Microorganisms grow on all kinds of materials, including metals, inorganic minerals and organic polymers under humid conditions. Complex community of microorganisms and their extracellular polysaccharides established as biofilm is a prerequisite for corrosion and/or deterioration of the underlying materials. This affects great-economic-value metallic structures like bridges and pipes; 70% of the corrosion in gas transmission lines are due to problems caused by microorganisms. Metallic structures are generally protected by anti-corrosion coatings, but biofilm over these coatings can lead to blistering and adhesion loss, causing failure of the protective system. Filamentous fungi are regarded as the micro-organisms that cause the most spoilage of paint films.Centro de Investigación y Desarrollo en Tecnología de Pinturas