From waste to biofuel: Bugs the way

Common Bacteria Tweaked To Digest Sugars From Biomass To Churn Out Green Diesel

Washington: Researchers have genetically engineered one of the most common bacteria on the planet — E coli — to digest simple sugars from plant waste and turn it into valuable biofuel.

They said their study, published on Wednesday in the journal Nature, is the first demonstration of a one-step conversion of a renewable nonfood plant to fuel. The technology could lead to low-cost, low-carbon, highperformance renewable fuels, researcher Stephen del Cardayre said.

“We looked at the ideal feedstock, which is biomass, and then looked at the product we wanted to make, which is diesel, then we engineered this Ecoli to contain the genes that catalyzed all of the chemical reactions required to convert that feedstock into that fuel,” del Cardayre said.

“It’s a one-step process, so there’s no need to have to do two or three buckets of chemistry,” he said. “You put in your feedstock, the bug converts it to fuel, which is an oil that you can just scrape off the top.” Del Cardayre of privately held industrial biotechnology firm LS9 worked in collaboration with researchers at the University of California, Berkeley.

The work represents the next step forward in biofuel technology developed by the South San Francisco-based company. Biofuels, made from plants and animal fat, are alternatives to petroleum-based fuels. Energy secretary Stephen Chu highlighted the research in remarks to a Capitol Hill forum on clean energy, jobs and security.

“The bacteria we find in our guts, E coli, they’ve taken and reprogrammed (with) simple sugars and made diesel,” Chu said. Chu said he was interested enough in the research to email the article’s authors and ask how soon the fuel might be available. He said they responded, “We’ll know in two years.”

Del Cardayre said his company expects to begin commercial production over the next two years in Brazil, where there is an abundant crop of cheap sugar cane juice that could be converted to diesel. Canada, which has invested heavily in the biofuel industry as a way to reduce greenhouse gas emissions, has ordered a study of the environmental impact of making biofuel. REUTERS

IT’S NO ROCKET SCIENCE: After feedstock is put into a bucket, the bug converts it to fuel, which can be just scraped off the top