title: Laboratory investigation of high pressure survival in Shewanella oneidensis MR-1 into the gigapascal pressure range.
abstract: The survival of Shewanella oneidensis MR-1 at up to 1500 MPa was investigated by laboratory studies involving exposure to high pressure followed by evaluation of survivors as the number (N) of colony forming units (CFU) that could be cultured following recovery to ambient conditions. Exposing the wild type (WT) bacteria to 250 MPa resulted in only a minor (0.7 log N units) drop in survival compared with the initial concentration of 10(8) cells/ml. Raising the pressure to above 500 MPa caused a large reduction in the number of viable cells observed following recovery to ambient pressure. Additional pressure increase caused a further decrease in survivability, with approximately 10(2) CFU/ml recorded following exposure to 1000 MPa (1 GPa) and 1.5 GPa. Pressurizing samples from colonies resuscitated from survivors that had been previously exposed to high pressure resulted in substantially greater survivor counts. Experiments were carried out to examine potential interactions between pressure and temperature variables in determining bacterial survival. One generation of survivors previously exposed to 1 GPa was compared with WT samples to investigate survival between 37 and 8°C. The results did not reveal any coupling between acquired high pressure resistance and temperature effects on growth.
authors.affiliation: Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK.
authors.forename: Rachael
authors.initials: R
authors.lastname: Hazael
authors.affiliation: Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK.
authors.forename: Fabrizia
authors.initials: F
authors.lastname: Foglia
authors.affiliation: Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK.
authors.forename: Liya
authors.initials: L
authors.lastname: Kardzhaliyska
authors.affiliation: Laboratoire de Géologie de Lyon, UMR 5276 CNRS, ENS de Lyon and Université Claude Bernard Lyon 1 - Université de Lyon Lyon, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Daniel
authors.affiliation: Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK ; Biomolecular and Analytical Mass Spectrometry group, Department of Chemistry, University of Antwerp Antwerpen, Belgium.
authors.forename: Filip
authors.initials: F
authors.lastname: Meersman
authors.affiliation: Christopher Ingold Laboratories, Department of Chemistry, University College London London, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: McMillan
keywords: Shewanella oneidensis MR-1; bacterial survival; high pressure biology; piston cylinder experiments; pressure adaptation studies; variable temperature bacterial growth