A future powered by microbes

Picture a future where microbes can be used to produce electricity in our homes, to clean wastewater or detect pollutants, or even be used in wearable health monitoring devices. It may sound far-off, but researchers are already working on it.

Some microbes can transfer electrons (negatively charged particles) to solid surfaces, including electrodes. These unique abilities have inspired microbial electrochemical technologies (METs), systems that use electroactive microbes as their key components to generate electricity or produce valuable chemicals. These technologies could help tackle challenges related to sustainability, environmental monitoring, and the circular economy. Yet scientific and technological barriers still limit their performance, robustness, and scalability, keeping many concepts in the lab rather than in everyday use.

A major goal of the Microbial Interactions Biotechnology laboratory at ITQB NOVA is to overcome those limitations. Catarina M. Paquete leads this new laboratory and is also a part of the International Society for Microbial Electrochemistry and Technologies (ISMET), a community of experts with a shared interest in how microbes and electrodes can work together to solve real-world problems.

Recently, members of this community engaged in a creative exercise, using LEGO to build a vision of what METs could become in the coming decades. Through this LEGO city, participants envisioned a future in which circular wastewater treatment enables resource recovery, microbial platforms produce valuable organic compounds, bioinspired materials power the next generation of wearable health monitors, and advanced biosensors enable real-time environmental and health monitoring.

Imagine a city where sensors constantly monitor and track water quality and detect contaminants in real time, running on electricity produced by microorganisms, with no fuels involved. Zooming out, wastewater treatment plants become miniature resource factories, with microbes capturing nutrients, recovering valuable metals, and generating energy while cleaning the water. Instead of simply treating wastewater as a waste, these systems turn it into a source of resources and return clean water safely to the environment, to agriculture, or even, where appropriate, back to our taps.  But the possibilities go even further.

Some species can work in the opposite direction, taking electrons from an electrode rather than releasing them. With this ability, we could feed electricity to microbes to convert carbon dioxide into useful compounds working as building blocks for bioplastics, lubricants, fragrances, coatings, cosmetics, pharmaceuticals, fuel, feed, and food ingredients. In this vision, METs become more than a technology for producing electricity; they offer a biological route to carbon capture and green chemistry.

“By working together, we were able to look beyond the boundaries of individual disciplines and imagine an ambitious yet achievable roadmap for the future of MET,” explains Catarina Paquete, chair of the Public Engagement and Outreach Committee of ISMET. At ITQB NOVA, her team is working to help turn this vision into reality by exploring how microbes interact with each other and with electrodes and how these interactions can be improved to develop new biological technologies for a more sustainable future. “While METs hold significant promise for addressing societal challenges through innovative applications, significant hurdles remain,” she adds. “We still need to understand how to reliably grow and control microorganisms in these systems, improve their performance, and translate these advances to larger-scale systems operating under real-world conditions, ultimately bringing the full potential of METs closer to reality.”

Researchers from ISMET mapped out these and other key bottlenecks and research priorities in a paper published in Trends in Biotechnology. With this shared vision, we are better positioned to move from a LEGO dream to real smart cities and to rethink what sustainable technology can look like when biology becomes part of the circuit.