title: Viability of Escherichia coli after combined osmotic and thermal treatment: a plasma membrane implication.
abstract: This study investigates the influence of temperature (T) and osmotic pressure (Pi) on the viability of Escherichia coli K12 during an osmotic treatment. Osmotic shock (dehydration and rehydration within 1 s) in liquid media at different temperatures (4, 10, 30 and 37 degrees C) and different levels of osmotic pressure (26, 30, 35, 40, 82 and 133 MPa) were realized. Results show that a sudden dehydration, below 40 MPa, destroyed up to 80% of the bacterial population for each tested temperature, whereas viability was greater than 90% for an osmotic pressure less than 26 MPa. The influence of T and Pi on the membrane's physical structure is finally considered to explain the results in light of FTIR and electron microscopy study of the influence of temperature and osmotic pressure on E. coli membrane phospholipids conformation.
authors.affiliation: Laboratoire de Génie des Procédés Alimentaires et Biotechnologiques, Ecole Nationale Supérieure de Biologie Appliquée à la Nutrition et à l'Alimentation, 1 Esplanade Erasme, Dijon 21000, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Mille
authors.forename: Laurent
authors.initials: L
authors.lastname: Beney
authors.forename: Patrick
authors.initials: P
authors.lastname: Gervais
mesh_terms: D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D004926:Escherichia coli / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D008563:Membrane Lipids / Q000378:metabolism; D008854:Microscopy, Electron; D009995:Osmosis; D010743:Phospholipids / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D008563:Membrane Lipids; D010743:Phospholipids