Main Article Content

Marin Georgiev Maria Baltadjieva Bogdan Goranov Mariya Brazkova Albert Krastanov


The antimicrobial activity of strains Lactobacillus delbrueckii ssp. bulgaricus MG1, Lactobacillus delbrueckii ssp. bulgaricus MG2, Lactobacillus delbrueckii ssp. bulgaricus MG3 and Lactobacillus delbrueckii ssp. bulgaricus MG4 has been investigated against pathogenic microorganisms Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 8739, Listeria monocytogenes, Salmonella sp. by the agar well diffusion method.  The biomass, the culture medium and the cell-free supernatant were tested. The antibiotic resistance of the strains against clinical practice antibiotics with different mechanisms of action has been determined. The maximum specific growth rate and the parameters of the respective models for the selected strains was determined. The experiments established that Lactobacillus delbrueckii ssp. bulgaricus MG 3 exhibits the most pronounced antimicrobial activity compared to the other strains tested.

Practical applications
This study was called for by the need to produce starter cultures with established purity and activity for use in the food industry. The aim of this work is to investigate a certain group of lactic acid bacteria widely used in practice and in the composition of starter cultures.

Article Details


Bauer A.W., Kirby W. M., Sherris J. C., Turck M., Antibiotic susceptibility testing by a standardized single disk method. American Journal of Clinical Pathology, Vol. 36, 49-52, 1966.

Bei Zhang, Yanping Wang, Zhongfang Tan, Zongwei Li, Zhen Jiao and Qunce Huang, Screening of Probiotic Activities of Lactobacilli Strains Isolated fromTraditional Tibetan Qula, A Raw Yak Milk Cheese, Asian-Australas. J. Anim. Sci.Vol. 29, No. 10: 1490-99, 2016.

Bhatia SJ, Kochar N., Abraham P., Lactobacillus acidophilus inhibits growth of Campylobacter pylori in vitro. J. Clin. Microbiol., Vol. 27, No. 10: 2328-30, 1989.

Bouguettoucha A., Balannec B., Amrane A., Unstructured Models for Lactic Acid Fermentation: A Review, Food Technol. Biotechnol., 49(1) p.3–12, 2011.

Charteris W.P., Kelly P. M., Morelli L., Collins J. K., Development and application of an in vitro methodology to determine the transit tolerance of potentially probiotic Lactobacillus and Bifidobacterium species in the upper human gastrointestinal tract. Journal of Applied Microbiology Vol. 84, No. 5, 759–68, 1998.

Danielsen, M., Wind A., Susceptibility of Lactobacillus spp. to antimicrobial agents. Int. J. of Food Microbiol., 82,1, 1-11, 2003.

Davidson R. H., Duncan S. E., Eigel W. N., Boling J. W., Probiotic Culture Survival and Implications in Fermented Frozen Yoghurt Characteristics. J. Dairy Sci., 83(4), 666-73, 2000.

Fang H., Adhesion of Bifidobacterium spp. to human intestinal mucus. Microbiol. Immunol., 45(3), 259-62, 2001.

Gordeev L., Koznov А., Skichko А., Gordeeva Yu. Unstructured mathematical models of the lactic acid biosynthesis kinetics: A Review, Theoretical Foundations of Chemical Engineering, 51(2), 175-190, 2017.

Kostov G. (2015). Intensification of fermentation processes with immobilized biocatalysts. Dissertation for Acquisition of the NSA "Doctor of Science“, [in Bulgarian]

Mathur S., Singh R., Antibiotic resistance in food lactic acid bacteria- A Review. Int. J. Food Microbiol., 105, 281-95, 2005.

Morelli L. In Vitro Selection of Probiotic Lactobacilli: a critical appraisal, Curr. Issues Intest. Microbiol. 1(2): 59-67, 2000.

O’Brien J., Crittenden R., Ouwehand A. C., Salminen S. Safety evaluation of probiotics. Trends in Food Science & Technology 10(12), 418 – 424, 1999.

Padmavathi Tallapragada, Bhargavi Rayavarapu, Priyanka Purushothama Rao, Niranjan Naige Ranganath, Pavitra Pogakul Veerabhadrapp. Screening of potential probiotic lactic acid bacteria and production of amylase and its partial purification, Journal of Genetic Engineering and Biotechnology 16(2), 357-62, 2018.

Puniya M, Ravinder Kumar M, Panwar H, Kumar N, Ramneek, et al. Screening of Lactic Acid Bacteria of Different Origin for their Probiotic Potential. J. Food Process Technol 7: 545, 2016.

Salminen S., von Wright A. Lactic acid bacteria, Copyright by “Marell Dekker” INC, New York, 1993.

Salminen S., von Wright A. Current Probiotics – Safety Assured?, Microbial Ecology in Health and Disease, 10(2), 68-77, 1998.

Teneva D., Goranov B., Denkova R., Denkova Z., Kostov G. Antimicrobial Activity of Lactobacillus Plantarum Strains Against Escherichia Coli Strains. Scientific works of University of Food Technologies, 63(1) 199-206, (2016a), [in Bulgarian]

Teneva D., Denkova Z., Goranov B., Denkova R., Kostov G., Atanasova T., Merdzhanov P. (2016b). Chemical composition and antimicrobial activity of essential oils from black pepper, cumin, coriander and cardamom against some pathogenic microorganisms. Acta Universitatis Cibiniensis Series E: Food technology, 20(2), 39-52, 2016.

Tishin V.B., Golovinskaia O.V. Experiment search and mathematical models of the kinetics of biological processes. Textbook. St. Petersburg, University ITMO Publ., 111 p, 2015, [in Russian]

Tishin V.B., Fedorov А.V. The peculiarities of mathematical modelling for the kinetics of microorganisms’ cultivation, Processes and Food Production Equipment, 9(4), 65-74, 2016, [in Russian]

How to Cite
GEORGIEV, Marin et al. Investigation of the probiotic properties and the acid production rate of strains Lactobacillus delbrueckii ssp. Bulgaricus. Food Science and Applied Biotechnology, [S.l.], v. 2, n. 2, p. 149-158, oct. 2019. ISSN 2603-3380. Available at: <>. Date accessed: 12 nov. 2019. doi: