Inter-relationships of MnO2 precipitation, siderophore–Mn(III) complex formation, siderophore degradation, and iron limitation in Mn(II)-oxidizing bacterial cultures

Parker, Dorothy L.; Morita, Takami; Mozafarzadeh, Mylene L.; Verity, Rebecca; McCarthy, James K.; Tebo, Bradley M.

doi:10.1016/j.gca.2007.03.042

Cited by 58 publications

(74 citation statements)

References 34 publications

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“…It is likely that the observed phenomenon is the result of a contribution from all four factors. There may be protection from scavenging by complexation for manganese as well, though little is known about the susceptibility of ligand-bound Mn(III) to bacterial manganese oxidation (Parker et al 2007). …”

Section: Discussionmentioning

confidence: 99%

“…The biotic oxidation of manganese and cobalt by manganese-oxidizing bacteria is thought to be an important removal mechanism for these two metals (Tebo et al 1984;Moffett and Ho 1996). Complexation by organic ligands is thought to protect iron and cobalt from scavenging to some degree (Johnson et al 1997;Saito and Moffett 2001), and recent work has suggested that manganese may also be complexed by some marine siderophores (Parker et al 2007), although the influence of complexation on manganese scavenging is still largely unknown.…”

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confidence: 99%

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Basin‐scale inputs of cobalt, iron, and manganese from the Benguela‐Angola front to the South Atlantic Ocean

Noble

Lamborg

Ohnemus

et al. 2012

Limnology & Oceanography

147

193

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We present full-depth zonal sections of total dissolved cobalt, iron, manganese, and labile cobalt from the South Atlantic Ocean. A basin-scale plume from the African coast appeared to be a major source of dissolved metals to this region, with high cobalt concentrations in the oxygen minimum zone of the Angola Dome and extending 2500 km into the subtropical gyre. Metal concentrations were elevated along the coastal shelf, likely due to reductive dissolution and resuspension of particulate matter. Linear relationships between cobalt, N 2 O, and O 2 , as well as low surface aluminum supported a coastal rather than atmospheric cobalt source. Lateral advection coupled with upwelling, biological uptake, and remineralization delivered these metals to the basin, as evident in two zonal transects with distinct physical processes that exhibited different metal distributions. Scavenging rates within the coastal plume differed for the three metals; iron was removed fastest, manganese removal was 2.5 times slower, and cobalt scavenging could not be discerned from water mass mixing. Because scavenging, biological utilization, and export constantly deplete the oceanic inventories of these three hybrid-type metals, point sources of the scale observed here likely serve as vital drivers of their oceanic cycles. Manganese concentrations were elevated in surface waters across the basin, likely due to coupled redox processes acting to concentrate the dissolved species there. These observations of basin-scale hybrid metal plumes combined with the recent projections of expanding oxygen minimum zones suggest a potential mechanism for effects on ocean primary production and nitrogen fixation via increases in trace metal source inputs.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Basin‐scale inputs of cobalt, iron, and manganese from the Benguela‐Angola front to the South Atlantic Ocean

Noble

Lamborg

Ohnemus

et al. 2012

Limnology & Oceanography

147

193

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“…One previously reported reason for the reduction of Mn(II) oxidation under iron-limiting conditions is the presence of a Mn(III)-binding siderophore, such as pyoverdine, which has been shown to preferentially bind Mn(III) and retard Mn(IV) oxide formation (29,30). This did not appear to explain our observations, however, as a common siderophore detection assay did not detect the production of any siderophore (indicating that the siderophore level was Ͻ0.8 M) from L. discophora SS-1 under iron-limited conditions.…”

Section: Discussionmentioning

confidence: 99%

“…Parker et al (30) observed that retarded Mn(IV) formation by iron-starved P. putida is a consequence of the binding of the Mn(III) intermediate (42) to the siderophore pyoverdine. Therefore, siderophore production was also evaluated as part of this research.…”

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confidence: 99%

Iron Requirement for Mn(II) Oxidation by Leptothrix discophora SS-1

Gheriany¹,

Bocioaga²,

Hay³

et al. 2009

Appl Environ Microbiol

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The biological catalysis of Mn(II) oxidation is thought to be responsible for the formation of most naturally occurring insoluble Mn(III, IV) oxides (40, 41) and consequently plays a key role in the biogeochemical cycling of Mn. The resulting biogenic Mn oxides have high adsorptive capacities for toxic metals (16, 17) and can oxidize both natural organic compounds (38) and organic contaminants (36). The binding of transition metals to biogenic Mn oxides can, in turn, greatly affect the phase distributions and residence times of these transition metals in many natural systems (16,17). An understanding of environmental conditions that favor or inhibit the production of the extracellular enzyme responsible for Mn(II) oxidation will contribute to insight into this important ecological process and is also a prerequisite for the design of any successful technology that uses microorganisms for the production of Mn oxides.A variety of phylogenetically distinct microorganisms are capable of the extracellular oxidation of Mn(II) (5). Based on the presence of conserved predicted amino acid motifs, the genes that encode putative Mn(II)-oxidizing enzymes (mofA in Leptothrix discophora [9], cumA in Pseudomonas putida GB-1 [7], and moxA in Pedomicrobium sp. strain ACM 3067 [33]) are all thought to produce multicopper oxidases. Recently, further support for the role of putative multicopper oxidases in Mn(II) oxidation has come from the recovery and sequencing of peptides excised from Mn(II)-oxidizing bands in polyacrylamide gel analyses of proteins from three Mn(II)-oxidizing Bacillus species (15). Specifically, Mn(II)-oxidizing bands from the exosporia of two of the three Bacillus species tested were shown by tandem mass spectrometric analyses to contain peptides with homology to the predicted C terminus of the putative multicopper Mn(II) oxidase MnxG.Despite this growing body of evidence regarding the role of multicopper oxidases in Mn(II) oxidation, little is known about how the concentrations of different nutrients (e.g., iron, carbon, and nitrogen) or growth conditions such as pH and the oxygen concentration regulate the production of the enzyme(s) which oxidizes Mn(II). Nelson et al. (26) evaluated the minimal growth conditions needed for Mn(II) oxidation and found that the addition of 0.1 M Fe(II) to the defined minimal mineral salt (MMS) medium used for growth was necessary for the complete oxidation of Mn(II) by L. discophora SS-1; however, adding 0.1 M Fe(II) to stationary-phase cells did not allow complete Mn(II) oxidation.In the present study, we grew L. discophora SS-1 in a controlled-reactor system and evaluated the time courses of Mn(II) oxidation and mofA transcript levels in batch cultures of cells with limited and sufficient iron. Parker et al. (30) observed that retarded Mn(IV) formation by iron-starved P. putida is a consequence of the binding of the Mn(III) intermediate (42) to the siderophore pyoverdine. Therefore, siderophore production was also evaluated as part of this research. MATERIALS AND METHODS...

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“…3A) showed an enrichment of Mn in the bacterial biomass both with and without Fe in the medium, suggesting that secondary abiotic oxidation of Mn was not occurring. However, the model Mn(II) oxidizer P. putida GB-1 uses different pathways for Mn oxidation, depending on iron availability (60,61). Under iron-replete conditions, enzymatic Mn oxidation is hypothesized to predominate, whereas under iron-limited conditions siderophore production is linked to abiotic oxidation (61).…”

Section: Actinobacteriamentioning

confidence: 99%

Identification of Mn(II)-Oxidizing Bacteria from a Low-pH Contaminated Former Uranium Mine

Akob

Bohu

Beyer

et al. 2014

Appl Environ Microbiol

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e 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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Inter-relationships of MnO2 precipitation, siderophore–Mn(III) complex formation, siderophore degradation, and iron limitation in Mn(II)-oxidizing bacterial cultures

Cited by 58 publications

References 34 publications

Basin‐scale inputs of cobalt, iron, and manganese from the Benguela‐Angola front to the South Atlantic Ocean

Basin‐scale inputs of cobalt, iron, and manganese from the Benguela‐Angola front to the South Atlantic Ocean

Iron Requirement for Mn(II) Oxidation by Leptothrix discophora SS-1

Identification of Mn(II)-Oxidizing Bacteria from a Low-pH Contaminated Former Uranium Mine

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