A research team at the University of Cambridge, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), has identified and studied the genes for two enzymes that toughen wood, straw and stalks making it difficult to extract sugars to make ethanol biofuel.
Lead Researcher, Professor Paul Dupree, says: “There is a lot of energy stored in wood and straw in the form of a substance called lignocellulose. We wanted to find ways of making it easier to get at this energy and extract it in the form of sugars that can be fermented to produce bioethanol and other products.”
Lignocellulose gives plants strength and rigidity. One of the main components of lignocellulose is xylan, which represents a third of the sugars that could be used to make biofuel from wood and straw.
The challenge was to make it easier to break down xylan without having ‘floppy’ plants, says Dupree.
The team studied Arabidopsis plants that lack two of the enzymes that build the xylan in lignocellulose. Although these plants are slightly weaker than normal, they grow normally and reach a normal size.
When attempting to extract biofuel from these plants, the researchers found that it takes less effort to convert all the xylan into sugar.
Dupress concludes: “The next stage will be to work with our colleagues who are developing new varieties of bioenergy crops such as willow and miscanthus grass to see if we can breed plants with these properties and to use our discovery to develop more sustainable processes for generating fuels from crop residues.
“We expect to work closely with industrial collaborators to see how we can quickly transfer this research into real applications for transport fuel.”