(312c) Engineering a New Self-Regenerative System to Achieve Effective Removal of Heavy Metal Contaminants from Polluted Waters

About 77 million Americans are exposed to contaminated water that contains heavy-metal toxins such as arsenic, lead and mercury.Ranked first on the Superfund List of Hazardous Substances (CDC) is arsenic (As). Arsenic is an ubiquitous toxic metalloid that can replace substitution of phosphates and interact with protein thiol groups; thus, interrupting major biochemical pathways and cleaves DNA leading to high risk of skin, kidney, lung and bladder cancers. Currently, millions of people are exposed to toxic levels of As, predominately through drinking water. Conventional techniques used for As removal from contaminated waters are limited by high cost, secondary pollutants, incomplete removal, and lack of metal specificity. Therefore, an effective method for removal is necessary. Here we engineered a new method of remediation by magnetizing arsenic for removal (M.A.R). Specifically, we have engineered a bacterial strain with a surface-displayed peptide, AfArsR, which binds specifically to arsenite As(III). In addition, the bacterium was engineered with a capability to respond to magnetism, allowing for an easy removal of As(III) ions from the water. Expression of the surface display was validated using a fluorescent protein and the engineered cells exhibited good magnetic response. The findings from this study will facilitate the design of new treatment facilities for economical remediation of water contamination as well as unwanted toxins in the environment.