Histidine decarboxylase activity was investigated in 21 strains of lactic acid bacteria isolated from Argentinian wines. This activity is not widely distributed between them, and occurs significatively only in some strains of Lactobacillus hilgardii. L.hilgardii 5w was selected for the study on the basis of its constitutive expression. Glucose is necessary for histidine transport. Maximum activity is observed at 37°C and pH 4.0. Enzyme activity is inhibited by SO2 and ethanol at concentrations usually found in wine. L-matic acid and citric acid act as stimulators of the activity.
