摘要：In order to select starter culture strains for white pickled cheese production, acidifying and proteolytic activities of 82 Lactobacillus lactis ssp. lactis, 49 Lc. lactis ssp. lactis biovar. d iacetilactis , 60 Lactobacillus casei and 37 Lb plantarum strain isolated at various stages of the production were investigated in skim milk medium. Acidifying activities measured by the decrease of pH value ( D pH) varied within the range of 0.55 to 1.83 for Lc. lactis ssp. lactis strains and of 0.50 to 1.81 for Lc. lactis ssp. lactis biovar. diacetilactis strains. Whereas this activity was found to be considerably weaker in Lb. casei and Lb. plantarum strains. Maximum D pH value obtained was 0.32 in strains belonging to each of these two species. The proteolytic activity values were also found to vary within a very broad range in Lactococcus species. Maximum and minimum values were 3.5 and 26.6 µg tyrosine/ml for Lc. lactis ssp. lactis strains and 4.4 and 26.2 µg tyrosine/ml for Lc. lactis ssp. lactis biovar. diacetilactis strains. Lactobacilli were less proteolytic than lactococci. The values obtained were found to range from 0.8 to 18.6 µg tyrosine/ml for Lb. casei and from 4.4 to 19.2 µg tyrosine/ml for Lb. plantarum strains.
