Project Description: NeoMineX

Background

Heavy metal contamination: The Looming danger lurking in water sources

In the wake of rapid industrialization and modern anthropogenic activities, our water sources now bear the weight of heavy metal contamination. Heavy metals consist of elements present in nature that are at least five times denser than water and have a big atomic weight. Depending on the dose, route of exposure, and chemical species, they can be toxic to human health and the environment [1]​​. The contamination of water sources by heavy metals has emerged as a significant environmental threat, putting human health and the aquatic ecosystems at risk [2]. They can enter the human body through contaminated water and food, the latter often tainted by irrigation with wastewater containing them [3]. When present in excess, heavy metals can cause problems such as liver and renal dysfunction, dermatological problems and malignancies [4]. Long-term exposure may also cause physical, muscular, and neurological degenerative disorders like muscular dystrophy, Alzheimer’s disease and Parkison’s disease [5]. The contamination of the aquatic ecosystems arises from complex interplay of diverse sources, encompassing both human activities and natural processes. Among these, industries emerge as one of the major contributors, releasing heavy metals directly and indirectly into the environment, thereby exacerbating contamination levels [4]. Despite advancements in remediation methods, wastewater treatment plants struggle to effectively remove soluble metals. Furthermore, conventional physicochemical methods raise concerns about the risk of secondary pollution, limitations in recovery and the hazardous chemicals used in the leaching process, which can hinder the reuse of treated wastewater when overabundant. These methods are also ineffective at low concentrations, where the residual metals have been reported to accumulate in tissues of aquatic organisms. This array of challenges drives our commitment to develop pioneering solutions for the effective remediation and sustainable management of water resources.

Global resource depletion: A call for sustainable practices

On our planet with finite resources, the relentless pursuit of metals and minerals driven by population growth and technological progression presents an unprecedented global challenge. What would we leave the future of humanity with, if we deplete these essential resources? [6]. Many of these materials are classified as critical, signifying their high economic importance and vulnerability to supply shortages (Fig. 1). On the other hand, there is ongoing debate regarding the practice of metal extraction from the Earth’s crust, especially given the concerns about the sustainability of existing mining strategies and geological scarcity at current extraction rates, projecting depletion of various metals within the next 50 years or less. The European Commission’s 2023 list of Critical raw materials highlights arsenic, cobalt, copper, lithium and nickel as essential resources facing potential depletion [7, 8]. Following our discussions with wastewater treatment companies, it became evident that the collected heavy metals are not recycled, enhancing the risk of resource depletion. Another point frequently raised during our Human Practices meetings is that regulations are becoming increasingly strict, and current methods are unable to meet the new standards, highlighting the need for new technologies. Considering the adverse effects of metal resource depletion and the growing demand for better solutions, we broadened our vision to ensure responsible use and conservation of essential metals for future generations, by tailoring our biomining strategy to facilitate selective removal and recycling of metals.

Figure about the distribution of global copper, lead, zinc and nickel resources in relation to various spatial indicators of water scarcity, and risk
Figure 1: Distribution of Global copper, lead, zinc and nickel resources in relation to various spatial indicators of water scarcity, and risk [8].

Recognizing these problems associated with heavy metal contamination and the risks of depletion, we embarked on developing a biomining strategy that could recover metals from water by a feasible downstream recovery process and recycle them further to reintroduce into the production cycle, thereby fostering a circular economy. This approach not only mitigates environmental impact but also addresses critical societal issues. By reusing metals that would otherwise be discarded, we aim to reduce reliance on new mining sites and curb child labor in hazardous mining conditions. According to the Child Labor Platform, over one million children worldwide endure unsafe conditions owing to mining practices, jeopardizing their health, safety, and prospects [9]. In addition, mining activities usually happened in remote areas, leaving the children without a proper education and sometimes no education at all. Moreover, recycling heavy metals reduces soil degradation, soil erosion and water contamination linked to conventional mining practices, aligning with principles of responsible usage and production. .

Our Solution

NeoMineX: Our commitment to a sustainable future

With our project NeoMineX, we take a holistic approach towards metal remediation and reuse, driven by a commitment to a sustainable and socially responsible future. The name “NeoMineX” embodies the fundamental objectives of our project. “NeoMine” signifies a novel alternative to traditional mining strategies advocating our approach of recovery of metals from water, which minimizes environmental pollution as well as reduces the need for conventional mining. The “X” symbolizes the multitude of metals that our method can potentially recover, highlighting the versatility of our approach.

Our project relies on transforming bacteria to express protein sequences tailored to bind and sequester specific metals. These proteins contain binding sites with amino acid residues characterized by chemical properties that facilitate interaction with metal ions, forming stable complexes. By polymerizing these metal binding proteins, we aim to enhance their binding properties and streamline the metal recovery process, even at low concentrations.

We are also exploring polymerization strategies like the SpyTag-mediated polymerization system [10]. By testing these methods with different metal-binding proteins, we aim to identify the most effective combinations for enhancing metal-binding capabilities. Our goal is to create biofibers that can be reused for metal cleansing and recovery.

Central to our project, in addition to remediation, is the efficient recovery of reusable metal of interest, with a strong emphasis on the selectivity of metal-binding proteins. Currently, the selectivity profiles of these proteins are largely unexplored, with potential binding to multiple metals. We will systematically characterize previously reported binding motifs for their affinity and specificity. Once the targeted metals are captured, they will be isolated and recycled for further applications, thereby closing the loop in metal resource management. Our innovative strategy holds the potential to attenuate the environmental impact of metal pollution and contribute to the sustainable management of metal resources.

“With NeoMineX, we are forging a path towards a future where innovation meets responsibility, ensuring a healthier planet for all”

Overview of the different steps in our project in a timeline

References

[1] Tchounwou, P. B., Yedjou, C. G., Patlolla, A. K., & Sutton, D. J. (2012). Heavy metal toxicity and the environment. In EXS (Vol. 101, pp. 133–164). https://doi.org/10.1007/978-3-7643-8340-4_6

[2] Hama Aziz, K. H., Mustafa, F. S., Omer, K. M., Hama, S., Hamarawf, R. F., & Rahman, K. O. (2023). Heavy metal pollution in the aquatic environment: efficient and low-cost removal approaches to eliminate their toxicity: a review. RSC Advances, 13(26), 17595. https://doi.org/10.1039/D3RA00723E

[3] Khan, S., Cao, Q., Zheng, Y. M., Huang, Y. Z., & Zhu, Y. G. (2008). Health risks of heavy metals in contaminated soils and food crops irrigated with wastewater in Beijing, China. Environmental Pollution, 152(3), 686–692. https://doi.org/10.1016/J.ENVPOL.2007.06.056

[4] Singh, V., Ahmed, G., Vedika, S., Kumar, P., Chaturvedi, S. K., Rai, S. N., Vamanu, E., & Kumar, A. (2024). Toxic heavy metal ions contamination in water and their sustainable reduction by eco-friendly methods: isotherms, thermodynamics and kinetics study. Scientific Reports, 14(1), 7595–13. https://doi.org/10.1038/s41598-024-58061-3

[5] Jaishankar, M., Tseten, T., Anbalagan, N., Mathew, B. B., Beeregowda, K. N., Blessy, A., & Mathew, B. (2014). Toxicity, mechanism and health effects of some heavy metals. https://doi.org/10.2478/intox-2014-0009

[6] Durrheim, R. J. (2014). Resourcing Future Generations: A Global Effort to Meet the World’s Future Needs Head-On. https://www.researchgate.net/publication/281068953

[7] European Comission. (n.d.). Study on the critical raw materials for the EU 2023. Publications Office of the EU. https://op.europa.eu/en/publication-detail/-/publication/57318397-fdd4-11ed-a05c-01aa75ed71a1

[8] Northey, S. A., Mudd, G. M., Werner, T. T., Jowitt, S. M., Haque, N., Yellishetty, M., & Weng, Z. (2017). The exposure of global base metal resources to water criticality, scarcity and climate change. Global Environmental Change, 44, 109–124. https://doi.org/10.1016/j.gloenvcha.2017.04.004

[9] International Labour Organization. (n.d.). Child labour in mining and global supply chains. https://www.ilo.org/publications/child-labour-mining-and-global-supply-chains

[10] Yang, X., Wei, J., Wang, Y., Yang, C., Zhao, S., Li, C., Dong, Y., Bai, K., Li, Y., Teng, H., Wang, D., Lyu, N., Li, J., Chang, X., Ning, X., Ouyang, Q., Zhang, Y., & Qian, L. (2018). A Genetically Encoded Protein Polymer for Uranyl Binding and Extraction Based on the SpyTag-SpyCatcher Chemistry. ACS Synthetic Biology, 7(10), 2331–2339. https://doi.org/10.1021/acssynbio.8b00223