title: Survival of cheese-ripening microorganisms in a dynamic simulator of the gastrointestinal tract.
abstract: A mixture of nine microorganisms (six bacteria and three yeasts) from the microflora of surface-ripened cheeses were subjected to in vitro digestive stress in a three-compartment "dynamic gastrointestinal digester" (DIDGI). We studied the microorganisms (i) grown separately in culture medium only (ii) grown separately in culture medium and then mixed, (iii) grown separately in culture medium and then included in a rennet gel and (iv) grown together in smear-ripened cheese. The yeasts Geotrichum candidum, Kluyveromyces lactis and Debaryomyces hansenii, were strongly resistant to the whole DIDGI process (with a drop in viable cell counts of less than <1 log CFU mL(-1)) and there were no significant differences between lab cultures and cheese-grown cultures. Ripening bacteria such as Hafnia alvei survived gastric stress less well when grown in cheese (with no viable cells after 90 min of exposure of the cheese matrix, compared with 6 CFU mL(-1) in lab cultures). The ability of Corynebacterium casei and Staphylococcus equorum to withstand digestive stress was similar for cheese and pure culture conditions. When grow in a cheese matrix, Brevibacterium aurantiacum and Arthrobacter arilaitensis were clearly more sensitive to the overall digestive process than when grown in pure cultures. Lactococcus lactis displayed poorer survival in gastric and duodenal compartments when it had been grown in cheese. In vivo experiments in BALB/c mice agreed with the DIDGI experiments and confirmed the latter's reliability.
authors.affiliation: AgroParisTech, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850 Thiverval Grignon, France; INRA, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850 Thiverval Grignon, France. Electronic address: nadege.adouard@grignon.inra.fr.
authors.forename: Nadège
authors.initials: N
authors.lastname: Adouard
authors.affiliation: INRA, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850 Thiverval Grignon, France. Electronic address: laurent.magne18@gmail.com.
authors.forename: Laurent
authors.initials: L
authors.lastname: Magne
authors.affiliation: INRA, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850 Thiverval Grignon, France. Electronic address: thomas.cattenoz@grignon.inra.fr.
authors.forename: Thomas
authors.initials: T
authors.lastname: Cattenoz
authors.affiliation: INRA, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850 Thiverval Grignon, France. Electronic address: guillemi@grignon.inra.fr.
authors.forename: Hervé
authors.initials: H
authors.lastname: Guillemin
authors.affiliation: Institut Pasteur de Lille, Lactic Acid Bacteria & Mucosal Immunity, Center for Infection and Immunity of Lille UMR 8204, 1 rue du Pr Calmette, BP 245, F-59019 Lille, France. Electronic address: benoit.foligne@ibl.cnrs.fr.
authors.forename: Benoît
authors.initials: B
authors.lastname: Foligné
authors.affiliation: INRA, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850 Thiverval Grignon, France. Electronic address: picque@grignon.inra.fr.
authors.forename: Daniel
authors.initials: D
authors.lastname: Picque
authors.affiliation: INRA, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850 Thiverval Grignon, France. Electronic address: pascal.bonnarme@grignon.inra.fr.
authors.forename: Pascal
authors.initials: P
authors.lastname: Bonnarme
mesh_terms: D000818:Animals; D018407:Bacterial Physiological Phenomena; D001951:Brevibacterium / Q000302:isolation & purification / Q000502:physiology; D002611:Cheese / Q000382:microbiology*; D003198:Computer Simulation; D003352:Corynebacterium / Q000302:isolation & purification / Q000502:physiology; D004063:Digestion; D041981:Gastrointestinal Tract / Q000737:chemistry / Q000382:microbiology*; D005848:Geotrichum / Q000302:isolation & purification / Q000502:physiology; D020611:Hafnia alvei / Q000302:isolation & purification / Q000378:metabolism; D066298:In Vitro Techniques; D013294:Lactococcus lactis / Q000302:isolation & purification / Q000502:physiology; D051379:Mice; D050296:Microbial Viability / Q000187:drug effects; D015203:Reproducibility of Results; D004718:Saccharomycetales / Q000302:isolation & purification / Q000502:physiology; D015003:Yeasts / Q000145:classification / Q000502:physiology*
keywords: Cheese; In vitro model of digestion; Murine in vivo model; Smear-cheese microflora