Date of Award
Summer 2020
Degree Type
Thesis
Degree Name
Master of Science in Integrative Biology (MSIB)
Department
Biology
Committee Chair/First Advisor
Dr. Melanie Griffin
Major Professor
Dr. Jean Lu
Second Committee Member
Dr. Tsai-Tien Tseng
Abstract
Fermented cucumbers are one of the most important fermented vegetables consumed worldwide. During cucumber fermentations, certain undesirable changes may occur. One of such changes is known as bloater defect (hollow cavities in fermented cucumbers), which is primarily caused by gas-producing bacteria including Enterobacter cloacae. Bloater defect lowers product quality and leads to significant economic loss to the pickle industry, and effective preventative methods are needed. Bacteriophages (phages) are highly host-specific bacteria killers. Use of phages to control unwanted bacteria in foods is a promising approach because phages do not change food properties. The goals of this research were to isolate, characterize, and evaluate phages infecting Enterobacter cloacae. The morphology, growth kinetics, host range, and effectiveness of two isolated phages, named Φ107E-p1 and Φ115E-p2, were examined. Additionally, DNA and protein analysis were performed. Based on acquired data, Φ115E-p2 is a potential candidate for use as a biocontrol method to prevent bloater defect during cucumber fermentations. Φ107E-p1 is not a candidate based on the effectiveness data obtained. More research is needed to further evaluate the efficacy of the phage infections against their hosts in cucumber fermentations.