Biorreceptividad de las dolomías a la colonización fúngica

Abstract

RESUMENEn este trabajo se evalúa cómo influye la textura de las dolomías en las estrategias adoptadas por los microorganismos para colonizar estos materiales pétreos. Para ello se han caracterizado muestras de dolomías con diferentes texturas mediante microscopía electrónica de barrido en modo de electrones retrodispersados (SEM-BSE), microscopía electrónica de barrido a bajas temperaturas (LTSEM), microscopía de luz transmitida (TLM) y porosimetría por intrusión de mercurio (MIP). De estas observaciones se deduce que los hongos son los microorganismos colonizadores más importantes en las dolomías estudiadas. Además, en esta colonización fúngica se han distinguido tres fases bien definidas que tienen como resultado final la disgregación completa de la roca. La presencia y extensión de cada fase de colonización se han visto determinadas por la magnitud y tipo de porosidad de las distintas dolomías analizadas. Los resultados de este estudio apuntan a que estas características de textura pueden condicionar la biorreceptividad de las dolomías y por tanto también los procesos de alteración asociados a esta colonización.Palabras clave: biorreceptividad, dolomías, estrategias de colonización, hongos litobiónticos, textura de las rocas. SUMMARYIn many historic monuments in which signs of biodeterioration have been frequently reported, dolostones were used as dimension stone for their construction. In an effort to assess the influence of the texture of dolostones on their potential bioreceptivity, we characterized microbial colonization strategies in dolostone samples of predictably different textural features by scanning electron microscopy in back scattered electron mode (SEM-BSE), low temperature scanning electron microscopy (LTSEM), transmission light microscopy (TLM) and mercury intrusion porosimetry (MIP). Fungi were the predominant microorganisms in the dolostones examined and their colonization showed three well defined stages with the final consequence of complete rock disaggregation. The results of this study indicate that porosity differences (mainly the extent and type) were particularly relevant for determining the presence and extent of each colonization stage. As a determinant of bioreceptivity, the porosity of dolostones will also condition the decay processes associated with this colonization.

The Role of Fungi and Lichens in the Biodeterioration of Stone Monuments

“…The inoculation of marble samples with fungi has shown that they are able to penetrate the substrate actively and produce pits. Camara et al [65], studying fungal colonization on three dolostones from monuments and natural outcrops, confirmed that the intercrystalline penetration was the initial stage of stone fungi interactions, followed by intracrystalline penetration and finally the complete disaggregation of the crystals. The different stages of interactions with the dolostones depend on the extent and type of porosity.…”

Distinct Microbial Communities in Adjacent Rock and Soil Substrates on a High Arctic Polar Desert

“…Although Meslier et al (2018) suggested that the chemical properties of the rock may not be an essential driver of community composition and diversity, the ability of microorganisms to use nutrients leached from rocks can affect the community composition in their niche. In addition, Cámara et al (2008) suggested that the microstructure of the rock, such as the space available for colonization and its physical structure, linked to water retention capabilities, can be a determinant of the potential bioreceptivity of lithic habitat. In our study, despite the clearly different chemical composition and microhabitat architecture of limestone and sandstone, the structures of archaeal, bacterial, and protistan communities were similar in both limestone and sandstone, which is consistent with the previous studies on lithic communities from polar deserts (de la Torre et al, 2003;Pointing et al, 2007;Archer et al, 2017).…”

Conservation of the Exterior of the National Museum of the American Indian Building

“…), on the yellow dolostone (mostly calcitic dolomite) of San Martín de Fuentidueña, originally located in Segovia, Spain, but now at the cloisters of the Metropolitan Museum of Art in New York (Figure 4). detected both epilithic and endolithic colonization by ascomycetous and basidiomycetous fungi, with green algae, cyanobacteria, and fungal-algal association, on dolostone samples from the Redueña quarry and also proposed that petrographic characteristics influenced endolithic growth (Cámara et al, 2008). In general, fungal filaments, hyphae, colonized existing pores, growing into the larger spaces regardless of whether they were inter-or intracrystalline.…”