Science - March 10, 2010

Breeding plants to produce cheap energy

Plant breeding can play a big role in the transition to a biobased economy, says PhD student Andres Torres Salvador of Wageningen University. He wants to cultivate plants from which energy can be obtained more efficiently and with less cost.

Torres Salvador, attached to the Laboratory of Plant Breeding, presented his research work on 9 March during the symposium 'A world in Transition' to commemorate the 92 nd Dies Natalis of Wageningen University. Torres Salvador has been studying how to make the inedible parts of the maize plant suitable for energy extraction. He looks at, in particular, the cell walls. 'These are composed mainly of cellulose which can be converted into alcohol during fermentation', he explains. 'Cellulose is the most common organic material on Earth and therefore has enormous potential.'
Nothing to it
The costs of converting cell walls into alcohol are currently too high. The bottleneck lies in the first step of this process: the breaking down of cellulose in the cell walls. Cellulose consists of a lengthy and robust chain of sugar molecules which require expensive enzymes to be separated from one another. As for the rest of the process, there's nothing to it: the individual sugar molecules can be easily fermented into bio-alcohol, which is suitable as a fuel. Torres Salvador therefore wants to find ways to cultivate maize plants whose cellulose can be broken down more efficiently. 'I am concentrating on cell wall properties which can influence the breaking down and fermentation process', the PhD student explains. 'In addition, it is essential for us to identify the genes which determine the properties of the cell walls.' With this approach, he hopes to change the maize plant in such a way that it can produce bio-alcohol which can compete with fossil fuels.
Virgin forests
Gene technology is another useful tool whereby energy from maize plants can be extracted more efficiently, says Torres Salvador. 'It would be ideal if we can cultivate a plant which produces enzymes to break down their own cell walls. But this wouldn't be easy to do.' Despite the enormous possibilities, there is also much resistance to the use of agricultural land for fuel production, as evident from the arguments put up by several members of the audience during the symposium: the planting of alcohol-producing vegetation can threaten food production and encourage the felling of virgin forests. To tackle this problem, Torres Salvador wants, for example, to make plants which can grow on marginal land where very little else can grow on. 'Despite problems which can arise, we have to remain optimistic', is his belief. 'What I really want to say is that plant breeding can be an excellent contribution to the transition to a sustainable biobased economy.'