Genetically modified microorganism could convert atmospheric CO2 into fuel
March 29, 2013
While much research is being done on capturing carbon dioxide emissions at their source to reduce the amount expelled into the atmosphere, researchers at the University of Georgia’s Bioenergy Systems Research Institute have taken a different approach to tackle the problem. Taking a leaf out of the process used by plants to convert CO2 into something useful, they have uncovered a way to take CO2 from the atmosphere and transform it into useful industrial products, including, potentially, fuel.
The method took inspiration from photosynthesis, whereby plants use sunlight to transform water and carbon dioxide into sugars they use for energy. The researchers created a microorganism that imitates what plants do by manipulating the genetic material of Pyrococcus furiosus or "rushing fireball," a microorganism that feeds on carbohydrates in the super-heated ocean waters near geothermal vents.
The team modified the organism so that is able to feed at lower temperatures. They then used hydrogen gas to create a chemical reaction in the microorganism that incorporates CO2 into 3-hydroxypropionic acid, a common industrial chemical that can be used to make acrylics and other products.
"What this discovery means is that we can remove plants as the middleman," said Michael Adams, lead researcher. "We can take carbon dioxide directly from the atmosphere and turn it into useful products without having to go through the inefficient process of growing plants and extracting sugars from biomass."
In addition to the production of industrial products, other genetic manipulations could allow the organism to produce other products, including fuels. However, at this point the conversion cycle still relies on fossil fuels because the researchers use hydrogen as the source of energy, whose most readily available source at the moment is natural gas, also a fossil fuel.
"In the longer term we would hope to use hydrogen from a renewable (non-fossil fuel) biological source, such as from photosynthetic algae or from waste-product fermentations," said Adams. However, the fuel produced with Pyrococcus furiosus is carbon-neutral because it releases the same amount of CO2 when burned as was used to create it, making it cleaner than gasoline, oil and coal.
This is not the first time scientists have looked to bacteria to produce fuel from carbon. A couple of years ago researchers from the University of Minnesota created a process using Synechococcus, a photosynthetic bacterium that fixes carbon dioxide in sunlight before converting it to sugars.
Adams says the research team will now look at refining the process and testing it on a larger scale.
Details of the study, which was supported by the U.S. Department of Energy, were published on March 25 in the early online edition of the Proceedings of the National Academies of Sciences.
Source: University of Georgia