New developments in solid state fermentation: I-bioprocesses and products.

Starting with a brief history of solid-state fermentation (SSF), major aspects of SSF are reviewed, which include factors affecting SSF, biomass, fermentors, modeling, industrial microbial enzymes, organic acids, secondary metabolites, and bioremediation. Physico-chemical and environmental factors such as inoculum type, moisture and water activity, pH, temperature, substrate, particle size, aeration and agitation, nutritional factors, and oxygen and carbon dioxide affecting SSF are reviewed. The advantages of SSF over Submerged Fermentation (SmF) are indicated, and the different types of fermentors used in SSF described. The economic feasibilities of adopting SSF technology in the commercial production of industrial enzymes such as amylases, cellulases, xylanase, proteases, phytases, lipases, etc., organic acids such as citric acid and lactic acid, and secondary metabolites such as gibberellic acid, ergot alkaloids, and antibiotics such as penicillin, cyclosporin, cephamycin and tetracyclines are highlighted. The relevance of applying SSF technology in the production of mycotoxins, biofuels, and biocontrol agents is discussed, and the need for adopting SSF technology in bioremediation of toxic compounds, biological detoxication of agro-industrial residues, and biotransformation of agro-products and residues is emphasized.

Solid-State Fermentation Systems—An Overview

Defined media and inert supports: their potential as solid-state fermentation production systems

Despite centuries of use and renewed interest over the last 20 years in solid-state fermentation (SSF) technology, and despite its good potential for a range of products, there are currently relatively few large-scale commercial applications. This situation can be attributed to the complexity of the system: Macroscale and microscale heat and mass transfer limitations are intrinsic to the system, and it is only over the last decade or so that we have begun to understand them. This review presents the current state of understanding of biochemical engineering aspects of SSF processing, including not only the fermentation itself, but also the auxiliary steps of substrate and inoculum preparation and downstream processing and waste disposal. The fermentation step has received most research attention. Significant advances have been made over the last decade in understanding how the performance of SSF bioreactors can be controlled either by the intraparticle processes of enzyme and oxygen diffusion or by the macroscale heat transfer processes of conduction, convection, and evaporation. Mathematical modeling has played an important role in suggesting how SSF bioreactors should be designed and operated. However, these models have been developed on the basis of laboratory-scale data and there is an urgent need to test these models with data obtained in large-scale bioreactors.

Biochemical Engineering Aspects of Solid State Bioprocessing

Publisher Summary This chapter presents an overview of fungal solid-state fermentation (FSSF). Fungal fermentation metabolites have an enormous impact on the food, pharmaceutical, and agricultural industries. The basis of production of fungal products has largely been by liquid-based submerged fermentation (SmF). At present, interest in solid-state fermentation (SSF) in the USA is small compared to the oriental countries where fungi are exploited for their natural affinity for moist environments. Japan has always been a trendsetter in the area of SSF and has some of the largest SSF production plants in the world. SSF can be defined as the growth of microorganisms on moist, water-insoluble solid substrates in the absence or near-absence of free liquid. One of the main advantages of FSSF is the ease with which fungi can grow on complex natural solid substrates like agro-industrial wastes, without much pretreatment. The bioreactor is the critical stage of the FSSF process as all the earlier and later stages are dependent on its capabilities. Unlike submerged fermentation, in FSSF, the choice of a suitable reactor system is difficult, given the heterogeneity of the substrate matrix. The selection depends on factors such as substrate type, process variables, extent of control required, etc. In the classical FSSF koji process, tray reactors have been traditionally employed. Other major types of reactors are the packed column, rotating drum, and fluidized bed.

C. Vergoignan

Papers

Use of solid state fermentation to produce Beauveria bassiana for the biological control of european corn borer