Production of a molybdophore during metal-targeted dissolution of silicates by soil bacteria

Liermann, Laura J.; Guynn, R. L.; Anbar, Ariel D.; Brantley, Susan L.

doi:10.1016/j.chemgeo.2005.04.013

Cited by 82 publications

(88 citation statements)

References 46 publications

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“…Second, Mo could have been made more bioavailable in Precambrian seawater if it was organically complexed by molybdophores or molybdate-binding siderophores, which are known to be excreted by some diazotrophs (Bellenger et al, 2008;Duhme et al, 1996;Liermann et al, 2005). The evolutionary history of molybdophores is unknown, but they could have facilitated Mo weathering (Liermann et al, 2005) as well as uptake from the water column (Duhme et al, 1996). In addition, organisms may have expressed enzymatic adaptations to facilitate Mo uptake and storage in the their cells (Glass et al, 2013).…”

Section: Was Molybdenum a Limiting Constituent In Nitrogen Metabolisms?mentioning

confidence: 99%

The evolution of Earth's biogeochemical nitrogen cycle

Stüeken

Kipp

Koehler

et al. 2016

Earth-Science Reviews

308

287

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Nitrogen is an essential nutrient for all life on Earth and it acts as a major control on biological productivity in the modern ocean. Accurate reconstructions of the evolution of life over the course of the last four billion years therefore demand a better understanding of nitrogen bioavailability and speciation through time. The biogeochemical nitrogen cycle has evidently been closely tied to the redox state of the ocean and atmosphere. Multiple lines of evidence indicate that the Earth"s surface has passed in a non-linear fashion from an anoxic state in the Hadean to an oxic state in the later Phanerozoic. It is therefore likely that the nitrogen cycle has changed markedly over time, with potentially severe implications for the productivity and evolution of the biosphere. Here we compile nitrogen isotope data from the literature and review our current understanding of the evolution of the nitrogen cycle, with particular emphasis on the Precambrian. Combined with recent work on redox conditions, trace metal availability, sulfur and iron cycling on the early Earth, we then use the nitrogen isotope record as a platform to test existing and new hypotheses about biogeochemical pathways that may have controlled nitrogen availability through time. Among other things, we conclude that (a) abiotic nitrogen sources were likely insufficient to sustain a large biosphere, thus favoring an early origin of biological N 2 fixation, (b) evidence of nitrate in the Neoarchean and Paleoproterozoic confirm current views of increasing surface oxygen levels at those times, (c) abundant ferrous iron and sulfide in the midPrecambrian ocean may have affected the speciation and size of the fixed nitrogen reservoir, and (d) nitrate availability alone was not a major driver of eukaryotic evolution.

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Section: Was Molybdenum a Limiting Constituent In Nitrogen Metabolisms?mentioning

confidence: 99%

The evolution of Earth's biogeochemical nitrogen cycle

Stüeken

Kipp

Koehler

et al. 2016

Earth-Science Reviews

308

287

View full text Add to dashboard Cite

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“…and -1.0‰ in cells relative to the surrounding solution (Liermann et al, 2005;Wasylenki et al, 2007;Zerkle et al, 2011), but the importance of this mechanism to bulk soil  98 Mo values is not known.…”

Section: Role Of Biologymentioning

confidence: 99%

Molybdenum isotope fractionation in soils: Influence of redox conditions, organic matter, and atmospheric inputs

Siebert

Pett-Ridge

Opfergelt

et al. 2015

Geochimica et Cosmochimica Acta

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“…Some of these substances include enzymes, alcohols, low molecular weight organic 85 acids (LMWOA), high molecular weight extracellular polymeric substances (EPS), and highly 86 Fe(III)-specific ligands called siderophores. Some high affinity ligands may also be released to 87 extract other metals (e.g., Liermann et al, 2005). 88…”

Section: Surface Colonization 51mentioning

confidence: 99%

Etch pit formation on iron silicate surfaces during siderophore-promoted dissolution

2007

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Understanding the effects of microbiota on mineral alteration requires the ability to recognize evidence of bacteria-promoted dissolution on mineral surfaces. Although siderophores are known to promote mineral dissolution, their effects on mineral surfaces are not well known. We have utilized atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Mirau vertical scanning interferometry (VSI) to investigate surfaces after incubation with the siderophore desferrioxamine-B mesylate (DFAM) and under colonies of bacteria. Iron-silicate glass planchets chemically similar to hornblende were incubated in buffered growth medium with siderophore-producing bacteria (Bacillus sp.) for 46 days with parallel abiotic experiments conducted with and without 240 μM DFAM, with and without 0.01 g/l of microbially produced extracellular polysaccharides (EPS, alginate or xanthan gum). Some glass planchets were protected by dialysis tubing from direct contact with the EPS. Weekly sampling and analysis of all filtered sample solutions showed negligible Fe and Al release in the control experiments and significant release of Fe and Al in the presence of DFAM, with negligible changes in pH. Concentration of Fe in the filtered solutions after incubation with bacteria was below detection, consistent with uptake of Fe by cells. Release of Fe, Al, and Si in control, xanthan-only, and alginate-only experiments was negligible. Release of these elements was enhanced in all experiments containing DFAM, and greatest in alginate + DFAM experiments. AFM and VSI analyses reveal widespread, small etch pits and greater root mean squared roughness on siderophore-exposed surfaces and fewer, localized, larger etch pits on bacteria-exposed surfaces. This is the first documented case of etch pit development during siderophore-promoted dissolution. Roughness was not affected by growth medium or alginate or xanthan gum alone. The roughness trends among samples correlate with trends in Fe depletion documented by XPS. Enhanced dissolution and roughness cannot be attributed to direct contact with EPS because no significant chemical or physical differences were observed between surfaces directly exposed to EPS and those protected by dialysis tubing. Acetate released from the EPS may have enhanced the siderophore-promoted dissolution. Siderophores produced by Bacillus sp. may be responsible for some of the 'biopits.' The difference in size and distribution of the biopits may be related to colonization. AFM and VSI analyses reveal widespread, small etch pits and greater root mean squared 36 roughness on siderophore-exposed surfaces and fewer, localized, larger etch pits on bacteria-37 exposed surfaces. This is the first documented case of etch pit development during siderophore-38 promoted dissolution. Roughness was not affected by the growth medium, alginate, or xanthan 39 gum alone. The roughness trends among samples correlate with trends in Fe depletion 40 2 documented by XPS. Enhanced dissolution and roughness cannot be attributed t...

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Production of a molybdophore during metal-targeted dissolution of silicates by soil bacteria

Cited by 82 publications

References 46 publications

The evolution of Earth's biogeochemical nitrogen cycle

The evolution of Earth's biogeochemical nitrogen cycle

Molybdenum isotope fractionation in soils: Influence of redox conditions, organic matter, and atmospheric inputs

Etch pit formation on iron silicate surfaces during siderophore-promoted dissolution

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