AVS 53rd International Symposium
    Biomaterial Interfaces Tuesday Sessions
       Session BI1-TuM

Paper BI1-TuM5
Minimising of Biofilm Formation by Surfaces Coated with Fish Proteins

Tuesday, November 14, 2006, 9:20 am, Room 2001

Session: Microbe-Surface Interactions
Presenter: P. Kingshott, University of Aarhus, Denmark
Authors: P. Kingshott, University of Aarhus, Denmark
N. Bernbom, Danish Institute for Fisheries Research
L.M. Meyer, University of Aarhus, Denmark
S. Xu, University of Aarhus, Denmark
F. Besenbacher, University of Aarhus, Denmark
L. Gram, Danish Institute for Fisheries Research
Correspondent: Click to Email
No surface exists that can prevent biofilm formation. Many surface treatments (e.g. use of antimicrobial agents) may help reduce biofilm formation, but the potential exists for developing bacterial resistance, and loss of function by agents getting depleted or covered up by organic matter (e.g. proteins). New surfaces that provide a barrier to bacterial attachment, but are not inhibitory and toxic, are highly desirable. We have recently discovered that attachment of bacteria found in the food industry is reduced by several orders of magnitude by coatings of an extract made from fish, compared to other organic layers (e.g. from meat, broth, milk). The coating does not per se inhibit microbial growth, the effect lasts up to 48 hours and the treatment is non-toxic. The coatings are equally effective against a range of bacteria persistent on food processing equipment including Ps. fluorescens strain AH2, E. coli strain MG1655, Vibrio anguillarum strain 90-11-287, and Aeromonas salmonicida strain Jno 3175/88. The extracts can be coated on metals (stainless steel) or polymers (polystyrene) and still be effective. Our aim is to use surface techniques (XPS, AFM, ToF-SIMS, surface-MALDI) to characterise the fish extract adlayer, and find out which component(s) reduce bacterial adhesion. Initial results demonstrate that the adlayer is protein in nature and that all surfaces adsorb high levels. Surface-MALDI shows that there are proteins of common molecular weight that adsorb to all surfaces tested, and these most likely play a role in the antifouling effect. The surface protein patterns are different to other conditioning media (e.g. TSB, chicken extract). Results will also be presented for the fish extract fractionated by chromatography and coated on surfaces, aimed at identifying more specifically the protein(s) involved. The results are discussed in terms of the potential antifouling mechanisms, such "steric-repulsive" effects or are the proteins antimicrobial.