Bacteria with probiotic potential: hematoimmunology, productive performance and survival of tambaqui (Colossoma macropomum)

Author(s)

Suzana Kotzent

• Document type: Doctoral Thesis
• Press: Jaboticabal. 2021-08-12.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2021-07-01
• Advisor: Fabiana Pilarski

Abstract

Probiotics are microorganisms that contribute to the improvement of one or more factors in the health of the host. In aquaculture, the use of probiotics is evidenced in the improvement of immune responses and survival to infections, productive performance, in addition to improving the quality of the production environment. For tambaqui (Colossoma macropomum), the most produced native fish species in Brazil, there is no indigenous probiotic to be marketed as a food additive. Thus, in this work, the effect of autochthonous strains with probiotic potential on the health and performance of tambaqui was evaluated. In a first experiment, the immunostimulant action of four bacterial strains selected in a previous study was investigated: Enterococcus hirae, Lactococcus lactis, Pediococcus pentosaceus and Staphylococcus hominis. The freeze-dried strains were incorporated into the diet at 106 CFU/g of ration, and the fish were fed for 60 days with the four experimental diets in addition to the control group. Hematological, biochemical and immunological analyzes were performed on days 0, 7, 15, 30, 45 and 60. On day 60, the intestinal histochemistry of all experimental groups was analyzed. In the second experiment, the bacteria L. lactis and P. pentosaceus were added separately to the PBS suspension diet at concentrations 107 and 109 CFU/g of feed, plus a control group. The diets were fed to the animals for 58 days, and during this period, on days 0, 15, 30 and 58, the hematological, biochemical, immunological and productive performance parameters were evaluated. On day 58, the hepatosomatic index, intestinal histochemistry, intestinal microbial composition and resistance to infection by Aeromonas hydrophila were also evaluated. The results found in the first experiment showed a significant increase in the respiratory activity of leukocytes in fish that received the diet containing the bacteria L. lactis and P. pentosaceus, thus these strains were selected for the second experiment. In the second study, the bacteria modulated the intestinal microbiota of fish, without changing the physiological parameters. Based on these results, further studies should be carried out to elucidate the action of probiotics on tambaqui, given the low responsiveness to this type of additive for this species. (AU)

• FAPESP's process: 18/07553-9 - Probiotic for black pacu (Colossoma macropomum): effects on productive performance, survival, hematoimmunology and intestinal evaluation
• Grantee: Suzana Kotzent
• Support Opportunities: Scholarships in Brazil - Doctorate