August 13, 2008

Plants Become Acid Factories

By Luntz, Stephen

CSIRO and the Grains Research and Development Corporation's joint Crop Biofactories Initiative has taken a step towards replacing petroleum-derived products with plant oils while avoiding the problems associated with biofuels. They have expressed significant quantities of vernolic acid, an unusual fatty acid (UFA), in the model plant Arabidopsis and hope to transfer their work to produce a range of other UFAs in safflower seeds, which are rich in oil. Dr Allan Green of CSIRO Plant Industry says that the oils normally produced by oilseed plants are "fairly simple structures and not very useful for industrial products such as plastics". In contrast, UFAs have double carbon bonds or other chemical groups located at unusual points on the carbon chain. This means that they can be broken down or reacted to make subunits that are useful for producing polymers.

The idea of getting plants to grow UFAs is not new, but Green says that other teams have struggled to get plants to turn more than 10% of their oil into high value acids. The CSIRO team has succeeded in reaching 30%, although he says the ultimate aim is to have 90- 95% of a plant's oil production being the target product.

The methods that Green and his colleagues have used remain confidential, but Green believes it will prove applicable to other UFAs. "There are two aspects: getting the right enzyme introduced into a plant, and then making its unusual fatty acid product accumulate at high concentrations. We've focused a lot on the second," Green says.

While biofuel production has contributed to the recent rise in food prices, and with it world hunger, Green is confident this will not be a problem with plant production of UFAs, since the world uses relatively little of these oils compared with the consumption of petroleum in transportation fuels.

Furthermore, the target plant safflower is not widely grown in Australia so Green says industrial uses "will not provide direct competition" for food. "Safflower is an ideal plant for industrial production for Australia," Green says. "It is hardy and easy to grow, widely adapted to Australian production regions and easily isolated from food production systems."

On the other hand, the high value of UFAs compared with transport fuels means that farmers stand to make significant profits if the research can be successfully commercialised.

Copyright Control Publications Pty Ltd Jul 2008

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