I heard that "the distinctive San Francisco sourdough flavor" was due to the water. The Hetchhetchy water in SF has a very distinctive taste. One of the only cities I go to regularly where the tap water tastes amazing
It's also called Fructilactobacillus sanfranciscensis in some places. I can't quickly tell which is the more recent naming and what lead to that change. It's lactic acid bacteria regardless.