A new study published in the journal Science describes the development of microbial fuel cells-a technology that uses natural bacteria to extract electrons from organic matter in wastewater to generate electrical current.

It is well known that bacterial populations can help to purify groundwater by breaking down harmful compounds, but the new research also shows a practical way to use renewable energy from this process.

The research was led by a team from the University of California, Los Angeles, and focused on the bacterium Shewanella, which can grow and reproduce in all types of environments, including soil, wastewater, and seawater, regardless of oxygen content.

Once inside the bacteria, the silver particles act as a microscopic transmission line to capture more electrons produced by the bacteria

The Shewanella species naturally breaks down organic waste into smaller molecules, and electrons are a by-product of the metabolic process. When bacteria grow into a thin film on the electrode, they can capture some electrons to form a microbial fuel cell to generate electricity.

However, the microbial fuel cell powered by Shewanella oneidensis has not previously captured enough current from bacteria to make the technology practical in industry. Few electrons can escape the bacterial membrane quickly enough to enter the electrode to provide sufficient current and power.

To solve this problem, the researchers added silver nanoparticles to an electrode composed of a type of graphene oxide. Nanoparticles release silver ions, and bacteria use electrons generated during metabolism to reduce silver ions into silver nanoparticles, which are then incorporated into cells. Once inside the bacteria, the silver particles act as a microscopic transmission line, capturing more electrons produced by the bacteria.

Duan Xiangfeng, the co-corresponding author of the study, said in a media statement: "Adding silver nanoparticles to bacteria is like creating a dedicated fast channel for electrons, which allows us to extract more electrons at a faster rate."

With the substantial increase in electron transmission efficiency, the resulting silver-infused Shivanella film will output more than 80% of the metabolic electrons to the external circuit, generating 0.66 milliwatts per square centimeter-the previous microbial-based fuel More than twice the optimal power of the battery.

With the increase in current and efficiency, studies have shown that fuel cells driven by silver-Shewanella mixed bacteria may pave the way for obtaining sufficient power output in the actual environment.