title: Pediocin SA-1: A selective bacteriocin for controlling Listeria monocytogenes in maize silages.
abstract: In this study, we assessed the potential as silage additive of a bacteriocin produced by Pediococcus acidilactici Northern Regional Research Laboratory (NRRL) B-5627 (pediocin SA-1). Maize was inoculated either with a bacterial starter alone (I) or in combination with the bacteriocin (IP), and untreated silage served as control. We monitored the products of fermentation (ethanol, and lactic and acetic acids), the microbial population, and the presence of the indicator strain Listeria monocytogenes Colección Española de Cultivos Tipo (CECT) 4032 (1×10(5) cfu/g) after 1, 2, 5, 8, 16, and 30d of ensiling. Our results indicated antilisterial activity of the bacteriocin, anticipating the disappearance of L. monocytogenes in IP compared with I and control silages. The PCR-denaturing gradient gel electrophoresis analysis revealed the addition of the bacteriocin did not affect the bacterial communities of the spontaneous fermentation, and the inoculant-containing bacteria (Lactobacillus plantarum, Lactobacillus buchneri, and Enterococcus faecium) were found in addition to the bacterial communities of untreated maize silages in I and IP silages. Both treatments increased the concentration of antimicrobial compounds (acetic acid, ethanol, and 1,2-propanodiol) and led to lower residual sugar contents compared with the control, which would provide enhanced aerobic stability. The fact that the identified species L. plantarum, L. buchneri, and E. faecium produce some of these inhibitory compounds, together with their persistence throughout the 30d of fermentation, suggest these bacteria could actively participate in the ensiling process. According to these results, pediocin SA-1 could be used as an additive to control the presence of L. monocytogenes in maize silages selectively, while improving their fermentative quality and eventually their aerobic stability.
authors: Departamento de Química Analítica y Alimentaria, Facultad de Ciencias de Ourense, Universidad de Vigo, As Lagoas s/n 32004, Spain. Electronic address: sabelara@uvigo.es.
authors: Isabel R
authors: IR
authors: Amado
authors: Departamento de Química Analítica y Alimentaria, Facultad de Ciencias de Ourense, Universidad de Vigo, As Lagoas s/n 32004, Spain; Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
authors: Clara
authors: C
authors: Fuciños
authors: ANFACO-CECOPESCA, Colegio Universitario 16, 36310 Vigo, Pontevedra, Spain.
authors: Paula
authors: P
authors: Fajardo
authors: International Iberian Nanotechnology Laboratory, Avda. Mestre José Veiga s/n, 4715 Braga, Portugal.
authors: Lorenzo
authors: L
authors: Pastrana
mesh_terms: D019342:Acetic Acid / Q000032:analysis; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004269:DNA, Bacterial / Q000302:isolation & purification; D016984:Enterococcus faecium / Q000378:metabolism; D000431:Ethanol / Q000032:analysis; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D048668:Lactobacillus delbrueckii / Q000378:metabolism; D048191:Lactiplantibacillus plantarum / Q000378:metabolism; D008089:Listeria monocytogenes / Q000187:drug effects*; D000070017:Pediocins / Q000494:pharmacology*; D000070016:Pediococcus acidilactici / Q000378:metabolism; D012820:Silage / Q000032:analysis / Q000382:microbiology*; D003313:Zea mays / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D000070017:Pediocins; D000431:Ethanol; D019342:Acetic Acid
keywords: antimicrobial; lactic acid bacteria; pathogenic bacteria; silage