Pages: 85

This chapter briefly introduces enzymes (nature and structure) and covers enzyme kinetics in detail. The main models for enzyme kinetics are included, e.g. Michaelis-Menten, effect of pH, temperature and inhibitors. The chapter also covers the kinetics of enzymatic reactions for enzymes immobilised on nonporous and porous supports.

Pages: 24

A general introduction to fermentation processes is given. The main concepts used in the rest of the book are defined, including a general introduction on microbial metabolism and on the key biochemistry concepts that are required to model and design fermentation processes. The main types of reactors used in fermentation are introduced. The chapter also introduces general concepts on feedstocks, culture maintenance, sterilisation, downstream processing and design of fermentation processes. Five questions on the introductory concepts are provided at the end. The chapter includes 20 solved examples and 13 questions and problems at the end.

Pages: 29

The most common models used to describe the growth rate of microorganisms or cell cultures and the quantitative relationships between reagents and products (stoichiometry) are presented. The chapter covers the Monod model for microbial growth and its modification to include inhibition, effect of temperature and pH, maintenance and endogenous metabolism. The use of experiments to calculate the kinetic parameters is described. Yield coefficients for microorganism and product production, nitrogen and oxygen consumption are introduced and their relationship with the growth stoichiometry is explained. The chapter includes 13 solved numerical examples and 12 questions and problems at the end.

Pages: 30

The focus of the chapter is the design of batch, continuous and fed-batch fermentation processes. The chapter covers how to calculate the required volume or residence time for fermentation processes, and how to calculate the composition of the fermentation effluents. Mass balances, which are the key equations for the design of these processes, are covered in detail using the kinetic models introduced in Chapter 3. The effect of design parameters on the performance of fermentation processes is discussed. Batch, continuous and fed-batch processes are compared based on their substrate removal rate as a function of the design parameters. The chapter includes 10 solved numerical examples and 18 questions and problems at the end.

Pages: 48

The two-film model for mass transfer is presented and is applied to oxygen transfer in bioreactors. The chapter starts from the fundamental theory of mass transfer and includes the measurements and correlations for mass transfer coefficients, calculations for power draw in agitated vessels, oxygen balances in batch and continuous fermenters. The effect of the design of the aeration system on the optimisation of fermentation processes is covered. The scale up and scale down of fermentation processes based on the capacity for oxygen transfer is presented in detail. The chapter includes 10 solved numerical examples and 20 questions and problems at the end.

Pages: 49

The chapter covers heat transfer and heat balances for fermentation processes. The chapter starts with fundamentals of heat generation in fermentation reactions, including the concepts of enthalpy and enthalpy of reaction. Heat balances in batch and continuous fermentations are then covered, followed by correlations for heat transfer coefficients and detailed theory of scale-up scale-down. The chapter includes 7 solved numerical examples and 13 questions and problems at the end.

Pages: 50

The chapter covers downstream processes, in particular: separation of microorganisms, crossflow filtration, ion exchange, adsorption, chromatography. For each process, the methodology for mass balances and, if applicable, for rate equations is presented. The chapter includes nine solved examples and seven questions and problems at the end.

Pages: 18

The chapter summarises the main steps in the design of industrial fermentation processes and covers examples of industrial examples. The following processes are presented: bioethanol, penicillin, whisky, citric acid, L-glutamic acid, cell-based virus vaccines, processes with undefined mixed cultures (biological wastewater treatment and anaerobic digestion) and production of cellulases. For each process, the main unit operations from the feedstock to the final product are presented and a typical process flowsheet is described. The chapter includes six questions and problems at the end.