Engineered bacterial spores display a protein that selectively captures and releases rare earth elements from harsh environments, offering a reusable, cost-effective, and environmentally safe method for extracting these valuable materials from industrial and environmental sources.
The extraction and recycling of rare earth elements (REEs) are critical challenges in modern industry, driven by the increasing demand for REEs in electronics, renewable energy, defense, and high-tech manufacturing. Traditionally, REEs are sourced through mining and chemical extraction processes that are not only environmentally damaging but also heavily concentrated in a few geographic regions, leading to supply chain vulnerabilities and geopolitical concerns. As global efforts intensify to secure sustainable and domestic REE supplies, there is a growing need for innovative, green, and scalable technologies that can efficiently recover REEs from both primary sources (like ores) and secondary sources (such as electronic waste and industrial effluents), especially under harsh environmental conditions.
Current approaches to REE extraction face significant limitations. Conventional chemical methods involve the use of strong acids and organic solvents, generating hazardous waste and causing substantial ecological harm. Biotechnological alternatives, such as the use of purified proteins or living microbial cells engineered to bind REEs, have been explored but are hindered by high production costs, limited scalability, and poor performance in extreme environments—particularly at the low pH levels typical of acid mine drainage or e-waste leachates. Living cells are prone to lysis and loss of function under such conditions, while protein immobilization on inert supports is labor-intensive and costly. Additionally, these methods often lack reusability and robustness, further limiting their practical application in industrial-scale REE recovery.
This technology utilizes genetically engineered Bacillus subtilis spores that display the lanthanide-binding protein Lanmodulin (LanM) on their surface, achieved by fusing LanM to spore coat proteins such as CotE or CotV-Z. The result is a high-density presentation of LanM—up to 20,000 copies per spore—enabling the spores to selectively capture rare earth elements (REEs) from both dilute and concentrated solutions, even under highly acidic conditions (pH 2–3). The captured REEs can be efficiently released by further lowering the pH or introducing chelating agents, allowing the spores to be reused in multiple extraction cycles. These spores are metabolically inactive, highly resistant to environmental extremes, and can be engineered to prevent germination, making them robust and safe for industrial-scale applications. The platform is designed to be cost-effective and scalable, with spores that can be mass-produced, desiccated for transport, and rehydrated for use.
What differentiates this technology is its unique combination of biological resilience, selectivity, and operational practicality. Unlike previous approaches that relied on purified proteins immobilized on beads or living bacterial cells, this solution leverages the extraordinary durability of bacterial spores, which remain functional in harsh, acidic, and toxic environments where other systems fail. The high-density display of LanM ensures efficient and selective REE binding, while the ability to prevent spore germination addresses biosafety concerns. Furthermore, the spores’ reusability and low production costs make the process both economically and environmentally sustainable, offering a green alternative to conventional chemical extraction methods. This positions the technology as a transformative solution for domestic and industrial REE recovery, particularly in contexts where current methods are either too costly, environmentally damaging, or technically unfeasible.
Engineered Bacillus subtilis spores display surface-fused Lanmodulin protein, enabling high-density rare earth element (REE) capture from acidic solutions (pH 2–3). Bound REEs release via lower pH or chelators, allowing reuse. Robust, metabolically inactive, and germination-preventable, these biological agents resist environmental extremes for industrial applications.
PCT/US2025/030789 conversion filed 05/23/25
Bacillus subtilis Spores for Lanthanide Biosorption from Groundwater | Springer Nature Link