Featured Post from University of Delaware

Research: Add space salad to the risks astronauts face

Jan 22, 2024

3 min

University of Delaware researchers grew lettuce under conditions that imitated the weightless environment aboard the International Space Station and found those plants were actually more prone to infections from Salmonella.

It’s been more than three years since the National Aeronautics and Space Administration made space-grown lettuce an item on the menu for astronauts aboard the International Space Station. Alongside their space diet staples of flour tortillas and powdered coffee, astronauts can munch on a salad, grown from control chambers aboard the ISS that account for the ideal temperature, amount of water and light that plants need to mature.

But as the UD researchers discovered, there is a problem. The International Space Station has a lot of pathogenic bacteria and fungi. Many of these disease-causing microbes at the ISS are very aggressive and can easily colonize the tissue of lettuce and other plants. Once people eat lettuce that’s been overrun by E. coli or Salmonella, they can get sick.

With billions of dollars poured into space exploration each year by NASA and private companies like SpaceX, some researchers are concerned that a foodborne illness outbreak aboard the International Space Station could derail a mission.

In the new study by UD's team, published in Scientific Reports and in npj Microgravity, researchers grew lettuce in a weightless environment similar to that found at the International Space Station. Plants are masters of sensing gravity, and they use roots to find it. The plants grown at UD were exposed to simulated microgravity by rotation. The researchers found those plants under the manufactured microgravity were actually more prone to infections from Salmonella, a human pathogen.

Stomata, the tiny pores in leaves and stems that plants use to breathe, normally close to defend a plant when it senses a stressor, like bacteria, nearby, said Noah Totsline, an alumnus of UD’s Department of Plant and Soil Sciences who finished his graduate program in December. When the researchers added bacteria to lettuce under their microgravity simulation, they found the leafy greens opened their stomata wide instead of closing them.

“The fact that they were remaining open when we were presenting them with what would appear to be a stress was really unexpected,” Totsline said.

Totsline, the lead author of both papers, worked with plant biology professor Harsh Bais as well as microbial food safety professor Kali Kniel and Chandran Sabanayagam of the Delaware Biotechnology Institute. The research team used a device called a clinostat to rotate plants at the speed of a rotisserie chicken on a spinner.

“In effect, the plant would not know which way was up or down,” Totsline said. “We were kind of confusing their response to gravity.”

Additionally, Bais and other UD researchers have shown the usage of a helper bacteria called B. subtilis UD1022 in promoting plant growth and fitness against pathogens or other stressors such as drought.

They added the UD1022 to the microgravity simulation that on Earth can protect plants against Salmonella, thinking it might help the plants fend off Salmonella in microgravity.

Instead, they found the bacterium actually failed to protect plants in space-like conditions, which could stem from the bacteria’s inability to trigger a biochemical response that would force a plant to close its stomata.

“The failure of UD1022 to close stomata under simulated microgravity is both surprising and interesting and opens another can of worms,” Bais said. “I suspect the ability of UD1022 to negate the stomata closure under microgravity simulation may overwhelm the plant and make the plant and UD1022 unable to communicate with each other, helping Salmonella invade a plant.”

To contact researchers from the team, visit the profiles for Bais or Kniel and click on the contact button.

Connect with:

Harsh Bais

Professor, Plant and Soil Sciences

Prof. Bais conducts research in plant signaling – how plants recognize and communicate with one another.

Plant-Microbe InteractionsPlant BiologyPlant SignalingRoot ExudationPlant and Soil Sciences and Horticulture

Kali Kniel

Professor, Microbial Food Safety

Prof. Kniel’s laboratory explores issues of food safety and public health that involve transmission of viruses and pathogenic bacteria.

Microbial Food SafetyFoodborne parasitesProduce SafetyCyclosporaFood Systems

Find Experts

Jul 22, 2026

2 min

Summer slide isn't just about academics

As summer reaches its midpoint, many parents are wondering how to keep their children engaged without turning the rest of the break into summer school. University of Delaware professors from the College of Education and Human Development say "summer slide" is real. However, preventing summer learning loss doesn't require expensive camps, tutors or educational apps. Instead, simple everyday activities can help children build academic skills, executive functioning and social-emotional development before they head back to school. Roberta Michnick Golinkoff, internationally recognized expert in child development and early learning can comment on: Why children lose academic skills over the summer – and why the effects are greatest for under-resourced families Why parents shouldn't rely on "educational" apps Free, research-backed ways to keep preschoolers and elementary-age children learning through play, reading and everyday activities like grocery shopping, puzzles and scavenger hunts Andrea Glowatz, expert in special education and child development can comment on: Why boredom is actually good for children – and how it builds creativity, problem-solving and independence How summer routines help children, particularly those with learning differences or neurodivergence Why chores, calendars and family routines strengthen executive functioning, not just responsibility Sara Goldstein, expert in adolescent development and parent-teen relationships can comment on: Why teenagers experience a version of the summer slide through increased screen time, disrupted sleep and reduced activity Healthy ways parents can encourage independence before college, from managing money to building life skills Research showing that strengthening parent-teen relationships during the summer benefits both parents and young adults These experts can also comment on broader parenting topics including screen time, executive functioning, preparing children for the new school year, supporting neurodivergent learners, and helping teens transition to college. If you're planning back-to-school or parenting coverage and want to speak with any of these experts, click on their profiles or email mediarelations@udel.edu.

Jul 17, 2026

1 min

Food safety expert available to discuss emerging health risks

The University of Delaware’s Kalmia Kniel can discuss foodborne parasites and food safety risks, including the ongoing cyclosporiasis outbreak spreading across the United States. Kniel, a professor of microbial food safety, can explain how foodborne parasites spread, why outbreaks (particularly those involving the Cyclospora parasite) can be challenging to investigate and what consumers should know about reducing their risk of illness. She co-authored a study published in December 2025 that examined challenges researchers face in detecting, studying and controlling Cyclospora cayetanensis, including gaps in understanding the parasite and improving prevention strategies. Kniel can also discuss why fresh produce and water are often a focus during investigations and the steps consumers can take to improve food safety. Kniel’s expertise includes: • Foodborne parasites and illness outbreaks • Produce and microbial food safety • Food contamination and prevention • Food safety research Kniel discussed the biology of this specific pathogen in detail at a recent presentation on cyclospora. To arrange an interview with Kniel, visit her profile page and click the contact button. Interested journalists can else email MediaRelations@udel.edu.

Jul 16, 2026

1 min

Wildfire smoke: Climatologist available to explain air quality and impacts

Wildfire smoke has increasingly affected communities across the United States, including the latest episode in which smoke from Canadian wildfires has moved into the Midwest and Mid-Atlantic regions. The University of Delaware’s Kevin Brinson is available to explain the atmospheric conditions that allow wildfire smoke to travel long distances and affect regional air quality. Brinson, an assistant research professor and Delaware’s state climatologist, can speak to: • How wildfire smoke travels long distances through the atmosphere. • The role of weather patterns, winds and atmospheric conditions in transporting and dispersing smoke. • How wildfire smoke events are monitored and forecast. • How atmospheric and seasonal weather patterns influence smoke transport and regional air quality. To arrange an interview with Brinson, visit his profile and click the contact button. Interested reporters can also send an email to MediaRelations@udel.edu.