UK – Researchers from Imperial College London have found that growing trees at an angle significantly increases the amount of fermentable sugars they can produce.Willow is a fast growing perennial energy crop, which is currently used in the production of wood chips and pellets for the heat and power market. But in the future it could also be an important feedstock for the production of next generation biofuel.
Willow can be converted into a road transport fuel by extracting the sugars within the crop and fermenting them to ethanol. It was found that in the wild, willows that had been blown sideways would produce more of the sugars needed to make ethanol but scientists could not explain why this happened.
Now researchers from Imperial College have identified a genetic trait that causes this effect. When a tree is grown at an angle or blown diagonally by the wind, it creates an excess of strengthening sugar molecules in the willows’ stems in an attempt to straighten the plant upwards.
The study was led by Dr Nicholas Brereton and Dr Michael Ray, both from the Department of Life Sciences at Imperial College London, who worked with researchers at Rothamsted Research, and the University of the Highlands and Islands’ Agronomy Institute. The study is published in the journal Biotechnology for Biofuels.
Dr Brereton said: “We’ve known for some time that environmental stresses can cause trees to naturally develop a slightly modified ‘reaction wood’ and that it can be easier to release sugars from this wood.”
“This is an important breakthrough, our study now shows that natural genetic variations are responsible for these differences and this could well be the key to unlocking the future for sustainable bioenergy from willow,” he added.
The research was conducted in controlled laboratory conditions at Imperial College’s Gro-dome facility in central London. The cultivated willows were grown at an angle of 45 degrees and compared to willows allowed to grow naturally straight upwards, in order to compare genetic traits.