ТOLERANCE TO FREEZE-DRYING CONDITIONS OF Lactobacillus delbrueckii subsp. bulgaricus STRAINS AFTER ACIDIC EXPOSE

Abstract

The goal of this work was to investigate the effect of fermentation pH and time on the acid tolerance, glycolytic activity, and survival during freeze drying of L. delbrueckii subsp. bulgaricus WDCM 00102 strains during cultivation in the medium, based on pretreated biomass of Spirulina platensis. During the study, when the fermentation process is carried out at a constant pH, a higher value of glycolytic activity is established in the cells of the probiotic culture, which decreases when the pH is lowered. The survival rate of cells of L. delbrueckii subsp. bulgaricus WDCM 00102 after lyophilization shows similar values after cultivation for 25 and 37 h (p < 0.05), while the opposite dependence is established in experiments related to changes in the pH of the cultivation medium. pH and fermentation time significantly influence the glycolytic activity of L. delbrueckii subsp. bulgaricus WDCM 00102 and on the resistance of its cells to acid stress and lyophilization conditions.