Sticky bacteria make better biofuel

 By Benjamin Plackett

Biofuel — energy that’s gleaned from photosynthesising microalgae — is a great idea, in theory. As a renewable energy source that can be grown and regrown time and time again, it holds great promise. But it’s also beset with problems that prevent it from becoming a truly viable means to generate electricity and power…

Perhaps one of the biggest problems is that separating the fuel from the microscopic algae bacterial cells themselves is costly. It forces up the price per kilowatt of energy produced by the algae, making it harder for biofuel to compete with other renewables and traditional energy sources. But scientists at Michigan State University have been working on that.

The researchers wanted, “to expand the capacity of these bacteria, which can harness solar energy for the production of useful compounds,” said Derek Fedeson, a graduate student at the university who led the research, in a statement. Their answer is a sort of molecular version of velcro, which when inserted into the algae bacteria cells makes them stick to other specially made surfaces — thus separating the cells from the energy compounds they produce.

One of the biggest problems is that separating the fuel from the microscopic algae bacterial cells themselves is costly

One of the specially engineered surfaces was a specific type of yeast, which has a molecular hook on its cell wall. Fedeson and his collaborators had the idea to take advantage of this yeast’s hook by engineering a corresponding hoop on the bacteria’s cell wall. This didn’t take the scientists long to do, but frustratingly they found the hoops and hooks weren’t meeting and so the bacteria wasn’t binding to the yeasts. That’s because the surface of the yeast was clogged up with various proteins and extracellular material, which blocked the hoops from getting to the hooks.

Fedeson knew he’d have to clear the yeast cell wall of this detritus to get the bacteria to bind to it. He looked for the genes that were responsible for producing them. Once he found them, he genetically modified the yeast cells to remove these genes and as he suspected, the algae bacteria then happily bound to the yeast. The hope is that this research could make biofuel more financially viable in the future. “In terms of biofuels, engineered cyanobacteria strains could greatly reduce the high production costs,” said Fedeson, “For example, we can genetically program these cells to recognize and stick to specific materials, reducing the need for specialized and expensive centrifuges or filters.”

SEE MORE: Fuel from algae by Nicholas Newman

about the author
Benjamin Plackett
I’m a journalist based in London. I report on all things science, tech, and health for a number of different publications. My work has been published by The Daily Dot, Inside Science and CNN among others. I earned my M.A. in Journalism at New York University and my B.Sci in Biology from Imperial College, London.