title: A microfluidic method and custom model for continuous, non-intrusive biofilm viscosity measurements under different nutrient conditions.
abstract: Straight, low-aspect ratio micro flow cells are used to support biofilm attachment and preferential accumulation at the short side-wall, which progressively reduces the effective channel width. The biofilm shifts downstream at measurable velocities under the imposed force from the constant laminar co-flowing nutrient stream. The dynamic behaviour of the biofilm viscosity is modeled semi-analytically, based on experimental measurements of biofilm dimensions and velocity as inputs. The technique advances the study of biofilm mechanical properties by strongly limiting biases related to non-Newtonian biofilm properties (e.g., shear dependent viscosity) with excellent time resolution. To demonstrate the proof of principle, youngPseudomonas sp. biofilms were analyzed under different nutrient concentrations and constant micro-flow conditions. The striking results show that large initial differences in biofilm viscosities grown under different nutrient concentrations become nearly identical in less than one day, followed by a continuous thickening process. The technique verifies that in 50 h from inoculation to early maturation stages, biofilm viscosity could grow by over 2 orders of magnitude. The approach opens the way for detailed studies of mechanical properties under a wide variety of physiochemical conditions, such as ionic strength, temperature, and shear stress.
authors.affiliation: Department of Chemistry, Université Laval , 1045 Ave. de la Médecine, Québec, Québec G1V 0A6, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Greener
authors.affiliation: Department of Chemistry, Université Laval , 1045 Ave. de la Médecine, Québec, Québec G1V 0A6, Canada.
authors.forename: M
authors.identifier: 0000-0001-6584-4827
authors.initials: M
authors.lastname: Parvinzadeh Gashti
authors.affiliation: Department of Chemical Engineering, Université Laval , Québec, Québec G1V 0A6, Canada.
authors.forename: A
authors.identifier: 0000-0001-6827-7709
authors.initials: A
authors.lastname: Eslami
authors.affiliation: Department of Chemistry, Université Laval , 1045 Ave. de la Médecine, Québec, Québec G1V 0A6, Canada.
authors.forename: M P
authors.initials: MP
authors.lastname: Zarabadi
authors.affiliation: Department of Chemical Engineering, Université Laval , Québec, Québec G1V 0A6, Canada.
authors.forename: S M
authors.identifier: 0000-0003-2263-0460
authors.initials: SM
authors.lastname: Taghavi