This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Molchanov, S.
Right arrow Articles by Lahav, O.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Molchanov, S.
Right arrow Articles by Lahav, O.
Agricola
Right arrow Articles by Molchanov, S.
Right arrow Articles by Lahav, O.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, March 2007, p. 1742-1752, Vol. 73, No. 6
0099-2240/07/$08.00+0     doi:10.1128/AEM.01521-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Improved Experimental and Computational Methodology for Determining the Kinetic Equation and the Extant Kinetic Constants of Fe(II) Oxidation by Acidithiobacillus ferrooxidans{triangledown}

Sharon Molchanov, Yuri Gendel, Ilya Ioslvich, and Ori Lahav*

Faculty of Civil and Environmental Engineering, Technion, Haifa 32000, Israel

Received 1 July 2006/ Accepted 6 January 2007

The variety of kinetics expressions encountered in the literature and the unreasonably broad range of values reported for the kinetics constants of Acidithiobacillus ferrooxidans underscore the need for a unifying experimental procedure and for the development of a reliable kinetics equation. Following an extensive and critical review of reported experimental techniques, a method based on batch pH-controlled kinetics experiments lasting less than one doubling time was developed for the determination of extant kinetics constants. The Fe(II) concentration in the experiments was measured by a method insensitive to Fe(III) interference. Kinetics parameters were determined by nonlinear fitting of the integrated form of the Monod equation to yield a KS of 31 ± 4 mg Fe2+ liter–1 (mean ± standard deviation), a KP of 139 ± 20 mg Fe3+ liter–1, and a µmax of 0.082 ± 0.002 h–1. The corresponding kinetics equation was as follows:

Formula
where S represents the Fe(II) concentration in mg liter–1, P0 represents the initial Fe(III) concentration in mg liter–1, X represents the suspended bacterial cell concentration in cells ml–1, and t represents time in hours. The measured data fit this equation exceptionally well, with an R2 of >0.99. Fe(III) inhibition was found to be of a competitive nature. Contrary to previous reports, the results show that the concentration of Acidithiobacillus ferrooxidans cells has no affect on the kinetics constants. The kinetics equation can be considered applicable only to A. ferrooxidans cells grown under environmental conditions similar to those of the inoculum tested in the study. In contrast, the experimental and computational procedure is completely general and can be applied to A. ferrooxidans irrespective of the culture history.

* Corresponding author. Mailing address: Faculty of Civil and Environmental Engineering, Technion, Haifa 32000, Israel. Phone: 972 4 9292191. Fax: 972 4 9228898. E-mail: agori{at}tx.technion.ac.il.

{triangledown} Published ahead of print on 19 January 2007.

Applied and Environmental Microbiology, March 2007, p. 1742-1752, Vol. 73, No. 6
0099-2240/07/$08.00+0     doi:10.1128/AEM.01521-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»