Sanfranciscensis

Sanfranciscensis is a Latin species epithet meaning "of San Francisco" and is used in the scientific names of organisms that originated in or were first described from that city. The most widely cited example is Fructilactobacillus sanfranciscensis (synonym Lactobacillus sanfranciscensis), a lactic acid bacterium closely associated with San Francisco sourdough starters. It is a Gram-positive, non-spore-forming rod that participates in dough fermentation by converting sugars to lactic acid, acetic acid, CO2, and other metabolites, thereby contributing to dough acidity, texture, and aroma. In typical sourdough ecosystems, F. sanfranciscensis coexists with other lactic acid bacteria and yeasts, and exhibits tolerance to low pH and high osmotic stress characteristic of fermented dough.

Historically linked to the distinctive flavor of San Francisco sourdough, the epithet sanfranciscensis has become a classic geographic name in microbial taxonomy. In recent decades the species has been reclassified from Lactobacillus to Fructilactobacillus, with the epithet retained. Although the term can appear in other species named for different locales, the San Francisco bacterium remains the best-known usage.

In literature and industry, strains of sanfranciscensis are studied for their role in aroma formation, interactions within microbial communities in dough, and potential applications in controlled fermentation processes.