Limitations to a microbial iron cycle on Mars

Nixon, Sophie L.; Cockell, Charles S.; Tranter, Martyn

doi:10.1016/j.pss.2012.04.003

Cited by 31 publications

(24 citation statements)

References 196 publications

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“…Nixon et al [106] discuss the available electron acceptors for iron reduction and conclude that a range of meteoritic organics could be plausible electron donors for iron reduction in the surface and near-surface of Mars. The use of ferrous iron as an electron donor, given the large resources of ferrous-bearing minerals such as olivines, seems plausible.…”

Section: Redox Couplesmentioning

confidence: 99%

11. The subsurface habitability of terrestrial rocky planets: Mars

Cockell¹

2014

Microbial Life of the Deep Biosphere

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Section: Redox Couplesmentioning

confidence: 99%

11. The subsurface habitability of terrestrial rocky planets: Mars

Cockell¹

2014

Microbial Life of the Deep Biosphere

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“…Several terrestrial environments where microbially driven Fe(III) reduction processes occur (Léveillé, 2009;Rothschild and Mancinelli, 2001) have been identified, such as Rio Tinto (SW Spain), Western Australian salt lake sediments (SW, Australia) and Ten Graben fault system of Green River (Utah, USA), have been proposed as terrestrial analogues to the types of conditions on Mars where iron cycling could have taken place (Nixon et al, 2012;Ruecker et al, 2016). These terrestrial analog systems allude to the existence of Fe(III)oxyhydroxide bio-signatures and fossilized microorganisms, with Fe(III)-oxyhydroxides susceptible to recrystallization to more stable forms (Léveillé, 2009;Nixon et al, 2012;Parenteau et al, 2014;Ruecker et al, 2016). Utilizing Laboratory studies and natural analogues can be used to help identify bio-signatures preserved from the past (NASA´s Mars…”

Section: Introductionmentioning

confidence: 99%

Abiotic versus biotic iron mineral transformation studied by a miniaturized backscattering Mössbauer spectrometer (MIMOS II), X-ray diffraction and Raman spectroscopy

Markovski

Byrne

Lalla

et al. 2017

Icarus

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Searching for biomarkers or signatures of microbial transformations of minerals is a critical aspect for determining how life evolved on Earth, and whether or not life may have existed in other planets, including Mars. In order to solve such questions, several missions to Mars have sought to determine the geochemistry and mineralogy on the Martian surface. This research includes the two miniaturized Mössbauer spectrometers (MIMOS II) on board the Mars Exploration Rovers Spirit and Opportunity, which have detected a variety of iron minerals on Mars, including magnetite (Fe 2+Fe3+2O4) and goethite (α-FeO(OH)). On Earth, both minerals can derive from microbiological activity (e.g. through dissimilatory iron reduction of ferrihydrite by Fe(III)-reducing bacteria). Here we used a lab based MIMOS II to characterize the mineral products of biogenic transformations of ferrihydrite to magnetite by the Fe(III)-reducing bacteria Geobacter sulfurreducens. In combination with Raman spectroscopy and X-ray diffraction (XRD), we observed the formation of magnetite, goethite and siderite. We compared the material produced by biogenic transformations to abiotic samples in order to distinguish abiotic and biotic iron minerals by techniques that are or will be available onboard Martian based laboratories. The results showed the possibility to distinguish the abiotic and biotic origin of the minerals. Mossbauer was able to distinguish the biotic/abiotic magnetite with the interpretation of the geological context (Fe content mineral assemblages and accompanying minerals) and the estimation of the particle size in a non-destructive way. The Raman was able to confirm the biotic/abiotic principal peaks of the magnetite, as well as the organic principal vibration bands attributed to the bacteria. Finally, the XRD confirmed the particle size and mineralogy

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“…The meaning and method for assigning oxidation states continues to be debated and discussed (Gupta Karen et al, 2014), but for now we still employ the IUPACrecommended convention (McNaught and Wilkinson, 1997). For a careful review of redox (oxidation-reduction) chemistry in a planetary setting other than Europa, see Nixon et al (2012). Table 1 lists the four inorganic compounds we studied.…”

Section: Introductionmentioning

confidence: 99%

Descent without Modification? The Thermal Chemistry of H₂O₂ on Europa and Other Icy Worlds

Loeffler

Hudson

2015

Astrobiology

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The strong oxidant H2O2 is known to exist in solid form on Europa and is suspected to exist on several other Solar System worlds at temperatures below 200 K. However, little is known of the thermal chemistry that H2O2 might induce under these conditions. Here, we report new laboratory results on the reactivity of solid H2O2 with eight different compounds in H2O-rich ices. Using infrared spectroscopy, we monitored compositional changes in ice mixtures during warming. The compounds CH4 (methane), C3H4 (propyne), CH3OH (methanol), and CH3CN (acetonitrile) were unaltered by the presence of H2O2 in ices, showing that exposure to either solid H2O2 or frozen H2O+H2O2 at cryogenic temperatures will not oxidize these organics, much less convert them to CO2. This contrasts strongly with the much greater reactivity of organics with H2O2 at higher temperatures, and particularly in the liquid and gas phases. Of the four inorganic compounds studied, CO, H2S, NH3, and SO2, only the last two reacted in ices containing H2O2, NH3 making NH4+ and SO2 making SO(4)2- by H+ and e- transfer, respectively. An important astrobiological conclusion is that formation of surface H2O2 on Europa and that molecule's downward movement with H2O-ice do not necessarily mean that all organics encountered in icy subsurface regions will be destroyed by H2O2 oxidation.

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Limitations to a microbial iron cycle on Mars

Cited by 31 publications

References 196 publications

11. The subsurface habitability of terrestrial rocky planets: Mars

11. The subsurface habitability of terrestrial rocky planets: Mars

Abiotic versus biotic iron mineral transformation studied by a miniaturized backscattering Mössbauer spectrometer (MIMOS II), X-ray diffraction and Raman spectroscopy

Descent without Modification? The Thermal Chemistry of H₂O₂ on Europa and Other Icy Worlds

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Limitations to a microbial iron cycle on Mars

Cited by 31 publications

References 196 publications

11. The subsurface habitability of terrestrial rocky planets: Mars

11. The subsurface habitability of terrestrial rocky planets: Mars

Abiotic versus biotic iron mineral transformation studied by a miniaturized backscattering Mössbauer spectrometer (MIMOS II), X-ray diffraction and Raman spectroscopy

Descent without Modification? The Thermal Chemistry of H2O2 on Europa and Other Icy Worlds

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Product

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Descent without Modification? The Thermal Chemistry of H₂O₂ on Europa and Other Icy Worlds