Algae grow faster
than any other photosynthetic
organism on Earth.
They produce more than
71 percent of Earth’s oxygen.
And perhaps as important,
they’re capable of
by Carol L. Spence
We stand on the threshold of a new era—a bio-based era. It may not arrive tomorrow or next year, but it’s a certainty in many minds that the future will demand a new way of thinking. Researchers in the College of Agriculture aren’t waiting. They are preparing for that future today.
“You have to think this is where we’re headed, undoubtedly, because everybody’s seen those projections of petroleum reserves leveling off and then, of course, being used up,” said Maelor Davies, director of the College’s Kentucky Tobacco Research and Development Center (KTRDC). “So we believe, ultimately, that we’re going to see a major shift from petroleum-based chemicals to new, renewable sources, plants being a critical one.”
In the future, Davies believes, non-food crops—which could include tobacco—will be grown to make many of the industrial materials and basic chemicals that go into a vast array of consumer goods, such as pesticides, plastics, and pharmaceuticals. And algae shows great potential for removing some of the carbon dioxide from coal-fired power plant emissions.
Today, a wealth of research in the College focuses on these and other new prospects for tomorrow’s crops.
The surface of a tobacco plant is fuzzy. These “hairs,” known as trichomes, come in a variety of shapes and purposes. Two types in particular produce biochemicals, which are compounds that are part of a plant’s defense system.
The tall ones, known as GSTs for glandular secreting trichomes, ooze compounds that drip down like wax and river out across the leaf surface. Insects hate it. With each step, an aphid walking across the surface will pick up more and more of the sticky stuff. Covered with the toxin, the pest is soon a goner.
A tobacco plant’s “fuzziness” is a
Professor George Wagner, conducting his research under the KTRDC umbrella, has spent years studying these tall hairs and their pesticidal properties. In the process, he and then doctoral student Ryan Shepherd stumbled on the sGSTs, or short glandular secreting trichomes. They discovered that these particular trichomes produce a different biochemical, phylloplanin, a protein that appears to protect the plant against fungi—blue mold disease, among others. Similar proteins are produced by sunflowers and a number of other plants.
“They inhibit not only blue mold, but many major fungal diseases, including a number of the major diseases of turfgrasses,” he said. “We came to realize that the biggest market for a natural product fungicide of this type would be in the turf industry.”
According to Wagner, 60 to 70 percent of the total fungicides used in agriculture are used on golf courses and other turf installations.
“In the turf industry, there’s a big movement to outlaw chemical fungicides,” he said. “One of the big problems with chemical fungicides or pesticides in general is that eventually they lose their potency, because the pathogens or pests devise ways of getting around them. With a protein, you can modify the protein so the pathogen doesn’t recognize it.”
It’s not just golf courses that could benefit from Wagner’s and his student’s discovery. Organic growers might benefit from access to a new natural fungicide. Production would differ, however, for the two markets. Using bacteria to produce the protein would be necessary to produce the quantities the turf industry would need, while entry into a niche market of organics would require that the fungicide be produced by plants.
“Whether or not it would be economically feasible to collect it from tobacco plants is still up in the air,” Wagner said. “Sunflower might be an alternative. It’s cheaper to grow.”
The advantage to producers is that once the proteins are gathered from the plant, the rest can be used for something else.
“In the case of sunflower, we wonder if we couldn’t harvest the seed for the oil industry or the bird food industry, and then use the rest of the plant’s phylloplanins to produce fungicide,” he said.
Potential in a Posy
“We’re learning there is much greater potential in these plants to produce far greater chemicals for pharmaceutical or agricultural applications than we ever thought,” said Professor Joseph Chappell referring to a study in which UK is leading a research team comprised of researchers from seven universities.
The purpose of the three-year project, funded by the National Institutes of Health, is to look at an array of plants that are known to be producers of pharmacologically active compounds and isolate those compounds.
Plants such as digitalis, more commonly known as foxglove, are part of the study.
“Some of the compounds in digitalis are very therapeutic for cardiac problems, but some of the other compounds might be very good as anti-inflammatories,” he said. “So trying to sort that out means being able to separate and identify all the different compounds in the plant.”
Besides isolating and identifying each compound, the researchers are also trying to capture the genetic blueprint that is responsible for the plant’s ability to produce these compounds.
Joe Chappell and Yunsoo Yeo harvest
“We try to identify the genes that are responsible for the biosynthesis of each of these different compounds,” he said. “If you have the genetic blueprint in your hand, you can actually manipulate it.”
Which means it can be produced in the needed quantities in a microbial host, such as yeast.
The research is focusing on 14 plants, including ginseng, periwinkle, and Echinacea. Formal drugs may be associated with each of them, but these plants also are filled with all kinds of other interesting compounds that might play a significant role in the development of pharmaceutical drugs, Chappell said.
The amount of the active component in many herbal medicines can vary greatly. Because there is currently no way to standardize the amount of compounds used in supplements and herbal remedies, the NIH and the Food and Drug Administration can’t advocate for the use of those sorts of treatments.
“That’s all within the context of our work,” Chappell said. “We’re trying to give them a baseline for what the chemical composition is of these plants.”
Green: the Color of Clean Air
As we move from a petroleum/fossil fuel based economy to a bio-based one, algae may prove to be a valuable tool during the transition phase. The amount of carbon dioxide in the atmosphere has increased steadily since the dawn of the industrial age, and most people agree that something needs to be done to reduce the level while cleaner fuels are developed. Algae might be an answer.
Algae grow faster than any other photosynthetic organism on Earth. They produce more than 71 percent of Earth’s oxygen. And perhaps as important, they’re capable of sequestering large amounts of carbon dioxide.
At the behest of the Kentucky Department of Energy Development and Independence, Czarena Crofcheck and Mike Montross, associate professors in Biosystems and Agricultural Engineering, along with researchers at the UK Center for Applied Energy Research, are studying the use of algae to mitigate carbon dioxide emissions from coal-fired power plants. The BAE team is evaluating different strains of algae for their effectiveness.
Czarena Crofcheck displays a beaker of algae, one of the many varieties she is testing for mitigation of carbon dioxide emitted from coal-fired power plants.
Because the system involves running hot flue gas from an on-site combustor through vertical, algae-filled tanks, the algae must like an acidic environment and high temperature. For that reason, Crofcheck has been testing samples of algae collected from the scene of a coal fire, an ash pond, and a river near a power plant, among others. Her team also is investigating whether some of the ingredients in the gas could harm the algae.
In the two years the project’s been under way, they’ve been able to capture some carbon dioxide, and capacity is increasing—capacity of the algae to capture carbon dioxide, as well as the tanks’ holding capacity. The team continues to make improvements. And because algae can double in as little as eight hours—though Crofcheck is trying for six—harvesting becomes another issue.
“The benefit might be that we can utilize those algae as a product,” Crofcheck said. “Maybe we can make biofuel from it and get double the bang for our buck.”
Or if not biofuel, then bio-oil that could be refined and used to replace chemicals currently made from petroleum. It might also be used as feed for livestock, Crofcheck said.
Biosystems and Agricultural Engineering majors Whitley Mills and
So Many Ideas, So Many Possibilities
In the College of Agriculture, researchers like Crofcheck, Davies, Wagner, and Chappell, from fields as diverse as engineering and crop science, are positioning the University and the Commonwealth to play a significant role in the bio-future that’s on the horizon.
“A bio-based economy will happen,” KTRDC’s Davies said. “It’s not going to be an overnight change, but it will happen. And we’re excited about the opportunity for agriculture.” ◆