General Information: This is the characteristic organism in wheat sourdough. They are commonly found in the oral, vaginal, and intestinal regions of many animals. They are important industrial microbes that contribute to the production of cheese, yogurt, and other products such as fermented milks, all stemming from the production of lactic acid, which inhibits the growth of other organisms as well as lowering the pH of the food product. Industrial production requires the use of starter cultures, which are carefully cultivated, created, and maintained, which produce specific end products during fermentation that impart flavor to the final product, as well as contributing important metabolic reactions, such as the breakdown of milk proteins during cheese production. The end product of fermentation, lactic acid, is also being used as a starter molecule for complex organic molecule syntheses.