Modeling of Growth Kinetics
247
Figure 7.4 Typical profile of biomass and substrate concentrations during a batch culture.
A. The time profile of the biomass concentration (♦) and the concentration of the limiting substrate (* ).
B. A cross plot of the specific growth rate (given by 1
lx
dx/dt) versus the substrate concentration.
Corresponding values of M
and
s
are taken from Fig. 7.4A. The value of A, is indicated.
The satisfactory fit of the Monod model to many experimental data should as mentioned in Chapter 6 never
be misconstrued to mean that Eq. (7.16) is a mechanism of fermentation processes. The Langmuir rate
expression of heterogeneous catalysis and the Michaelis-Menten rate expression in enzymatic catalysis are
formally identical to Eq. (7.16), but in both cases the denominator constant has a direct physical
interpretation (the equilibrium constant for dissociation of a catalytic site-reactant complex), whereas A, in
Eq. (7.16) is no more than an empirical parameter used to fit the average substrate influence on all cellular
reactions, pooled into the single reaction in which
une /.1 eommiauon oi
A .
values tor aiitere
Snecies
mt micromai cells erowine on ail
Substrate
rerent sugars.________
K.
fms L ‘l
Aerobacter aerogenes
Glucose
8
Escherichia coli
Glucose
4
Klebsiella aerogenes
Glucose
9
Glycerol
9
Klebsiella oxytoca
Glucose
10
Arabinose
50
Fructose
10
Lactococcus cremoris
Glucose
2
Lactose
10
Fructose
3
Saccharomyces cerevisiae
Glucose
180
Pénicillium chrysogenum
Glucose
4
Aspereillus orvzae
___________________
Glucose
5
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