Using naturally occurring and engineered proteins and bacteria, scientists from Lawrence Livermore National Laboratory (LLNL) and partners, Livermore, California, USA, intend to separate and purify rare earth elements (REEs) for the defence sector. The team hopes to leverage advances in microbial and biomolecular engineering to develop a scalable bio-based separation and purification strategy for REEs using under-developed domestic sources.
“To date, the chemical processes required to extract and purify REEs have been complex and harmful to the environment,” stated Yongqin Jiao, LLNL scientist and principal investigator for the project. “Extracting or recycling REE from new sources, like low-grade ores and tailings, while using natural products could be a game-changer for the REE supply chain.”
In the defence sector, REEs are vital in lasers, precision-guided weapons, magnets for motors and other devices; although the US has adequate domestic REE resources, its supply chain is vulnerable due to dependence on foreign entities for separation and purification of these elements. ‘Biomining’ – an approach that uses microbes to extract or separate target metals like gold or copper from a variety of sources – is not yet useful for REEs, given that a role for REEs in biological processes has only recently been discovered.
In the new project, the LLNL team will leverage the diversity, specificity and customisability of environmental microbiology, synthetic biology, and protein engineering to enable new biomining methods for the separation, purification and conversion of REEs into manufacturing-ready forms.
“By cultivating new and translating existing bioengineered REE-converting bacteria and proteins, we will deliver platform biotechnologies for REE separation and purification with high commercialisation potential,” stated Dan Park, LLNL scientist, one of the technical leads for the project.
In addition to exploiting previously identified microbes and proteins that have been tested and used to purify and separate REEs, the team will conduct a bioprospecting campaign to identify new REE-associated microorganisms that seem to exhibit REE-utilisation capacity. Results are expected to expand the repertoire of REE-biomining hosts and REE-binding biomolecules.
Under the Defense Advanced Research Projects Agency (DARPA) Environmental Microbes as a BioEngineering Resource (EMBER) programme, the team was awarded an initial $4 million in funding R&D in Phase 1 with an option for up to an additional $9 million based on programme performance in follow-on phases.
Shankar Sandaram, the LLNL’s programme liaison to DARPA, added, “If successful, the biomining process developed in this project has the potential to help alleviate REE supply vulnerability by reestablishing a domestic REE supply chain, which is critical for advanced defence and commercial manufacturing processes.”
Institutions collaborating in the project include Penn State, Columbia University, Tufts University, University of Kentucky, Purdue University, and industry partner Western Rare Earths.