S.-O. Enfors: Fermentation Process Engineering, 2011

Content

 

1. Introduction ..................................................................................................................... 1

2. Fermentation media.......................................................................................................... 3

3 A general mass balance of the bioreactor........................................................................... 9

4 Biological reaction rate models........................................................................................ 11

4.1 Substrate consumption ................................................................................................. 12

4.2 Cell growth and biomass yield ...................................................................................... 14

4.3 Consumption of non-limiting substrates ....................................................................... 17

4.4 Cell death ..................................................................................................................... 17

4.5 Product formation......................................................................................................... 17

4.6 Metabolic heat evolution............................................................................................... 17

4.7 The maintenance coefficient ........................................................................................ 18

4.8 Oxygen consumption ................................................................................................... 19

4.9 Overflow metabolism.................................................................................................... 22

4.10 Summary of equations used for specific rates and biomass yield................................. 24

5 Stoichiometry and calculation of yield coefficients.......................................................... 25

5.1 Carbon and degree of reduction balances ..................................................................... 25

5.2 Checking consistency of measured data........................................................................ 27

5.3 Calculation of specific rates .......................................................................................... 28

5.4 Conversion of parameters between C-mole and gram units ........................................... 28

5.5 Summary of equations used for calculation of yield coefficients and specific rates ....... 29

6 Oxygen transfer in bioreactors ........................................................................................ 31

6.1 The oxygen demand .................................................................................................... 31

6.2 The oxygen transport.................................................................................................... 32

6.3 Control of the oxygen transfer rate .............................................................................. 33

6.4 Determination of the oxygen transfer capacity ............................................................. 37

6.5 Rheology of fermentation broths ................................................................................. 41

6.6 Calculation of KLa from power input data ................................................................... 43

6.7 Summary of equations used for OTR and KLa calculations........................................... 46

7 Batch fermentation .......................................................................................................... 47

8 Continuous fermentation ................................................................................................. 55

8.1 The chemostat .............................................................................................................. 56

8.2 Presentation of the chemostat properties........................................................................ 58

8.3 Summary of steady state equations for a chemostat ...................................................... 66

8.4 The metabolic control of the chemostat ........................................................................ 67

8.5 Control of cell concentration and growth rate in a chemostat......................................... 67

8.6 Applications of the chemostat ...................................................................................... 69

8.7 Simulation of a chemostat ............................................................................................ 70

9 Fed-batch fermentation ................................................................................................... 73

9.1 A fed-batch model........................................................................................................ 77

9.2 High cell density cultures.............................................................................................. 78

9.3 Exponential fed-batch cultures...................................................................................... 82

9.4 DOT controlled feeding ............................................................................................... 84

9.5 Simulation of a fed-batch process ................................................................................ 85

10 Determination of kinetic process parameters ................................................................. 89

11 List of symbols ............................................................................................................. 95

12 Subject index ................................................................................................................ 97