Proteolytic activity of Lactobacillus strains isolated from dryfermented sausages on muscle sarcoplasmic proteins

The proteolytic activity of seven strains of Lactobacillus from two species isolated from dry cured sausages was assayed using a soluble muscle extract as a source of proteins, at a temperature of 30 °C. The results indicated that the strains of Lactobacillus plantarum tested had the more active proteolytic system, showing the highest amino acid release in the medium after 72 hr of incubation (L. plantarum CRL 681) when the microorganism was in the stationary phase of growth. The strains of L. casei showed a continued hydrolytic activity with a lower amino acids concentration along the studied period. The SDS-PAGE profiles showed that the major changes in sarcoplasmic proteins were produced in the 13 kDa and 36-40 kDa molecular weights region.