Metabolic Characterization of Bacillus subtilis and Bacillus amyloliquefaciens Strains Isolated from Traditional Dry-Cured Sausages

The aim of this study was to investigate the effect of pH, temperature, and NaCl on growth, proteolytic and lipolytic activities, and the ability to produce biogenic amines of 19 strains of Bacillus isolated from Androlla and Botillo (two Spanish traditional sausages) to elucidate the role of these bacteria in sausage manufacture. All strains grew in the presence of 10% salt and at pH values of 5.0 and 5.5, whereas only 9 strains grew at 10 degrees C. Proteolytic activity was assessed by the agar plate method, which revealed that 100 and 94.7% of the strains were able to hydrolyze sarcoplasmic and myofibrillar proteins, respectively. These results were confirmed by electrophoretic assays. The titration method revealed that only two strains hydrolyzed pork fat to any extent, and the profiles of the fatty acids freed were different. Most strains produced biogenic amines, but the quantities were generally low.