Enhancing xylanases production by a new Amazon Forest strain of Aspergillus oryzae using solid-state fermentation under controlled operation conditions

Bioprocess studies towards improving the production of xylanases are of great value due to the importance of these enzymes on several industrial applications. This work evaluates the effects of operational conditions on xylanase production by a new strain of Aspergillus oryzae (P6B2) isolated from the Amazon Rain Forest. The fungus was cultivated under solid-state fermentation (SSF) using an instrumented lab-scale bioreactor equipped with an on-line automated monitoring and control system. The effects of initial substrate moisture content and temperature on xylanase production were evaluated and compared to static conditions. It was outstanding the positive effect on xylanase production by SSF cultivations under controlled conditions of forced over static aeration conditions. The conditions selected for further characterization resulted in the highest production of xylanase (2830.7IU/g), which was achieved using an initial substrate moisture content of 80%, at 28 C with an air flow rate of 20 mL/min and an inlet air humidity of 80%. Results of respirometric analysis showed good agreement with enzyme production, suggesting that these data could be very useful for optimization and scale-up studies. (C) 2013 Elsevier B.V. All rights reserved.