A temperature responsive biopolymer for mercury remediation

Area of Science:

• Biotechnology
• Environmental Science
• Materials Science

Background:

• Mercury contamination poses significant environmental and health risks.
• Existing remediation methods often lack selectivity or require complex recovery processes.
• Elastin-like polypeptides (ELP) offer tunable properties for biomaterial applications.

Purpose of the Study:

• To engineer novel biopolymers for selective and efficient mercury removal.
• To develop a sustainable and reusable technology for environmental remediation.
• To demonstrate the efficacy of ELP-based materials fused with metalloregulatory proteins.

Main Methods:

• Fusion of bacterial MerR protein with elastin-like polypeptides (ELP).
• Exploitation of ELP's reversible thermal precipitation for mercury recovery.
• Testing of biopolymer selectivity against mercury and competing heavy metals (cadmium, nickel, zinc).
• Evaluation of mercury removal efficiency in laboratory settings and contaminated natural water.

Main Results:

• Successfully engineered biopolymers demonstrated high selectivity for mercury binding.
• Minimal binding of competing heavy metals observed even at high concentrations.
• Efficient mercury recovery and continuous reuse of biopolymers achieved through thermal precipitation.
• Mercury concentrations reduced to parts-per-billion (ppb) levels, meeting drinking water standards.
• Effective performance in mercury-contaminated natural water (Lake Elsinore).

Conclusions:

• The developed ELP-MerR biopolymers offer a "green" and effective solution for mercury remediation.
• The technology enables selective sequestration and easy recovery of mercury, facilitating biopolymer reuse.
• This approach holds promise for the removal of other heavy metal pollutants by utilizing different metalloregulatory proteins.