Seung-Wuk Lee, professor of bioengineering, has genetically engineered viruses to extract rare earth elements. (Photo by Yungyu Lee)Back to the elements
Today’s high-tech electronics and green energy technologies would not function without rare earth elements (REEs). But extracting these substances from raw materials is a dirty process that relies on toxic chemicals and leaves behind polluted waste.
Now, a Berkeley-led team may have solved this problem — thanks to a tiny virus. The researchers genetically engineered a harmless virus to act like a “smart sponge” that grabs REEs from water, and, with a change in temperature and acidity (pH), releases them for collection.
“This is a significant move toward more sustainable mining and resource recovery,” said Seung-Wuk Lee, professor of bioengineering. “Our biological solution offers a greener, low-cost and recyclable way to secure the critical materials we need for a clean energy future while helping to protect the environment.”
The key was transforming the virus into a “highly selective recycling machine” by adding two specialized proteins to its surface. One protein, a lanthanide-binding peptide, acts like a molecular claw, tuned to grab REEs. The other, an elastin motif peptide, acts as a temperature-sensitive switch: when the virus is gently warmed, it drops out of the solution, along with the REEs.
The researchers successfully tested this system by adding the engineered viruses to acid mine drainage. The viruses immediately attached themselves to REEs, ignoring all other metals. By warming the solution, the researchers caused the viruses to clump together and sink to the bottom of the tank. After draining the liquid, the researchers were left with a concentrated sludge of viruses and captured metals. As a final step, they adjusted the pH of this stew to release the pure metal ions for harvesting.
“Our work also has the potential to solve a huge supply chain problem for this country,” said Lee.
Learn more: Researchers pioneer greener way to extract rare earth elements; Virus-based thermoresponsive separation of rare-earth elements (Nano Letters)