Engineering Tobacco Plants for Fuel

Researchers at Philadelphia's Thomas Jefferson University, have tweaked two genes in the tobacco plant, causing the tobacco leaves to produce over twice the amount of oil normally produced.

According to Vyacheslav Andrianov, Ph.D., assistant professor of Cancer Biology at Jefferson Medical College of Thomas Jefferson University, tobacco can generate biofuel more efficiently than other agricultural crops. However, most of the oil is typically found in the seeds � tobacco seeds are composed of about 40 percent oil per dry weight.

Although the seed oil has been tested for use as fuel for diesel engines, tobacco plants yield a modest amount of seeds, at only about 600 kg of seeds per acre. Dr. Andrianov and his colleagues sought to find ways to engineer tobacco plants, so that their leaves expressed the oil.

"Tobacco is very attractive as a biofuel because the idea is to use plants that aren't used in food production," Dr. Andrianov said. "We have found ways to genetically engineer the plants so that their leaves express more oil. In some instances, the modified plants produced 20-fold more oil in the leaves."

Typical tobacco plant leaves contain 1.7 percent to 4 percent of oil per dry weight. The plants were engineered to overexpress one of two genes: the diacyglycerol acytransferase (DGAT) gene or the LEAFY COTYLEDON 2 (LEC2) gene. The DGAT gene modification led to about 5.8 percent of oil per dry weight in the leaves, which about two-fold the amount of oil produced normally. The LEC2 gene modification led to 6.8 percent of oil per dry weight. _Eurekalert

An interesting fallacy in the above report: Andrianov claims that using plants not used in food production for biofuels is somehow "better" than using food plants for biofuels. In actuality, if one wants to maximise food production, one must make sure that he produces his biofuels plants on land that is unsuitable for food crop production, AND utilises only equipment, personnel, fertiliser, water, and any other production materials that could not have otherwise been used for food production.

But since the US has long produced significant excess food, and since less than half the arable land in the US is being used for food production, and since the productivity of food farming (per land used) seems to improve virtually every year, allowing for weather fluctuations -- the food vs. fuels controversy has always been more than a little bit over-hyped.

When humans starve, it is virtually always due to political factors. Warring factions that deny their opponents access to food aid -- generally shipped at great expense in massive amounts. Without such unscrupulous practises by warlords and dictators, starvation would be virtually unknown.

As for the cost of commodities, the 2007 to 2008 spike in oil prices had far more to do with high costs of grain than did biofuels production. Food production in the US expands according to demand, which helps to regulate price. When more maize is used for multiple purposes, more maize is grown.

Al Fin has always preferred 2nd and 3rd generation (non-food) biofuels to biofuels from food. That is because the feedstock for 2nd and 3rd generation biofuels can be more plentifully and cheaply grown on more marginal soils, often using brackish or even salt water. The hysteria over "food for fuels" is greatly misplaced.