Phototrophic Deteriogens and Their Elimination from Surfaces by Nanoparticles

This review deals with the current state of biodeterioration caused mainly by phototrophic organisms. Due to their metabolic activity, growth and life strategy, the microorganisms cause, erosion, degradation and colouring of building surface. Physical and chemical effects also contribute to biodeterioration. Identification of biodeteriogens and determination of the degree of surface colonization are the basis of conservation of building surface. Chemical methods of surface treatment might be hazardous and, therefore, the use of environment-friendly methods based on nanotechnologies seem more promising. This review deals with toxicity of Ag compounds, colloids, particles and ions. Some commercial products were tested both outdoors and in laboratory. The algal toxicity test has been modified and carried out on chlorococcal algae Desmodesmus quadricauda Greifswald 15. The preparations containing Ag nanoparticles are highly effective in solution and on materials surface. Their toxicity was mainly affected by their concentration and particle size. Ag nanoparticles are more toxic than Ag ions. The highest toxicity was found with preparations containing Ag nanoparticles with reactive surface.