title: High-salt brines compromise autoinducer-mediated bacteriocinogenic Lactobacillus plantarum survival in Spanish-style green olive fermentations.
abstract: The effect of NaCl on plantaricin production by five Lactobacillus plantarum strains was investigated. Plantaricin production in these strains was found to be regulated by three-component regulatory systems ruled by two different autoinducer peptides (AIPs), either PLNC8IF or Plantaricin A. Bacteriocin activity exhibited by these strains came to a halt in liquid medium containing NaCl concentrations of or above 2%. In contrast, bacteriocin activity was still observed when the producing strains were growing on solid medium containing up to 4% NaCl. Bacteriocin activity in liquid medium containing up to 2% NaCl could be restored by coculturing the producing strains with a selected plantaricin-production inducing strain of Lactococcus lactis. Growth of these bacteriocinogenic L. plantarum strains was monitored in traditional Spanish-style green olive fermentations. Survival of these strains could not be enhanced when provided with a range of plantaricin-production inducing mechanisms previously described, such as constitutive AIP production or coinoculation with a specific bacteriocin-production inducing strain of L. lactis. Our results suggest that it is advisable the use of constitutive bacteriocin producers, or at least non-AIP-dependant ones, as starters for olive fermentations due to the intrinsic physical characteristics of this food fermentation, especially the high salt concentration of the brines currently used.
authors.affiliation: Departamento de Biotecnología de Alimentos, Instituto de la Grasa, Consejo Superior de Investigaciones Científicas, Avda. Padre García Tejero 4, Aptdo. 1078, 41012 Sevilla, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Caballero-Guerrero
authors.forename: Helena
authors.initials: H
authors.lastname: Lucena-Padrós
authors.forename: Antonio
authors.initials: A
authors.lastname: Maldonado-Barragán
authors.forename: José Luis
authors.initials: JL
authors.lastname: Ruiz-Barba
mesh_terms: D001430:Bacteriocins / Q000096:biosynthesis* / Q000378:metabolism; D005285:Fermentation; D048191:Lactiplantibacillus plantarum / Q000254:growth & development / Q000378:metabolism*; D031658:Olea / Q000378:metabolism / Q000382:microbiology*; D012965:Sodium Chloride / Q000378:metabolism*; D013030:Spain
chemical_list: D001430:Bacteriocins; C084446:plantaricin A; D012965:Sodium Chloride