Tuesday, April 30, 2013
Exhibit Hall
Increased hydrolysis of glucans in plant biomass can be achieved by supplementing cellulase preparations with accessory enzymes such as xylanase, arabinofuranosidase, α-glucuronidase, acetyl xylan esterase, feruloyl esterase and others. In particular, xylanase and feruloyl esterase (FAE) are two groups of enzymes of great importance in biomass deconstruction. Xylanase catalysis the hydrolysis of xylan, principal type of hemicellulose, and its activity can be increased in the presence of esterases, such as FAE. Ferulate side chains function as crosslinkers to either another xylan chain or lignin. This study aimed to select and cultivate different fungi isolated from the Amazon rainforest capable of synthesizing xylanase and FAE. Initially, a screening was conducted by inoculating the different fungi in agar plates containing ethyl ferulate. The enzyme production was evidenced by a clear halo around the colony, which was formed by seven of the twelve strains tested. Then, the fungi were cultivated in a liquid nutrient medium supplemented with 1% wheat bran. The Aspergillus oryzae P27C3 strain showed maximum values for both xylanase (58.33 IU/mL) and feruloyl esterase activity (52.69 IU/L) after 24 hours of cultivation. It was also interesting that the production of both enzymes followed a very similar profile. Given the potential of Aspergillus oryzae strains and its recognized application for industrial enzymes production, there is a great interest in further characterize this fungus in terms of xylanase and FAE production.