image: A first-year microbiology graduate student works with samples in test tubes under a fume hood in a marine microbiology lab in UT's Science and Engineering Research Facility.
Credit: University of Tennessee
Four faculty members at the University of Tennessee, Knoxville, have been elected 2024 Fellows of the American Association for the Advancement of Science. AAAS Fellows are elected to a lifetime appointment annually by their peers on the AAAS Council in recognition of their extraordinary achievements.
Elected faculty are Professor Albrecht von Arnim of the Department of Biochemistry and Cellular and Molecular Biology; Alison Buchan, the Carolyn W. Fite Professor and associate head of the Department of Microbiology; Research Professor Susan Kalisz of the Department of Ecology and Evolutionary Biology; and Herbert College of Agriculture Dean and Professor David G. White.
“Our newly elected AAAS Fellows help ensure UT remains a world-class research university through their pioneering work,” said Deborah Crawford, vice chancellor for research, innovation and economic development. “Every day they are redefining how to tackle big problems with creativity and innovation, as well as educating and mentoring our next generation of groundbreaking scientists.”
Albrecht von Arnim
How cells in plants build proteins is the foundation for many branches of research, from agriculture to nutrition, helping scientists to optimize crop yields and improve the quality of food for humans and livestock.
Albrecht von Arnim, a professor in UT’s Department of Biochemistry and Cellular and Molecular Biology, has spent his career researching how cells and organisms synthesize thousands of different proteins.
“This really underpins everything an organism does and that is important to us,” von Arnim said. “To me, the ribosome — the machine in the cell where protein synthesis takes place — is very fascinating because all life on earth depends on it.”
As a plant scientist, von Arnim studies how plants can adjust the way they synthesize their various proteins in response to variable environmental conditions. His lab was the first to publish a paper on the effects of the circadian clock on protein synthesis, in 2015.
“Protein synthesis is a very energy-intensive process and therefore needs to be carefully regulated — where it’s made, when it’s made,” von Arnim explained. “Our work on plants complemented similar work in animals. Because food intake directly regulates protein synthesis, this work explains why it not only matters how many calories we take up or from what kinds of foods, but at what time of day we take them up.”
This kind of research, he said, is scientifically important from agriculture to nutrition, but von Arnim said his teaching has also been quite rewarding. For 14 years von Arnim led the Genome Science and Technology program, which operates jointly between UT and Oak Ridge National Laboratory. This unique multidisciplinary Ph.D. program focuses on decoding the complexity of genomes to advance the understanding of life, from microorganisms to more complex biological systems, and to tackle fundamental problems that impact the health and well-being of individuals and the environment.
“Genome science is a topic that resonated with my research expertise at the time when the program was founded in 1998,” said von Arnim, who led the program from 2010 to 2024. “Genomics was an emerging discipline at the time, but it was clear that genomics was going to guide and drive life science for the next decades.”
Alison Buchan
Marine microbes — most of which are good bacteria that are abundant and active in the world’s oceans — are critical to keeping the earth functioning and could hold the key to everything from antibiotic resistance to breaking down manufactured pollutants that can be toxic in high concentrations.
Alison Buchan, the Carolyn W. Fite Professor and associate head of the Department of Microbiology in UT’s College of Arts and Sciences, studies the physiology and ecology of these marine microbes, which she calls “the workhorses for a lot of the biogeochemical cycles that are critical for Earth’s functioning.”
“Biogeochemical cycles are like the earth’s recycling system for essential elements like carbon, nitrogen and phosphorus,” said Buchan, who cultures and grows these marine microbes in her lab at UT. “They ensure these elements are continuously available for plants, animals and other organisms.”
One aspect of Buchan’s research looks at the way these bacteria are influenced by and interact with the viruses that infect and sometimes kill them. The relationships between the viruses and their hosts are far more nuanced than expected, with intracellular decision-making leading to one of two outcomes: death of the bacterial cell or harmonious coexistence. And these entanglements are likely not unique to marine bacteria and their viruses.
“We think it is plausible that the interactions we are deciphering are commonplace in the microbial world and may ultimately inform research looking to address the antibiotic resistance crisis,” she said. “Globally, there’s a tremendous amount of research in terms of trying to understand the interactions that bacteria have with their viruses, because we’re trying to come up with new and clever ways to deal with microbial pathogens.”
Buchan’s research also looks at the way these marine bacteria break down tough materials, including the components of woody plants and structurally related synthetic compounds such as those found in some plastics. These compounds are not only difficult to break down but can be toxic at high concentrations, so understanding how the bacteria are able to both tolerate and degrade contaminants from things like paper production, plastic waste and municipal solid waste may ultimately lead to advancements in how we prevent those compounds from accumulating in the environment.
“What brings me joy is the continual promise of uncovering and identifying new phenomena, new things that haven’t been discovered or seen previously,” Buchan said. “You think things are going to work one way and they don’t work that way, but when something works — either as you expected it to or not as you expected it to — it gives you something else to think about and perhaps changes the way you were originally approaching the question. It’s t he continual possibility of discovery that’s great.”
Susan Kalisz
The health of most plants depends on a mutually beneficial nutritional relationship with the fungi that live in their roots, so what happens when stressors like drought, heat or invasive species disrupt that partnership?
Susan Kalisz, a professor emerita and research professor in UT’s Department of Ecology and Evolutionary Biology, has spent her career investigating the impact of invasive species on native plants. Over 20 years, her lab conducted a field experiment in a deciduous forest, during which she either removed or allowed invasive species to so that she could observe their impact on native perennial wildflowers’ fitness.
“The reason I chose trillium, jack-in-the-pulpit and Solomon’s seals as the focal species in my research is that they’re really common — plants that most people who have hiked in the Smoky Mountains will have seen,” Kalisz said. “These plants have a wide distribution in North America and are important keystone species in the understory (the layer of vegetation beneath the main canopy of a forest) as sources of food for pollinators and beauty for humans.”
Plants receive water, phosphorus and nitrogen from the fungi that extend their hyphae into the soil and function like additional roots for the plant, while the plant is the sole source of carbon that these beneficial fungi need for growth. But chemicals produced by some invasive plants that protect them from fungal and bacterial diseases in their native lands can have negative effects when they invade foreign soils, killing the fungi that are beneficial to native plants and disrupting the critical partnership.
“Without fungi providing water, phosphorus, nitrogen and other micronutrients, the plants are starved for these key elements they need for photosynthesis, growth and reproduction,” she said. “Understanding how stressors alter this beneficial interaction between plants and fungi is fundamental to understanding the health and viability of both agricultural crops, horticultural plants and forest systems.”
Kalisz previously served as head of the Department of Ecology and Evolutionary Biology at UT, president of the American Society of Naturalists, a co-leader of two working groups at National Evolution Synthesis Center at Duke University, editor of the American Naturalist, program director in the Division of Environmental Biology at the National Science Foundation, and on the editorial boards of Evolution, The American Naturalist and Journal of Ecology. Yet she describes herself as still in as much awe of plants as she was as an undergraduate.
“I find joy in working with my collaborators to discover how ecological and evolutionary systems work,” Kalisz said. “Observing the exquisite nature of plants and how they adapt to diverse environments gives me joy every day.”
David G. White
Antibiotic use in animals, especially in food production, is a public health concern because it can lead to antibiotic-resistant bacteria that can spread to humans, making infections harder to treat.
David G. White, dean of UT’s Herbert College of Agriculture and a professor of food science, has spent his career focusing on the intersections of animal health, food safety and human health through a One Health approach. One Health recognizes that the health of humans, animals and ecosystems are interconnected and is particularly relevant when it comes to addressing an issue like antibiotic resistance, where a multidisciplinary approach is needed to combat the global spread.
“My specific area as a molecular microbiologist was characterizing how bacterial pathogens developed resistance to antimicrobials used in veterinary and human medicine and deciphering potential public health implications,” White explained. “A great deal of my work focused on accurately assessing the risks associated with different antimicrobial classes used in food-producing animals and developing coordinated, collaborative and cross-sectoral approaches to mitigate spread across multiple ecosystems.”
Although White developed “the bug” for research about halfway through his animal science undergraduate program, he eventually evolved to translating his research into national and international policy. He spent many years serving in the U.S. Food and Drug Administration, where he had an opportunity to help set global policy for agencies such as the World Health Organization, the World Organization for Animal Health and the Codex Ad Hoc Intergovernmental Task Force on Antimicrobial Resistance. White is a past member of the Presidential Advisory Council on Combating Antibiotic-Resistant Bacteria and currently serves on the WHO Advisory Group on Critically Important Antimicrobials for Human Medicine.
“Addressing the problem of antimicrobial resistance is a top priority of federal and international health agencies globally, and much still needs to be done regarding understanding the factors that drive emergence and spread, assessing economic impacts and finding viable mitigation strategies,” he said.
Asked what brings him joy in his current role at UT, White was quick to point to educating the next generation of microbiologists and One Health experts.
“Established microbiologists are getting older, and we need young investigators entering the field to determine both the drivers of emerging antibiotic resistance and what are the most effective measures to mitigate this worldwide problem,” he said. “The highly sought magic bullet has still not been discovered, and antimicrobial resistance is not likely to go away any time soon, so using these miracle drugs as judiciously as possible is the key to minimize negative impacts to both animal and human health.”