Photo‐switchable microbial fuel‐cells. Issue 5 (26th February 2018) - Schlesinger, Orr
Abstract: Regulation of Bio‐systems in a clean, simple, and efficient way is important for the design of smart bio‐interfaces and bioelectronic devices. Light as a non‐invasive mean to control the activity of a protein enables spatial and temporal control far superior to other chemical and physical methods. The ability to regulate the activity of a catalytic enzyme in a biofuel‐cell reduces the waste of resources and energy and turns the fuel‐cell into a smart and more efficient device for power generation. Here we present a microbial‐fuel‐cell based on a surface displayed, photo‐switchable alcohol dehydrogenase. The enzyme was modified near the active site using non‐canonical amino acids and a small photo‐reactive molecule, which enables reversible control of enzymatic activity. Depending on the modification site, the enzyme exhibits reversible behavior upon irradiation with UV and visible light, in both biochemical, and electrochemical assays. The change observed in power output of a microbial fuel cell utilizing the modified enzyme was almost five‐fold, between inactive and active states. Abstract : Schlesinger et al. have generated a photo‐switchable ethanol oxidizing bacteria. Depending on the site of incorporation of a photo‐switch site‐specifically attached to a surface displayed alcohol dehydrogenase. Ethanol oxidation could be switched on and off by irradiating E. coli with different wave‐lengths. This spatial‐temporal control of bacterial activity has enabled to switch on and off of a microbial‐fuel‐cell.