Wine composition plays an important role in the control of carcinogenic precursor formation by Lactobacillus hilgardii X1B

Abstract

Lactobacillus hilgardii, a wine lactic acid bacterium, is able to use arginine, through the arginine deiminase pathway with the formation of citrulline, a precursor of the carcinogen ethyl carbamate. The influence of different Argentine wine varieties (Merlot, Cabernet Sauvignon and Malbec), on bacterial growth and arginine metabolism was examined. Furthermore, the effect of different components normally present in wines on the enzyme activities of the arginine deiminase system was determined. Malbec wine under all conditions assayed (33, 50 and 100% supplemented wine:basal media) showed higher arginine consumption and citrulline production than the other wines, as well as the highest bacterial growth and survival of Lactobacillus hilgardii X₁B. Glucose and L-malic inhibited both arginine deiminase enzymes while fructose and citric acid only inhibited arginine deiminase. The red wines assayed in this study had different composition, and this is an explanation for the different behavior of the bacterium. The highest citrulline production in Malbec wine could be correlated with its lower concentrations of glucose, fructose, citric and phenolic acid than the other wines. Therefore, a wine with lower concentration of these sugars and acids could be dangerous due to the formation of ethyl carbamate precursors.