Chemical and microbiological comparison of biodeterioration in Colombian heritage constructions

Mortars from Bogotá, Villa de Leyva and Barichara were compared chemically and microbiologically. We analyzed the samples using atomic absorption and emission spectrometry, Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Oxides of silicon, aluminum, calcium, iron, magnesium, gypsum, weddellite, despujolsite, quartz, berlinite, carbonate, mica, feldspars, silicates, nitrate salts, sulfites, and organic compounds were identified. In addition, irregular particles between 10, 50 an 100 μm were found, as well organic fibers of 20 μm. Was performed a CFU count using a dilution method to identify fungal microorganisms and found following genera Aspergillus, Venicillium, Alternaria, Fusarium, Mucor and Syncephalastrum. The mortar sample taken in Bogotá presented the highest number of CFU/mL and the highest percentage of relative humidity. The concentration of fungi in this sample, unlike those from Villa de Leyva and Barichara, caused degradation in most of the metals identified. This chemical and microbiological comparison proposes an effective plan of action to eliminate and prevent biodeterioration in support of the conservation of heritage constructions.