Shewanella Use Riboflavin to Make Electricity

Researchers at the University of Minnesota studying bacteria capable of generating electricity have discovered that riboflavin (commonly known as vitamin B-2) is responsible for much of the energy produced by these organisms.

The bacteria, Shewanella, are commonly found in water and soil and are of interest because they can convert simple organic compounds (such as lactic acid) into electricity, according to Daniel Bond and Jeffrey Gralnick, of the university's BioTechnology Institute and department of microbiology, who led the research effort.

"This is very exciting because it solves a fundamental biological puzzle," Bond said. "Scientists have known for years that Shewanella produce electricity. Now we know how they do it."

The discovery means Shewanella can produce more power simply by increased riboflavin levels. Also, the finding opens up multiple possibilities for innovations in renewable energy and environmental cleanup. The research is published in the March 3 issue of the Proceedings of the National Academy of Sciences.

The interdisciplinary research team, which included several students, showed that bacteria growing on electrodes naturally produced riboflavin. Because riboflavin was able to carry electrons from the living cells to the electrodes, rates of electricity production increased by 370 percent as riboflavin accumulated.

Scaled-up "microbial fuel cells" using similar bacteria could generate enough electricity to clean up wastewater or power remote sensors on the ocean floor.

"Bacteria could help pay the bills for a wastewater treatment plant," Bond said.

But more ambitious applications, such as electricity for transportation, homes, or businesses, will require significant advances in biology and in the cost-effectiveness of fuel cell materials.

Why do these bacteria produce electricity? In nature, bacteria such as Shewanella need to access and dissolve metals such as iron. Having the ability to direct electrons to metals allows them to change their chemistry and availability.

"Bacteria have been changing the chemistry of the environment for billions of years," said Gralnick. "Their ability to make iron soluble is key to metal cycling in the environment and essential to most life on earth."

The process could be reversed to prevent corrosion of iron and other metals on ships. Bond and Gralnick were each recently awarded funding from the U.S. Navy to explore this and other potential applications.

This research was funded by the Initiative for Renewable Energy and the Environment, the National Science Foundation, the National Institutes of Health and Cargill.

Download Center

  • Your Guide to Environmental Metrics that Drive Performance

    Translating sustainability into action starts with implementing the right metrics to assess your environmental risk and performance. Learn how to design metrics that improve your decision-making process and drive enterprise performance.

  • Unpacking ESG: 6 Questions You Were Too Afraid to Ask

    Environmental and Sustainability experts from Arcadis and Cority answer 6 of the most pressing questions EHS professionals have about getting started with Environmental, Social, and Governance (ESG) reporting.

  • 5 Keys to Best-in-Class Chemical Management

    Running a safe chemical program is challenging and complex: from knowing what's on-site to proper handling and disposal - all while navigating regulatory changes. Learn the best ways to mitigate chemical risk, get the most value out of your data, and gain buy-in for a chemical management solution.

  • Streamline Your Air Emissions Management

    See how consolidating all your emissions management functions into one centralized system can help you streamline your operations, more easily maintain compliance, and achieve greater time and cost savings.

  • A Crash Course in Creating the Right Environmental Scoring System

    Learn how to develop the right environmental scoring system so you can easily benchmark performance across all your facilities and gain a holistic view of your environmental programs.

  • Industry Safe