Microbiological oxidation of antimony(III) with oxygen or nitrate by bacteria isolated from contaminated mine sediments

Applied and Environmental Microbiology
By: , and 

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Abstract

Bacterial oxidation of arsenite [As(III)] is a well-studied and important biogeochemical pathway that directly influences the mobility and toxicity of arsenic in the environment. In contrast, little is known about microbiological oxidation of the chemically similar anion antimonite [Sb(III)]. In this study, two bacterial strains, designated IDSBO-1 and IDSBO-4, which grow on tartrate compounds and oxidize Sb(III) using either oxygen or nitrate, respectively, as a terminal electron acceptor, were isolated from contaminated mine sediments. Both isolates belonged to the Comamonadaceae family and were 99% similar to previously described species. We identify these novel strains as Hydrogenophagataeniospiralis strain IDSBO-1 and Variovorax paradoxus strain IDSBO-4. Both strains possess a gene with homology to the aioA gene, which encodes an As(III)-oxidase, and both oxidize As(III) aerobically, but only IDSBO-4 oxidized Sb(III) in the presence of air, while strain IDSBO-1 could achieve this via nitrate respiration. Our results suggest that expression of aioA is not induced by Sb(III) but may be involved in Sb(III) oxidation along with an Sb(III)-specific pathway. Phylogenetic analysis of proteins encoded by the aioA genes revealed a close sequence similarity (90%) among the two isolates and other known As(III)-oxidizing bacteria, particularly Acidovorax sp. strain NO1. Both isolates were capable of chemolithoautotrophic growth using As(III) as a primary electron donor, and strain IDSBO-4 exhibited incorporation of radiolabeled [14C]bicarbonate while oxidizing Sb(III) from Sb(III)-tartrate, suggesting possible Sb(III)-dependent autotrophy. Enrichment cultures produced the Sb(V) oxide mineral mopungite and lesser amounts of Sb(III)-bearing senarmontite as precipitates.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Microbiological oxidation of antimony(III) with oxygen or nitrate by bacteria isolated from contaminated mine sediments
Series title Applied and Environmental Microbiology
DOI 10.1128/AEM.01970-15
Volume 81
Issue 24
Year Published 2015
Language English
Publisher American Society for Microbiology
Publisher location Washington, D.C.
Contributing office(s) National Research Program - Western Branch
Description 11 p.
First page 8478
Last page 8488
Country United States
State Idaho
Other Geospatial Stibnite/Yellow Pine mining area
Online Only (Y/N) N
Additional Online Files (Y/N) N