatic complex produced by a selected strain of Aspergillus fumigatus cultivated using different agro-industrial residues (wheat bran, sugar cane bagasse, soybean bran, and orange peel) as substrate in solid state fermentation (SSF). The highest levels of endoglucanase (CMCase) corresponded to 160 IU/g and it was obtained using soybean bran as the carbon source, after 96h of cultivation at 35°C. This enzymatic extract was used to run a zymogram analysis that showed 3 bands of endoglucanase activity. The CMCase activity was higher at 65°C and pH 3-3.5, indicating that this microorganism produces a thermophilic and acid endoglucanase. The fungal isolates from the Amazon forest were highly efficient producers of cellulases and xylanases as well.