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Published November 1986 | public
Journal Article

Kinetics and mechanism of dissimilative Fe(III) reduction by Pseudomonas sp. 200

Abstract

The kinetics and mechanism of Fe(III) reduction to Fe(II) were studied in pure batch cultures of Pseudomonas sp. 200. The rate of iron reduction has been mechanistically related to aqueous phase iron speciation. In the absence of microbial activity the iron reduction rate was negligible. Initial rates of microbial iron reduction were accelerated more than 20-fold by the addition of equimolar quantities of nitrilotriacetic acid (NTA) to media initially containing 1.86 × 10^(−3)M total Fe(III). Numerical techniques were utilized to quantify relationships between the observed rate of Fe(II) production and the calculated (equilibrium) aqueous phase speciation. These results indicate that soluble ferric iron species are not equivalent in terms of their susceptibility to bacterial (dissimilative) iron reduction. The concentration of Fe(NTA)(OH)math image correlated strongly with observed iron reduction rates. Ferrous iron species appeared to inhibit the reduction process.

Additional Information

© 1986 John Wiley & Sons, Inc. Accepted for publication December 13, 1985. The authors gratefully acknowledge Dr. D. W. S. Westlake of the Department of Microbiology, University of Alberta, Canada, for generously providing the microorganism used in this study, Pseudomonas sp. 200. This work was supported by U.S. Department of Energy Contract No. DE-AS03-83ER13125 administered within the Division of Advanced Energy Projects, Office of Basic Energy Sciences. We appreciate the support and encouragement of Drs. Ryszard Gajewski and Duane L. Barney. Thanks to Ms. Sandy Brooks and Ms. Nancy Tomer for clerical and drafting assistance in preparation of our manuscript.

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023