Biofuels strengthen case for GM crops

Biofuels strengthen case for GM crops

By Fiona Harvey in London

Published: May 17 2008 02:31 | Last updated: May 17 2008 02:31

Genetically modified plants would make better feedstock for biofuels than the current generation of crops used for fuel, says a study published on Saturday.

Biofuels distilled from plants require large amounts of farmland, competing with food crops for resources. They have been blamed for contributing to rising food prices.

But genetically engineering plants to make them more suitable for biofuels production would help to solve these problems, according to the article published in the journal Nature Reviews Genetics.

Biofuel production plants usually use grains or sugar to make bioethanol or vegetable oils to produce biodiesel. These are becoming more expensive to produce because of high feedstock and energy prices, and they have come under fire from environmentalists and poverty campaigners for their effect on food prices.

Attempts are under way, encouraged by governments anxious to reduce their dependency on oil, to develop a new generation of biofuels using waste products, such as straw or other animal and vegetable waste, or tough grasses that grow on land unsuited to normal agriculture.

Scientists have been working on such second-generation biofuels since the early 1970s, although much of the research was shelved when oil price pressures eased. There are significant obstacles to converting waste materials to liquid fuel – the tough cell walls of plants, containing a substance known as lignin, are hard to break down. Researchers have produced enzymes that can break down these materials, but so far they have only been able to do so in laboratories.

The enzymes are also costly to produce, requiring large “bioreactors” fed with specialised microbes.

Mariam Sticklen of the department of crop and soil sciences at Michigan State University, author of the report, said genetically modifying plants could hold the answer, for instance by changing the nature of the lignin in the crop.

“Plant genetic engineering ... promises to have key roles in decreasing biofuel production costs,” she said.

By genetically engineering plants, she said it may be possible to make plants that produce the enzymes needed to break down lignin within their own cells.

An alternative would be to genetically manipulate plants to produce cell wall material that was easier to break down.