Packed-bed solid-state fermentation bioreactor scale-up for cellulase production

Abstract

The main purpose of this project is to scale-up the cellulase production by solid-state fermentation (SSF) in packed-bed bioreactors, using solid agro-industrial by-products as substrates. Several scaling-up strategies will be used. Although SSF results in high yields of enzymes, this technique lacks of technological knowledge for large production. This project include experimental and simulation steps to contribute for such purpose. From a bench scale bioreactor, several scaling-up strategies will be applied to overcome typical drawbacks usually found when operating this class of bioreactor, namely the moisture segregation and the thermal heterogeneity. The thermophilic fungus Myceliophtora thermophila I-1D3b and the mesophilic Trichoderma reesei will be cultivated in sugar cane bagasse and wheat bran. The use of fungi of distinct thermal characteristics will answer the question if the technological strategies found for scaling-up are wide. Empirical and model-based scaling-up strategies will be applied. The empirical alternative will be based on traditional strategies found in the classical literature for heterogeneous chemical reactors, while the model-based alternative will use heat and mass transfer models to foresee temperature and moisture distribution within the packed-bed. For the process simulation, microorganism growing kinetics will be required and will be experimentally determined. The topmost procedure will be an economical evaluation of a piulot plant for celluase production. The project is inserted in the FAPESP-BIOEN Program and in the Paulista Bioenergy Research Center. It also is an extension of the thematic project Application of physical-chemical and enzymatic methods for sugar-cane bagasse saccharification: studies on microorganisms, fermentation process and hydrolysis methods (Proc. FAPESP 2010/12624-0), coordinated by Prof. Eleni Gomes. (AU)