Video transcript: Biofuel from inedible plant material easier to produce following enzyme discovery

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September 2010

Professor Paul Dupree, University of Cambridge
The world really needs to reduce its use of fossil fuels such as oil so one of the ways to do this will be to use plants as an alternative source of fuels. So far we have been using food crops to make fuels but in the future we really need to avoid use of food materials because it could have a detrimental impact on the price of food and the availability of food.

This willow here is at least half sugars and if we knew how to get the sugars out of this and ferment them then we could make fuel or plastics from this material.

Dr Jenny Mortimer, University of Cambridge
The problem that we need to solve is that the sugars we want to use to make biofuels are really tightly locked away by the plant. The plants absorb carbon-dioxide from the atmosphere and they converse it into sugars. These sugars are made into a longer structure that is used to give support and strength to the plant. One of these structures that the plant has made out of these sugars is called zilan. It is a long thin molecule and it is quite complex and the aim of our research was to understand both how the plant makes this molecular and then to see if we could produce a plant with a simplified version of it and the idea is that if this molecular is simpler it will be easier to break down to make sugars to make biofuels.

So to answer questions about how we can simplify this molecule, zilan, we have been using the plant Arabadopsis and this is Arabadopsis here. So the plant looks very commonly used within labs and we understand its biology very well. Even though it is so small it is surprisingly similar to bigger plants such as willow that we might eventually use as bioenergy crops within the UK. So we managed to identify the genes responsible for making the zilan molecule more complicated within the plant and the next step was then to make plants which had simpler zilan molecules and, to our surprise, they grew normally. So although the plants grew normally we wanted to check this in more detail and we know that over in the engineering department they test the strength of all sorts of stuff and we thought why not see if we can test the strength of our stems. So we went over there and found they have a piece of equipment they use to test the strength of steel beams and they managed to modify it so we could actually put our plant stems in there to test the strength and under those conditions we could see a small difference between our normal plants and those with a simple zilan but if you just grow them in our normal conditions they look fine.

So the next step was to look at how the simplified zilan molecule could be extracted from the cell wall. The idea if it is simpler is that it should come out the cell wall more easily and that’s what we found.

Professor Paul Dupree
And this could have a big impact because if we could transfer this to crop plants then that could allow us to extract the sugars much more cheaply and perhaps with a high yield then we currently can. So if this is all aimed at reducing the amount of fossil oil that we use and replacing it with plant materials but replacing it in a sustainable way with plant materials that are not used for food but are rather waste plants or plants grown on marginal land that are not used at the moment for food production.