Lactobacillus sanfranciscensis (formerly L. sanfrancisco) is a species of bacteria that helps give sourdough bread its characteristic taste. Sourdough starters are leavened by a mixture of yeast and lactobacilli in a ratio of about 1:100. The yeast is most commonly Candida milleri, a non-spore forming variety of Saccharomyces exigus formerly called Torulopsis homii. This yeast cannot metabolize the maltose found in the dough, while the lactobacillus needs 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. The lactobacilli produces an antibiotic cycloheximide which kills many organisms (but not the Candida), and the Candida tolerates the acetic acid produced by the lactobacilli. Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Subgroups Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular: bacterium) are a major group of living organisms. ... Classes Bacilli Clostridia Mollicutes The Firmicutes are a division of bacteria, most of which have Gram-positive stains. ... Orders Bacillales Lactobacillales The term bacilli (singular bacillus) is used to refer to any rod-shaped bacteria. ... Families Aerococcaceae Carnobacteriaceae Enterococcaceae Lactobacillaceae Leuconostocaceae Streptococcaceae The Lactobacillales are an order of Gram-positive bacteria, placed within the Firmicutes. ... Genera Lactobacillus Paralactobacillus Pediococcus The Lactobacillaceae is a family of Gram-positive bacteria, placed within the order of Lactobacillales. ... Species L. acidophilus L. bulgaricus L. casei L. plantarum L. reuterietc. ... In biology, binomial nomenclature is the formal method of naming species. ... Subgroups Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular: bacterium) are a major group of living organisms. ... Sourdough is a symbiotic culture of lactobacilli and yeasts used to leaven bread. ...

For commercial use, specific strains of the L. sanfranciscensis are grown on defined media, freeze-dried, and shipped to bakeries worldwide.

References

• Handbook of Dough Fermentation, edited by Karel Kulp, Klaus Lorenz.

External links

• Metabolism of L. sanfrancisco