U. Lendenmann et T. Egli, KINETIC-MODELS FOR THE GROWTH OF ESCHERICHIA-COLI WITH MIXTURES OF SUGARS UNDER CARBON-LIMITED CONDITIONS, Biotechnology and bioengineering, 59(1), 1998, pp. 99-107
In natural environments, heterotrophic microorganisms encounter comple
x mixtures of carbon sources, each of which is present only at very lo
w concentrations. Under such conditions no significant growth could be
expected if cells utilized only one of;he available carbon compounds
as suggested by the principle of diauxic growth. Indeed, there is much
evidence that microbial cells utilize many carbon sources simultaneou
sly. In order to predict bacterial growth under such conditions we dev
eloped a model describing the specific growth rate as a function of th
e individual concentrations of several simultaneously utilized carbon
substrates. Together with multisubstrate models previously published,
this model was evaluated for its ability to describe growth of Escheri
chia coli during the simultaneous utilization of mixtures of sugars in
carbon-limited continuous culture. Using the mu(max) and K-s constant
s determined for single substrate growth with six different sugars, th
e model was able for most experiments to adequately describe the speci
fic growth rate of the culture, i.e., the experimentally set dilution
rate, from the measured concentrations of the individual sugars. The m
odel provides an explanation why bacteria can still grow relatively fa
st under environmental conditions where the concentrations of carbon s
ubstrates are usually extremely low. (C) 1998 John Wiley & Sons, Inc.