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Councell, Terry B.; Landa, Edward R.; Lovley, Derek R.

doi:10.1023/a:1018370423790

Cited by 73 publications

(28 citation statements)

References 22 publications

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“…Possession of both dmsEFAB and mtrCAB gene clusters suggests that these bacteria are capable of reducing IO 3 − extracellularly. This is consistent with the previous observations that in addition to S. oneidensis MR-1, other Shewanella species, such as S. putrefaciens, reduced IO 3 − (Councell et al, 1997;Farrenkorf et al, 1997;Mok et al, 2018;Toporek et al, 2019;Guo et al, 2022;Shin et al, 2022).…”

Section: Resultssupporting

confidence: 92%

Global occurrence of the bacteria with capability for extracellular reduction of iodate

Guo

Jiang²,

Peng³

et al. 2022

Front. Microbiol.

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The γ-proteobacterium Shewanella oneidensis MR-1 reduces iodate to iodide extracellularly. Both dmsEFAB and mtrCAB gene clusters are involved in extracellular reduction of iodate by S. oneidensis MR-1. DmsEFAB reduces iodate to hypoiodous acid and hydrogen peroxide (H2O2). Subsequently, H2O2 is reduced by MtrCAB to facilitate DmsEFAB-mediated extracellular reduction of iodate. To investigate the distribution of bacteria with the capability for extracellular reduction of iodate, bacterial genomes were systematically searched for both dmsEFAB and mtrCAB gene clusters. The dmsEFAB and mtrCAB gene clusters were found in three Ferrimonas and 26 Shewanella species. Coexistence of both dmsEFAB and mtrCAB gene clusters in these bacteria suggests their potentials for extracellular reduction of iodate. Further analyses demonstrated that these bacteria were isolated from a variety of ecosystems, including the lakes, rivers, and subsurface rocks in East and Southeast Asia, North Africa, and North America. Importantly, most of the bacteria with both dmsEFAB and mtrCAB gene clusters were found in different marine environments, which ranged from the Arctic Ocean to Antarctic coastal marine environments as well as from the Atlantic Ocean to the Indian and Pacific Oceans. Widespread distribution of the bacteria with capability for extracellular reduction of iodate around the world suggests their significant importance in global biogeochemical cycling of iodine. The genetic organization of dmsEFAB and mtrCAB gene clusters also varied substantially. The identified mtrCAB gene clusters often contained additional genes for multiheme c-type cytochromes. The numbers of dmsEFAB gene cluster detected in a given bacterial genome ranged from one to six. In latter, duplications of dmsEFAB gene clusters occurred. These results suggest different paths for these bacteria to acquire their capability for extracellular reduction of iodate.

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Section: Resultssupporting

confidence: 92%

Global occurrence of the bacteria with capability for extracellular reduction of iodate

Guo

Jiang²,

Peng³

et al. 2022

Front. Microbiol.

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“…Under NO 3 Ϫ -reducing anaerobic conditions, microorganisms, including the phytoplankton Navicula and the bacteria Pseudomonas sp. strain SCT, Agrobacterium-related strain DVZ35, and Escherichia coli, reduce IO 3 Ϫ to I Ϫ , which led to the hypothesis that NO 3 Ϫ reductase reduces IO 3 Ϫ as an alternative terminal electron acceptor (6,7,30,32,45,46). The IO 3 Ϫ -reducing NO 3 Ϫ reductase hypothesis was recently brought into question, however, by findings with S. oneidensis, which demonstrated that NO 3 Ϫ and IO 3…”

Section: Discussionmentioning

confidence: 99%

“…reduction is a major component of the iodine biogeochemical reaction network (1)(2)(3). In marine environments, microbial IO 3 Ϫ reduction is the primary mechanism for IO 3 Ϫ reduction to I Ϫ (4)(5)(6)(7)(8). Microbial IO 3 Ϫ reduction has also attracted interest as a component of alternative strategies for remediation of waters and sediments contaminated with radioactive iodine released to the environment (9).…”

mentioning

confidence: 99%

Metal Reduction and Protein Secretion Genes Required for Iodate Reduction by Shewanella oneidensis

Toporek

Mok

Shin

et al. 2019

Appl Environ Microbiol

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The metal-reducing gammaproteobacterium Shewanella oneidensis reduces iodate (IO 3 Ϫ ) as an anaerobic terminal electron acceptor. Microbial IO 3 Ϫ electron transport pathways are postulated to terminate with nitrate (NO 3 Ϫ ) reductase, which reduces IO 3 Ϫ as an alternative electron acceptor. Recent studies with S. oneidensis, however, have demonstrated that NO 3Ϫ reductase is not involved in IO 3 Ϫ reduction. The main objective of the present study was to determine the metal reduction and protein secretion genes required for IO 3 Ϫ reduction by Shewanella oneidensis with lactate, formate, or H 2 as the electron donor. With all electron donors, the type I and type V protein secretion mutants retained wild-type IO 3Ϫ reduction activity, while the type II protein secretion mutant lacking the outer membrane secretin GspD was impaired in IO 3 Ϫ reduction. Deletion mutants lacking the cyclic AMP receptor protein (CRP), cytochrome maturation permease CcmB, and inner membrane-tethered c-type cytochrome CymA were impaired in IO 3Ϫ reduction with all electron donors, while deletion mutants lacking c-type cytochrome MtrA and outer membrane ␤-barrel protein MtrB of the outer membrane MtrAB module were impaired in IO 3Ϫ reduction with only lactate as an electron donor. With all electron donors, mutants lacking the c-type cytochromes OmcA and MtrC of the metalreducing extracellular electron conduit MtrCAB retained wild-type IO 3 Ϫ reduction activity. These findings indicate that IO 3 Ϫ reduction by S. oneidensis involves electron donor-dependent metal reduction and protein secretion pathway components, including the outer membrane MtrAB module and type II protein secretion of an unidentified IO 3 Ϫ reductase to the S. oneidensis outer membrane.IMPORTANCE Microbial iodate (IO 3 Ϫ ) reduction is a major component in the biogeochemical cycling of iodine and the bioremediation of iodine-contaminated environments; however, the molecular mechanism of microbial IO 3 Ϫ reduction is poorly understood. Results of the present study indicate that outer membrane (type II) protein secretion and metal reduction genes encoding the outer membrane MtrAB module of the extracellular electron conduit MtrCAB are required for IO 3 Ϫ reduction by S. oneidensis. On the other hand, the metal-reducing c-type cytochrome MtrC of the extracellular electron conduit is not required for IO 3 Ϫ reduction by S. oneidensis. These findings indicate that the IO 3 Ϫ electron transport pathway terminates with an as yet unidentified IO 3Ϫ reductase that associates with the outer membrane MtrAB module to deliver electrons extracellularly to IO 3 Ϫ .

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“…Indeed, it has been observed that for IO 3 − concentrations lower than 6.67 mM, iodate ions had a significant impact on bacteria metabolism and for higher concentrations, a cellular lysis occurred as well as growth inhibition. However, some specific microorganisms such as Shewanella oneidensis (Toporek et al, 2019), Shewanella putrifaciens, and Desulfovibrio desulfuricans (Councell et al, 1997) are able to use iodate ion as final electron acceptor in anaerobic conditions. In the anoxic conditions of the biological treatment performed in this study, it is difficult to specify the impact of iodate ions on the microbial culture.…”

Section: Biological Treatmentmentioning

confidence: 99%

Electrochemical Processes Coupled to a Biological Treatment for the Removal of Iodinated X-ray Contrast Media Compounds

et al. 2020

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Untitled

Cited by 73 publications

References 22 publications

Global occurrence of the bacteria with capability for extracellular reduction of iodate

Global occurrence of the bacteria with capability for extracellular reduction of iodate

Metal Reduction and Protein Secretion Genes Required for Iodate Reduction by Shewanella oneidensis

Electrochemical Processes Coupled to a Biological Treatment for the Removal of Iodinated X-ray Contrast Media Compounds

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