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
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
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
- 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. …