Effect of flow regime on the architecture of a Pseudomonas fluorescens biofilm

Authors

  • Maria Olivia Pereira,

    1. University of Minho, Centro de Engenharia Biológica/IBQF, 4710-057 Braga, Portugal
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  • Martin Kuehn,

    1. Institute of Water Quality Control and Waste Management, Technical University of Munich, Am Coulombwall, D-85748 Garching, Germany
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  • Stefan Wuertz,

    1. Department of Civil and Environmental Engineering, University of California, Davis, One Shields Avenue, Davis, California
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  • Thomas Neu,

    1. Institute of Inland Water Research Magdeburg, UFZ Centre for Environmental Research, Leipzig-Halle, Brueckstr. 3A, 39114 Magdeburg, Germany
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  • Luis F. Melo

    Corresponding author
    1. University of Minho, Centro de Engenharia Biológica/IBQF, 4710-057 Braga, Portugal
    2. Faculty of Engineering of the University of Porto, Chemical Engineering Department, LEPAE, 4200-465 Porto, Portugal; telephone: +351 225081588; fax: +351 225081449
    • University of Minho, Centro de Engenharia Biológica/IBQF, 4710-057 Braga, Portugal
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Abstract

A comparison of the effects of laminar versus turbulent flow regime on the characteristics of a single-species biofilm is presented. The study was carried out by growing Pseudomonas fluorescens biofilms in a flow cell and studying the different layers of the biological matrix with a confocal laser-scanning microscope. The following conclusions were obtained: i) a higher concentration of cells was found in the upper layers of the microbial films than in their inner layers, regardless of the flow regime; ii) the fraction of cells in the overall biofilm mass decreased with time as the film grew; and iii) under laminar flow the total number of cells was higher than in biofilms formed under turbulent flow, but the latter had a higher number of cells per unit volume. Such conclusions, together with the fact that the biofilms were more dense and stable when formed in contact with turbulent flows, favor the design of more compact and efficient biofilm reactors operating in turbulent conditions. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 78: 164–171, 2002; DOI 10.1002/bit.10189

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