title: Genetic diversity and some aspects of antimicrobial activity of lactic acid bacteria isolated from goat milk.
abstract: Lactic acid bacteria (LAB, n = 57) were previously obtained from raw goat milk, identified as Lactococcus spp. (n = 24) and Enterococcus spp. (n = 33), and characterized as bacteriocinogenic. Fingerprinting by pulsed field gel electrophoresis (PFGE) demonstrated high genetic diversity, and 30 strains were selected and exhibited strong antimicrobial activity against 46 target strains (LAB, spoilage, and foodborne pathogens). Six strains (Lactococcus lactis: GLc03 and GLc05; and Enterococcus durans: GEn09, GEn12, GEn14, and GEn17) were selected to characterize their bacteriocinogenic features, using Listeria monocytogenes ATCC 7644 as the target. The six strains produced bacteriocins at higher titer when incubated in MRS at 37 °C up to 12 h, when compared to growth at 25 and 30 °C. The produced bacteriocins kept their antimicrobial activity after exposure to 100 °C for 2 h and 121 °C for 20 min; the antimicrobial activity was also observed after treatment at pH 2.0 to 10.0, except for GLc03. L. monocytogenes populations were reduced approximately two logs after treatment with cell-free supernatants from the selected strains. These data show that goat milk can contain a diverse microbiota able to inhibit L. monocytogenes, a common pathogen found in dairy products, and can be potentially employed in biopreservation of food produced under different processing conditions.
authors: Departamento de Veterinária, Universidade Federal de Viçosa, Campus UFV, 36570 900, Viçosa, MG, Brazil.
authors: Valéria Quintana
authors: VQ
authors: Cavicchioli
authors: Wesley Dos Santos
authors: Wdos S
authors: Dornellas
authors: Luana Martins
authors: LM
authors: Perin
authors: Fábio Alessandro
authors: FA
authors: Pieri
authors: Bernadette Dora Gombossy de Melo
authors: BD
authors: Franco
authors: Svetoslav Dimitrov
authors: SD
authors: Todorov
authors: Luís Augusto
authors: LA
authors: Nero
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001430:Bacteriocins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D014644:Genetic Variation; D006041:Goats; D006863:Hydrogen-Ion Concentration; D007777:Lactobacillaceae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008892:Milk / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins