Produzione del metabolita antimicrobico acido fenillattico da parte di batteri lattici

The ability of 29 lactic acid bacteria strains to produce phenyllactic (PLA) and 4-hydroxy-phenyllactic (OH-PLA) acids, metabolites involved in food quality and preservation, has been evaluated by HPLC analysis. Metabolite production was demonstrated for all strains of the species Lactobacillus plantarum, L. alimentarius, L. rhamnosus, L. sanfranciscensis, L. hilgardii, Leuconostoc citreum. Improvement of phenyllactic acid production was obtained in a selected strain by increasing the concentration of phenylalanine in culture and using low amounts of tyrosine. Finally, a particular procedure of bread-making aiming to reduce or delay microbial spoilage of bread and other yeast-leavened bakery products has been patented.