Role of iron in azoreduction by resting cells of Shewanella decolorationis S12.

X Chen, G Sun, M Xu

Index: J. Appl. Microbiol. 110(2) , 580-6, (2011)

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Abstract

To investigate the role of soluble and insoluble iron in azoreduction by resting cells of Shewanella decolorationis S12.A series of analytical experiments were carried out. Results showed that insoluble Fe(2) O(3) all delayed the reduction of amaranth but did not inhibit it. Adsorption to Fe(2) O(3) particles by the bacterial cell surface could be the reason leading to the delay in azoreduction. For the soluble iron, an important finding was that azoreduction activities were inhibited by soluble iron in high concentration because of its higher redox potential, and the inhibition was strengthened when the electron donor supply was insufficient. However, activities of azoreduction could be enhanced by low concentration of soluble iron. This stimulating effect was because of the electron transfer but not the cell growth.The effects of iron on azoreduction by the resting cells depended on the solubility and concentration of the iron compounds, which was different from what was observed by the growing cells in the previous studies.This study has both theoretical significance in the microbial physiology and practical significance in the bioremediation of azo dyes-contaminated environment.© 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.