(ex Kline & Sugihara 1971)
Weiss & Schillinger 1984
Lactobacillus sanfranciscensis (formerly L. sanfrancisco) is a species of lactic acid bacteria which, through the production mainly of lactic and acetic acids, helps give sourdough bread its characteristic taste. It is named after San Francisco, where sourdough was found to contain the variety, though it is not endemic to the area.
Sourdough starters are leavened by a mixture of yeast and lactobacilli in a ratio of about 1:100. The yeast is most commonly Candida humilis. This yeast cannot metabolize the maltose found in the dough, while the Lactobacillus requires maltose. They therefore act without conflict for substrate, with the Lactobacillus utilizing maltose and the yeast utilizing the other sugars, including the glucose produced by the Lactobacillus.