Vignolo Graciela M, de Ruiz Holgado Aida Pesce, Oliver Guillermo
Centro de Referencia para Lactobacilos (CERELA), Chacabuco 145, 4000 Tucumán, Argentina, and Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán.
J Food Prot. 1988 Jun;51(6):481-484. doi: 10.4315/0362-028X-51.6.481.
The acid-producing capacity and proteolytic activity of 13 strains of Lactobacillus plantarum and 5 strains of Lactobacillus casei isolated from dry sausages was determined at different temperatures and at different NaCl concentrations. Most strains exhibited a maximum acid-producing rate at 30°C. According to the acidification rate at this temperature, strains were divided into three rate groups: fast (I), medium (II) and slow (III), with titratable acidity values above 1.7, between 0.7 and 1.4, and below 0.7, respectively. The decrease in pH ranged between 3.1 and 3.95 according to the group to which the strains belonged. The addition of 3% NaCl produced a marked decrease in the rate of acidification for strains in group II, a slight decrease for those in group I and no effect for those in group III. The proteolytic activity of the strains under study reached a maximum at 40°C, with values between 5.2 and 10 mg% tyrosine released. At 30°C, and in the presence of 3% NaCl, the greatest activity (5.4 mg% tyrosine) was observed in L. plantarum GV 417 and the lowest (3.4 mg% tyrosine) in L. plantarum GV 420. A decrease of approximately 80% in proteolytic activity for all strains was observed in the presence of 5% NaCl.
测定了从干香肠中分离出的13株植物乳杆菌和5株干酪乳杆菌在不同温度和不同NaCl浓度下的产酸能力及蛋白水解活性。大多数菌株在30°C时产酸率最高。根据该温度下的酸化率，将菌株分为三个速率组：快速（I）、中等（II）和缓慢（III），其可滴定酸度值分别高于1.7、介于0.7和1.4之间以及低于0.7。根据菌株所属的组，pH值的下降范围在3.1至3.95之间。添加3% NaCl后，II组菌株的酸化率显著下降，I组菌株略有下降，III组菌株则无影响。所研究菌株的蛋白水解活性在40°C时达到最高，释放的酪氨酸值在5.2至10 mg%之间。在30°C且存在3% NaCl的情况下，植物乳杆菌GV 417的活性最高（5.4 mg%酪氨酸），植物乳杆菌GV 420的活性最低（3.4 mg%酪氨酸）。在存在5% NaCl的情况下，所有菌株的蛋白水解活性均下降了约80%。
