P. ZHELEVA1, T. VASILEVA1, T. MANDADZHIEVA2, I. IVANOVA2 and I. ILIEV1
1 Plovdiv University “P. Hilendarski”, Department of Biochemistry and Microbiology, BG – 4000 Plovdiv, Bulgaria
2 Sofia University “St. Kliment Ohridski”, Department of Microbiology, Biological Faculty, BG – 1164 Sofia, Bulgaria
ZHELEVA, P., T. VASILEVA T. MANDADZHIEVA, I. IVANOVA and I. ILIEV, 2014. Infl uence of lactose concentration on the α-galactosidase and β-galactosidase activity of Lactobacillus plantarum. Bulg. J. Agric. Sci., Supplement 1: 62–65
Twenty seven lactic acid bacteria (LAB) strains identifi ed as Lactobacillus plantarum, Lactobacillus brevis and Lactobacillussakei, isolated from sausages were tested for their ability to utilize and grow on lactose at concentration by 10%, 12.5%, 15% and 5% lactulose. Results clearly demonstrated that the growth-rates on high percent of lactose showed very different preferences. It could be propose that the studied β-galactosidase catalyzes trans-glycosylation reaction at concentration of lactose 12.5% and 15%. The activity of α-galactosidase is 10 times lower than β-galactosidase on modifi ed MRS (mMRS) with 12.5% lactose concentration. On media with 5% lactulose, α-galactosidase activity of the studied strain S26 is 20% lower than measured β-galactosidase activity. It could be concluded that lactulose is better inductor for α-galactosidase than lactose.