title: Characterization of the antifungal activity of Lactobacillus harbinensis K.V9.3.1Np and Lactobacillus rhamnosus K.C8.3.1I in yogurt.
abstract: Few antifungal protective cultures adapted to fermented dairy products are commercially available because of the numerous constraints linked to their market implementation. Consumer's demand for naturally preserved food products is growing and the utilization of lactic acid bacteria is a promising way to achieve this goal. In this study, using a 2(5-1) factorial fractional design, we first evaluated the effects of fermentation time, of initial sucrose concentration and of the initial contamination amount of a spoilage yeast, on antifungal activities of single and mixed cultures of Lactobacillus rhamnosus K.C8.3.1I and Lactobacillus harbinensis K.V9.3.1Np in yogurt. L. harbinensis K.V9.3.1Np, the most relevant strain with regard to antifungal activity was then studied to determine its minimal inhibitory inoculation rate, its antifungal stability during storage and its impact on yogurt organoleptic properties. We showed that L. harbinensis K.V9.3.1Np maintained a stable antifungal activity over time, which was not affected by initial sucrose, nor by a reduction of the fermentation time. This inhibitory activity was an all-or-nothing phenomenon. Once L. harbinensis K.V9.3.1Np reached a population of ∼ 2.5 × 10(6) cfu/g of yogurt at the time of contamination, total inhibition of the yeast was achieved. We also showed that an inoculation rate of 5 × 10(6) cfu/ml in milk had no detrimental effect on yogurt organoleptic properties. In conclusion, L. harbinensis K.V9.3.1Np is a promising antifungal bioprotective strain for yogurt preservation.
authors.affiliation: Université de Brest, UEB, EA3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, SFR148 ScInBioS, ESIAB, Technopôle de Brest-Iroise, Plouzané, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Delavenne
authors.affiliation: Université de Brest, UEB, EA3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, SFR148 ScInBioS, ESIAB, Technopôle de Brest-Iroise, Plouzané, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Cliquet
authors.affiliation: Université de Brest, UEB, EA3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, SFR148 ScInBioS, ESIAB, Technopôle de Brest-Iroise, Plouzané, France.
authors.forename: Clément
authors.initials: C
authors.lastname: Trunet
authors.affiliation: Université de Brest, UEB, EA3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, SFR148 ScInBioS, ESIAB, Technopôle de Brest-Iroise, Plouzané, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Barbier
authors.affiliation: Université de Brest, UEB, EA3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, SFR148 ScInBioS, ESIAB, Technopôle de Brest-Iroise, Plouzané, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Mounier
authors.affiliation: Université de Brest, UEB, EA3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, SFR148 ScInBioS, ESIAB, Technopôle de Brest-Iroise, Plouzané, France; Université de Brest, UEB, Institut Universitaire Européen de la Mer (IUEM) - UMR UBO, CNRS, IFREMER 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Place Nicolas Copernic, Plouzané, France. Electronic address: gwenaelle.leblay@univ-brest.fr.
authors.forename: Gwenaëlle
authors.initials: G
authors.lastname: Le Blay
mesh_terms: D000898:Antibiosis; D000935:Antifungal Agents; D015169:Colony Count, Microbial; D005285:Fermentation; D005506:Food Contamination; D005516:Food Microbiology; D005519:Food Preservation; D007778:Lactobacillus / Q000502:physiology*; D052201:Lacticaseibacillus rhamnosus / Q000502:physiology; D013395:Sucrose / Q000378:metabolism; D025062:Yarrowia / Q000254:growth & development*; D015014:Yogurt / Q000382:microbiology*
chemical_list: D000935:Antifungal Agents; D013395:Sucrose
keywords: Antifungal activity; Bioprotective culture; Lactobacillus harbinensis