R. TROPCHEVA1, J. HRISTOVA1, R. GEORGIEVA1, A. SALAGEANU2, D. N. SGOURAS3 and S. DANOVA1
1 Department of Microbial Genetics, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, BG – 1113 Sofia, Bulgaria
2 Infection and Immunity Laboratory, Cantacuzino Institute 103, Spl. Independentei, Sector 5050096, Bucharest, Romania
3 Laboratory of Medical Microbiology, Hellenic Pasteur Institute, Athens, Greece
TROPCHEVA, R., J. HRISTOVA, R. GEORGIEVA, A. SALAGEANU, D. N. SGOURAS and S. DANOVA, 2013. In vitro assessment of prebiotic utilization by dairy lactobacilli. Bulg. J. Agric. Sci., Supplement 2, 19: 105–107
The new consumers’ demand for healthy products on the market enhances intensive researches on lactic acid bacteria (LAB) and prebiotics. Individually and in combinations (in a synbiotic form), they can be effective microbial modulators, with a positive impact on human health and wellbeing. Thus, the selection of successful combinations LAB strain-prebiotic is a milestone in the development of new functional foods and products. With this aim, the potential of 33 Bulgarian LAB strains to growth in the presence of galactoologosacharide (GOS), glucooligosacharide (GLOS) and fructooligosacharide (FOS) were estimated. Thirty-three original LAB strains, from traditional Bulgarian dairy products have been identified and pre-selected on the base of widely accepted in vitro criteria for probiotics. The in vitro assessment of prebiotic’s utilization was evaluated in a mini-plate model system with a modified MRS broth. The major part of tested LAB was able to growth in medium containing 10% v/v GLOS (69–76% of the tested strains) and GOS (88–99.82%) as a single carbon source. About the FOS, approximately 67% of the tested strains utilized it partially, and only 3% of them – completely. A higher metabolic activity has been proved for LAB strains belonging to the species Lactobacillus plantarum and Lactobacillus brevis. A strict correlation has been reported between the ability of different Lactobacillus plantarum to ferment GOS and their β-galactosidase activity. The results revealed that the oligosaharide utilization patterns are strain-specific and they do not dependent from the origin of the tested LAB. Obtained data is promising for further development of new synbiotic formulas.