Summary

The aim of this research was to select strains of lactic acid bacteria with antagonistic activity against bacteria of importance in food. One hundred and fifty three lactic acid bacteria strains were isolated from Italian artisan salami elaborated without the use of starter culture. Two tests were used to verify the antagonistic activity of the isolated strains: the indirect inhibition method and the well diffusion method. Three species of lactic acid bacteria (Lactobacillus brevis; Lb. plantarum; and Lb. delbrueckii subsp. delbrueckii) showed antagonistic activity for at least one of the indicator microorganisms: Listeria monocytogenes, Staphylococcus aureus ATCC 25923 and Leuconostoc mesenteroides subsp. cremoris CCT 0672. It was shown that strains of lactic acid bacteria of the same specie, mainly Lb. brevis, presented differences with respect to the pattern of carbohydrate assimilation. The products analyzed presented very low numbers of lactic acid bacteria (approx. 103 CFUg-1 per sample). It was concluded that in the region where the Italian salami was made there was a convenient source of lactic acid bacteria with antagonistic activity against undesirable microorganisms in food products