A protein mines, sorts rare earths better than humans, paving way for green tech
Rare earth elements, like neodymium and dysprosium, are a critical component to almost all modern technologies, from smartphones to hard drives, but they are notoriously hard to separate from the Earth's crust and from one ...
Penn State scientists have discovered a new mechanism by which bacteria can select between different rare earth elements, using the ability of a bacterial protein to bind to another unit of itself, or "dimerize," when it is bound to certain rare earths, but prefer to remain a single unit, or "monomer," when bound to others.
By figuring out how this molecular handshake works at the atomic level, the researchers have found a way to separate these similar metals from one another quickly, efficiently, and under normal room temperature conditions. This strategy could lead to more efficient, greener mining and recycling practices for the entire tech sector, the researchers state.
"Biology manages to differentiate rare earths from all the other metals out there—and now, we can see how it even differentiates between the rare earths it finds useful and the ones it doesn't," said Joseph Cotruvo Jr., associate professor of chemistry at Penn State and lead author on a paper about the discovery published today in the journal Nature. "We're showing how we can adapt these approaches for rare earth recovery and separation."
Rare earth elements, which include the lanthanide metals, are in fact relatively abundant, Cotruvo explained, but they are what mineralogists call "dispersed," meaning they're mostly scattered throughout the planet in low concentrations.
A protein found naturally in a bacterium (Hansschlegelia quercus) isolated from English oak buds exhibited strong capabilities to differentiate between rare earths. Harnessing its power could revolutionize all tech sectors by fundamentally changing how critical minerals like rare earths are harvested. Credit: Penn State
The Penn State lab turned to nature to find an alternative to the conventional solvent-based separation process for rare earths, because biology has already been harvesting and harnessing the power of rare earths for millennia, especially in a class of bacteria called “methylotrophs” that often are found on plant leaves and in soil and water and play an important role in how carbon moves through the environment. Credit: Patrick Mansell/Penn State
Joseph Cotruvo Jr., associate professor of chemistry at Penn State, is lead author on a paper about the discovery of a new mechanism by which bacteria can select between different rare earth elements, using the ability of a bacterial protein to bind to another unit of itself, or “dimerize,” when it is bound to certain rare earths, but prefer to remain a single unit, or “monomer,” when bound to others. Credit: Patrick Mansell/Penn State