Indium holds significant importance in various industrial applications due to its unique properties and versatile characteristics, contributing significantly to technological advancements, energy efficiency, and medical diagnostics. However, the technical complexity and high costs associated with extracting indium solely from minerals pose a considerable challenge in meeting the growing market demand. In addition, the present extraction methods using acid leaching and reduction involve chemical processes that can be detrimental to the environment. Coal and its byproducts represent a potential source of indium recovery, while biological approaches hold considerable promise for separation and purification. In this study, lanmodulin, a highly selective lanthanide-binding protein, that is also concurrently found to have a high affinity to indium, has been enhanced on the microbial cell surface and used to separate and purify indium from solutions derived from coal and its byproducts. Lanmodulin was successfully displayed on the surface of Saccharomyces cerevisiae and Escherichia coli, confirmed by a split green fluorescent protein evaluation system. The adsorption results show that both lanmodulin-bearing cells can effectively recover indium from solutions. This study demonstrates the feasibility of utilizing a microbial surface display system for the protein-based adsorption of indium ions. These findings lay a foundation for further investigations into environmentally friendly biological methods for targeted isolation of indium ions.

Indium,separation,Lanmodulin,surface display