title: Measurement of microbial adhesive forces with a parallel plate flow chamber.
abstract: OBJECTIVE
  It was predicted that the colloidal behaviors of archaea and bacteria with disparate surface structure were different. In this study, the effects of the physicochemical properties of microbial cell surfaces on colloidal behavior were analyzed with Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, thermodynamics, and powder technology.
  
  
  METHODS
  Cell attachment and detachment from model substrates were directly observed using a parallel plate flow chamber. Gram-negative Escherichia coli and archaeal Methanosarcina barkeri were used as model microbial cells, and positively and negatively charged glass slides were used as model substrates.
  
  
  RESULTS
  Microbial adhesion on both substrates agreed well with predictions calculated from DLVO theory, using experimental parameters. The total number of cells detached from the substrates as a function of flow rate was fit with the Weibull distribution function. In addition, the drag force required for detachment, which was estimated from the hydrodynamic forces, had a wide distribution; however, the forces became smaller with increasing ionic strength because of reduced electrostatic interactions between the cells and the substrate. M. barkeri could not be detached from positively charged substrates because it would entail a negative change in the interfacial energy of interaction. Thus adhesion was thermodynamically favored in this case.
authors.affiliation: Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan; Corporate Engineering Center, Corporate Production Management & Engineering Div., Sumitomo Bakelite Co., Ltd., 2100 Takayanagi, Fujieda, Shizuoka 426-0041, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Yoshihara
authors.affiliation: Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Hisaya
authors.initials: H
authors.lastname: Narahara
authors.affiliation: Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Kuriyama
authors.affiliation: Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Syunsuke
authors.initials: S
authors.lastname: Toyoda
authors.affiliation: Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Tokumoto
authors.affiliation: Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Konishi
authors.affiliation: Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan. Electronic address: nomura@chemeng.osakafu-u.ac.jp.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Nomura
keywords: Derjaguin–Landau–Verwey–Overbeek; Drag force distribution; Hydrodynamic force; Interfacial energy; Microbial adhesion; Parallel plate flow chamber; Soft particle theory; Weibull distribution function