title: The electrostatic behavior of the bacterial cell wall using a smoothing function to describe the charge-regulated volume charge density profile.
abstract: The Donnan potential can be observed in many biological systems due to the presence of polyelectrolytes as proteins and nucleic acids. The aim of this work was to present a useful tool to describe the fixed and charge-regulated volume charge density profile through the use of a smoothing function and to obtain the electrostatic potential profile as well as the Donnan potential of this system by solving Poisson-Boltzmann (PB) equation. When we use the smoothing function, the Donnan potential arises automatically from the solution of only one Poisson-Boltzmann equation and it is not necessary to impose this potential for treating charged system in the presence of a membrane. The electrostatic behavior across the Bacillus brevis wall considering the dependence on the ionization of the cell wall functional groups as a function of the solution pH was analyzed. An important issue was to show that potentiometric titration data could be used together with the Poisson-Boltzmann equation to predict the electrostatic behavior (e.g., zeta potential) of the bacterial cell surface.
authors.affiliation: Programa de Pós-graduação em Engenharia Química, Universidade do Estado do Rio de Janeiro, CEP 20550-013, Rio de Janeiro, RJ, Brazil.
authors.forename: Nathalia S V
authors.initials: NS
authors.lastname: Barbosa
authors.affiliation: Programa de Pós-graduação em Engenharia Química, Universidade do Estado do Rio de Janeiro, CEP 20550-013, Rio de Janeiro, RJ, Brazil.
authors.forename: Eduardo R A
authors.initials: ER
authors.lastname: Lima
authors.affiliation: Escola de Química, Universidade Federal do Rio de Janeiro, CEP 21949-900, Rio de Janeiro, RJ, Brazil; Programa de Engenharia Química, COPPE, Universidade Federal do Rio de Janeiro, CEP 21945-970, Rio de Janeiro, RJ, Brazil. Electronic address: tavares@eq.ufrj.br.
authors.forename: Frederico W
authors.initials: FW
authors.lastname: Tavares
mesh_terms: D018407:Bacterial Physiological Phenomena; D002473:Cell Wall / Q000502:physiology*; D055672:Static Electricity
keywords: Donnan potential; Fixed charge; Poisson–Boltzmann equation; Regularization function