Selección de cepas de Lactobacillus sp procedentes del tracto digestivo del cerdo como posibles cepas probióticas.

Abstract

This research carried out the selection, characterization and, identification of lactobacillus sp strains from the gastrointestinal tract of pigs as possible probiotic strains. This study slaughtered four piglets of 21-day-old and four piglets of 40-day-old which were of the same breed, age, farm, and type of feeding. The gastrointestinal tract from the piglets slaughtered was extracted to make a stock solution and carry out the dilutions. The microorganisms were sown in MRS agar at pH five and, the bacteria were incubated for 72 hours at 37ºC. The isolation of the bacteria found in the small intestine was carried out according to the macroscopic morphology such as the shape, size and, color, and later the colony-forming units were counted. Basic biochemical tests such as catalase, oxidase, Gram staining, hydrogen peroxide, and characterization tests such as acidification, carbohydrate fermentation, growth in ox bile, and motility were performed, finding eight strains in total. The average CFU/g count was 106, giving positive with all bacteria Bacillus; catalase, oxidase, and KOH negative. The acidification test showed at more hours plus pH decrease, the growth in bile at 0.3% all survived this test; the carbohydrate fermentation identified the species to which it belongs. This study concluded that the isolated strains can be used as probiotics and recommended applying other biochemical tests such as API 50 CHL or real-time PCR for a better characterization of each bacteria isolated from the small intestine of pigs.