Researchers discover key for converting waste to electricity using bacteria

Washington, March 4 : Researchers at the University of Minnesota (UM) have discovered the key for converting waste to electricity by taking the help of the bacteria, Shewanella, that can convert simple organic compounds into electricity.

Shewanella are commonly found in water and soil and much of the energy produced by them is because of riboflavin, which is commonly known as vitamin B-2.

"This is very exciting because it solves a fundamental biological puzzle," said Daniel Bond of the University of Minnesota's BioTechnology Institute. "Scientists have known for years that Shewanella produce electricity. Now we know how they do it," he added.

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 clean-up.

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.

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 Jeffrey Gralnick of the department of microbiology at UM.

"Their ability to make iron soluble is key to metal cycling in the environment and essential to most life on earth," he added.

The process could also be reversed to prevent corrosion of iron and other metals on ships.

Also, 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," said Bond.

ANI