Scientist Sees a Branching out in Biofuels; Five Questions; Head of Renewable Fuels Institute Says Grasses Hold a Lot of Promise

Article excerpt

Oil prices remain below their pre-recession peak. Gasoline demand may never return to 2008 levels, especially with a new thrust on auto e ciency. But the quest continues to advance the next generation of biofuels; specifically more sustainable fuel sources that help address climate change and don't impact food supplies or prices.

A local hub for biofuels research is the Donald Danforth Plant Science Center in Creve Coeur. Much of the biofuels work there is funded by the Enterprise Rent-A-Car Institute for Renewable Fuels, a scientific center established five years ago with a $25 million gift from Enterprise owners Jack and Susan Taylor.

Tom Brutnell, who took over as director of the institute a year ago, recently discussed the center's ongoing work with the

- Will there be a particular plant or crop that becomes the feedstock of choice for the next generation of biofuels?

There will be many. In Illinois and Missouri, dedicated bio- energy grasses like hold a lot of promise. These are perennials, so they come back year after year, and they require very little inputs. There have been some studies where they've grown these things for a decade with no lost productivity, with no fertilizer. It's a very sustainable form of biomass production. They grow well in the Midwest. But they won't grow so well in the Northeast, and that's where other things such as willow or some of the other small woody species might be the ideal biomass. Then as you go closer to the Gulf Coast, it might be sugar cane or sweet sorghum.

- What role will genetic engineering play in the development of these crops?

What we haven't really seen with any of the feedstock production is the use of transgenic technology. So all of the dedicated bio- energy feedstocks, they are just these grasses that have been bred. Switchgrass, for instance, has been bred to prevent soil erosion. No one's really pushed these things for use as bioenergy. So there may be different qualities of the grass you'd want for combustion or fermentation that are not ideal for, say, the rumen of a cow's gut. So it's going to be possible to alter the chemical structure through transgenics, through GMOs, to make things amenable to fuel production. ... We're also engineering for improved drought tolerance, improved salt tolerance or other abiotic stresses. Frost tolerance is important. As we move some of these bioenergy grasses into climes that they are not naturally grown in, as we move something that's normally in the Midwest into the Northwest, it's going to experience early season frost, so it may need more tolerance to frost, and that can all be achieved through transgenics.

- Can you explain the use of model plant systems at Danforth to help with this research?

At the Danforth Center, no one is really working on the feedstocks themselves, so that would be or sugarcane or switchgrass. What we're focusing on are these model grasses (such as) Seteria viridis. (is a grass that's very closely related to switchgrass, but it's a very small plant. It'll fl ower when it's about 6 inches tall, it has a very rapid life cycle, so it'll go from seed to seed in six to eight weeks, and its transformable, so we can put genes in it. So we can do things like a genetic screen where we look at thousands or tens of thousands of individuals for those qualities I mentioned before altered cell wall composition, altered lignin content, altered tolerance to cold, heat, drought. …