Fall 2022

Eureka! Industry-Changing Breakthroughs

From the food we eat to the species we protect to the ways we care for our bodies, North Carolina State University’s College of Agriculture and Life Sciences continues its long tradition of transformative innovation.

by: Emma Macek 13-min. read

Prestage student works in a lab in BTECH on Centennial Campus.

From the food we eat, to the species we protect, to the ways we care for our bodies, North Carolina State University’s College of Agriculture and Life Sciences has helped lead the way in discovery and innovation, bettering our lives and supporting the natural resources we depend on. Here are just a few examples of scientific breakthroughs from CALS researchers that continue to seed the future of the life sciences.

Viruses Carrying Beneficial Traits

By Emma Macek and Juliana Proffitt McCully

Feeding a rapidly growing population has many challenges, including pests and environmental conditions that threaten the crops that nourish us. Generally, viruses are also included in the list of challenges because they reduce crops’ quality and yield, but that may be changing.

Anna Whitfield, a plant virologist from the Department of Entomology and Plant Pathology and a faculty member in the Chancellor’s Faculty Excellence Program in the Emerging Plant Disease and Global Food Security Cluster, uses viral vectors to insert beneficial traits into crops. Essentially, her method armors the plants to fight their challenges themselves.

“Generally, it’s considered bad to have a virus in your plants, but this project takes plant viruses and uses them for good,” says Whitfield, whose project is supported by a Bayer Crop Science Grants4Ag award. “Plant viruses are powerful tools for delivering molecules to their plant hosts, so we created an infectious clone of a plant rhabdovirus that can be engineered to carry beneficial proteins or RNA to plants with the goal of protecting them from stressors such as drought, disease and pests.”

The idea of taking viruses and genetically manipulating them isn’t new, but Whitfield is using a different type of RNA virus that is more challenging to work with but is also more dependable and can, as she says, “carry more cargo.”

“That means you can put more genetic information into them to express different genes in plants, and they keep their inserts for a longer amount of time,” says Whitfield.

Whitfield’s methods have shown great promise in a variety of applications that are considered safer and more environmentally friendly than traditional methods.

“Instead of applying pesticides, the novel virus system could deliver a protein or RNA that could target and kill pests, which can also be better for the environment and could reduce farmworker exposure to pesticides,” says Whitfield.

The benefits are also seen within the scientific community. The production time of a transgenic plant using traditional methods is usually long due to the need for using multiple generations over several seasons. Whitfield’s technology delivers the virus directly to the plant, and different traits can be tested in a single season. For example, corn, sometimes called maize, is a major crop in the U.S. and worldwide, and an efficient and stable virus vector could cut years off the current methods.

“The ability to modify a plant phenotype in a single crop cycle can greatly facilitate identification and deployment of beneficial traits to increase crop yields and plant resilience,” says Whitfield.

Whitfield is also developing technologies to fight tomato spotted wilt virus (TSWV), a global challenge that impacts hundreds of different species of plants, including tomatoes and peanuts in North Carolina.

Using knowledge of the virus genome, Whitfield and her colleague Dorith Rotenberg developed tomato plants that express small pieces of viral RNA. This protects them from virus infection, resulting in tomatoes resistant to TSWV and other related viruses. A new isolate of TSWV has emerged that overcomes the resistance gene most commonly used in tomatoes, but recent experiments showed that Whitfield and Rotenberg’s new tomato plants are protected from the resistance-breaking TSWV strain.

Whether she’s using viruses to armor crops to fight stresses or developing crops resistant to devastating viruses, Whitfield is committed to helping ensure an abundant food supply well into the future.

Expand to read moreCollapse

Food Safety and Convenience: A Package Deal

Have you ever wondered how some foods and beverages stay fresh for so long in a carton without refrigeration or freezing? Some products, including milk, soups and wines, are shelf-stable at room temperature for as long as 18 months. Aseptic processes make this possible by freeing our favorite foods and beverages from contamination caused by harmful bacteria, viruses or other microorganisms, as well as maintaining their sterility during packaging. They also create high-quality foods that can taste better and are more nutritious than canned goods.

William Roberts, the inaugural head of the North Carolina State University department now known as Food, Bioprocessing and Nutrition Sciences, brought aseptic processing and packaging technologies developed overseas to the United States for the first time. He also helped establish NC State as a leader in food science research, a status that continues today.

Roberts began his dairy manufacturing research at NC State in 1943, during the thick of World War II. In the first role of its kind at the university, he visited commercial dairy facilities around North Carolina to oversee processed milk and help meet the military’s milk demands.

When the university recruited faculty members from several departments into the Department of Food Science in 1961, Roberts advocated for a central building, known as Schaub Hall. It soon became a testing area for aseptic equipment that was previously only available overseas.

In the 1940s and ’50s, most of North Carolina experienced a considerable loss of milk due to a carry-over of wild onion flavor from the pastures that the cows were feeding on. The Vacreator, developed in New Zealand, used steam injection, high temperatures and a vacuum technology to process dairy and eliminate feed and weed flavors. The department borrowed a Vacreator and successfully removed the unwanted flavor, returning thousands of dollars in milk revenue to farmers.

Roberts later brought a semi-rigid packaging unit developed by Sweden-based Tetra-Pak to Schaub Hall for testing. Soon, all major food companies sought the department’s packaging abilities, making NC State the first academic institution in the country to work contractually with food industry professionals. Today, the unit is housed in the Smithsonian Institution.

Roberts’ legacy lives on both in industry and at the university. Many shelf-stable liquid food products—including sauces, soups and baby food―were first tested using ultra-high-temperature processing methods in Schaub Hall. Breakthroughs continued in the Department of Food, Bioprocessing and Nutrition Sciences, thanks to those who followed Roberts. Vic Jones, Art Hansen, Harold Swaisgood and Ken Swartzel were among them.

Research Professor Josip Simunovic is doing the most recent work. He studies advanced aseptic processing, which includes working with advanced microwave technologies and products that are difficult to process by conventional methods, such as sensitive baby and infant foods, thicker and chunky soups, and purees with pieces of fruits and vegetables.

Simunovic and his teams are also leading the push to electrify aseptic processing. Although the teams developed the novel electric/microwave processing technology more than 20 years ago to decrease processing times and increase nutrient preservation, popularity has picked up recently due to concerns with conventional technologies generating excessive carbon dioxide.

Currently, they are studying solid-state microwave heating and cooling technologies, which also include continuous temperature data readings throughout the aseptic process. These technologies will further reduce food waste, minimize the destruction of nutrients and extend the functional lives of machinery.

“Dr. Roberts created the culture and the structure of innovation in our field,” says Simunovic. “He also instilled the spirit of collaboration and engagement across different disciplines of food science, which is essential today.”

Expand to read moreCollapse

Avian Stem Cells Stemmed from CALS

When you get a vaccine, you’re sometimes asked if you’re allergic to eggs. This is because some vaccines, including the influenza vaccine, are produced using embryonated eggs. However, vaccines are now being developed using cell lines instead. Thanks to the work of Jim Petitte, an emeritus professor in the Prestage Department of Poultry Science, avian embryonic stem cells are among them.

A cell line is created by removing cells from an organism and growing them in an artificial environment. Cultures from a single cell can be propagated easily and repeatedly, and the genetic uniformity offers advantages that have revolutionized biological research, vaccine and antibody production, and more.

The U.S. Food and Drug Administration has approved vaccines from avian embryonic stem cells for use in veterinary and human medicine, and they are crucial in creating a wide variety of vaccines and other medical therapies, including vaccines for egg drop syndrome and influenza.

Embryonic stem cells are developed by collecting cells during the early stages of embryo development, and those cells are then grown in media to produce a continuous cell culture. One of the key characteristics of embryonic stem cells versus other stem cells is that they can grow indefinitely into any kind of tissue.

When Petitte started his Ph.D. in animal and poultry reproduction at the University of Guelph in Ontario, Canada, only mouse embryonic stem cells had been developed, but scientists were actively developing stem cells from cows, rabbits and other mammals. However, avian stem cells were not yet developed, and Petitte wanted to be the first to do so.

“I knew how the egg forms, all about the ovulation cycle and how the gametes form,” says Petitte. “And then biotechnology evolved, and so did embryonic stem cells. I was fascinated by it, and I wanted to see if that same phenomenon existed in birds.”

After years of thorough development, Petitte patented the method of developing all avian embryonic stem cells with the initial goal of using them in transgenic technology. However, companies using his licensed technology also found the cells worked well for vaccine development.

“It was discovered that avian embryonic stem cells can be infected by multiple kinds of viruses,” says Petitte. “It turns out that this is a jack-of-all-trades cell type to produce vaccines. The battery of diseases that are being targeted using avian embryonic stem cells is quite a long list.”

The first vaccine using avian stem cells was approved in Japan for egg drop syndrome, a duck adenovirus that affects layers by stopping them from laying eggs. The FDA then approved them for use in an influenza vaccine along with many other applications, including recombinant proteins, monoclonal antibodies and therapeutics.

“Multiple companies wanted to use the platform to produce their own vaccines, so the cells were licensed out,” says Petitte. “It’s been quite successful, and most people don’t realize that avian embryonic stem cells now make up a large portion of the vaccine industry.”

Using avian embryonic stem cells instead of embryonated eggs or other traditional methods holds many benefits, including avoiding egg allergies, reducing animal involvement and providing a more efficient manufacturing process.

Patenting avian embryonic stem cells was just one of Petitte’s advancements throughout his decades-long career. He also applied transgenic technology to poultry and studied poultry as a model for human disease, focusing on ovarian cancer.

“The whole poultry industry is based on biology,” Petitte says. “When you approach things as a biologist who happens to work with poultry, it broadens the impact you can have.”

Expand to read moreCollapse

A Natural Wellness Booster for Bees

Bees’ pollination activities increase biodiversity and help grow the food we eat. However, despite their importance, bee populations have been declining for years. Rebecca Irwin, a professor in the Department of Applied Ecology, and collaborators at the University of Massachusetts-Amherst and other institutions are working on a simple solution to promote bee health and well-being: sunflower pollen.

In addition to nectar, pollen is an important aspect of bees’ diets, and the insects spend a significant part of their lives gathering pollen. When a bee lands on a pollinating flower, it collects the pollen, and the sticky, powdered substance clings to the bee’s body. When the bee then lands on another flower, the pollen collected on the bee sticks to the new flower and pollinates it, which helps the plant reproduce.

What you may not know is that pollen from each pollinating flower varies widely in nutritional content, visual characteristics and chemistry. For example, sunflower pollen is low in protein and some amino acids, but Irwin found that it has another important benefit: lowering pathogen infection in bees.

Bees can be infected by diverse pathogens, slowing bee colony growth rates and increasing bee death. When Irwin and her team fed bumblebees and honeybees a diet of sunflower pollen mixed with wildflower pollen, they noticed dramatically lower infection rates by specific pathogens, including two parasites.

The team also found that bumblebees on the mixed sunflower diet had generally better colony reproduction than bees fed on diets of other flower pollens. The same was not seen for honeybees, as honeybees on the sunflower diet had mortality rates roughly the same as honeybees not on the diet.

The team has tried other types of pollens, but sunflower pollen trumped them in providing consistently better medicinal effects. The researchers also found that feeding on sunflowers speeds up the rate at which food moves through a bee’s gut, and that the benefits likely aren’t based on the pollen’s chemical or nutritional properties.

Research on the topic continues with Irwin, her NC State team and collaborators at other institutions comparing sunflower pollen to the pollen of other flowers and whether these flowers provide the same benefits. They’re also studying if sunflower pollen’s benefits apply to other bee species.

There’s still a lot to learn about the topic, but for now, Irwin urges individuals to consider planting sunflowers as part of diverse wildflower gardens.

“Bees we have studied only need sunflower pollen to make up about 50% of their diet to receive the medicinal benefit, but since sunflower pollen is low in protein, sunflowers should be provided as part of a diverse wildflower planting.”

Expand to read moreCollapse

Enjoying Fresh Produce and Florals For Longer

If you’ve ever bought any fresh produce or flowers, chances are you’ve benefited from an invention from researchers in North Carolina State University’s College of Agriculture and Life Sciences.

By significantly extending the freshness and storage life of fruits, vegetables and cut floral products, 1-methylcyclopropene, or 1-MCP, allows you to enjoy fresh produce and cut flowers for longer. It also reduces food waste, creates year-round access and enables transportation over greater distances.

Professor emerita Sylvia Blankenship, a horticulturist, and the late professor Edward Sisler, a biochemist, commercialized 1-MCP. Earlier this year, the two were inducted into the National Inventors Hall of Fame for their work with the molecular compound.

Blankenship and Sisler’s collaboration started when Blankenship, then a postharvest researcher, saw apples and other crops maturing too quickly, often ripening before even making it to the supermarket for consumers to enjoy.

Researchers knew that ethylene, a naturally occurring gas, was responsible for plant development and fruit ripening. They also knew that apples, along with many other crops, were very sensitive to this compound.

Sisler and Blankenship collaborated to develop a molecular compound that deterred ethylene’s effects. This miracle molecule blocked the plants’ ethylene binding sites. With ethylene unable to bind, the plant wouldn’t experience the compound’s ripening effects and would stay fresh for longer.

Blankenship and Sisler then commercialized 1-MCP. As the food industry’s first compound of its kind, 1-MCP experienced wide acceptance. It was patented in 1996, and companies soon wanted a taste. Floralife paid NC State to license the technology for floral crops, then AgroFresh did the same for fruits and vegetables in 1999. Following approval from the United States Environmental Protection Agency, AgroFresh launched SmartFresh™ in 2002. Licensing fees topped $25 million, making 1-MCP one of NC State’s most lucrative inventions.

Today, the technology is used on up to 70% of all apples harvested in the United States. It’s also widely used internationally on apples and 30 other crops, including kiwis, pears, plums and many floriculture crops. New formulations of 1-MCP are available commercially, and the technology continues to evolve into new products.

Mike Parker, who worked with Blankenship for years as an Extension tree fruit specialist in NC State’s Department of Horticultural Science, said the invention has yielded benefits not just for the companies that sell it but also for farmers and consumers.

He calls 1-MCP “one of the greatest advances for the apple industry in the past 50 years.”

Expand to read moreCollapse

Beneficial Bacteria

Bacteria usually have a negative connotation. What most people don’t consider is that some bacteria are beneficial, and we eat them. For example, Lactobacillus acidophilus is added to most yogurts as a probiotic supplement to enhance health by boosting our immune systems and digestion.

The late Todd Klaenhammer, who retired from North Carolina State University’s Department of Food, Bioprocessing and Nutrition Sciences in 2017, was a food microbiologist and an international expert on lactic acid bacteria used in starter cultures for dairy foods and in health-enhancing probiotics. The William Neal Reynolds Distinguished Professor also played a role in mentoring and enabling the team that first developed CRISPR-Cas technology, which continues to transform areas of science such as health care and sustainability by allowing scientists to locate and cut DNA targeted for gene editing.

NC State’s microbiology-based food science lineage began with Marvin L. Speck, who developed sweet acidophilus milk, first marketed in the 1970s. Klaenhammer built on Speck’s foundation, and his former student and successor Rodolphe Barrangou, who was inducted into the National Inventors Hall of Fame in January 2023, carries on their legacy as the Todd R. Klaenhammer Distinguished Professor in Probiotics Research and director of NC State’s CRISPR Lab.

The first food scientist to be elected to the National Academy of Sciences, Klaenhammer is remembered for increasing dairy starter cultures’ resilience to industrial processing and for mapping the genome of what’s become the most widely consumed probiotic strain, L. acidophilus. Later in his career, he transitioned to studying a new field aimed at engineering probiotics to improve intestinal and digestive health.

Using borrowed equipment from Klaenhammer’s lab, Barrangou and three other alumni working with the Danisco/DuPont Nutrition and Health group went on to discover and explain CRISPR technology. Barrangou then demonstrated the importance of Cas9 when used with CRISPR. Now, Cas9 is arguably the most powerful enzyme on earth.

He said that Klaenhammer “reached milestones in scientific pursuits and commercial pursuits that are very hard to do over the course of a career.”

“Having done it multiple times speaks for itself,” Barrangou says.

Like Klaenhammer, Barrangou continues to work with industry and academia to commercialize products.

The influence of Klaenhammer’s 40-year NC State career continues through the Southeast Dairy Foods Research Center, one of six National Dairy Foods Research Centers. Klaenhammer was the center’s inaugural director. Now led by fellow William Neal Reynolds Distinguished Professor of Food Science MaryAnne Drake, the center studies whey protein functionality, extended shelf-life processing; probiotics; dairy starter cultures; and the flavor, flavor chemistry and sensory quality of cheese and other dairy ingredients.

“If we think in the lens of Todd extending real-world use of probiotics, the context of human health and gut health are very much still in play,” Barrangou says. “And beyond that, he inspired us to go where things are headed next.”

Expand to read moreCollapse