Microcalorimetric Investigation of the Toxic Effect of Iron Species on Escherichia coli.
ABSTRACT A microcalorimetric technique based on bacterial heat output was explored to evaluate the toxic effect of iron species on Escherichia coli. Power-time curves of the growth metabolism of E. coli and the effect of different iron species on it were studied using the TAM III multichannel microcalorimetric system, isothermal mode, at 37 degrees C. The differences in shape of the power-time curves and the thermodynamic and kinetic characteristics of E. coli growth have been compared. The thermodynamic parameters, that is, growth rate constant (k), inhibitory ratio (I), half-inhibitory concentration (IC(50)), P(max), and Q(total), have been calculated. The experimental results reveal that the sequence of antibiotic activity of the different iron species (three forms) on E. coli growth is Fe(3+) (ferric citrate) > Fe(2+) (ferrous chloride) > Fe(3+) (ferric chloride). These results are important to further studies of the physiology and pharmacology of iron species as antibacterial agents.
Wang
Fei
F
School of Environmental Studies & Key Laboratory of Biogeology and Environmental Geology of Chinese Ministry of Education, China University of Geosciences, Wuhan, 430074, P. R. China.
Yao
Jun
J
Wang
Yanxin
Y
Tian
Lin
L
Chen
Huilun
H
Djak
Atakora
A
Choi
Martin M E
MM
Stupar
Janez
J