US govt investigates duckweed DNA

Scientists at the US Department of Energy's laboratories will begin sequencing duckweed DNA in an effort to tap its potential to clean up water pollution.

The humble aquatic plant has been chosen as one of 44 projects that the department’s Joint Genome Institute (JGI) will take on in the next year to investigate potential bioenergy and environmental uses for common plants and microbes.

Greater Duckweed, or Spirodela polyrhiza, grows to less than 10mm but can be used to test water toxicity, clean wastewater and feed animals.

Used on agricultural or household wastewater, duckweed can extract excess nitrogen and phosphate pollutants, the scientists said.

It can also reduce algal growth, the bacteria found in wastewater and mosquito larvae while maintaining water’s PH balance, concentrating heavy metals and encouraging the growth of aquatic animals.

Scientists have discovered that the fast-growing organism could also be used as a biofuel.

Eddy Rubin, JGI director, said: “Duckweed relates to all three of DOE JGI’s mission areas: bioenergy, bioremediation, and global carbon cycling.”

He added: “These plants produce biomass faster than any other flowering plant, and their carbohydrate content is readily converted to fermentable sugars by using commercially available enzymes developed for corn-based ethanol production.

The project was submitted to the JGI’s Community Sequencing Programme by plant biologist Todd Michael, a member of the Waksman Institute of Microbiology, at Rutgers University in New Jersey.

“The Spirodela genome sequence could unlock the remarkable potential of a rapidly growing aquatic plant for absorbing atmospheric carbon dioxide, ecosystem carbon cycling and biofuel production,” he said.

Scientists from a total of six institutions worked on the duckweed project.

Kate Martin

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie