ALUMINIUM COATING FUNGI INTERACTING ABILITIES

摘要

The aim of this work is to expand previous reported data, suggesting coated aluminium vulnerability to fungal action. Working in the context of the PATINA project, CYTED program, which have foresaw an experimental strategy which included sample's visual inspection carried on annually, it is found in the test site named Punta del Este (Uruguay), after 19 months from the starting, that aluminium lacquered schemes show light fungal growth according to ASTM D 3274. The exposed samples, consist of three different schemes, type A (chemical pre-treatment/polyester TGIC powder paint as top coat), type B (chemical pre-treatment/acrylic isocianate liquid paint as topcoat; type C (chemical pretreatment/conventional alquidic system as topcoat). Consequently, mycobiota isolations from the surface samples are then systematically performed, all through the experiment, in order to: a- obtain a taxonomic identification of species, b- to evaluate the degree of affinity among the protective technologies and the natural bio-system involved. Conventional mycological methods are employed, bearing in mind available data concerning the habitat. The recognised species show: that fungus come from the soil; that a broad biodiversity exists - exhibiting 25 filamentous taxa and 2 yeast species - compared to results obtained in a parallel study carried on in a tropical test site belonging also to Patina's net, which showed narrower biodiversity. Mycobiota shows greater affinity for the top coats from scheme C, showing pigmented mycelia growth, leaving permanent tracks, ability which is not verified neither in the schemes A and B, nor in the case of the tropical test site for none of the schemes. In the present work the fungal composition and frequency is reported. The effect of fungal colonization process over the sample's surface is also described. Suggestions are proposed with the aim of contributing to future reviews concerning standard ASTM D 3274.