Science & Tech Editor
Senior biochemistry, cell and molecular biology major Samantha Scott recently defended her honors thesis on Burkholderia gladioli growth on onions, and she presented her results at the 15th Annual Celebration of Student Scholars at The University Tuesday.
The research on which Scott based her honors thesis and presented her poster focused on the growth of a specific species of bacteria found on yellow onions grown in the United States. Scott purchased these yellow onions from local grocery stores and grew them in specific temperature and carbon dioxide conditions that facilitated bacterial growth. She then cultured the isolates that grew on the onions in an oxidation fermentation polymyxin bacitracin lactose agar that only allows for the growth of Burkholderia. Scott delved into the primary literature and found surprisingly little depth in the scientific community’s understanding of the species in the U.S. With the most recent paper addressing the species’ effects on onions in the U.S. being published in 1942, Scott hopes to revive an interest in the bacteria in the United States.
Scott used both real-time and conventional polymerase chain reaction (PCR) techniques to specifically determine the species of the bacteria growing on the onions, and she found that 51 of the 139 onions that she purchased and cultured under standard conditions for bacterial growth were positive for Burkholderia gladioli.
Scott made sure to note that the presence of the bacteria should not stymie the practice of eating onions grown in the U.S., however.
“For individuals without compromised immune systems, the bacteria pose no problem, and even for susceptible individuals, the bacteria likely are harmless because I cultured them at ideal conditions for bacterial growth,” she said.
Scott’s research focused on the identification of the bacteria on the onions, and she noted that there may be clinical applications for future researchers.
Scott’s previous research focused on the same species of bacteria in mushrooms, where she continued the work of a previous honors student whose work with mushrooms yielded unexpected results when controls yielded unexpected positive results for the presence of the genus. Scott presented her work at the American Society for Microbiology national meeting in 2014.
Following graduation this month, Scott will matriculate as a graduate student intending to pursue a Ph.D. in microbiology at Cornell University. As part of the program, she will receive full funding for her research and a teaching assistantship. Scott attributed her success to her mentor in the laboratory, Michael Sulzinski, Ph.D., a professor at The University interested in the molecular biology of bacteria.
“I cannot speak enough praise for Dr. Sulzinski. Once we recognized a shared research interest, everything fell into place,” she said.