Construction of the lithium binding peptide displayed recombinant Escherichia coli for the specific lithium removal from various metal polluted wastewater

Considering the immense increase of lithium battery use, the development of efficient and environmentally friendly lithium recovering process is required. Here, we demonstrate a novel strategy for lithium extraction from battery-polluted water using a biosorbent consisting of whole cells displaying a lithium-binding peptide (LBP). For this goal, the surface of Escherichia coli was engineered to display the lithium binding peptide GPGAP (LBP) by using OmpC as an anchoring motif. Further, the lithium binding capacity of the peptide LBP was increased by construct dimers, trimers, and tetramers of LBP. The trimeric construct of LBP exhibited the highest level of lithium adsorption (3240.187 mu mol g DCW-1) at 20 mM of LiCl concentration. The trimeric construct of LBP displayed E. coli showed high lithium selectivity over cobalt, chromium, and copper respectively present in artificially wastewater. When the purified lithium battery polluted wastewater through the recombinant strain was used for the growth of plants, normal growth of plant was observed while significant growth inhibition was observed in wastewater watered plant. The method developed in this study opens up a new path for the bioremediation of wastewater based on the design of synthetic peptides and their expression on microbial surfaces.