Comparative characteristics of Bacillus subtilis strains as promising candidates for probiotics for animal husbandry

УДК 579.64
DOI 10.33861/2071-8020-2024-5-23-27

Mukhammadiev Rish.S., Mukhammadiev Rin.S., Karimullina I.G., Shangaraev R.I., Mukhammadieva A.S., Akbashev I.R., Sorokina D.A., Khusainova G.I.

Summary. The study carried out a comparative assessment of the properties of the spore-forming B. subtilis strains, MP2 and RF-45, their potential as candidates for probiotics for livestock. The studied bacilli showed antimicrobial potential against bacteria S. aureus, E. coli and S. enterica - causative agents of various infections in farm animals, as well as toxin-producing micromycetes F. graminearum, F. moniliforme and F. sporotrichioides. Compared with the bacillary strain MP2, B. subtilis RF-45 was 8.18-18.07 and 16.74-28.10% more effective in inhibiting the growth of test-bacteria and test-micromycetes, respectively. It was found that after sequentially keeping the spores of both bacilli in a medium with pepsin (pH 2.5) for 3 hours and bovine bile (pH 7.5) for 8 hours, their viability was at the control level. The highest degree of adhesion was found in strain MP2: after incubation for 2 hours at 37.0°C, the number of viable spores adhered to NT-29 cells was 1.87 times higher than the values of this indicator for spores of strain RF-45. Vegetative cells of both bacilli were not characterized by hemolytic activity, and also did not carry genes responsible for the synthesis of enterotoxins and cytotoxin K, indicating their potential safety. Separate or joint feeding of spores of the studied bacilli led to an increase in the number of Escherichia coli, bifidobacteria and lactobacilli in the intestinal contents of white mice with dysbiosis induced by the antibiotic gentamicin. Moreover, in the group of mice that received a suspension of RF-45 strain spores, the amount of E. coli was higher by 1.02 times, Bifidobacterium spp. - by 1.12 times, Lactobacillus spp. - by 1.04 times higher than the values of the indicated indicator in the group of animals that received a suspension of spores of strain MP2. It was concluded that B. subtilis strains MP2 and RF-45 are promising candidates for probiotics for livestock.

Keywords: Bacillus subtilis, antimicrobial potential, resistance, bile, pepsin, adhesion to cells, safety, disturbances of intestinal microecology, effectiveness, probiotics, animal husbandry.

Author affiliation:

Mukhammadiev Rinat S., Ph. D. in Biology, Senior Scientific Researcher of the Laboratory of Applied and Experimental Microbiology of the All-Russian Research Institute of Phytopathology; Laboratory of Feeds and Feed Additives, Federal Center for Toxicological, Radiation and Biological Safety; Scientific town-2, Kazan, 420075; phone: 8-987-4214127; e-mail: tanirtashir@mail.ru.

Karimullina Ilsiyar G., Ph. D. in Biology, Senior Scientific Researcher of the Laboratory of Virology of the Federal Center for Toxicological, Radiation and Biological Safety; Scientific town-2, Kazan, 420075; phone: 8-904-7699225; e-mail: 89047699225@mail.ru.

Shangaraev Rafkat I., Ph. D. in Veterinary Medicine, Scientific Researcher of the Laboratory of Molecular Genetic Analysis of the Federal Center for Toxicological, Radiation and Biological Safety; Scientific town-2, Kazan, 420075; phone: 8-917-22883344; e-mail: rafkat.shangaraev@mail.ru.

Mukhammadieva Alina S., Ph. D. in Veterinary Medicine, Junior Scientific Researcher of the Laboratory of Nutrient Media and Cell Cultures of the Federal Center for Toxicological, Radiation and Biological Safety; Scientific town-2, Kazan, 420075; phone: 8-917-2396095; е-mail: alinasakura_mail.ru@mail.ru

Akbashev Ilgizar R., Ph. D. in Veterinary Medicine, Scientific Researcher of the Laboratory of Virology of the Federal Center for Toxicological, Radiation and Biological Safety; Scientific town-2, Kazan, 420075; phone: 8-950-9474056; e-mail: ilgizar.92@mail.ru.

Sorokina Diana A., Junior Scientific Researcher of the Laboratory of Virology of the Federal Center for Toxicological, Radiation and Biological Safety; Scientific town-2, Kazan, 420075; phone: 8-927-8875729; e-mail: diana-sorokina2013@mail.ru.

Khusainova Gulnara I., Ph. D. in Biology, Senior Scientific Researcher of the Laboratory of Virology of the Federal Center for Toxicological, Radiation and Biological Safety; Scientific town-2, Kazan, 420075; phone: 8-917-2627283; e-mail: GulnaraI13@yandex.ru.

Responsible for correspondence with the editorial board: Mukhammadiev Rishat S., Ph. D. in Biology, Senior Scientific Researcher of the Laboratory of Applied and Experimental Microbiology of the AllRussian Research Institute of Phytopathology; Scientific Researcher of the Laboratory of Feeds and Feed Additives of the Federal Center for Toxicological, Radiation and Biological Safety; Scientific town-2, Kazan, 420075; phone: 8-939-3728789; e-mail: tashir9891@mail.ru.