Use of flow cell reactors to quantify biofilm formation kinetics

1992 ◽  
Vol 6 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Ching-Tsan Huang ◽  
Steven W. Peretti ◽  
James D. Bryers
Keyword(s):  
Biofilm Formation ◽  
Flow Cell ◽  
Formation Kinetics

scholarly journals Altering the Ratio of Phenazines in Pseudomonas chlororaphis (aureofaciens) Strain 30-84: Effects on Biofilm Formation and Pathogen Inhibition

2008 ◽  
Vol 190 (8) ◽  
pp. 2759-2766 ◽  
Author(s):  
V. S. R. K. Maddula ◽  
E. A. Pierson ◽  
L. S. Pierson
Keyword(s):  
Fungal Pathogen ◽  
Biofilm Formation ◽  
Flow Cell ◽  
Gaeumannomyces Graminis ◽  
Pseudomonas Chlororaphis ◽  
Wild Type ◽  
Initial Attachment ◽  
Pathogen Inhibition ◽  
Biofilm Development ◽  
Derivatives Of

ABSTRACT Pseudomonas chlororaphis strain 30-84 is a plant-beneficial bacterium that is able to control take-all disease of wheat caused by the fungal pathogen Gaeumannomyces graminis var. tritici. The production of phenazines (PZs) by strain 30-84 is the primary mechanism of pathogen inhibition and contributes to the persistence of strain 30-84 in the rhizosphere. PZ production is regulated in part by the PhzR/PhzI quorum-sensing (QS) system. Previous flow cell analyses demonstrated that QS and PZs are involved in biofilm formation in P. chlororaphis (V. S. R. K. Maddula, Z. Zhang, E. A. Pierson, and L. S. Pierson III, Microb. Ecol. 52:289-301, 2006). P. chlororaphis produces mainly two PZs, phenazine-1-carboxylic acid (PCA) and 2-hydroxy-PCA (2-OH-PCA). In the present study, we examined the effect of altering the ratio of PZs produced by P. chlororaphis on biofilm formation and pathogen inhibition. As part of this study, we generated derivatives of strain 30-84 that produced only PCA or overproduced 2-OH-PCA. Using flow cell assays, we found that these PZ-altered derivatives of strain 30-84 differed from the wild type in initial attachment, mature biofilm architecture, and dispersal from biofilms. For example, increased 2-OH-PCA production promoted initial attachment and altered the three-dimensional structure of the mature biofilm relative to the wild type. Additionally, both alterations promoted thicker biofilm development and lowered dispersal rates compared to the wild type. The PZ-altered derivatives of strain 30-84 also differed in their ability to inhibit the fungal pathogen G. graminis var. tritici. Loss of 2-OH-PCA resulted in a significant reduction in the inhibition of G. graminis var. tritici. Our findings suggest that alterations in the ratios of antibiotic secondary metabolites synthesized by an organism may have complex and wide-ranging effects on its biology.

scholarly journals Synergistic Interaction between Candida albicans and Commensal Oral Streptococci in a NovelIn VitroMucosal Model

2011 ◽  
Vol 80 (2) ◽  
pp. 620-632 ◽  
Author(s):  
Patricia I. Diaz ◽  
Zhihong Xie ◽  
Takanori Sobue ◽  
Angela Thompson ◽  
Basak Biyikoglu ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Gastrointestinal Tract ◽  
Oral Mucosa ◽  
Biofilm Formation ◽  
Salivary Flow ◽  
Flow Cell ◽  
Synergistic Interaction ◽  
Esophageal Mucosa ◽  
Oral Streptococci ◽  
Content Type

ABSTRACTCandida albicansis a commensal colonizer of the gastrointestinal tract of humans, where it coexists with highly diverse bacterial communities. It is not clear whether this interaction limits or promotes the potential ofC. albicansto become an opportunistic pathogen. Here we investigate the interaction betweenC. albicansand three species of streptococci from the viridans group, which are ubiquitous and abundant oral commensal bacteria. The ability ofC. albicansto form biofilms withStreptococcus oralis,Streptococcus sanguinis, orStreptococcus gordoniiwas investigated using flow cell devices that allow abiotic biofilm formation under salivary flow. In addition, we designed a novel flow cell system that allows mucosal biofilm formation under conditions that mimic the environment in the oral and esophageal mucosae. It was observed thatC. albicansand streptococci formed a synergistic partnership whereC. albicanspromoted the ability of streptococci to form biofilms on abiotic surfaces or on the surface of an oral mucosa analogue. The increased ability of streptococci to form biofilms in the presence ofC. albicanscould not be explained by a growth-stimulatory effect since the streptococci were unaffected in their growth in planktonic coculture withC. albicans. Conversely, the presence of streptococci increased the ability ofC. albicansto invade organotypic models of the oral and esophageal mucosae under conditions of salivary flow. Moreover, characterization of mucosal invasion by the biofilm microorganisms suggested that the esophageal mucosa is more permissive to invasion than the oral mucosa. In summary,C. albicansand commensal oral streptococci display a synergistic interaction with implications for the pathogenic potential ofC. albicansin the upper gastrointestinal tract.

Finding the comfort zone: Online-monitoring of electroactive bacteria colonising electrode surfaces with different chemical properties

2020 ◽  
Author(s):  
Hanna Frühauf ◽  
Markus Stöckl ◽  
Dirk Holtmann
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Confocal Laser Scanning Microscopy ◽  
Electrode Surface ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Electrochemical Impedance ◽  
Flow Cell ◽  
Laser Scanning Microscopy ◽  
Confocal Laser

<p>Mechanisms of electron transfer vary greatly within the diverse group of electroactive microorganisms and so does the need to attach to the electrode surface, e.g. by forming a biofilm.</p> <p>Electrochemical impedance spectroscopy (EIS) and confocal laser scanning microscopy (CLSM) are well established methods to monitor cell attachment to an electrode surface and have therefore been combined in a flow cell as a screening system. The flow cell, equipped with a transparent indium tin oxide working electrode (ITO WE), allows monitoring of attachment processes in real time with minimal needs for additional biofilm preparation. In preliminary experiments the flow cell was successfully used as microbial fuel cell (MFC) with a potential of +0.4 V vs. Ag/AgCl using <em>Shewanella oneidensis</em> as electroactive model organism. [1]</p> <p>Commonly, graphite-based electrode materials are used in bioelectrochemical systems due to their low costs and high conductivity. However, the hydrophobic and negatively charged surface is not yet optimal for microbial attachment. There are numerous attempts on electrode surface engineering in order to overcome this problem. In the majority of studies the biofilm analysis and evaluation of the attachment takes place at the end of the experiment, neglecting the impacts of the chemical surface properties and initial electrode conditioning during the very beginning of biofilm formation.</p> <p>To investigate initial attachment and biofilm formation in real-time, the transparent ITO-electrode is coated with polyelectrolytes differing in hydrophobicity and polarity to evaluate their effects on the initial surface colonisation by different electroactive microorganisms. Combining CLSM and EIS, both, surface coverage and electrochemical interaction of electrode-associated bacteria can be assessed.</p> <p>With this we aim to understand and ease initial steps of biofilm formation to improve efficiency of bioelectrochemical applications, e.g. with regards to start-up time.</p> <p> </p> <p>[1] Stöckl, M., Schlegel, C., Sydow, A., Holtmann, D., Ulber, R., & Mangold, K. M. (2016). Membrane separated flow cell for parallelized electrochemical impedance spectroscopy and confocal laser scanning microscopy to characterize electro-active microorganisms. <em>Electrochimica Acta</em>, 220, 444-452.</p>

scholarly journals Induction of native c-di-GMP phosphodiesterases leads to dispersal of Pseudomonas aeruginosa biofilms

2021 ◽  
Author(s):  
Jens Bo Andersen ◽  
Kasper Nørskov Kragh ◽  
Louise Dahl Hultqvist ◽  
Morten Rybtke ◽  
Martin Nilsson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Single Cell ◽  
Biofilm Formation ◽  
Ectopic Expression ◽  
Second Messenger ◽  
Flow Cell ◽  
Diguanylate Cyclases ◽  
Biofilm Dispersal ◽  
High Level

A decade of research has shown that the molecule c-di-GMP functions as a central second messenger in many bacteria. A high level of c-di-GMP is associated with biofilm formation whereas a low level of c-di-GMP is associated with a planktonic single-cell bacterial lifestyle. C-di-GMP is formed by diguanylate cyclases and is degraded by specific phosphodiesterases. We have previously presented evidence that ectopic expression in Pseudomonas aeruginosa of the Escherichia coli phosphodiesterase YhjH results in biofilm dispersal. More recently, however, evidence has been presented that induction of native c-di-GMP phosphodiesterases does not lead to dispersal of P. aeruginosa biofilms. The latter result may discourage attempts to use c-di-GMP signaling as a target for development of anti-biofilm drugs. However, here we demonstrate that induction of the P. aeruginosa c-di-GMP phosphodiesterases PA2133 and BifA indeed does result in dispersal of P. aeruginosa biofilms in both a microtiter tray biofilm assay and in a flow-cell biofilm system.

scholarly journals Role of SCFAs for Fimbrillin-Dependent Biofilm Formation of Actinomyces oris

2018 ◽  
Vol 6 (4) ◽  
pp. 114 ◽  
Author(s):  
Itaru Suzuki ◽  
Takehiko Shimizu ◽  
Hidenobu Senpuku
Keyword(s):  
Stress Responses ◽  
Biofilm Formation ◽  
Short Chain Fatty Acids ◽  
Flow Cell ◽  
Cell System ◽  
Oral Bacteria ◽  
Microtiter Plates ◽  
Metabolic Products

Actinomyces oris expresses type 1 and 2 fimbriae on the cell surface. Type 2 fimbriae mediate co-aggregation and biofilm formation and are composed of the shaft fimbrillin FimA and the tip fimbrillin FimB. Short-chain fatty acids (SCFAs) are metabolic products of oral bacteria, but the effects of exogenous SCFAs on FimA-dependent biofilm formation are poorly understood. We performed two types of biofilm formation assays using A. oris MG1 or MG1.ΔfimA to observe the effects of SCFAs on FimA-dependent biofilm formation in 96-well and six-well microtiter plates and a flow cell system. SCFAs did not induce six- and 16-hour biofilm formation of A. oris MG1 and MG1.ΔfimA in saliva-coated 96-well and six-well microtiter plates in which metabolites produced during growth were not excluded. However, 6.25 mM butyric acid and 3.125 mM propionic acid induced FimA-dependent biofilm formation and cell death in a flow cell system in which metabolites produced during growth were excluded. Metabolites produced during growth may lead to disturbing effects of SCFAs on the biofilm formation. The pure effects of SCFAs on biofilm formation were induction of FimA-dependent biofilm formation, but the stress responses from dead cells may regulate its effects. Therefore, SCFA may play a key role in A. oris biofilm formation.

scholarly journals Viscoelasticity of Staphylococcus aureus Biofilms in Response to Fluid Shear Allows Resistance to Detachment and Facilitates Rolling Migration

2005 ◽  
Vol 71 (4) ◽  
pp. 2175-2178 ◽  
Author(s):  
Cory J. Rupp ◽  
Christoph A. Fux ◽  
Paul Stoodley
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Bloodstream Infections ◽  
Flow Cell ◽  
Fluid Shear ◽  
Surface Colonization

ABSTRACT Staphylococcus aureus is a leading cause of catheter-related bloodstream infections and endocarditis. Both involve (i) biofilm formation, (ii) exposure to fluid shear, and (iii) high rates of dissemination. We found that viscoelasticity allowed S. aureus biofilms to resist detachment due to increased fluid shear by deformation, while remaining attached to a surface. Further, we report that S. aureus microcolonies moved downstream by rolling along the lumen walls of a glass flow cell, driven by the flow of the overlying fluid. The rolling appeared to be controlled by viscoelastic tethers. This tethered rolling may be important for the surface colonization of medical devices by nonmotile bacteria.

scholarly journals Development of an electrochemically integrated SR-GIXRD flow cell to study FeCO3 formation kinetics

2016 ◽  
Vol 87 (10) ◽  
pp. 105125 ◽  
Author(s):  
D. Burkle ◽  
R. De Motte ◽  
W. Taleb ◽  
A. Kleppe ◽  
T. Comyn ◽  
...  
Keyword(s):  
Flow Cell ◽  
Formation Kinetics

Biofilm formation by Pseudomonas fluorescens WCS365: a role for LapD

Microbiology ◽  
2006 ◽  
Vol 152 (5) ◽  
pp. 1375-1383 ◽  
Author(s):  
Shannon M. Hinsa ◽  
George A. O'Toole
Keyword(s):  
Cell Surface ◽  
Pseudomonas Fluorescens ◽  
Outer Membrane ◽  
Gene Product ◽  
Biofilm Formation ◽  
Flow Cell ◽  
Cell System ◽  
Inner Membrane ◽  
Apparent Change

A role for the outer-membrane-associated LapA protein in early biofilm formation by Pseudomonas fluorescens WCS365 has previously been shown. This paper reports that lapD, a gene located adjacent to the lapA gene, also plays a role in biofilm formation. A mutation in lapD results in a conditional biofilm defect in a static assay – this biofilm phenotype is exacerbated when biofilm formation is assayed in a flow-cell system. Furthermore, a lapD mutation shows a partial defect in the transition from reversible to irreversible attachment, consistent with an early role for the lapD gene product in biofilm formation. LapD is shown to be localized to the inner membrane of P. fluorescens. The data show decreased LapA associated with the cell surface, but no apparent change in cytoplasmic levels of this protein or lapA transcription, in a lapD mutant. A model is proposed wherein the role of LapD in biofilm formation is modulating the secretion of the LapA adhesin.

scholarly journals Setup and Validation of Flow Cell Systems for Biofouling Simulation in Industrial Settings

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Joana S. Teodósio ◽  
Manuel Simões ◽  
Manuel A. Alves ◽  
Luís F. Melo ◽  
Filipe J. Mergulhão
Keyword(s):  
Dilution Rate ◽  
Biofilm Formation ◽  
Average Velocity ◽  
Cell Concentration ◽  
Flow Simulation ◽  
Flow Cell ◽  
Planktonic Cell ◽  
Time Analysis ◽  
Cell Systems ◽  
Average Wall Shear Stress

A biofouling simulation system consisting of a flow cell and a recirculation tank was used. The fluid circulates at a flow rate of 350 L⋅ h−1in a semicircular flow cell with hydraulic diameter of 18.3 mm, corresponding to an average velocity of 0.275 m⋅ s−1. Using computational fluid dynamics for flow simulation, an average wall shear stress of 0.4 Pa was predicted. The validity of the numerical simulations was visually confirmed by inorganic deposit formation (using kaolin particles) and also by direct observation of pathlines of tracer PVC particles using streak photography. Furthermore, the validity of chemostat assumptions was verified by residence time analysis. The system was used to assess the influence of the dilution rate on biofilm formation byEscherichia coliJM109(DE3). Two dilution rates of 0.013 and 0.0043 h−1were tested and the results show that the planktonic cell concentration is increased at the lower dilution rate and that no significant changes were detected on the amount of biofilm formed in both conditions.

Effects of Enterococcus faecium on Streptococcus mutans Biofilm Formation Using Flow Cell System

2008 ◽  
Vol 50 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Masayuki Kumada ◽  
Hidenobu Senpuku ◽  
Mizuho Motegi ◽  
Ryoma Nakao ◽  
Hideo Yonezawa ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Enterococcus Faecium ◽  
Biofilm Formation ◽  
Flow Cell ◽  
Cell System
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