title: Cultivation of an immobilized (hyper)thermophilic marine microbial community in a bioreactor.
abstract: Cultivation in a bioreactor of immobilized deep-sea hydrothermal microbial community was tested in order to assess the stability and reactivity of this new system. A community composed of eight hydrothermal strains was entrapped in a polymer matrix that was used to inoculate a continuous culture in a gas-lift bioreactor. The continuous culture was performed for 41 days at successively 60°C, 55°C, 60°C, 85°C and 60°C, at pH 6.5, in anaerobic condition and constant dilution rate. Oxic stress and pH variations were tested at the beginning of the incubation. Despite these detrimental conditions, three strains including two strict anaerobes were maintained in the bioreactor. High cell concentrations (3 × 10(8) cells mL(-1)) and high ATP contents were measured in both liquid fractions and beads. Cloning-sequencing and qPCR revealed that Bacillus sp. dominated at the early stage, and was later replaced by Thermotoga maritima and Thermococcus sp. Acetate, formate and propionate concentrations varied simultaneously in the liquid fractions. These results demonstrate that these immobilized cells were reactive to culture conditions. They were protected inside the beads during the stress period and released in the liquid fraction when conditions were more favorable. This confirms the advantage of immobilization that highlights the resilience capacity of certain hydrothermal microorganisms after a stress period.
authors.affiliation: Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Université de Bretagne Occidentale (UBO, UEB), Institut Universitaire Européen de la Mer (IUEM)-UMR 6197, Technopôle Brest-Iroise, Place Nicolas Copernic, F-29280 Plouzané, France CNRS, IUEM-UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Place Nicolas Copernic, F-29280 Plouzané, France Ifremer, UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Technopôle Pointe du diable, F-29280 Plouzané, France.
authors.forename: M
authors.initials: M
authors.lastname: Landreau
authors.affiliation: Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Université de Bretagne Occidentale (UBO, UEB), Institut Universitaire Européen de la Mer (IUEM)-UMR 6197, Technopôle Brest-Iroise, Place Nicolas Copernic, F-29280 Plouzané, France CNRS, IUEM-UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Place Nicolas Copernic, F-29280 Plouzané, France Ifremer, UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Technopôle Pointe du diable, F-29280 Plouzané, France.
authors.forename: F
authors.initials: F
authors.lastname: Duthoit
authors.affiliation: Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Université de Bretagne Occidentale (UBO, UEB), Institut Universitaire Européen de la Mer (IUEM)-UMR 6197, Technopôle Brest-Iroise, Place Nicolas Copernic, F-29280 Plouzané, France CNRS, IUEM-UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Place Nicolas Copernic, F-29280 Plouzané, France Ifremer, UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Technopôle Pointe du diable, F-29280 Plouzané, France.
authors.forename: E
authors.initials: E
authors.lastname: Roussel
authors.affiliation: Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Université de Bretagne Occidentale (UBO, UEB), Institut Universitaire Européen de la Mer (IUEM)-UMR 6197, Technopôle Brest-Iroise, Place Nicolas Copernic, F-29280 Plouzané, France CNRS, IUEM-UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Place Nicolas Copernic, F-29280 Plouzané, France Ifremer, UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Technopôle Pointe du diable, F-29280 Plouzané, France.
authors.forename: S
authors.initials: S
authors.lastname: Schönherr
authors.affiliation: Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Université de Bretagne Occidentale (UBO, UEB), Institut Universitaire Européen de la Mer (IUEM)-UMR 6197, Technopôle Brest-Iroise, Place Nicolas Copernic, F-29280 Plouzané, France CNRS, IUEM-UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Place Nicolas Copernic, F-29280 Plouzané, France Ifremer, UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Technopôle Pointe du diable, F-29280 Plouzané, France.
authors.forename: Myriam
authors.initials: M
authors.lastname: Georges
authors.affiliation: Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Université de Bretagne Occidentale (UBO, UEB), Institut Universitaire Européen de la Mer (IUEM)-UMR 6197, Technopôle Brest-Iroise, Place Nicolas Copernic, F-29280 Plouzané, France CNRS, IUEM-UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Place Nicolas Copernic, F-29280 Plouzané, France Ifremer, UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Technopôle Pointe du diable, F-29280 Plouzané, France.
authors.forename: A
authors.initials: A
authors.lastname: Godfroy
authors.affiliation: Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Université de Bretagne Occidentale (UBO, UEB), Institut Universitaire Européen de la Mer (IUEM)-UMR 6197, Technopôle Brest-Iroise, Place Nicolas Copernic, F-29280 Plouzané, France CNRS, IUEM-UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Place Nicolas Copernic, F-29280 Plouzané, France Ifremer, UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Technopôle Pointe du diable, F-29280 Plouzané, France gwenaelle.leblay@univ-brest.fr.
authors.forename: G
authors.initials: G
authors.lastname: Le Blay
mesh_terms: D001421:Bacteria, Anaerobic / Q000254:growth & development; D001431:Bacteriological Techniques; D019149:Bioreactors; D018914:Cells, Immobilized; D003470:Culture Media; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D059013:Microbial Consortia; D012336:RNA, Ribosomal, 16S; D012623:Seawater / Q000382:microbiology*
chemical_list: D003470:Culture Media; D012336:RNA, Ribosomal, 16S
keywords: anaerobiosis; continuous culture; immobilization; marine (hyper)thermophiles