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Graduation Term
Summer 2025
Degree Name
Master of Science (MS)
Department
School of Biological Sciences
Committee Chair
Thomas Hammond
Committee Member
Kyle Floyd
Committee Member
Kevin Edwards
Abstract
Propionibacterium freudenreichii is an important bacterium for numerous commercial production applications. P.freudenreichii is found in various Swiss-style cheeses and other dairy products, as it aids in the fermentation process. Propionic acid, acetic acid, probiotics, and B-vitamins are several of the commercially important by-products that can result from the several environment-dependent biochemical pathways of P. freudenreichii. Propionic acid commercial production is particularly dependent upon P. freudenreichii fermentation. However, relying upon organisms for commercial production is often unreliable and prone to unexpected results. One possible method to constrain the range of outcomes of fermen- tation production runs is to modify the growth media of P. freudenreichii. The Design of Experiments method is a statistical approach to reducing the complexity of an experiment when a full factoral approach is unfeasible. DoE is a promising approach for developing a new growth medium that increases the quantity of propionic acid per fermentation run.
Differing strains of P. freudenreichii are used for different types of production, e.g. propi- onic acid productions relies upon different strains than B-vitamin production. Some of these strains result from proprietary gene modification, but these mutations are difficult to main- tain after several generations. Traditional genetic profiling and genomic analysis is typically cost and time prohibitive in production settings. Newer techniques, such as basecalling, allow for rapid sequencing of bacterial genomes to determine whether genetic drift presents after several generations. Supermarkets provide excellent source material to test whether rapid genomic analysis is possible for identification and comparison of P. freudenreichii strains.
Access Type
Thesis-ISU Access Only
Recommended Citation
Bracht, Blake J.G., "Propionibacterium Freudenreichii and Its Role in Propionic Acid Production" (2025). Theses and Dissertations. 2170.
https://ir.library.illinoisstate.edu/etd/2170
DOI
https://doi.org/10.30707/ETD.1763755358.885872