Hydrodynamic conditions control two interlinked parameters; mass transfer and drag, and will, therefore, significantly influence many of the processes involved in biofilm development. The goal of this research was to determine the effect of flow velocity and nutrients on biofilm structure. Biofilms were grown in square glass capillary flow cells under laminar and turbulent flows. Biofilms were observed microscopically under flow conditions using image analysis. Mixed species bacterial biofilms were grown with glucose (40 mg/l) as the limiting nutrient. Biofilms grown under laminar conditions were patchy and consisted of roughly circular cell clusters separated by interstitial voids. Biofilms in the turbulent flow cell were also patchy but these biofilms consisted of patches of ripples and elongated 'streamers' which oscillated in the flow. To assess the influence of changing nutrient conditions on biofilm structure the glucose concentration was increased from 40 to 400 mg/l on an established 21 day old biofilm growing in turbulent flow. The cell clusters grew rapidly and the thickness of the biofilm increased from 30 μ to 130 μ within 17 h. The ripples disappeared after 10 hours. After 5 d the glucose concentration was reduced back to 40 mg/l. There was a loss of biomass and patches of ripples were re-established within a further 2 d.
Four slime-producing isolates of Staphylococcus aureus were used in an antibiotic susceptibility assay for biofilms developed on 96-well polystyrene tissue culture plates. The s...
ABSTRACT Studies of steady-state metabolic fluxes in Escherichia coli grown in nutrient-limited chemostat cultures suggest remarkable flux alterations in response to changes of ...
ABSTRACT A perfused biofilm fermentor, which allows growth-rate control of adherent microbial populations, was used to assess whether the susceptibility of Candida albicans biof...
ABSTRACT Slow growth has been hypothesized to be an essential aspect of bacterial physiology within biofilms. In order to test this hypothesis, we employed two strains of Escher...
The rapidly growing mycobacteria (RGM) are broadly disbursed in the environment. They have been recovered from freshwater, seawater, wastewater and even potable water samples an...
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