New Way to Clean Mercury Pollution Using Microbes and Magnets

Greg Howard
25th August, 2025

New Way to Clean Mercury Pollution Using Microbes and Magnets

In non-sterile soil bioaugmented with Pseudomonas stutzeri LBR, the application of a static magnetic field significantly enhanced bacterial growth and increased mercury remediation efficiency compared to the absence of a magnetic field.

Image adapted from: Werfelli et al. / CC BY (Source)

Key Findings

  • This study, conducted in Tunisia, investigated enhancing mercury removal from contaminated soil using the bacterium Pseudomonas stutzeri LBR and a static magnetic field (SMF)
  • Combining Pseudomonas stutzeri LBR with an SMF significantly increased mercury removal from soil, boosting efficiency by 49.36% in natural soil and 72.49% in sterile soil
  • Pseudomonas stutzeri LBR was more effective at removing mercury in sterile soil, likely due to reduced competition from other microbes, and the SMF further enhanced this effect
Heavy metal contamination, especially from mercury, is a serious global problem due to its toxicity and ability to build up in the food chain, posing risks to both environmental and human health. Traditional methods for cleaning up contaminated sites can be expensive and disruptive. Researchers at the University of Carthage and Universidad Tecnica de Manabi[1] have been investigating more sustainable approaches, focusing on using microorganisms to remove or neutralize mercury in polluted soils – a process called bioremediation. Mercury enters the environment through both natural processes and human activities. Historical silver mining, for example, released substantial amounts of mercury into the atmosphere, significantly increasing global levels compared to pre-industrial times[2]. This increase has led to wider distribution of mercury in soils and water systems, with a roughly 450% increase in atmospheric concentrations above natural levels[2]. The challenge isn’t just the presence of mercury, but its conversion into more toxic forms, particularly methylmercury, which readily accumulates in organisms[3][4]. The recent study explores a novel way to enhance bioremediation. They focused on using a specific bacterium, Pseudomonas stutzeri LBR, known for its ability to interact with mercury. However, the researchers didn't stop there; they also applied a static magnetic field (SMF) to the contaminated soil at the beginning of the remediation process. A static magnetic field is a constant magnetic force, unlike a changing magnetic field. The experiment involved two types of soil: one with its natural microbial community (non-sterile) and one sterilized to remove existing microorganisms. Both types of soil were contaminated with mercury and then treated with Pseudomonas stutzeri LBR, with and without the application of the SMF. The researchers then monitored the amount of mercury removed over a 30-day period. The results showed a clear benefit from combining the SMF with bioremediation. In non-sterile soils, the combination of the SMF, the existing soil microbes, and Pseudomonas stutzeri LBR increased mercury removal by 49.36% compared to using only bioaugmentation (adding the bacteria) without the magnetic field. Even more striking was the effect in sterile soils, where the combined approach increased mercury removal by 72.49% compared to 38.1% without the SMF. These findings suggest that the SMF isn’t simply acting as a standalone solution, but rather enhancing the activity of the bacteria and potentially the overall microbial community. While the exact mechanism isn’t fully understood, it’s hypothesized that the magnetic field could alter the permeability of bacterial cell walls, making it easier for them to take up and process mercury. It could also influence enzymatic reactions involved in mercury transformation. This research builds on the broader understanding of mercury cycling in the environment. Studies have shown that specific genes, like hgcAB, play a crucial role in mercury methylation by anaerobic bacteria[4]. Understanding these microbial processes is key to developing effective bioremediation strategies. The work by researchers[3] also highlights the potential of using “Omics” techniques – large-scale analysis of genes and proteins – to identify new bacterial strains and their biotechnological applications for bioremediation. The current study takes this a step further by adding a physical factor – the SMF – to the equation, potentially unlocking even greater remediation efficiency. The increased mercury deposition observed in surface marine waters[2] underscores the need for effective remediation techniques. While the increase in deeper marine waters is smaller, the overall environmental burden of mercury remains significant. The approach developed by the University of Carthage and Universidad Tecnica de Manabi offers a promising avenue for addressing this challenge, particularly in soil environments.

AgricultureEnvironmentBiotech

References

Main Study

1) Novel method for combining microbial bioremediation with static magnetic fields to remediate mercury-contaminated soils

Published 22nd August, 2025

https://doi.org/10.1371/journal.pone.0330872

Related Studies

2) Updated Global and Oceanic Mercury Budgets for the United Nations Global Mercury Assessment 2018.

https://doi.org/10.1021/acs.est.8b01246

3) Bioremediation of environments contaminated with mercury. Present and perspectives.

https://doi.org/10.1007/s11274-023-03686-1

4) Overview of Methylation and Demethylation Mechanisms and Influencing Factors of Mercury in Water.

https://doi.org/10.3390/toxics12100715


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