K. Kovarova et al., TEMPERATURE-DEPENDENT GROWTH-KINETICS OF ESCHERICHIA-COLI ML-30 IN GLUCOSE-LIMITED CONTINUOUS-CULTURE, Journal of bacteriology, 178(15), 1996, pp. 4530-4539
Detailed comparison of growth kinetics at temperatures below and above
the optimal temperature was carried out with Escherichia coli ML 30 (
DSM 1329) in continuous culture. The culture was grown with glucose as
the sole limiting source of carbon and energy (100 mg liter(-1) in fe
ed medium), and the resulting steady-state concentrations of glucose w
ere measured as a function of the dilution rate at 17.4, 28.4, 37, and
40 degrees C. The experimental data could not be described by the con
ventional Monod equation over the entire temperature range, but an ext
ended form of the Monod model [mu = mu(max) . (s-s(min))/(K-s + s-s(mi
n))], which predicts a finite substrate concentration at 0 growth rate
(s(min)), provided a good fit. The two parameters mu(max) and s(min)
were temperature dependent, whereas, surprisingly, fitting the model t
o the experimental data yielded virtually identical K-s, values (appro
ximately 33 mu g liter(-1)) at all temperatures. A model that describe
s steady-state glucose concentrations as a function of temperature at
constant growth rates is presented. In similar experiments with mixtur
es of glucose and galactose (1:1 mixture), the two sugars were utilize
d simultaneously at all temperatures examined, and their steady-state
concentrations were reduced compared with to growth with either glucos
e or galactose alone. The results of laboratory-stale kinetic experime
nts are discussed with respect to the concentrations observed in natur
al environments.