Researchers have discovered key plant enzymes that normally make the energy stored in wood, straw, and other non-edible parts of plants difficult to extract.
The findings, published in Proceedings of the National Academy of Sciences, could be used to improve the economics of producing biofuels from none-food plant crops.
The team based Cambridge University and now part of the Biotechnology and Biological Sciences Research Council's Sustainable Bioenergy Centre (BSBEC), have identified and studied the genes for two enzymes that toughen wood, straw and stalks, making it difficult to extract sugars to make bioethanol or other biofuels.
These insights can now be applied in crop breeding programs to enable the production of non-edible plant material that requires less processing, less energy and fewer chemicals for conversion to biofuels or other renewable products.
The research also increases the economic viability of producing biofuels from plant material.
Lead researcher Paul Dupree noted much energy in plants and wood is stored in the form of 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 is an important structural component of plants, giving them strength and rigidity. One of its main components is xylan, which contains about a third of the sugars in plant biomass. Dupree continued, “What we didn’t want to do was end up with floppy plants that can’t grow properly, so it was important to find a way of making xylan easier to break down without having any major effects.”
The team studied Arabidopsis plants that lack two of the enzymes that build the xylan part of lignocellulose in plants. They found that although the stems of the plants are slightly weaker than normal, they grow normally and reach a normal size. They also tested how easy it is to extract sugars from these plants and found it takes less effort to convert all the xylan into sugar.
The next stage will be to work with researchers who are developing new varieties of bioenergy crops such as willow and miscanthus grass to try and breed plants with these properties and use the 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 fuels,” Dupree said.
For more information, visit: http://www.bbsrc.ac.uk/media/releases/2010/100913-pr-biofuel-enzyme-discovery.aspx