A. S. Tishchenko1 , D. V. Mikryakov2 , A. G. Koshchaev1 , D. O. Alferov1, T. A. Suvorova2 , S. V. Kuzmicheva2
1 Kuban State Agrarian University named after I. T. Trubilin, Krasnodar, Russia
2 I. D. Papanin Institute of Biology of Inland Waters, Russian Academy of Sciences, Borok settlement, Yaroslavl region, Russia
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Volume 26 No. 6
Date of paper submission: 08.04.2026, date of review: 27.04.2026, date of acceptance: 06.05.2026.
Published: 06/30/2026
Abstract. The study is aimed at establishing the effect of a preparation based on Enterococcus faecium and Pediococcus acidilactici bacteria in its pure form and a feed additive with these microorganisms grown on a nutrient medium with the addition of inactivated metabolites of Aeromonas salmonicida on the immunological parameters of fish. The purpose is to study the effect of drugs on the indicators of nonspecific immunity of fingerlings of Siberian sturgeon. The research methods used were microbiological (bacteriological cultures of indigenous bacteria), biotechnological (feed additive design), and immunological (determination of the bacteriostatic activity of blood serum, immune complexes, and C-reactive protein). Scientific novelty. This is the first study to examine the effect of Aeromonas metabolites and indigenous microorganisms in a feed additive on fish immune parameters. As a result, it was found that the fingerlings of the Siberian sturgeon who received the drug with a probiotic at the end of the experiment showed a higher level of BABS and a low content of IC in immunocompetent organs compared with the control group. Thus, the bacteriostatic activity of blood serum after 14 days of the experiment in individuals of the experimental group receiving the probiotic was 3.7 % higher than in the control group. On the 30th day of the experiment, the indicator of bacteriostatic activity in the fish of this group exceeded the control by 21.6 %. The content of immune complexes in the liver, kidneys, and spleen in the group of fish treated with probiotics was lower than in the control group by 24.1 %, 71.4 %, and 20.3%, respectively. Fish whose diet included a probiotic with the addition of formalin-inactivated metabolites of A. salmonicida bacteria, on the contrary, had a higher index of bacteriostatic activity on day 14, exceeding the control by 6.8 %, the level of immunocomplexes was higher than the control group in the blood serum by 28.6 %, and in the liver by 39.8 %. On day 30, the BABS was 8.7 % lower than in the control, and the IC in the liver was almost 2 times higher than in the control, the level in the kidneys was 26.2 % higher, and in the spleen it increased 5.7 times. The results of the conducted studies show the prospects of using probiotic additives based on the autochthonous microflora of fish in industrial aquaculture.
Keywords: aquaculture, hybrid sturgeon, probiotic preparation, metabolite, nonspecific humoral immunity, antimicrobial properties of blood serum, immune complexes, C-reactive protein
Acknowledgements. The study was carried out with the financial support of the Kuban Science Foundation within the framework of scientific project No. H-25.1/39.
For citation: Tishchenko A. S., Mikryakov D. V., Koshchaev A. G., Alferov D. O., Suvorova T. A., Kuzmicheva S. V. Effect of an experimental probiotic preparation on some indices of nonspecific immunity in juvenile Siberian sturgeon. Agrarian Bulletin of the Urals. 2026; 26 (06): 1112‒1120. https://doi. org/10.32417/1997-4868-2026-26-06-1112-1120.
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