Carbohydrate fermentation tests detect the ability of microorganisms to ferment a specific carbohydrate. Fermentation patterns can be used to differentiate among bacterial groups or species . For example, all members of the Enterobacteriaceae family are classified as glucose fermenters because they can metabolize glucose anaerobically. Within this family however, maltose fermentation differentiates Proteus vulgaris (positive) from Proteus mirabilis (negative). While fermentation tests can be performed on microorganisms other than bacteria, this protocol only addresses fermentation of carbohydrates by bacteria.