This will allow understanding physicochemical mechanisms underlying the optimized biological systems and bridge the knowledge gap on the chemistry and structure of the biofilms’ inter​faces. The design-build-test-learn approach will be implemented for the development of a novel concept for protection of various building materials. A prototype microbial coating based on biofilm built by the yeast-like ubiquitous and widespread oligotroph fungus, Aureobasidium pullulans, will be developed. The idea is based on a technically applicable, controlled, and optimized biofilm formation that effectively protects the substrate surfaces assuring optimal service life performance and different functionalities including self-healing. Two main parallel research lines related to the optimization of coating formulation applicable to porous and non-porous materials will be conducted. Interaction of active ingredients with A. pullulans and the biological, chemical and mechanical stability of the developed coatings will be tested in laboratory and field conditions (artificial and natural weathering trials) to follow in-situ growth, development, maturation and reveal kinetics and mechanisms of biofilm formation, stability and resilience.