Towards real-time observation of conditioning film and early biofilm formation under laminar flow conditions using a quartz crystal microbalance

• Published in: Biochemical engineering journal Vol. 53; no. 1; pp. 121 - 130
• Main Authors: Chen, Ming-Yang, Chen, Ming-Jen, Lee, Pei-Fang, Cheng, Li-Hsin, Huang, Li-Jen, Lai, Chin-Hsing, Huang, Kuei-Hsiang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.12.2010; Elsevier
• Subjects: Biological and medical sciences; Biotechnology; Conditioning film; Early biofilm formation; Environmental conditions; Fundamental and applied biological sciences. Psychology; Laminar flow-through chamber; Pseudomonas fluorescens; Quartz crystal microbalance; Conditioning film; Pseudomonas fluorescens; Quartz crystal microbalance; Laminar flow-through chamber; Early biofilm formation; Environmental conditions; Pseudomonadales; Crystals; Real time; Laminar flow; Biofilm; Bacteria; Pseudomonadaceae; Quartz microbalance
• ISSN: 1369-703X; 1873-295X
• DOI: 10.1016/j.bej.2010.10.003

▶ The QCM technique has been demonstrated to be a useful tool for direct in situ real-time observation of the overall sequence of biofilm development processes, starting with conditioning film formation, followed by initial bacterial adhesion and subsequently by biofilm formation. ▶ Early biofilm formation may be facilitated through calcium-cation bridging or adsorption via polysaccharide-related compounds on the cell surface. ▶ Conditioning film may play a vital role in initial bacterial attachment due to the accumulated nutrient-rich environment and the conditioning film-induced modification of substratum. ▶ However, subsequent biofilm formation could be mediated by environmental conditions, reflecting the complex and dynamic process of biofilm development. A real-time quartz crystal microbalance (QCM) technique was employed to monitor early formation of Pseudomonas fluorescens biofilms. To better understand the dynamic process of conditioning film and early biofilm formation, all experiments were conducted in a laminar flow-through chamber under various environmental conditions. Prior to early biofilm formation, a conditioning film comprising organic, inorganic and macromolecular substances was detected over the sensor chip surface within an extremely short duration due to their instantaneous adsorption. Based on atomic force microscopy (AFM) observations, we identified different surface features associated with various conditioning films, demonstrating that the sensor chip surface displayed complex properties in terms of surface topography, roughness, water contact angle, and conditioning film chemistry. There appeared to be a lag time before early biofilm formation. The rate of early biofilm formation was found to differ considerably, depending upon the characteristics of conditioning films and environmental conditions. However, subsequent biofilm formation could be mediated by environmental conditions, reflecting the complex and dynamic process of biofilm development. Of particular interest was the direct in situ real-time observation of the overall sequence of biofilm development processes using a QCM, starting with conditioning film formation, followed by initial bacterial adhesion and subsequently by biofilm formation.