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

Abstract

In this study bacterial isolates from <em>Ventricina del Vastese</em> sausage, previously identified as <em>Lactobacillus (L.) sakei</em>, were characterised genotypically, physiologically and on the basis of some technologically relevant traits. A total of 70 <em>L. sakei</em> 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-polymerase chain reaction 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 characterised. 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 <em>in vitro</em>. One strain was able to slightly inhibit <em>Listeria (L.) monocytogenes</em> and <em>L. innocua</em> and all six strains were able to slightly inhibit <em>Enterobacteriaceae</em> isolated from <em>Ventricina del Vastese</em> sausages <em>in vitro</em>. Results showed that most <em>L. sakei</em> strains can have a role in improving the safety of low acidity fermented sausages, even though a limited acidifying capacity was observed in a meat-like substrate, and that <em>L. sakei</em> strains able to produce biogenic amines are unlikely to occur in spontaneously fermented meat products.