title: Antimicrobial activity and partial characterization of bacteriocin-like inhibitory substances produced by Lactobacillus spp. isolated from artisanal Mexican cheese.
abstract: Lactobacillus spp. from Mexican Cocido cheese were shown to produce bacteriocin-like substances (BLS) active against Staphylococcus aureus,Listeria innocua,Escherichia coli, andSalmonella typhimurium by using the disk diffusion method. Crude extracts of Lactobacillus fermentum showed strong inhibitory activity against Staph. aureus, L. innocua, E. coli, and Salmonella cholerae. Complete inactivation of antimicrobial activity was observed after treatment of crude extracts with proteinase K, pronase, papain, trypsin, and lysozyme, confirming their proteinaceous nature. However, antimicrobial activity was partly lost for some of the crude extracts when treated with α-amylase, indicating that carbohydrate moieties were involved. The antimicrobial activity of the crude extracts was stable at 65°C for 30min over a wide pH range (2-8), and addition of potassium chloride, sodium citrate, ethanol, and butanol did not affect antibacterial activity. However, antimicrobial activity was lost after heating at 121°C for 15min, addition of methanol or Tween 80. Fourteen out of 18 Lactobacillus spp. showed antimicrobial activity against different test microorganisms, and 12 presented bacteriocin-like substances. Generation time and growth rate parameters indicated that the antimicrobial activity of crude extracts from 3 different strains was effective against the 4 indicator microorganisms. One of the crude extracts showed inhibition not only against gram-positive but also against gram-negative bacteria. Bacteriocin-like substances produced by this specific Lactobacillus strain showed potential for application as a food biopreservative.
authors.affiliation: Laboratorio de Química y Biotecnología de Productos Lácteos, Coordinación de Tecnología de Alimentos de Origen Animal (CTAOA), Carretera a La Victoria Km 0.6, Apartado Postal 1735 Hermosillo, Sonora, 83304, México.
authors.forename: Priscilia Y
authors.initials: PY
authors.lastname: Heredia-Castro
authors.affiliation: Laboratorio de Química y Biotecnología de Productos Lácteos, Coordinación de Tecnología de Alimentos de Origen Animal (CTAOA), Carretera a La Victoria Km 0.6, Apartado Postal 1735 Hermosillo, Sonora, 83304, México.
authors.forename: José I
authors.initials: JI
authors.lastname: Méndez-Romero
authors.affiliation: Laboratorio de Química y Biotecnología de Productos Lácteos, Coordinación de Tecnología de Alimentos de Origen Animal (CTAOA), Carretera a La Victoria Km 0.6, Apartado Postal 1735 Hermosillo, Sonora, 83304, México.
authors.forename: Adrián
authors.initials: A
authors.lastname: Hernández-Mendoza
authors.affiliation: Laboratorio de Microbiología Molecular, Coordinación de Ciencia de los Alimentos (CA), Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD, A.C.) Carretera a La Victoria Km 0.6, Apartado Postal 1735 Hermosillo, Sonora, 83304, México.
authors.forename: Evelia
authors.initials: E
authors.lastname: Acedo-Félix
authors.affiliation: Laboratorio de Química y Biotecnología de Productos Lácteos, Coordinación de Tecnología de Alimentos de Origen Animal (CTAOA), Carretera a La Victoria Km 0.6, Apartado Postal 1735 Hermosillo, Sonora, 83304, México.
authors.forename: Aarón F
authors.initials: AF
authors.lastname: González-Córdova
authors.affiliation: Laboratorio de Química y Biotecnología de Productos Lácteos, Coordinación de Tecnología de Alimentos de Origen Animal (CTAOA), Carretera a La Victoria Km 0.6, Apartado Postal 1735 Hermosillo, Sonora, 83304, México. Electronic address: vallejo@ciad.mx.
authors.forename: Belinda
authors.initials: B
authors.lastname: Vallejo-Cordoba
mesh_terms: D001430:Bacteriocins / Q000494:pharmacology*; D002611:Cheese / Q000032:analysis / Q000382:microbiology*; D004926:Escherichia coli / Q000187:drug effects; D005506:Food Contamination; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000737:chemistry* / Q000302:isolation & purification; D008087:Listeria / Q000187:drug effects; D012486:Salmonella typhimurium / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D001430:Bacteriocins
keywords: antimicrobial activity; bacteriocin; lactic acid bacteria