Fungi in Fermentation and Biotransformation Systems

Abstract

Microfungi were used to produce products for human consumption, such as cheese and tea, long before the development of bioprocess engineering methods to control fermentations and biotransformations. However, such processes have been substantially improved in the last decades. Mathematical models have been developed to optimise the design and operation of both solid and submerged fermentations, and rheological properties of the broth (influenced by biomass concentration, growth rate, and morphology) have been used to better understand fungal performance in bioreactors. New strategies and bioreactor configurations have also been proposed, including rotating drums for solid-state fermentation, internal-loop airlift reactors, and disposable bag reactors (which allow the growth of shear stress sensitive basidiomycetes). Fungal secondary metabolites have provided important therapeutical agents, since the discovery of penicillin and cyclosporine (effective antibacterial and immunosuppressant drugs, respectively). Furthermore, fungal biotransformations of terpenes, terpenoids, and steroids are nowadays successful biotechnological processes. This chapter aims at reviewing the latest developments in fermentation and biotransformation processes using fungal cells.