Related Experiment Video
Updated: Aug 5, 2026
06:29
A Method to Preserve Wetland Roots and Rhizospheres for Elemental Imaging
Published on: February 15, 2021
Physicochemical and Microbial Regulation Inhibit Rice Mercury Accumulation in the Karst Region with High Geological
Yanxin Hu1,2, Zhengcheng Song2, Lu Qiao1,2
1College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, China.
Toxics
|July 28, 2026
Summary
A new study shows that combining selenium foliar spraying and a calcium oxide soil conditioner effectively reduces mercury (Hg) and methylmercury (MeHg) in rice grains. This strategy mitigates food safety risks in high geological background regions.
Area of Science:
- Environmental Science
- Agricultural Science
- Geochemistry
Background:
- Methylmercury (MeHg) accumulation in rice poses significant human health risks, particularly in high geological background (HGB) regions.
- Understanding mercury (Hg) accumulation mechanisms in rice from HGB areas is crucial for effective remediation.
Purpose of the Study:
- To investigate the effectiveness of a combined remediation strategy for reducing Hg and MeHg in rice grains.
- To elucidate the mechanisms underlying Hg transfer and accumulation in rice within a karst HGB region.
Main Methods:
- Conducted a field-scale remediation experiment using selenium foliar spraying and a calcium oxide-based soil conditioner.
- Analyzed total Hg and MeHg concentrations in rice grains and soil.
- Investigated changes in soil properties, microbial communities, and Hg-related gene expression.
Main Results:
- The combined treatment significantly reduced total Hg (63.0%) and MeHg (80.0%) in rice grains.
- Root uptake was identified as the primary pathway for Hg transfer into rice.
- The strategy decreased bioavailable Hg, MeHg production, and Hg-methylating microorganisms, while promoting Hg-resistant taxa.
Conclusions:
- The synergistic remediation strategy effectively reduces Hg bioavailability and bioaccumulation in rice.
- This approach offers a viable solution for mitigating Hg-related food safety risks in HGB regions.
- Combined physicochemical and microbial interventions are key to successful mercury remediation in agricultural systems.
Related Concept Videos
01:25Microbial Bioremediation of Uranium
Microorganisms play a critical role in the transformation and immobilization of uranium in contaminated environments through four main pathways: bioreduction, biosorption, bioaccumulation, and biomineralization. These mechanisms reduce uranium’s toxicity and prevent its migration through groundwater systems, offering sustainable approaches for in situ bioremediation.Bioreduction of UraniumBioreduction is driven by anaerobic bacteria such as certain strains of Geobacter and Shewanella, which use...
01:24Microbes and Other Elemental Cycles
Microbial activity plays a pivotal role in the biogeochemical cycling of iron and manganese, especially at the redox gradients characteristic of stratified aquatic environments. These cycles are driven by microbial transformations between oxidized and reduced forms of the metals, allowing organisms to exploit them for metabolic energy and structural purposes.Iron Cycling Across Redox GradientsIn neutral, oxygen-rich surface waters, iron is predominantly found in its oxidized, insoluble ferric...
01:30Microbial Wastewater Treatment
Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water.
01:24Microbial Corrosion
Microbiologically Influenced Corrosion (MIC) is a significant form of material degradation caused by the metabolic activities of microorganisms. This phenomenon poses substantial challenges across various industries, including oil and gas, maritime, and water treatment sectors.MIC occurs when microorganisms, such as bacteria, archaea, and fungi, colonize metal surfaces, forming biofilms that alter the local electrochemical environment. These biofilms can lead to the production of corrosive...
01:27Microbial Leaching
Microbial leaching, also known as bioleaching, is an environmentally favorable method for extracting metals from low-grade ores using specific microorganisms. This biotechnological approach is particularly valuable for mining operations targeting copper, gold, and uranium, where traditional extraction methods may be economically or environmentally impractical.Copper Leaching and Microbial CatalysisIn copper bioleaching, crushed ore is arranged into heaps and irrigated with a dilute sulfuric...
01:19Acid Mine Drainage
Mining activities that disturb sulfide-rich rocks, particularly those containing pyrite (FeS₂), initiate a cascade of geochemical and microbiological processes with serious environmental implications. When exposed to air and water, pyrite undergoes oxidation, releasing sulfate, ultimately forming sulfuric acid and mobilizing heavy metals into surrounding water systems. This phenomenon, known as acid mine drainage (AMD), results in low pH waters laden with toxic elements that threaten aquatic...