Solid-State Fermentation Bioreactors: Fundamentals of Design and Operation

Although solid-state fermentation (SSF) has been practiced for many centuries in the preparation of traditional fermented foods, its application to newer products within the framework of modern biotechnology is relatively restricted. It was c- sidered for the production of enzymes in the early 1900s and for the production of penicillin in the 1940s, but interest in SSF waned with the advances in submerged liquid fermentation (SLF) technology. The current dominance of SLF is not s- prising: For the majority of fermentation products, it gives better yields and is e- ier to apply. It is notoriously difficult to control the fermentation conditions in SSF; these difficulties are already apparent at small scale in the laboratory and are exacerbated with increase in scale. However, there are particular circumstances and products for which SSF technology is appropriate. For example, a desire to reuse solid organic wastes from agriculture and food processing rather than simply discarding them leads naturally to the use of SSF. Further, some microbial pr- ucts, such as fungal enzymes and spores, amongst others, are produced in higher yields or with better properties in the environment provided by SSF systems. With recognition of this potential of SSF, a revival of interest began in the mid- 1970s. However, the theoretical base for SSF bioreactor technology only began to be established around 1990.

Table of Contents:
Solid-State Fermentation Bioreactor Fundamentals: Introduction and Overview.- The Bioreactor Step of SSF: A Complex Interaction of Phenomena.- to Solid-State Fermentation Bioreactors.- Basics of Heat and Mass Transfer in Solid-State Fermentation Bioreactors.- The Scale-up Challenge for SSF Bioreactors.- Group I Bioreactors: Unaerated and Unmixed.- Group II Bioreactors: Forcefully-Aerated Bioreactors Without Mixing.- Group III: Rotating-Drum and Stirred-Drum Bioreactors.- Group IVa: Continuously-Mixed, Forcefully-Aerated Bioreactors.- Group IVb: Intermittently-Mixed Forcefully-Aerated Bioreactors.- Continuous Solid-State Fermentation Bioreactors.- Approaches to Modeling SSF Bioreactors.- Appropriate Levels of Complexity for Modeling SSF Bioreactors.- The Kinetic Sub-model of SSF Bioreactor Models: General Considerations.- Growth Kinetics in SSF Systems: Experimental Approaches.- Basic Features of the Kinetic Sub-model.- Modeling of the Effects of Growth on the Local Environment.- Modeling of Heat and Mass Transfer in SSF Bioreactors.- Substrate, Air, and Thermodynamic Parameters for SSF Bioreactor Models.- Estimation of Transfer Coefficients for SSF Bioreactors.- Bioreactor Modeling Case Studies: Overview.- A Model of a Well-mixed SSF Bioreactor.- A Model of a Rotating-Drum Bioreactor.- Models of Packed-Bed Bioreactors.- A Model of an Intermittently-Mixed Forcefully-Aerated Bioreactor.- Instrumentation for Monitoring SSF Bioreactors.- Fundamentals of Process Control.- Application of Automatic Control Strategies to SSF Bioreactors.- Design of the Air Preparation System for SSF Bioreactors.- Future Prospects for SSF Bioreactors.