Propionibacterium freudenreichii is a mouthful to pronounce and an essential bacterium used in the production of Swiss cheese. There are several synonyms for this unique bacterium, including Propionibacterium shermanii, Propionibacterium jensenii, and Propionibacterium propionicus. P. freudenreichii is a common anaerobic bacterium, and its interactions during cheese production give Swiss cheese its distinct nutty and sweet flavor. This bacterium is often used in the fermentation industry for the production of vitamin B12, propionic acid, and other industrial compounds, making its synonyms vital for research and development in the area of microbiology. P. freudenreichii plays a crucial role in the dairy industry and has a significant impact on the sensory characteristics and quality of Swiss cheese.