Bacteriophage-Based Sorption of Rare Earth Elements from Dilute Aqueous Solutions

To address an ongoing need for environmentally benign approaches for extracting rare earth elementsRare earth elements (REEs) from ores and secondary sources, we present a novel biosorptionBiosorption method for separating REEs from dilute aqueous solutions using bacteriophageBacteriophage. Our approach involves the genetic engineering of the major coat protein pVIII of the M13 bacteriophageBacteriophage (phage) with the lanmodulin mimetic peptideLanmodulin mimetic peptide, which binds REEs. We present results demonstrating the ability of the modified bacteriophageBacteriophage to extract REEs from dilute aqueous chloride solutions (on the order of μM concentrations) buffered by sodium acetate at pH 5, the structural changes of the pVIII protein, and the aggregation of the engineered phage induced by the REE uptake. We also report on the ability to desorb REE from the phage by pH modulation and demonstrate the recyclability of phage. Finally, we discuss how phage-based biosorptionBiosorption might be scaled up for commercial application.