PROBIOTICS FOR AQUACULTURE: FROM THE AUTOCHTHONOUS MICROBIOTA TO A VETERINARY PRODUCT

GUIDOLI, MARCOS G.; SÁNCHEZ, SEBASTIÁN; NADER MACÍAS, MARÍA E.

Egham

Conferencia; UK PROBIOTICS CONFERENCE; 2015

The use of the native fish specie Piaractus mesopotamicus in aquaculture increased the production in Argentinean Northeast. The limited knowledge about this animal and the characteristics of the intensive systems led to the occurrence of diseases and a decrease in the number and final weight of fishes. The use of antibiotics in animals for human consumption have been restricted and replaced for different alternatives such as the administration of probiotics with a general consensus that microorganisms isolated from the same niche where will be applied have a higher possibility to colonize and remain. Thus the objective of our group was to isolate and select autochthonous potentially beneficial bacteria to be administered to P. mesopotamicus larvae. A total of 522 autochthonous cultivable isolates were obtained. Lactic Acid Bacteria (LAB) and Bacillus were preselected and evaluated regarding the expression of beneficial properties such as pathogens inhibition, characteristics of the bacterial surface and production of hydrogen peroxide, exopolysaccharides, surfactants and emulsifiers. A total of eight strains showing the best beneficial properties (4 Enterococcus faecium, 1 Pediococcus acidilactici and 3 Bacillus subtilis) were selected for in vivo assays and grouped into four mixtures (LAB, ENT, BAC and MIX). Administration was performed in three different stages and in three different doses for each microbial mixture except MIX that was administered only in one dose composed by the optimal doses of each of the other three mixtures. Results of the administration of microbial mixtures LAB, ENT and BAL did not exerted significant differences over biometrical parameters. The administration of mixture MIX in stages L and E&L produced a significant increment of the three biometrical parameters evaluated (survival, mean weight and biomass) showing values that duplicated those obtained in control group. These results allowed our group to patent a product consistent of a microbial mixture able to enhance the breeding of a native fresh water fish from our region.