Prospeção e uso de probióticos autóctone isolados do intestino de Colossoma Macropomum no desempenho zootécnico e na profilaxia da aeromonose na larvicultura de Tambaqui
Date
2023-07-21Author
http://lattes.cnpq.br/9633984856179736
SANTOS, Thayná Moura dos
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This study aimed to investigate the feasibility and effectiveness of
supplementation with strains of lactic acid bacteria isolated from the intestinal microbiota of
healthy tambaqui, on the pathophysiological and zootechnical responses in larvae of the
same species of chal-lenged Aeromonas hydrophila. Ten tambaquis were purchased from
local fishermen from the Amazon River in Santarém-Pa. The animals were euthanized by
deepening the anesthetic plane and the gastrointestinal tract was removed for seeding in a
Petri dish containing TSA and MRS media plus Aniline Blue dye. The culture was obtained
from the direct sowing of stomach and intestinal contents and the mix (intestine + feces). A
total of 11 5 bacterial strains were isolated and characterized to investigate their in vitro
viability and probiotic potential. Initially, Catalase tests and Gram staining were performed,
and 66 of the isolates were positive for lactic acid bacteria. Subsequently, the hemolytic
activity of positive bacilli with negative catalase was evaluated, in which 5 did not present
he-molysis, and these were selected for the other analyses (I3, I1 0, F4, M1 3, and M1 4).
For the probiotic characterization of the bacteria, the viability and growth of lactic acid
bacteria were verified at different pH values (2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, and 9.0) for 1 2
h, as well as bile resistance, antagonist activity, auto- and co-aggregation, biofilm
formation, antibiogram, hydrophobicity, and lyophilization tests. For molecular identification
of the worked species, PCR was performed using three primers: Lac 1 and 2 for
Lactobacillus sp., Bac, and 1 6S for Bacillus sp., and their products were separated by gel
electrophoresis. The in vitro analysis was initially carried out by the pathogenicity test in 30
juvenile tambaquis, divided into 6 groups, 0.5 mL of the isolates was inoculated into the
coelomic cavity, where it was verified that there was no mortality and/or clinical behavioral
alterations or tissues in all animals. In larviculture, better zootechnical performance was
verified in strains I3 and M1 3 in relation to the control, without alteration of
morphophysiological development. Sepsis induced in the larvae improved the survival and
innate immunity of larvae supplemented with M1 3 and M1 4. The preliminary results
obtained in the tests showed that the isolates belonging to the genus Lactobacillus present
characteristics of potential probiotics for tambaqui larvae. Prospecting their technological
and functional potential is extremely important for sustainable aquaculture production.