Could biomining be a game-changer for rare earth elements and other metals?

Urban mining

Urban mining refers to the recovery of metals and other valuable materials from waste streams rather than disposing of them in landfills. Lithium and cobalt have long been regarded as the critical resources, particularly for battery technologies used in devices ranging from smartphones to electric vehicles. REEs have recently attracted increasing attention. Rare earth elements, often described as the “vitamins of industry,” play an essential role in numerous applications, including hydrogen-oxygen fuel cells, glass manufacturing, permanent magnets, catalysts, electronic devices, and magnetic resonance imaging.

Uncertain supplies

Lithium and cobalt are widely regarded as key raw materials and rank among the most sought-after resources worldwide. According to the Australian Strategic Policy Institute (ASPI), China dominates 66 out of 74 critical technologies and continues to exert overwhelming control over the REE market. This dominance has enabled China to leverage rare earth exports as a geopolitical tool, notably to marginalize the United States during tariff disputes. China currently holds a near-monopoly on REEs, and recent export restrictions are increasingly affecting not only global markets but also countries such as Switzerland, leading to growing concerns about supply security and market uncertainty.

Increasing demand

In recent years, a decline in rare earth prices has been observed, most notably since 2021 for neodymium, dysprosium, praseodymium, and terbium, materials that are essential for the energy transition (lern more). However, despite short-term price fluctuations, the long-term price trend remains clearly upward. Although magnets account for only about 30% of total REE volume, they represent more than 80% of the total market value. Global demand for magnetic REEs is projected to rise sharply, increasing from approximately 59 kilotonnes in 2022 to 176 kilotonnes by 2035. Continued reliance on a limited number of exporting countries, particularly China, therefore constitutes a significant strategic and economic risk.

Rare earth elements and Switzerland

Switzerland imports REEs primarily in the form of processed intermediate and finished goods, such as magnets, batteries, and other high-tech products. Swiss industry generally does not procure mineral raw materials directly from producing countries, but rather via the European Union, often through parent or affiliated companies. As the cost share of rare earths in final products is relatively small, even a substantial increase in prices would have only a limited impact on the overall competitiveness of Swiss industry.

However, in the event of supply shortages or sharp price increases, ensuring access to raw materials becomes primarily a responsibility of the private sector and requires advance preparation (Die Versorgung der Schweiz mit Seltenen Erden; Versorgung der Schweizer Industrie mit mineralischen Rohstoffen für die Energiewende). Domestic mining is not a viable option in Switzerland. Instead, potential strategies include substitution with non-critical raw materials, improvements in material efficiency, and the closing of material cycles. Yet, viable non-critical substitutes are currently not in sight, and industry is already operating close to the limits of material efficiency.

This leaves recycling, or so-called “urban mining,” as a remaining option. However, recycling is far from cost-free, and the recovery of trace amounts of metals such as gallium, cadmium, tellurium, and others is technically and economically challenging, in contrast to more easily recyclable metals like aluminum or copper.

Recycling

In Switzerland, recycling of REEs from electronic waste remains minimal. Globally, less than one percent of rare elements are currently recycled, although research developments suggest that recycling efficiencies could be significantly improved in the future. But effective recycling has to overcome three hurdles: 

1. the collection of relevant waste streams, such as end-of-life electronics, permanent magnets, and lamps,
2. the dismantling and separation of collected waste into defined sub-products,
3. the extraction and isolation of REEs and other valuable metals. Biotechnology could play a particularly critical role.

Biotechnological approaches must be integrated into a multi-step recycling chain. When combined with robotics and artificial intelligence, they hold the potential to enable highly selective, efficient, and environmentally less burdensome large-scale processes.

Back to nature

Approximately 13.7 billion years have passed since the Big Bang. The first prokaryotic life forms emerged around four billion years ago, and microbial oxygenic photosynthesis began between 3.0 and 2.7 billion years ago, giving rise to an extraordinary diversity of microbial life. Yet the search for biotechnological solutions is severely constrained by the fact that only about one percent of bacterial species are known and can be cultivated using standard laboratory techniques. While our knowledge is somewhat more advanced for fungi and microalgae, more than ninety percent of these organisms likewise remain unexplored. Considering the wealth of products and services already derived from the small fraction of organisms known today, one can only imagine the vast potential that remains undiscovered.

Why biotechnology?

Biotechnology offers four distinctive advantages:

• Metabolic diversity: Biological pathways enable the production of an exceptionally broad spectrum of predominantly organic, and in some cases highly complex, molecules.
• High specificity: Enzymes and biological systems exhibit remarkable selectivity in catalysis and binding, including toward specific substrates and metal ions such as REEs.
• Process safety and mild conditions: Biotechnological processes typically operate under benign conditions, enhancing safety and facilitating scale-up.
• Self-replication and exponential growth: Biological systems can reproduce and expand autonomously, enabling efficient biomass and product generation.

Given the high energy demand and environmental impact of conventional physicochemical REE recovery methods, sustainable biological processes such as bioleaching, biosorption, and bioaccumulation are increasingly being explored.

Extremophiles

The harsh conditions associated with electronic waste processing and mining favor the use of extremophiles, which thrive at extreme pH and temperatures. These organisms often produce metal-binding proteins or chelating molecules, and in some taxa, REEs even serve as enzymatic cofactors. Although other biological systems exist, extremophiles are particularly attractive for urban mining because they combine tolerance to harsh environments with the potential for scalable and environmentally benign processes.

Metagenomics vs. bioprospecting

The development of biobased tools for urban biomining requires the targeted collection, isolation, and screening of organisms from natural environments. The much easier in silico screening, which browses through existing DNA sequence databases, is not useful as this metagenomic approach has the disadvantage that new activities or structures cannot be found. Finding biobased tools for urban biomining requires collecting organisms from natural environments. Although the Swiss academic research ecosystem is internationally strong in environmental sciences, its activities are largely focused on environmental monitoring, detection, and biodiversity assessment rather than systematic organism isolation and functional screening. Historically, SwissAustral Biotech SA was one of the few companies in Switzerland actively engaged in such “bioprospecting” efforts, operating laboratories in Monthey and maintaining a dedicated extremophile library. Since then, comparable industrial-scale initiatives focused on discovering and exploiting novel environmental microorganisms have largely disappeared from the Swiss landscape.

Actors in Switzerland

The start-up REEcover, founded in 2023 at ETH Zürich, has developed a patented technology originating from Victor Mougel’s research group to recover rare earth elements from electronic waste (Recovery of europium from E-waste using redox active tetrathiotungstate ligands, Nature 2024). Its first proof of concept addresses the recycling of europium and yttrium from energy-saving lamps. However, the process depends on synthetic tetrathiotungstate ligands rather than biobased alternatives.

At ETH Zürich, Raffaele Mezzenga has developed protein aggregates based on amyloid fibrils that can be used to produce membranes functionalized for water purification or for recovering gold from electronic waste (learn more).

Separately, an ETH Zürich student team created a photobioreactor system as part of a 2025 iGEM project, enabling the cultivation of algae to bioaccumulate red mud produced during the refining of bauxite into alumina.

Methylobacterium extorquens synthesizes lanmodulin, a lanthanide-binding protein capable of adsorbing rare earth elements (Lanmodulin: A Highly Selective Lanthanide-Binding Protein from a Lanthanide-Utilizing Bacterium). Swiss entrepreneur Oliver Siegel evaluated founding the start-up Magmatic in Switzerland, but the company was ultimately established in Vienna under his leadership.

Conclusions

REE biomining is an emerging and promising method. Since 2023 (Rare earth elements – how to handle future challenges) the technological landscape has shifted toward integrated solutions combining biotechnology, AI, and robotics. However, achieving scalability and economic feasibility requires advances at multiple levels and across diverse sites, underscoring the fundamentally interdisciplinary nature of this approach.   

1. Waste containing metals, most commonly from electronic devices, needs a structured collection and sorting system. Ideally, metal components should be separated from housings and other plastic parts before processing.  
2. Collected e-waste is ideally processed through automated robotic disassembly, with artificial intelligence guiding the separation of REEs and other metal-containing parts. Automated mechanical dismantling constitutes an important cost element while reducing the need for manual intervention.
3. Once disassembled, metal-rich components require size reduction using shredding and milling techniques, along with supplementary physical separation methods.
4. Biobased approaches should be used to capture and isolate REEs and other metals, aiming to minimize or eliminate chemical pretreatment. The screening of previously unknown microbes that produce compounds capable of selectively binding specific metals should be integrated with synthetic biology tools, enabling the transfer of these binding principles into alternative, better-suited platform organisms.
5.  The subsequent steps of isolating, recovering, purifying, and refining REEs or other metals.

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