title: Effect of growth time on the surface and adhesion properties of Lactobacillus rhamnosus GG.
abstract: OBJECTIVE
  To investigate the changes in the surface properties of Lactobacillus rhamnosus GG during growth, and relate them with the ability of the Lactobacillus cells to adhere to Caco-2 cells.
  
  
  RESULTS
  Lactobacillus rhamnosus GG was grown in complex medium, and cell samples taken at four time points and freeze dried. Untreated and trypsin treated freeze dried samples were analysed for their composition using SDS-PAGE analysis and Fourier transform infrared spectroscopy (FTIR), hydrophobicity and zeta potential, and for their ability to adhere to Caco-2 cells. The results suggested that in the case of early exponential phase samples (4 and 8 h), the net surface properties, i.e. hydrophobicity and charge, were determined to a large extent by anionic hydrophilic components, whereas in the case of stationary phase samples (13 and 26 h), hydrophobic proteins seemed to play the biggest role. Considerable differences were also observed between the ability of the different samples to adhere to Caco-2 cells; maximum adhesion was observed for the early stationary phase sample (13 h). The results suggested that the adhesion to Caco-2 cells was influenced by both proteins and non-proteinaceous compounds present on the surface of the Lactobacillus cells.
  
  
  CONCLUSIONS
  The surface properties of Lact. rhamnosus GG changed during growth, which in return affected the ability of the Lactobacillus cells to adhere to Caco-2 cells.
  
  
  CONCLUSIONS
  The levels of adhesion of Lactobacillus cells to Caco-2 cells were influenced by the growth time and reflected changes on the bacterial surface. This study provides critical information on the physicochemical factors that influence bacterial adhesion to intestinal cells.
authors.affiliation: Department of Food Biosciences, The University of Reading, PO Box 226, Whiteknights, Reading RG6 6AP, UK. d.charalampopoulos@reading.ac.uk
authors.forename: G
authors.initials: G
authors.lastname: Deepika
authors.forename: R J
authors.initials: RJ
authors.lastname: Green
authors.forename: R A
authors.initials: RA
authors.lastname: Frazier
authors.forename: D
authors.initials: D
authors.lastname: Charalampopoulos
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins / Q000032:analysis*; D018938:Caco-2 Cells; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007778:Lactobacillus / Q000737:chemistry / Q000254:growth & development / Q000502:physiology*; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000032:analysis*; D019936:Probiotics; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins