Biotic and abiotic products of Mn(II) oxidation by spores of the marine<i>Bacillus sp.</i>strain SG-1

Bargar, John R.; Tebo, Bradley M.; Bergmann, Uwe; Webb, Samuel M.; Glatzel, Pieter; Chiu, Van Q.; Villalobos, Mario

doi:10.2138/am.2005.1557

Cited by 247 publications

(238 citation statements)

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“…Other spectra attempted as references included: d-MnO 2 , synthetic manganite (c-MnOOH), groutite (a-MnOOH), synthetic feitknechtite (b-MnOOH), bixbyite ((Mn,Fe) 2 O 3 ), synthetic hausmannite (Mn 3 O 4 ), pyrolusite (b-MnO 2 , Aldrich), nsutite (c-MnO 2 , Nsuta, Ghana), and synthetic todorokite ((Na,Ca,K)(Mg,Mn)Mn 6 O 14 Á5H 2 O). Synthesis/ origin and identification of reference spectra were described in detail previously (Villalobos et al, 2003;Bargar et al, 2005). Estimated standard deviations (ESDs) for fits to Mn K-edge data were obtained by analysis of transmission spectra measured from a series of well defined mixtures of MnSO 4 , Mn 2 O 3 , and d-MnO 2 , diluted and homogenized into a LiCO 3 matrix.…”

Section: Xanes and Exafs Spectroscopymentioning

confidence: 99%

“…(Bargar et al, 2005;Webb et al, 2005a). It has also been proposed that Mn(III) produced enzymatically or via excitation of photoactive ligand-Mn(II) complexes may disproportionate to Mn(II) and Mn(IV), the latter polymerizing to form Mn(IV) (Hansel and Francis, 2006).…”

Section: Stability Of Pinal Creek Biogenic Mn Oxides: Constraints Onmentioning

confidence: 99%

“…However, laboratory-produced bacteriogenic Mn oxides are reactive and may transform into abiotic secondary Mn oxides in the presence of the common solutes (e.g., Bargar et al, 2005;Webb et al, 2005a). The assertion that ''primary" biogenic Mn oxides dominate Mn oxide chemistry in aquatic environments thus remains open to testing.…”

Section: Introductionmentioning

confidence: 99%

“…X-ray diffraction and EXAFS spectroscopy measurements of bacteriogenic Mn oxides produced by the common soil and freshwater bacterium, Pseudomonas putida, MnB1, show these materials to be a poorly-crystalline birnessite-like layered Mn oxide having hexagonal symmetry and containing only edge-sharing Mn 4+ O 6 octahedra, with one-sixth of the cation (Mn 4+ ) sites vacant (Villalobos et al, 2003(Villalobos et al, , 2006. Similarly, Mn biooxides produced by the marine bacterium, Bacillus sp., strain SG-1, were found to be layered Mn oxides possessing hexagonal layer symmetry with abundant layer Mn(IV) site vacancies (Bargar et al, 2005;Webb et al, 2005b,c). It was posited that protons, Mn 3+ , and Mn 2+ bonded to the sheets above or below these vacancy sites, along with solvated interlayer cations, help to balance charge.…”

Section: Introductionmentioning

confidence: 99%

“…Following reaction with solutes such as Mn 2+ or Ca 2+ , SG-1 biooxides showed increased stacking and in-plane layer ordering (Bargar et al, 2005;Webb et al, 2005b,c), indicating that these solutes were reacting with the biooxides to produce more crystalline products. It can thus be concluded that, in sea water, SG-1 biooxides exhibited a strong affinity for Ca 2+ as the interlayer cation, in spite of the fact that Mg 2+ is present at higher concentration.…”

Section: Introductionmentioning

confidence: 99%

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Structural characterization of terrestrial microbial Mn oxides from Pinal Creek, AZ

Bargar

Fuller

Marcus

et al. 2009

Geochimica et Cosmochimica Acta

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110

106

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The microbial catalysis of Mn(II) oxidation is believed to be a dominant source of abundant sorption-and redox-active Mn oxides in marine, freshwater, and subsurface aquatic environments. In spite of their importance, environmental oxides of known biogenic origin have generally not been characterized in detail from a structural perspective. Hyporheic zone Mn oxide grain coatings at Pinal Creek, Arizona, a metals-contaminated stream, have been identified as being dominantly microbial in origin and are well studied from bulk chemistry and contaminant hydrology perspectives. This site thus presents an excellent opportunity to study the structures of terrestrial microbial Mn oxides in detail. XRD and EXAFS measurements performed in this study indicate that the hydrated Pinal Creek Mn oxide grain coatings are layer-type Mn oxides with dominantly hexagonal or pseudo-hexagonal layer symmetry. XRD and TEM measurements suggest the oxides to be nanoparticulate plates with average dimensions on the order of 11 nm thick Â 35 nm diameter, but with individual particles exhibiting thickness as small as a single layer and sheets as wide as 500 nm. The hydrated oxides exhibit a 10-Å basal-plane spacing and turbostratic disorder. EXAFS analyses suggest the oxides contain layer Mn(IV) site vacancy defects, and layer Mn(III) is inferred to be present, as deduced from Jahn-Teller distortion of the local structure. The physical geometry and structural details of the coatings suggest formation within microbial biofilms. The biogenic Mn oxides are stable with respect to transformation into thermodynamically more stable phases over a time scale of at least 5 months. The nanoparticulate layered structural motif, also observed in pure culture laboratory studies, appears to be characteristic of biogenic Mn oxides and may explain the common occurrence of this mineral habit in soils and sediments.

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Section: Xanes and Exafs Spectroscopymentioning

confidence: 99%

Section: Stability Of Pinal Creek Biogenic Mn Oxides: Constraints Onmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Structural characterization of terrestrial microbial Mn oxides from Pinal Creek, AZ

Bargar

Fuller

Marcus

et al. 2009

Geochimica et Cosmochimica Acta

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110

106

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Manganese Cycling in the Oceans

Tebo

Luther

2019

Encyclopedia of Water

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Manganese (Mn) is an essential element for life. Although its concentration is at (sub)nanomolar levels throughout the ocean, it affects the oxygen concentration of the ocean because it is central to the photosynthetic formation of dioxygen, O 2 , in photosystem center II. Mn inputs into the ocean are from atmospheric transport of particles and their dissolution to form dissolved Mn, and from the flux of dissolved Mn from rivers, sediments, and hydrothermal vents. The main removal mechanism is transport of particulate Mn from dust and organic matter to the sediments. The environmental chemistry of manganese centers on its +2, +3, and +4 oxidation states. Most recent data show that Mn(II) is dissolved, that Mn(IV) is particulate MnO 2 , and that Mn(III) can be particulate or dissolved when bound to organic complexes [denoted as Mn(III)‐L]. Mn(II) is oxidized primarily by microbial processes whereas MnO 2 is reduced by abiotic and biotic processes. Photochemical processing aids redox cycling in surface waters. In suboxic zones, which are defined as areas where both dissolved O 2 and H 2 S concentrations are below 3 μM, both oxidation and reduction processes can occur but usually at different depths. In suboxic zones, dissolved Mn is also released from organic matter during its decomposition and from MnO 2 reduction.

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Tunable Biogenic Manganese Oxides

Simonov

Hocking

Tao

et al. 2017

Chemistry A European J

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Influence of the conditions for aerobic oxidation of Mn2+(aq) catalysed by the MnxEFG protein complex on the morphology, structure and reactivity of the resulting biogenic manganese oxides (MnO ) is explored. Physical characterisation of MnO includes scanning and transmission electron microscopy, and X-ray photoelectron and K-edge Mn, Fe X-ray absorption spectroscopy. This characterisation reveals that the MnO materials share the structural features of birnessite, yet differ in the degree of structural disorder. Importantly, these biogenic products exhibit strikingly different morphologies that can be easily controlled. Changing the substrate-to-protein ratio produces MnO either as nm-thin sheets, or rods with diameters below 20 nm, or a combination of the two. Mineralisation in solutions that contain Fe2+(aq) makes solids with significant disorder in the structure, while the presence of Ca2+(aq) facilitates formation of more ordered materials. The (photo)oxidation and (photo)electrocatalytic capacity of the MnO minerals is examined and correlated with their structural properties.

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Biotic and abiotic products of Mn(II) oxidation by spores of the marineBacillus sp.strain SG-1

Cited by 247 publications

References 42 publications

Structural characterization of terrestrial microbial Mn oxides from Pinal Creek, AZ

Structural characterization of terrestrial microbial Mn oxides from Pinal Creek, AZ

Manganese Cycling in the Oceans

Tunable Biogenic Manganese Oxides

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