Impact of Medium on the Development and Physiology of Pseudomonas fluorescens Biofilms on Polyurethane Paint

Since the 1950s, the Air Force has battled microbial contamination of its fuel systems. Within these systems, microbes are commonly found as biofilms adhered to tank coatings. Thus strategies for mitigating microbial contamination of fuel systems include deterring biofilm growth on coatings. This study investigated how Pseudomonas fluorescens biofilms grow on polyurethane coatings, and contribute to the degradation of those coatings. Specifically, we characterized how medium conditions and substrate composition contribute to growth of P. fluorescens on an antistatic polyurethane coating. We found that P. fluorescens biofilms grew in systems where the only carbon source was the coupon, suggesting that P. fluorescens can use polyurethane as a nutrient source. In addition, we examined the impact of substrate on biofilm growth by quantitating biofilm growth on pigmented and non-pigmented paint. There was no difference in the ability of the biofilm to grow on the pigmented vs. non-pigmented paint, suggesting that the biofilm was utilizing the polyurethane and not the pigment as a carbon source. Prepared in collaboration with UES, Inc., Ohio State University, and U.S. Naval Research Laboratory.