Features of Lactobacillus sakei isolated from Italian sausages: focus on strains from Ventricina del Vastese

In this study bacterial isolates from Ventricina del Vastese sausage, previously identified as Lactobacillus sakei, were characterized genotypically, physiologically and on the basis of some technologically relevant traits. A total of 70 L. sakei isolates from sausages manufactured with spontaneous fermentation in the same producing plant were taken into account. Six genotypic groups were distinguished on the basis of Rep-PCR with the GTG5 primer, some of which were found only in the sausages ripened at temperatures lower than 10°C for the first two months and lower than 16°C for the remaining three months, according to the traditional ripening process. Six strains were selected as representative of the genotypic profiles and further characterized. A high diversity in their fermentation profiles was observed, and different groups were separated on the basis of growth and acidifying capacity in meat extract. None of the strains produced histamine or tyramine in vitro. One strain was able to slightly inhibit Listeria monocytogenes and L. innocua and all six strains were able to slightly inhibit Enterobacteriaceae isolated from Ventricina del Vastese sausage in vitro. Results showed that most L. sakei strains can have a role in improving the safety of low acidity fermented sausages, even though a limited acidifying capacity was observed in a meatlike substrate, and that the presence of L. sakei strains able to produce biogenic amines is unlikely in spontaneously fermented meat products.