Genetically Engineered Virus Works as a Smart Sponge to Cleanly Extract Rare Earth Elements

Researchers from UC Berkeley and Lawrence Berkeley National Laboratory have developed a surprisingly elegant solution to one of modern technology’s biggest resource problems: extracting rare earth elements (REEs) without destroying the environment.

Their approach uses a genetically engineered virus that behaves like a smart sponge, efficiently pulling valuable metals out of water and then releasing them with a simple temperature and pH change. This discovery opens the door to cleaner mining, better recycling, and more sustainable access to the materials that power everything from smartphones to electric vehicles.

A Straightforward Look at What the Researchers Did

Rare earth elements are essential for modern electronics, green energy systems, and advanced manufacturing. They are used in phosphors for display screens, magnets for electric vehicles and wind turbines, and numerous high-tech applications. Yet traditional REE extraction is messy and problematic. The process typically involves toxic chemicals, harsh solvents, and high energy consumption, and it leaves behind polluted waste streams.

The UC Berkeley team, led by bioengineering professor Seung-Wuk Lee, wanted a cleaner and smarter way to recover these metals. Their solution was a harmless bacteriophage—a virus that infects only bacteria. It cannot harm humans, animals, or plants. The researchers modified this virus so that it can selectively grab REE ions from water while ignoring other metal ions that might be present.

To turn the virus into a working extraction tool, the team added two specialized proteins to its outer surface:

• A lanthanide-binding peptide, which functions like a molecular claw designed specifically to latch onto rare earth metal ions.
• An elastin-motif peptide, which behaves as a temperature-responsive switch. When the solution is gently heated, the virus becomes insoluble and sinks, taking the captured metals with it.

This thermoresponsive behavior is what makes the system act like a smart sponge. The virus soaks up REEs, and a slight temperature increase makes it clump together and fall out of solution. Once separated from the water, the viruses can be treated with a simple pH adjustment to release the captured metal ions. This produces a concentrated solution of recovered REEs ready for collection.

The researchers successfully tested this process using acid mine drainage, one of the most challenging contaminated water sources associated with mining. The engineered viruses selectively captured rare earth ions even in the presence of many other metals and impurities. After warming the solution, the virus-REE complexes precipitated to the bottom, leaving behind clearer water. Adjusting the pH then caused the viruses to let go of the pure metal ions.

A significant advantage of this method is that the viruses remain reusable. They do not degrade or lose effectiveness after use. They can also be produced in large quantities at low cost because bacteriophages naturally self-replicate when introduced to bacteria.

This entire process requires nothing more complex than a mixing tank and a modest heat source, making it far simpler and cleaner than conventional REE extraction. The researchers see this as a strong candidate for sustainable, scalable biomining.

Why This Matters for Technology and the Environment

Rare earth elements are crucial for the technologies that support renewable energy, advanced electronics, and national infrastructure. However, global REE supply is heavily concentrated in certain regions, and conventional mining carries significant environmental consequences. Acidic wastewater, harmful chemicals, and large waste volumes pose serious challenges.

A virus-based biomining system offers several advantages:

• It could help build a domestic supply of rare earth elements, reducing dependence on foreign sources.
• It provides a cleaner extraction method, decreasing environmental damage.
• It allows recovery of REEs from waste streams, not just mined ores.
• It may reduce the need for toxic chemicals used in refining processes.

The research team emphasizes that this innovation supports both environmental protection and economic security. A system that can harvest REEs from wastewater or discarded electronics represents a major step toward a circular economy—one where valuable materials are recovered and reused instead of being thrown away or extracted with damaging processes.

The Technology Behind the Virus-Based Approach

The bacteriophage used in this study acts as a programmable tool. By changing its genetic instructions, researchers can fine-tune what materials it binds to. In this case, the engineered virus is optimized for rare earth elements, but the same platform can be adapted for many other purposes.

The key components are:

• Lanthanide-binding peptides designed to target REE ions.
• Elastin-motif peptides that make the virus thermoresponsive.
• The virus scaffold, which is safe, stable, and simple to mass-produce.

Together, these parts create a biological tool that performs complex metal separation tasks without chemicals, energy-intensive processing, or specialized machinery.

What Else This Platform Could Do

The researchers highlight that this technology is not limited to rare earth elements. By swapping in different binding peptides, the same system could be engineered to collect:

• Lithium and cobalt, key metals for batteries.
• Platinum-group metals, used as catalysts in industrial reactions.
• Toxic heavy metals like mercury and lead, which contaminate water sources.

This versatility could make engineered viruses a valuable tool for both resource recovery and environmental cleanup. Wastewater treatment plants, electronics recyclers, and mining operations may eventually use virus-based tools to reclaim valuable elements or remove dangerous contaminants.

Additional Context: Why Rare Earth Elements Are Hard to Extract

To give a fuller picture, it helps to understand why rare earth elements pose such challenges:

• They are not actually rare, but they are rarely found in concentrated deposits.
• They occur mixed with many other metals, making separation difficult.
• Traditional extraction uses strong acids and organic solvents.
• The environmental impact of REE mining is among the worst in the resource sector.

Because of these difficulties, researchers worldwide have been exploring biomining—using biological materials like bacteria, proteins, or viruses to extract metals in cleaner, more efficient ways. The new virus-based method represents one of the most promising advancements in this field to date.

Where This Research Fits Into Broader Scientific Progress

Professor Lee’s lab has spent more than 20 years engineering viruses for technological applications. Before this project, they used similar viruses to construct:

• Biosensors
• Electric generators
• Tissue-regeneration scaffolds
• Molecular building blocks for self-assembling materials

This new REE-sponge virus is a natural extension of that work. It shows how biological systems can be repurposed to handle industrial challenges that previously required harsh chemistry.

What Comes Next

Although the initial results are promising, scaling this technology will require further testing:

• Large-scale industrial trials
• Long-term stability assessments
• Regulatory review
• Cost modeling compared to existing extraction methods

If successful, virus-based metal recovery could reshape how societies obtain critical materials and manage waste streams.

Research Paper Reference

Virus-Based Thermoresponsive Separation of Rare-Earth Elements
Nano Letters (2025)
https://doi.org/10.1021/acs.nanolett.5c04468