Thornton, Sherie; Cardona,Rebecca (Weber State University)
Faculty Advisor: Culumber, Michele (Weber State University, Microbiology); Oberg, Craig (Weber State University, Microbiology)
Lactobacillus wasatchensis was initially isolated from cheese produced at Utah State University and was found to be a Non-Starter Lactic Acid Bacteria (NSLAB) that causes late-gas production in cheese that can damage packaging and produce defects in the cheese. The goal of this project was to locate an environmental reservoir for Lactobacillus wasatchensis. Five samples of silage that were in different stages of fermentation and content and raw milk samples were obtained at the Utah State University dairy. Samples were serially diluted, plated on de Man, Rogosa and Sharpe agar supplemented with 1% D-Ribose (NRS-R) and incubated anaerobically for 5 days. Colonies that looked like potential Lb. wasatchensis were selected and regrown for isolation. All isolates were gram-positive rods. The isolates were further grown in broth for DNA extraction, sequencing, and analysis with API 50 carbohydrate panel (API 50CH). The API 50CH results were significantly different from Lb. wasatchensis, which only demonstrates use of ribose in this assay. Sequencing of the 16S rRNA gene, however, produced a match to three isolates from two different silage samples that had 99% sequence identity to Lb. wasatchensis. Further analysis of the isolates is being done to confirm this finding and describe the organism isolated from the soil. We hypothesize that these organisms are very closely related to Lb. wasatchensis and that silage could be an environmental source of contamination.