- Category: Bioenergy
21 Jan 2013
- Published on Monday, 21 January 2013 09:39
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The gentle sway of willow trees in the wind does not only paint a pretty picture; it also triggers the production of more fermentable sugars for the biofuel industry.
British researchers have identified a genetic trait within willows that is activated when the trees sense they are at an angle, such as when they are blown sideways in the wind. The effect is an excess of strengthening sugar molecules in the willows’ stems as the plant seeks to straighten upwards.
This effect, observed in the wild and in outdoor plantations, results in higher energy sugars to be fermented into biofuels. The scientists believe that – in cultivated willows – allowing them to grow diagonally can trigger this effect and allow them to yield five times more biofuel compared when they are grown straight up.
“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,” said Dr. Nicholas Brereton from the Department of Life Sciences of the Imperial College, London.
“Our study 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 concluded.
Dr. Brereton, together with his colleague Dr. Michael Ray, worked with researchers at Rothamsted Research and the University of the Highlands and Islands’ Agronomy Institute at Orkney College UHI to study willows under various circumstances.
Under controlled laboratory conditions on a rooftop in central London at Imperial’s South Kensington Campus, willows were grown at an angle of 45 degrees and were scrutinized for genetic differences with willows which grew straight upwards.
They then looked for the same effect with willows growing in natural conditions on Orkney Island at the northern-most coast of Scotland. Orkney willows are subjected to winds so strong they naturally grow bent at sever angles.
The results showed that some willows responded more to environmental stresses and changed the composition of their wood to be “stronger” resulting in the production of more sugar. This is good news for breeders of cultivated willow as it means the trees can be improved to produce more biofuel.
Willows are currently cultivated widely across the United Kingdom as promising feedstock for biofuels for motor vehicles, heating systems and industry. They require less than a tenth of the fertilizer used for cereal biofuel crops and have shoots that can quickly re-grow after harvesting. Additionally, they can be grown in plantations that are also attractive to a variety of wildlife, for a positive impact not just on the biofuel industry but on local biodiversity.
The work at Imperial College was part of the BBSRC Sustainable Bioenergy Center’s program for improving the conversion of biomass to fuels. – K. Jalbuena