Arginine catabolism in wine lactic acid bacteria: is it via the arginine deiminase pathway or the arginase‐urease pathway?

The wine lactic acid bacteria Leuconostoc oenos OENO and Lactobacillus buchneri CUC‐3 catabolize L‐arginine to ornithine and ammonia as major end‐products, with 1 mole of arginine converted into 2 moles of ammonia and 1 mole of ornithine. Some citrulline was also excreted into the medium. The excreted citrulline was reassimilated and catabolized by the lactobacillus strain, though not by the leuconostoc. Urea was not detected during arginine degradation. The activities of all three enzymes of the arginine deiminase pathway (arginine deiminase, ornithine transcarbamylase and carbamate kinase) increased significantly over time in the presence of arginine. On the other hand, arginase and urease activities were undetectable in cell extracts of cultures grown in the presence of arginine. The results show that the arginine deiminase pathway, and not the arginase‐urease pathway, is the route for arginine degradation in wine lactic acid bacteria.