Reprogramming Shewanella Biofilms as Adsorptive Materials for Efficient and Selective Arsenic Removal via...

Area of Science:

• Environmental microbiology
• Biotechnology
• Materials science

Background:

• Arsenic (As) contamination in water poses significant health risks, driving demand for effective remediation strategies.
• Current methods like membrane filtration and chemical precipitation are often costly and chemically intensive.
• Microbial biofilms offer a promising, sustainable alternative for sequestering arsenic.

Purpose of the Study:

• To engineer the biofilm matrix of *Shewanella oneidensis* for enhanced arsenic sorption.
• To incorporate arsenic-binding sites (ArsR) into the biofilm matrix using matrix-associated protein BpfA.
• To develop a generalizable platform for creating functional matrix-integrated materials.

Main Methods:

• Constructed a chromosome-modified *Shewanella oneidensis* strain with constitutive BpfA-ArsR expression.
• Developed two mutant strains with inducible plasmid constructs linking ArsR to truncated BpfA.
• Assessed biofilm formation and arsenic sorption capabilities compared to wild-type strains.

Main Results:

• Engineered strains produced biofilms comparable to wild-type, demonstrating successful matrix integration.
• Engineered biofilms exhibited 2.4-3.8 times greater arsenic sorption performance than wild-type biofilms.
• The modified biofilm matrix showed a strong preference for arsenic sorption, even in the presence of phosphate.

Conclusions:

• Engineered biofilms provide a highly effective and selective method for arsenic removal from water.
• The biofilm matrix serves as a programmable platform for developing functional materials.
• This approach has broad implications for biosensing, resource recovery, and adaptive materials.