title: Enterococcus faecium isolated from Lombo, a Portuguese traditional meat product: characterisation of antibacterial compounds and factors affecting bacteriocin production.
abstract: Strain ST211CH, identified as a strain of Enterococcus faecium, isolated from Lombo produced a bacteriocin that inhibited the growth of Enterococcus spp., Listeria spp., Klebsiella spp., Lactobacillus spp., Pseudomonas spp., Staphylococcus spp. and Streptococcus spp. The mode of action of the bacteriocin named as bacteriocin ST211Ch was bactericidal against Enterococcus faecalis ATCC19443. As determined by Tricine-SDS-PAGE, the approximate molecular mass of the bacteriocin was 8.0 kDa. Loss in antimicrobial activity was recorded after treatment with proteolytic enzymes. Maximum activity of bacteriocin ST211Ch was measured in broth cultures of E. faecium strain ST211Ch after 24 h; thereafter, the activity was reduced. Bacteriocin ST211Ch remained active after exposure to various temperatures and pHs, as well as to Triton X-100, Tween-80, Tween-20, sodium dodecyl sulfate, NaCl, urea and EDTA. Effect of media components on production of bacteriocin ST211Ch was also studied. On the basis of PCR reactions targeting different bacteriocin genes, i.e. enterocins, curvacins and sakacins, no evidences for the presence of these genes in the total DNA of E. faecium strain ST211Ch was obtained. The bacterium most probably produced a bacteriocin different from those mentioned above. Based on the antimicrobial spectrum, stability and mode of action of bacteriocin ST211CH, E. faecium strain ST211Ch might be considered as a potential candidate with beneficial properties for use in biopreservation to control food spoilage bacteria.
authors.affiliation: Universidade de São Paulo, Departamento de Alimentos e Nutrição Experimental, Laboratório de Microbiologia de Alimentos, São Paulo SP, Brasil.
authors.forename: S D
authors.initials: SD
authors.lastname: Todorov
authors.forename: L
authors.initials: L
authors.lastname: Favaro
authors.forename: P
authors.initials: P
authors.lastname: Gibbs
authors.forename: M
authors.initials: M
authors.lastname: Vaz-Velho
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001430:Bacteriocins / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D002452:Cell Count; D003470:Culture Media / Q000737:chemistry; D003902:Detergents; D004492:Edetic Acid; D004591:Electrophoresis, Polyacrylamide Gel; D013293:Enterococcus faecalis / Q000187:drug effects; D016984:Enterococcus faecium / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D007709:Klebsiella / Q000187:drug effects; D007778:Lactobacillus / Q000187:drug effects; D008087:Listeria / Q000187:drug effects; D008461:Meat Products / Q000382:microbiology*; D017830:Octoxynol; D011174:Portugal; D055550:Protein Stability; D011549:Pseudomonas / Q000187:drug effects; D012967:Sodium Dodecyl Sulfate; D013696:Temperature; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D003470:Culture Media; D003902:Detergents; D012967:Sodium Dodecyl Sulfate; D017830:Octoxynol; D004492:Edetic Acid