JP is an Associate Professor (with tenure) in the Department of Food Science. He is a trainer in the MDTP, MBTG and IGPNS programs, and is Chair of the Food Science Graduate Program. He is also a member of the Executive Committee of the Food Research Institute. JP received his Ph.D. degree from the Alimentary Pharmabiotic Center, University College Cork, Ireland. He conducted his postdoctoral studies at the Cork Cancer Research Center (Cork, Ireland) and at Michigan State University. JP lives in Madison, and in his spare time, he likes to ride his bicycle and cook.

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Jee-Hwan joined our laboratory as a Research Associate in 2013. His aim is to develop innovative technologies that will help to understand the mechanism, and improve the function, of health-promoting properties of select lactic acid bacteria strains. He is actively involved in mentoring undergraduate and graduate students in our laboratory. In his spare time, Jee-Hwan likes outdoor activities, and he likes to make traditional Korean Kimchi.

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Laura is a fourth year graduate student in the Microbiology Doctoral Training Program (MDTP) at UW-Madison. She received her B.S. in Microbiology at the University of Georgia in 2014. Her current project is the development of Lactobacillus reuteri as a biotherapeutic delivery system. In her spare time, Laura enjoys ballroom dancing, reading for pleasure, and playing sports.

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Vivian is a second year graduate student in the Food Science program at UW-Madison. She received her B.S. in Food Science at the University of Wisconsin-Madison in 2015. Her current project is to develop a genetic tool that allows multiplex gene insertions/deletions for Lactobacillus reuteri in a high throughput manner. Vivian is from Shanghai, China. In her spare time, she enjoys playing with her cat Henry and cooking Chinese food.



Theresa joined the van Pijkeren lab as a research technician (official title, Associate Research Specialist) in September 2020. She graduated from the University of Vermont in 2019 with a B.S. in Animal Science and a minor in French. As the lab technician she is involved in numerous ongoing projects in the lab as well as collaborations with other labs; her personal project, however, is focused on studying the physiology of high-ethanol-producing strains of Klebsiella pneumoniae, a pathogenic species associated with multidrug antimicrobial resistance. Outside of the lab, she enjoys riding horses, hiking, and travel.



Mark received his Bachelors of Science in Agricultural Biochemistry from Iowa State University in 2020. He is a first-year graduate student in the Interdepartmental Graduate Program in Nutritional Sciences (IGPNS). As part of the lab, he is currently working on exploring the use of environmental signals for therapeutic delivery in limosilactobacillus reuter. Outside his academic aspirations, Mark is an avid reader, enjoys running, and brewing beer.



Qiu, Ling—Food Science and Microbiology   | Spring 2018–Summer 2019

Ms. Qiu was a student in the course Food Microbiology FS324. After completion of the course in Fall 2017, she joined my laboratory in Spring 2018. During Summer 2018, Ms. Qiu was sponsored by the Food Research Institute Summer Scholar Program. In this project, she aimed to understand the mechanism by which select probiotic strains inhibit foodborne pathogens. After completion of this research experience, she continued to work in my laboratory for credit (FS699). Currently, Ms. Qiu is in pursuit of a M.S. degree, research track, in the Department of Microbiology & Immunology at the University of Michigan, Ann Arbor.

Ruiz Ramirez, Silvette—Industrial Microbiology    | Summer 2018

Ms. Ruiz Ramirez was an undergraduate student the University of Puerto Rico-Mayagūez. She visited UW-Madison as part of the NSF-RUE program, and Ms. Ruiz Ramirez gained research experience in my laboratory during the summer of 2018. Ms. Ruiz Ramirez worked together with Mr. Özçam. She aimed to gain a deeper understanding of the spectrum of antimicrobial activity of a probiotic-derived secondary metabolite. She did a fantastic job mapping the antimicrobial activity in over 50 L. reuteri strains, and she found that the antimicrobial activity was dependent on host-origin of the strain. Her contributions resulted in a co-authorship of a manuscript that is in preparation. Ms. Ruiz Ramirez presented her findings at the Beta-Beta-Beta Biological Honor Society and was awarded with the second price in the category John C. Johnson Award for Excellence in Student Research. In June 2019, Ms. Ruiz Ramirez was accepted to the Postbaccalaureate Research Education Program (PREP) at University of Massachusetts-Amherst.

Gierczic, Ben—Food Science                               | Summer and Fall 2018

Mr. Gierczic joined my laboratory on an hourly basis. Mr. Gierczic shared with me he was not interested in conducting research, but he was merely interested in supporting researcher in our laboratory. For six months, Mr. Gierczic helped members of our group by preparing media, plates, chemical solutions and other general laboratory tasks. He was supervised by Ms. Zhang. Mr. Gierczic graduated in 2018 and is employed by PPD (Middleton, WI), a global contract research organization.

Cavadini, Chris—Microbiology                              | Fall 2017–Spring 2018

Mr. Cavadini completed his MICRO551 project in my laboratory and conducted research under the supervision of Ms. Alexander. The goal of his project was to characterize sugar-inducible promoters in the probiotic Lactobacillus reuteri, which could be applied for sugar-induced gene expression and therapeutic delivery. Mr. Cavadini graduated in May 2018, after which he took on a job as a Product Manager Quality Assurance at Oakhouse Farm Bakery. 

Wang, Yixuan (Daphne)—Nutritional Science       | Summer 2017

For 3.5 moths, Ms. Wang worked with Dr. Oh to obtain research experience. She was involved in generating several plasmid constructs to heterologous express proteins in Lactobacillus reuteri to modulate the host immune-system. After graduation, Ms. Wang was employed by the Wisconsin Department of Health. 

Lacrosse, Jordan—Food Science                         | Spring 2016–2017

Mr. LaCrosse was interested in supporting researcher in our laboratory. For one year, Mr. LaCrosse helped members of our group by preparing media, plates, chemical solutions and other general laboratory tasks. Mr. LaCrosse graduated in 2017. 

Pan, Meichen (Echo)—Food Science                  | Summer 2016–Fall 2017

Following completion of Food Microbiology Laboratory, course FS324, Ms. Pan started as an undergraduate researcher in my laboratory under the supervision of Dr. Oh, and partly Mr. Özçam. For about one year, Ms. Pan conducted experiments with a newly developed platform to understand the production of bacterial viruses, i.e.bacteriophages, in response to environmental stimuli. She made an important finding demonstrating that exposure to acetic acid—one of the dominant short-chain fatty acids in the colon—promotes phage production by the gut symbiont Lactobacillus reuteri. She was a co-author of one publication in CellHost&Microbe which was selected for preview in the same journal, and which was highlighted in Nature Reviews Microbiology. Currently, Ms. Pan is in pursuit of her Ph.D. degree in the laboratory of Dr. Rodolphe Barrangou at North Carolina State University, Raleigh.

Barham, Caroline—Food Science                       | Spring 2016–2017

Ms. Barham was one of the students in my class Food Microbiology 324 (FS324), and she expressed a strong interest in health-promoting microbes, i.e. probiotics. After she finished the course in Fall 2015, she joined my laboratory in Spring 2016 where she worked for ~1 year. She continued some of the work that Ms. Lawrence conducted (see below) to further increase our knowledge of mutation rates in the probiotic Lactobacillus reuteri. Our aim was to further decrease the mutation rate to increase the genome stability, which is expected to improve the stability of the microbial therapeutic platform. She obtained interesting findings, which serves as a foundation for a separate project. Following graduation in 2017 (B.S. Food Science), Ms. Barham was a research technician at the University of Arkansas for Medical Sciences and she is currently in the same institution in pursuit of a medical degree. 

Lawrence, Abigail—Food Science                       | Spring 2015

Ms. Lawrence completed her BIO152 project in my laboratory under the supervision of Dr. Oh. Ms. Lawrence graduated in 2018, and was afterwards employed by Cargill, Minnesota. 

Strelow, James—Food Science                           | Summer 2015

The Food Research Institute Summer Undergraduate Research Program supported Mr. Strelow to conduct research in my laboratory. Mr. Strelow aimed to understand to what extent a recombinant probiotic could produce the plant enzyme myrosinase. Myrosinase activity combined with ingestion of Brassica vegetables is known to activate the aryl-hydrocarbon receptor and has implications to improve immune-function. Mr. Strelow graduated with a B.S. degree in Food Science in 2016, and was afterwards employed by Covance, Madison. 

Dorsey, Bridget—Microbiology                            | 2014–2016

Ms. Dorsey joined my laboratory to conduct research to fulfill the requirements for the BIO152 program. Upon completion of the BIO152 work experience, Ms. Dorsey continued research in my laboratory on an hourly basis and later to fulfill requirements for the course MICRO551. Over the nearly 2.5 years Ms. Dorsey was in our laboratory, she worked mostly on establishing a cell culture model to measure activation of the aryl-hydrocarbon receptor (AhR), and to test the activity of mucosal microbiota isolates for their ability to modulate AhR. She was supervised in the laboratory by Dr. Oh and Mr. Özçam. Ms. Dorsey graduated in 2016, and is currently employed as a Quality Control Analytical Chemist at Coating Place Inc.

Zhang, Shenwei (Vivian)—Food Science            | Spring 2015

Ms. Zhang worked for one semester in my laboratory under the supervision of Dr. Oh. She optimized the use of an expression vector for heterologous gene expression in probiotic bacteria by colimetric assays. Ms. Zhang received research credits for her contributions, and in May 2015 she received her Food Science B.S. degree. In September 2015 she joined my laboratory in pursuit of a Food Science M.S. degree. During this time she completed the bypass exam and she is currently in pursuit of a Ph.D. degree under my supervision.  

Maegli, Kathryn—Microbiology                            | Fall 2015

Ms. Maegli conducted research in my laboratory as part of the BIO152 program. She worked under the supervision of Dr. Oh. The aim of her project was to determine to what extent an engineered probiotic could reduce invasion of the foodborne pathogen Listeria monocytogenes. Here, she gained experience in molecular microbiology and procedures for tissue culture. Ms. Maegli graduated in 2018 and is currently employed as a microbiologist at Water Quality Investigations, LLC.

Dunphy, Case—Food Science                             | Spring 2014

Ms. Dunphy was the first undergraduate student in my laboratory and was recruited through the Food Research Institute Summer Research Scholar Program. Her project pertained understanding the distribution of active prophages in Lactobacillus reuteri. In the laboratory, she was supervised by Dr. Oh. Her findings were included in a manuscript that is currently under review. Ms. Dunphy graduated in 2015 and is currently a R&D Product Developer at Richelieu Foods.

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