Starch is the major component of cereal grains and starchy foods, and changes in its biophysical and biochemical properties (e.g., amylose, amylopectin, pasting, gelatinization, viscosity) will have a direct effect on its end use properties (e.g bread, malt, polymers). Lactobacillus brevis and Debaromyces polymorphous earlier obtained from fermented sweet potato broth were used to ferment sweet potato and these starter cultures broke down the carbohydrate (starch) to produce alcohol, organic acid and carbondioixde (CO2). Studies on identified starter cultures of Lactobacillus brevis and Debaromyces polymorphous used in fermenting sweet potato a carbohydrate source produced alcohol, organic acid and carbondioixde (CO 2).