BIOELECTRIC BOOST:​ Optimizing a Yeast-Based Biological Fuel Cell​

Grade:

6

Teacher:

Karen Maninang

As global energy consumption continues to rise, communities face increasing environmental and economic challenges associated with fossil fuel–based electricity production. Conventional power generation contributes significantly to air pollution and greenhouse gas emissions, while fluctuating fuel prices can lead to high electric bills for households and businesses. Microbial fuel cells (MFCs) represent an emerging bioelectrochemical technology capable of converting organic matter into electrical energy using living microorganisms. However, a major limitation of microbial fuel cells is their low power density, primarily due to inefficient electron transfer between microbial metabolic pathways and electrode surfaces. Enhancing electron transfer efficiency is critical for improving the practicality of this renewable energy system. This project investigated the optimization of a yeast-based biological fuel cell through the use of an electron mediator, methylene blue. A dual-chamber fuel cell was constructed using Saccharomyces cerevisiae, glucose substrate, phosphate buffer, potassium ferricyanide as the cathodic electron acceptor, and carbon electrodes connected by a salt bridge. Voltage and current were monitored using NeuLog sensors to quantify electrochemical performance. After establishing a 30-minute baseline stabilization period, methylene blue was introduced to the anode chamber to facilitate electron shuttling between yeast cells and the electrode surface. Results demonstrated a significant increase in stabilized voltage during one trial following mediator addition, indicating improved electron transfer kinetics. These findings support the potential of mediator-enhanced microbial fuel cells as a step toward more efficient, sustainable bioenergy systems capable of contributing to pollution reduction and long-term energy cost mitigation.

Project presentation

Research paper