Identification, characterization and selection of autochthonous lactic acid bacteria as probiotic for feedlot cattle

MALDONADO, NATALIA C.; FICOSECO, CECILIA ARISTIMUÑO; MANSILLA, FLAVIA I.; MELIÁN, CONSTANZA; HÉBERT, ELVIRA MARIA; VIGNOLO, GRACIELA M.; NADER-MACÍAS, MARIA E. FÁTIMA

LIVESTOCK SCIENCE

ELSEVIER SCIENCE BV

Año: 2018 vol. 212 p. 99 - 110

1871-1413

Livestockmicrobiota is becoming a focus of interest for veterinaries, animalnutritionists and microbiologists in view to select beneficial bacteria withimpact in health and animal productivity. As resident adapted microorganisms, lacticacid bacteria (LAB) were isolated, identified and characterized from thehomologous host to promote their permanence/efficiency acting as additives infeedlot cattle feeding. Cultivable LAB numbers from cattle feces (CF), penssoil (PS) and feed rations (FR) ranged from 5 to 6 log CFU/g during feedlotpermanence. Isolates (500) were identified by (GTG)5-PCR and sequence analysisof 16S rRNA, being represented by Enterococcus, Lactobacillus, Leuconostoc,Pediococcus and Weissella genera and 20 different species. Genetic mappingshowed that predominant LAB species in CF and PS samples were Lactobacillus(Lb) mucosae (34%), Enterococcus (E) hirae (26%) and E. faecium-durans (20%),while in FR E. faecium-durans (46%), Pediococcus (P). pentosaceous, P.acidilactici (17%) and Lb. acidophilus (11%) were mainly isolated. Surfacecharacterization showed most of LAB as high hydrophilic, however severalstrains from CF and PS revealed strong hydrophobic and auto-aggregativecharacter with a positive correlation between both superficial properties.Adhesion to polystyrene displayed variable biofilm formation patterns forEnterococcus and Lactobacillus strains depending on the presence of Tween inMRS medium. When antagonistic activity of isolated LAB against bovine relevant pathogenswas evaluated, organic acids and hydrogen peroxide production were mostlyresponsible for inhibition; bacteriocin production was shown only by a Lb.mucosae strain. In addition, tolerance to acid and bile salts showedlactobacilli to withstand GIT conditions, while enterococci were more sensitiveto low acid environment. On these bases, several Lactobacillus strains may beselected to explore their potential use as direct fed bacteria in feedlotcattle.