Lanmodulin‐Decorated Microbes for Efficient Lanthanide Recovery

Abstract

Abstract Rare earth elements (REEs) are essential for many clean energy technologies. Yet, they are a limited resource currently obtained through carbon‐intensive mining. Here, bio‐scaffolded proteins serve as simple, effective materials for the recovery of REEs. Surface expression of the protein lanmodulin (LanM) on E. coli , followed by freeze‐drying of the microbes, yields a displayed protein material for REE recovery. Four REE cations (Y 3+ , La 3+ , Gd 3+ , and Tb 3+ ) are captured efficiently, with over 80% recovery even in the presence of competitive ions at one‐hundred‐fold excess. Moreover, these materials are readily integrated into a filter with high capture capacity (12 mg g −1 dry cell weight) for the selective isolation and recovery of REEs from complex matrices. Further, the proteins in the filter remain stable over ten bind‐and‐release cycles and a week of storage. To improve the deployability of this filter material, a simple colorimetric assay with the dye alizarin‐3‐methyliminodiacetic acid is incorporated. The assay can be performed in under 5 min, enabling rapid monitoring of REE recovery and filter efficiency. Overall, this low‐cost, robust material will enable environmentally friendly recycling and recovery of critical elements.