Bacterial assay for the rapid assessment of antifouling and fouling release properties of coatings and materials

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• 作者：Fraddry D¡¯Souza ; Anouk Bruin ; Rens Biersteker ; Glen Donnelly ; Job Klijnstra ; Corne Rentrop and Peter Willemsen
• 关键词：Antifouling ; Biofilm ; Cobetia ; Fluorescence ; SYTO 13
• 刊名：Journal of Industrial Microbiology and Biotechnology
• 出版年：2010
• 出版时间：April, 2010
• 年：2010
• 卷：37
• 期：4
• 页码：363-370
• 全文大小：435.3 KB

文摘

An assay has been developed to accurately quantify the growth and release behaviour of bacterial biofilms on several test reference materials and coatings, using the marine bacterium Cobetia marina as a model organism. The assay can be used to investigate the inhibition of bacterial growth and release properties of many surfaces when compared to a reference. The method is based upon the staining of attached bacterial cells with the nucleic acid-binding, green fluorescent SYTO 13 stain. A strong linear correlation exists between the fluorescence of the bacterial suspension measured (RFU) using a plate reader and the total bacterial count measured with epifluorescence microscopy. This relationship allows the fluorescent technique to be used for the quantification of bacterial cells attached to surfaces. As the bacteria proliferate on the surface over a period of time, the relative fluorescence unit (RFU) measured using the plate reader also shows an increase with time. This was observed on all three test surfaces (glass, Epikote and Silastic T2) over a period of 4 h of bacterial growth, followed by a release assay, which was carried out by the application of hydrodynamic shear forces using a custom-made rotary device. Different fixed rotor speeds were tested, and based on the release analysis, 12 knots was used to provide standard shear force. The assay developed was then applied for assessing three different antifouling coatings of different surface roughness. The novel assay allows the rapid and sensitive enumeration of attached bacteria directly on the coated surface. This is the first plate reader assay technique that allows estimation of irreversibly attached bacterial cells directly on the coated surface without their removal from the surface or extraction of a stain into solution.