# A Biofuel Cell for Electricity Generation from Biomass-Derived Cellobiose

## TL;DR

Researchers created a biofuel cell that generates electricity from cellobiose using enzymes and found that certain biomass pretreatments improve performance.

## Contribution

A novel bioanode design using β-glucosidase and glucose oxidase for efficient electricity generation from cellobiose.

## Key findings

- Alkaline pretreatment of biomass improves biofuel cell performance compared to phosphoric acid.
- Adding β-glucosidase enhances current generation even with commercial cellulase.
- The bioanode efficiently converts cellobiose to electricity via a two-enzyme cascade.

## Abstract

We have developed a new bioanode based on a cascade of reactions catalyzed by two enzymes. A glassy carbon electrode is modified with β-glucosidase and glucose oxidase enzymes entrapped within an osmium redox polymer. Cellobiose, the fuel for the anode, is hydrolyzed by β-glucosidase (TxGH116), yielding two molecules of D-glucose. Glucose is then oxidized by glucose oxidase (GOx) into δ-gluconolactone and produces electrons that are transferred to the electrode mediated by osmium redox polymer. We investigated the kinetic parameters of both enzymes at different temperatures. For GOx, the effect of enzyme loading and enzyme/polymer ratio were also optimized. The proposed bioanode is coupled to a biocathode based on horseradish peroxidase (HRP) in which H2O2, the oxidant, is reduced. We investigated the performance of the biofuel cell on cellobiose and sugarcane hydrolysates subjected to different pretreatments. Alkaline pretreatments of biomass were found to be more effective than phosphoric acid pretreatment. Adding TxGH116 β-glucosidase further enhanced current generation, even when commercial cellulase was used.