scholarly journals The Impact of Ecological Restoration on Biogeochemical Cycling and Mercury Mobilization in Anoxic Conditions on Former Mining Sites in French Guiana

2021 ◽  
Vol 9 (8) ◽  
pp. 1702
Author(s):  
Ewan Couic ◽  
Alicia Tribondeau ◽  
Vanessa Alphonse ◽  
Alexandre Livet ◽  
Michel Grimaldi ◽  
...  
Keyword(s):  
Ecological Restoration ◽  
French Guiana ◽  
Acacia Mangium ◽  
Anaerobic Conditions ◽  
Mining Sites ◽  
Iron Reducing Bacteria ◽  
Sulfate Reducing ◽  
Sulphide Production ◽  
Reducing Bacteria ◽  
The Impact

Successive years of gold mining in French Guiana has resulted in soil degradation and deforestation leading to the pollution and erosion of mining plots. Due to erosion and topography, gold panning sites are submitted to hydromorphy during rainfall and groundwater increases. This original study focused on characterizing the impact of hydromorphic anaerobic periods on bio-geochemical cycles. We sampled soil from five rehabilitated sites in French Guiana, including sites with herbaceous vegetation and sites restored with fabaceous plants, Clitoria racemosa (Cli) mon-oculture, Acacia mangium (Aca) monoculture, Clitoria racemosa and Acacia mangium (Mix) bi-culture. We conducted mesocosm experiments where soil samples were incubated in anaerobic conditions for 35 days. To evaluate the effect of anaerobic conditions on biogeochemical cycles, we measured the following parameters related to iron-reducing bacteria and sulfate-reducing bacteria metabolism throughout the experiment: CO2 release, carbon dissolution, sulphide production and sulphate mobilization. We also monitored the solubilization of iron oxyhydroxides, manganese oxides, aluminum oxides and mercury in the culture medium. Iron-reducing bacteria (IRB) and sulfate-reducing bacteria (SRB) are described as the major players in the dynamics of iron, sulfur and metal elements including mercury in tropical environments. The results revealed two trends in these rehabilitated sites. In the Aca and Mix sites, bacterial iron-reducing activity coupled with manganese solubilization was detected with no mercury solubilization. In herbaceous sites, a low anaerobic activity coupled with sulphide production and mercury solubilization were detected. These results are the first that report the presence and activity of iron- and sulfate-reductive communities at rehabilitated mining sites and their interactions with the dynamics of metallic elements and mercury. These results report, however, the positive impact of ecological restoration of mining sites in French Guiana by reducing IRB and SRB activities, the potential mobility of mercury and its risk of transfer and methylation.

scholarly journals Integrative analysis of <i>Geobacter</i> spp. and sulfate-reducing bacteria during uranium bioremediation

2012 ◽  
Vol 9 (3) ◽  
pp. 1033-1040 ◽  
Author(s):  
M. Barlett ◽  
K. Zhuang ◽  
R. Mahadevan ◽  
D. Lovley
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Field Trials ◽  
Second Phase ◽  
Sulfate Reducing ◽  
Organic Electron ◽  
Poor Understanding ◽  
Key Factor ◽  
Reducing Bacteria ◽  
The Impact

Abstract. Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III) was depleted whereas the SRB grow more slowly and reached dominance after 30–40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III) would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III) availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.

Sulfate-reducing bacteria mediate thionation of diphenylarsinic acid under anaerobic conditions

2014 ◽  
Vol 26 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Ling Guan ◽  
Ayaka Shiiya ◽  
Shihoko Hisatomi ◽  
Kunihiko Fujii ◽  
Masanori Nonaka ◽  
...  
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Anaerobic Conditions ◽  
Sulfate Reducing ◽  
Reducing Bacteria

scholarly journals Can Primary Ferroan Dolomite and Ankerite Be Precipitated? Its Implications for Formation of Submarine Methane-Derived Authigenic Carbonate (MDAC) Chimney

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 413 ◽  
Author(s):  
Fan Xu ◽  
Xuelian You ◽  
Qing Li ◽  
Yi Liu
Keyword(s):  
Iron Reduction ◽  
Extracellular Polymeric Substances ◽  
Microbial Culture ◽  
Reduction Zone ◽  
Secondary Products ◽  
Iron Reducing Bacteria ◽  
Sulfate Reducing ◽  
Dolomite Problem ◽  
Reducing Bacteria ◽  
Ferroan Dolomite

Microbes can mediate the precipitation of primary dolomite under surface conditions. Meanwhile, primary dolomite mediated by microbes often contains more Fe2+ than standard dolomite in modern microbial culture experiments. Ferroan dolomite and ankerite have been regarded as secondary products. This paper reviews the process and possible mechanisms of microbial mediated precipitation of primary ferroan dolomite and/or ankerite. In the microbial geochemical Fe cycle, many dissimilatory iron-reducing bacteria (DIRB), sulfate-reducing bacteria (SRB), and methanogens can reduce Fe3+ to Fe2+, while SRB and methanogens can also promote the precipitation of primary dolomite. There are an oxygen respiration zone (ORZ), an iron reduction zone (IRZ), a sulfate reduction zone (SRZ), and a methanogenesis zone (MZ) from top to bottom in the muddy sediment diagenesis zone. DIRB in IRZ provide the lower section with Fe2+, which composes many enzymes and proteins to participate in metabolic processes of SRB and methanogens. Lastly, heterogeneous nucleation of ferroan dolomite on extracellular polymeric substances (EPS) and cell surfaces is mediated by SRB and methanogens. Exploring the origin of microbial ferroan dolomite may help to solve the “dolomite problem”.

scholarly journals Simultaneous Biological and Chemical Removal of Sulfate and Fe(II)EDTA-NO in Anaerobic Conditions and Regulation of Sulfate Reduction Products

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 330 ◽  
Author(s):  
Yu Zhang ◽  
Lijian Sun ◽  
Jiti Zhou
Keyword(s):  
Sulfate Reduction ◽  
Flue Gas ◽  
Elemental Sulfur ◽  
Biofilm Reactor ◽  
Flue Gas Desulfurization ◽  
Moving Bed Biofilm Reactor ◽  
Anaerobic Conditions ◽  
Biological Reduction ◽  
Sulfate Reducing ◽  
Reducing Bacteria

In the simultaneous flue gas desulfurization and denitrification by biological combined with chelating absorption technology, SO2 and NO are converted into sulfate and Fe(II)EDTA-NO which need to be reduced in biological reactor. Increasing the removal loads of sulfate and Fe(II)EDTA-NO and converting sulfate to elemental sulfur will benefit the application of this process. A moving-bed biofilm reactor was adopted for sulfate and Fe(II)EDTA-NO biological reduction. The removal efficiencies of the sulfate and Fe(II)EDTA-NO were 96% and 92% with the influent loads of 2.88 kg SO42−·m−3·d−1 and 0.48 kg NO·m−3·d−1. The sulfide produced by sulfate reduction could be reduced by increasing the concentrations of Fe(II)EDTA-NO and Fe(III)EDTA. The main reduction products of sulfate and Fe(II)EDTA-NO were elemental sulfur and N2. It was found that the dominant strain of sulfate reducing bacteria in the system was Desulfomicrobium. Pseudomonas, Sulfurovum and Arcobacter were involved in the reduction of Fe(II)EDTA-NO.

scholarly journals Suspension Array Analysis of 16S rRNA from Fe- and SO42-Reducing Bacteria in Uranium-Contaminated Sediments Undergoing Bioremediation

2006 ◽  
Vol 72 (7) ◽  
pp. 4672-4687 ◽  
Author(s):  
Darrell P. Chandler ◽  
Ann E. Jarrell ◽  
Eric R. Roden ◽  
Julia Golova ◽  
Boris Chernov ◽  
...  
Keyword(s):  
16S Rrna ◽  
Total Rna ◽  
Iron Reducing Bacteria ◽  
Suspension Array ◽  
Sulfate Reducing ◽  
Subsurface Sediments ◽  
Reducing Bacteria ◽  
Bead Arrays ◽  
Microbiological Analyses

ABSTRACT A 16S rRNA-targeted tunable bead array was developed and used in a retrospective analysis of metal- and sulfate-reducing bacteria in contaminated subsurface sediments undergoing in situ U(VI) bioremediation. Total RNA was extracted from subsurface sediments and interrogated directly, without a PCR step. Bead array validation studies with total RNA derived from 24 isolates indicated that the behavior and response of the 16S rRNA-targeted oligonucleotide probes could not be predicted based on the primary nucleic acid sequence. Likewise, signal intensity (absolute or normalized) could not be used to assess the abundance of one organism (or rRNA) relative to the abundance of another organism (or rRNA). Nevertheless, the microbial community structure and dynamics through time and space and as measured by the rRNA-targeted bead array were consistent with previous data acquired at the site, where indigenous sulfate- and iron-reducing bacteria and near neighbors of Desulfotomaculum were the organisms that were most responsive to a change in injected acetate concentrations. Bead array data were best interpreted by analyzing the relative changes in the probe responses for spatially and temporally related samples and by considering only the response of one probe to itself in relation to a background (reference) environmental sample. By limiting the interpretation of the data in this manner and placing it in the context of supporting geochemical and microbiological analyses, we concluded that ecologically relevant and meaningful information can be derived from direct microarray analysis of rRNA in uncharacterized environmental samples, even with the current analytical uncertainty surrounding the behavior of individual probes on tunable bead arrays.

The Disinfection Efficacy of Chlorine on Sulfate-Reducing Bacteria and Iron Bacteria in Water Supply Systems

2013 ◽  
Vol 316-317 ◽  
pp. 657-660
Author(s):  
Bei Meng Qi ◽  
Bei Jia Wang ◽  
Chen Guang Wu ◽  
Yi Xing Yuan
Keyword(s):  
Water Supply ◽  
Sulfate Reducing Bacteria ◽  
Metal Corrosion ◽  
Water Supply Systems ◽  
Supply Networks ◽  
Minimum Requirement ◽  
Iron Reducing Bacteria ◽  
Sulfate Reducing ◽  
Reducing Bacteria ◽  
Supply Systems

Sulfate reducing bacteria (SRB) and iron reducing bacteria (IRB) that widely exist in water supply networks are the main microorganisms leading to metal corrosion in pipelines. Chlorine is widely used in drinking water supply systems. The concentration of chlorine with SRB declined rapidly after 10 mins and reached 0 mg/L finally whereas it decreased more slowly with IRB. If the concentration of chlorine is lower than 0.2mg/L, IRB cannot be sterilized. It indicates that at the end of water pipes where the concentration of chlorine is required to be 0.05mg/L, chlorine is not effective since the concentration is below the minimum requirement of removing IRB

scholarly journals Influence of Ecological Restoration on Mercury Mobility and Microbial Activities on Former Guyanese Mining Sites

2021 ◽  
Vol 11 (5) ◽  
pp. 2231
Author(s):  
Ewan Couic ◽  
Vanessa Alphonse ◽  
Alexandre Livet ◽  
Stéphanie Giusti-Miller ◽  
Noureddine Bousserrhine
Keyword(s):  
Soil Quality ◽  
Ecological Restoration ◽  
Microbial Activities ◽  
Potential Toxicity ◽  
Mining Sites ◽  
Soil Microbial ◽  
Rehabilitation Protocols ◽  
French Guyana ◽  
The Impact ◽  
Positive Effect

As rehabilitation efforts in Guyana are recent, there is little information on the effect of different ecological rehabilitation protocols for Guyana’s mining sites on biogeochemical cycles and mercury mobility. This study was conducted to assess the impact of different ecological restoration protocols on soil quality with the use of soil microbial indicators and by estimating the mercury mobility. We sampled soil from six rehabilitated mining sites in French Guyana with different ecological restoration procedures. We carried out measurements of enzymatic activities and an analysis of mercury environmental speciation to assess its potential toxicity according to a mobility gradient. The results obtained in this study show that the rehabilitation of mining sites has been carried out in a heterogeneous manner and soil quality is very variable, even in nearby sites. Sites that have been rehabilitated with fabaceous species have positive soil quality indicators. In addition, the results highlight a change in mercury mobility that is 82.1% correlated after co-inertia analysis with soil texture properties, which also confirms a direct effect of rehabilitation on mercury mobility. The non-restored sites had a much higher potential of mercury mobility and toxicity than the sites where ecological restoration was successful. These results highlight the positive effect of controlled rehabilitation and ecological restoration on microbiological activities and the potential toxicity of mercury.

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