Identification of Mn(II)-oxidizing bacteria from a low-pH contaminated former uranium mine

Applied and Environmental Microbiology
By: , and 



Biological Mn oxidation is responsible for producing highly reactive and abundant Mn oxide phases in the environment that can mitigate metal contamination. However, little is known about Mn oxidation in low-pH environments, where metal contamination often is a problem as the result of mining activities. We isolated two Mn(II)-oxidizing bacteria (MOB) at pH 5.5 (Duganella isolate AB_14 and Albidiferax isolate TB-2) and nine strains at pH 7 from a former uranium mining site. Isolate TB-2 may contribute to Mn oxidation in the acidic Mn-rich subsoil, as a closely related clone represented 16% of the total community. All isolates oxidized Mn over a small pH range, and isolates from low-pH samples only oxidized Mn below pH 6. Two strains with different pH optima differed in their Fe requirements for Mn oxidation, suggesting that Mn oxidation by the strain found at neutral pH was linked to Fe oxidation. Isolates tolerated Ni, Cu, and Cd and produced Mn oxides with similarities to todorokite and birnessite, with the latter being present in subsurface layers where metal enrichment was associated with Mn oxides. This demonstrates that MOB can be involved in the formation of biogenic Mn oxides in both moderately acidic and neutral pH environments.

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Publication type Article
Publication Subtype Journal Article
Title Identification of Mn(II)-oxidizing bacteria from a low-pH contaminated former uranium mine
Series title Applied and Environmental Microbiology
DOI 10.1128/AEM.01296-14
Volume 80
Issue 16
Year Published 2014
Language English
Publisher American Society for Microbiology
Publisher location Washington, D.C.
Contributing office(s) National Research Program - Eastern Branch
Description 12 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Applied and Environmental Microbiology
First page 5086
Last page 5097
Country Germany
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