title: Microcalorimetric Investigation of the Toxic Effect of Iron Species on Escherichia coli.
abstract: 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.
authors.affiliation: 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.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.forename: Yanxin
authors.initials: Y
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Tian
authors.forename: Huilun
authors.initials: H
authors.lastname: Chen
authors.forename: Atakora
authors.initials: A
authors.lastname: Djak
authors.forename: Martin M E
authors.initials: MM
authors.lastname: Choi
authors.forename: Janez
authors.initials: J
authors.lastname: Stupar