CT State Housatonic Professor Leads Research on Why Engineered Microbes Struggle Outside the Lab
New research led by Joseph D. Shih, Ph.D., a science faculty member at Connecticut State Community College Housatonic, is helping scientists understand why engineered microbes that perform well in laboratories often struggle when introduced into real-world environments.
The study explores why genetically engineered microbes—designed to detect contaminants or break down pollutants—lose effectiveness in complex ecosystems such as wastewater systems, soil and aquatic environments.
In laboratory settings, microbes are tested under controlled conditions with minimal competition. Shih’s research shows that once these organisms enter natural environments, they must compete intensely for limited resources, placing added stress on engineered systems.
“In real ecosystems, microbes are under constant pressure to survive,” Shih said. “That pressure can turn engineered genetic devices into a disadvantage rather than a benefit, which helps explain why many systems stop working outside the lab.”
The study focuses on genetic devices, engineered DNA components added to microbes to give them specific functions. Researchers found that when microbes carrying these devices compete with other organisms, they are more likely to develop mutations that disable the engineered features.
To test this, researchers examined bacterial growth under three conditions: in isolation, alongside a competing species, and within a natural wastewater microbial community. As competition increased, microbes carrying genetic devices accumulated significantly more disabling mutations.
The research also points to a potential solution. Genetic devices that are constantly active placed high energy demands on microbes and were more likely to fail. Devices designed to activate only under specific environmental conditions proved more stable and effective.
The findings have implications for bioremediation, environmental monitoring and pollution control, including efforts to remove contaminants, manage waste systems and address microplastic pollution.
The study, titled “The Effects of Intraspecies and Interspecies Competition on Genetic Device Construction and Performance,” was published Dec. 17, 2025, in mSphere, a peer-reviewed journal of the American Society for Microbiology.
The research was supported by a National Science Foundation grant awarded to Shih and collaborators and was conducted from March 2021 through June 2025. Undergraduate students played a key role throughout the project, contributing to experiments from fall 2021 through spring 2025.
Shih teaches microbiology and anatomy and physiology at CT State Housatonic and has more than 15 years of experience teaching undergraduate biology. His research background includes genetics, immunology, cell and molecular biology, nutrition and bioengineering.
“My work bridges laboratory science and real-world systems,” Shih said. “Understanding how biology behaves outside controlled environments is essential if we want these technologies to succeed where they matter most.”
Contact:
Sherifdeen Dhikrullah
Public Relations Coordinator, CT State Housatonic
W: 203-332-5086 | C: 475-450-2900
