FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Peptidase activity of some Lactobacillus strains


Non-starter lactic acid bacteria has been proved to be more potent in paracasein degradation into low molecular nitrogen compounds and in production of taste and aroma of Gouda cheese than peptidases liberated during autolysis of leaven cultures. In cheese technology application of selected strains of Lactobacillus leads to reduce non-starter lactic acid bacteria growth and, simultaneously, makes possible intensification and modification of sensorial features of cheese. The indispensable requirement to use the lactobacilli in ripening cheese production is to recognise their peptidase activity. The aim of the paper was to evaluate activities of amino- and dipeptidases of some strains of Lactobacillus (L. acidophilus, L. casei, L. casei ssp. rhamnosus ). The Lactobacillus strains synthesised peptidases hydrolysing preferential similar substrates. Amino peptidases composed the dominant group for all the strains under the study. Amino peptidases that were synthesised by the individual lactobacilli strains hydrolysed all the substrates utilised during the experiment. However, each strain was characterised by different activity level of individual amino peptidases (from 3.00 to 13.75 JA). Comparing activity of dipeptidases synthesised by the Lactobacillus strains it has been found that majority of the substrates utilised in the experiment, typical for lactobacilli, were hydrolysed, though in various extent (from 1.08 to 7.25 JA). The L. casei strain was characterised by highest activity of both: amino- and dipeptidase, activity. The L. acidophilus synthesised amino peptidases of about 2 times lower activity in comparison to the rest of the strains of lactobacilli and dipeptidases of lower activity than those synthesised by L. casei, but comparable to dipeptidases activity of L. casei ssp rhamnosus. High peptidase activity of the examined Lactobacillus strains proved their potential usefulness in ripening cheese technology.


aminopeptidase, dipeptidase, Lactobacillus