title: In Lactobacillus pentosus, the olive brine adaptation genes are required for biofilm formation.
abstract: Lactobacillus pentosus is one of the few lactic acid bacteria (LAB) species capable of surviving in olive brine, and thus desirable during table olive fermentation. We have recently generated mutants of the efficient strain L. pentosus C11 by transposon mutagenesis and identified five mutants unable to survive and adapt to olive brine conditions. Since biofilm formation represents one of the main bacterial strategy to survive in stressful environments, in this study, the capacity of adhesion and formation of biofilm on olive skin was investigated for this strain and five derivative mutants which are interrupted in metabolic genes (enoA1 and gpi), and in genes of unknown function ("oba" genes). Confocal microscopy together with bacteria count revealed that the sessile state represented the prevailing L. pentosus C11 life-style during table olive fermentation. The characterization of cell surface properties showed that mutants present less hydrophobic and basic properties than the wild type (WT). In fact, their ability to adhere to both abiotic (polystyrene plates) and biotic (olive skin) surfaces was lower than that of the WT. Confocal microscopy revealed that mutants adhered sparsely to the olive skin instead of building a thin, multilayer biofilm. Moreover, RT-qPCR showed that the three genes enoA1, gpi and obaC were upregulated in the olive biofilm compared to the planktonic state. Thus enoA1, gpi and "oba" genes are necessary in L. pentosus to form an organized biofilm on the olive skin.
authors.affiliation: Faculty of BioScience and Technology for Food, Agriculture and Environment, University of Teramo, Italy; UMR PAM, Univ. Bourgogne Franche-Comté, AgroSup Dijon, Dijon, France.
authors.forename: G
authors.initials: G
authors.lastname: Perpetuini
authors.affiliation: UMR PAM, Univ. Bourgogne Franche-Comté, AgroSup Dijon, Dijon, France.
authors.forename: B N
authors.initials: BN
authors.lastname: Pham-Hoang
authors.affiliation: UMR PAM, Univ. Bourgogne Franche-Comté, AgroSup Dijon, Dijon, France.
authors.forename: H
authors.initials: H
authors.lastname: Scornec
authors.affiliation: Faculty of BioScience and Technology for Food, Agriculture and Environment, University of Teramo, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Tofalo
authors.affiliation: Faculty of BioScience and Technology for Food, Agriculture and Environment, University of Teramo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Schirone
authors.affiliation: Faculty of BioScience and Technology for Food, Agriculture and Environment, University of Teramo, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Suzzi
authors.affiliation: UMR PAM, Univ. Bourgogne Franche-Comté, AgroSup Dijon, Dijon, France.
authors.forename: J F
authors.initials: JF
authors.lastname: Cavin
authors.affiliation: UMR PAM, Univ. Bourgogne Franche-Comté, AgroSup Dijon, Dijon, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Waché
authors.affiliation: Faculty of BioScience and Technology for Food, Agriculture and Environment, University of Teramo, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Corsetti
authors.affiliation: UMR PAM, Univ. Bourgogne Franche-Comté, AgroSup Dijon, Dijon, France. Electronic address: helene.licandro@u-bourgogne.fr.
authors.forename: H
authors.initials: H
authors.lastname: Licandro-Seraut
mesh_terms: D000064:Acclimatization; D001422:Bacterial Adhesion / Q000235:genetics*; D018441:Biofilms / Q000254:growth & development*; D005285:Fermentation / Q000235:genetics; D057927:Hydrophobic and Hydrophilic Interactions; D007778:Lactobacillus / Q000235:genetics* / Q000378:metabolism; D018613:Microscopy, Confocal; D016296:Mutagenesis; D031658:Olea / Q000382:microbiology*; D010933:Plankton / Q000235:genetics; D012492:Salts
chemical_list: D012492:Salts; C017082:brine
keywords: Biofilms; Fermentation; Lactic acid bacteria; Mutagenesis; Olive brine; Stress