Beta-Glycosidase Activities of Lactobacillus spp. and Bifidobacterium spp. and The Effect of Different Physiological Conditions on Enzyme Activity

In this research, food (cheese, yoghurt) and animal (chicken) origin 39 Lactobacillus spp. and human origin (newborn faeces) three Bifidobacterium spp. were used. To designate the β-glycosidase enzyme and specific activities of the cultures, p-nitrophenyl-β-D glikopiranozit (p-NPG) was used as a substrate. The best specific activities between Lactobacilli cultures were observed at Lactobacillus rhamnosus BAZ78 (4.500 U/mg), L. rhamnosus SMP6-5 (2.670 U/mg), L. casei LB65 (3.000 U/mg) and L. casei LE4 (2.000 U/mg) strains. Bifidobacterium breve A28 (2.670 U/mg) and B. longum BASO15 (2.330 U/mg) strains belonging to the Bifidobacterium cultures had the highest specific activity capabilities. Optimization studies were performed to designate the impact of different pH, temperature, and carbon sources on the β-glucosidase enzyme of L. rhamnosus BAZ78 strain (β-Glu-BAZ78), which exhibits high specific activity. As optimum conditions, pH was detected as 7.5, the temperature as 30° C, and the carbon source as 2% glucose for the enzyme. Although the enzyme activity changed as the physiological conditions changed, the β-Glu-BAZ78 showed the highest specificity in the control groups.