Genetic Surfaceome E. coli Reprogramming Enables Selective Water Oxidation

TL;DR

Scientists engineered E. coli to perform efficient water oxidation, a key step in artificial photosynthesis.

Contribution

A synthetic operon in E. coli was engineered to reprogram its surfaceome for selective water oxidation using a fungal bilirubin oxidase.

Findings

The engineered E. coli achieved water oxidation at near-zero overpotential (27 mV at pH 9.1).

The system completely suppressed the oxygen reduction reaction.

The material enables regenerable microbial platforms for selective catalysis and artificial photosynthesis.

Abstract

Programming catalytic behavior at the microbial genome level is a frontier in synthetic biology with direct impact on bioelectrocatalysis. A key challenge is the coordinated control of gene expression, localization, folding, and cofactor maturation required to achieve proper bioelectrocatalytic activity. Here, a synthetic operon in Escherichia coli is engineered to reprogram its surfaceome for selective water oxidation. Using orthogonal IPTG‐inducible control and codon‐optimized expression, a fungal bilirubin oxidase (BOD) displayed at the cell surface is produced by ice nucleation protein anchoring (BOD‐E. coli). Post‐overexpression copper catalytic site reconstitution provides an active holoenzyme. The developed engineered living material performs water oxidation at near‐zero overpotential (27 mV at pH 9.1), with complete suppression of the oxygen reduction reaction. These results show how regenerable microbial platforms can be designed for selective catalysis and artificial photosynthesis.

A novel enzymatic material based on bilirubin oxidase (BOD) surface‐expressed on E. coli for effective electrocatalysis is reported. With this material, highly efficient and selective water oxidation is achieved, a critical half reaction for synthetic photosynthesis.

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