Growth of phototrophic biofilms from limestone monuments under laboratory conditions

Abstract

a b s t r a c tIn the current study, five phototrophic biofilms from different Southern Europe limestone monuments were characterised by molecular techniques and cultivated under laboratory conditions. Phototrophic biofilms were collected from Orologio Tower in Martano (Italy), Santa Clara-a-Velha Monastery and Ajuda National Palace, both in Portugal, and Seville and Granada Cathedrals from Spain. The biofilms were grown under laboratory conditions and periodically sampled in order to monitor their evolution over a three-month period. Prokaryotic communities from natural samples and cultivated biofilms were monitored using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene fragments in conjunction with clone sequencing and phylogenetic analysis. DNA-based molecular analysis of 16S rRNA gene fragments from the natural green biofilms revealed complex and different communities composition with respect to phototrophic microorganisms. The biofilms from Orologio Tower (Martano, Italy) and Santa Clara-a-Velha Monastery (Coimbra, Portugal) were dominated by the microalga Chlorella. The cyanobacterium Chroococcidiopsis was the dominating genus from Ajuda National Palace biofilm (Lisbon, Portugal). The biofilms from Seville and Granada Cathedrals (Spain) were both dominated by the cyanobacterium Pleurocapsa. The DGGE analysis of the cultivated biofilms showed that the communities developed differently in terms of species establishment and community composition during the threemonth incubation period. The biofilm culture from Coimbra (Portugal) showed a remarkable stability of the microbial components of the natural community in laboratory conditions. With this work, a multiple-species community assemblage was obtained for further stone colonisation experiments.

Speleothems in a wave-cut notch, Cayman Brac, British West Indies: The integrated product of subaerial precipitation, dissolution, and microbes

“…The discoloration and staining evident on many cliff faces and the surfaces of stone buildings, especially in the tropical regions of the world, are usually attributable to the pigmentation of the biofilms growing on their surfaces (e.g., Ortega-Morales et al, 2000;Crispim et al, 2003Crispim et al, ,2004Crispim and Gaylarde, 2005;de los Rios et al, 2009;Miller et al, 2009;Scheerer et al, 2009). The biofilms are complex ecosystems with a diverse biota that may include any combination of algae, cyanobacteria, fungi, bacteria, actinomycetes, lichens, and protozoa along with small animals (mites) and lower and higher plants (e.g., Ortega-Morales et al, 2000;Gorbushina, 2007;Abdulla et al, 2008;Miller et al, 2009;Scheerer et al, 2009). The subaerial biofilms typically have a patchy distribution pattern that reflects their colonization (commonly from wind-borne spores) and growth patterns that are controlled by many different variables.…”

“…Heterotrophs that commonly follow use the phototrophs as an organic food source. Subaerial biofilms found on historic buildings constructed with limestone and/or dolostone have been extensively studied because the biofilms are responsible for significant biodeterioration (Crispim et al, 2003(Crispim et al, ,2004Crispim and Gaylarde, 2005;Cámara et al, 2008;de los Rios et al, 2009;Miller et al, 2009;Scheerer et al, 2009). Although focused largely on the destructive aspects of the biofilms, examples of microbes mediating CaCO 3 precipitation have also been found.…”

“…Crispim et al (2004), for example, noted that many forms belonging to order Pleurocapsales, "…do not conform to the genera listed in standard modern works". This issue is further compounded by the spatial and temporal variability of the biofilms; some are dominated by cyanobacteria (Crispim et al, 2004;Miller et al, 2009), some are formed mainly of lichens (de los Rios et al, 2009), whereas others are dominated by actinomycetes (Abdulla et al, 2008). The morphologically diverse arrays of filamentous and non-filamentous microbes found in the notch speleothems on Cayman Brac (Figs.…”

A multiproxy approach to evaluate biocidal treatments on biodeteriorated majolica glazed tiles

“…7). DGGE is a well-known tool for monitoring microbial populations on cultural heritage assets (e.g., Miller et al, 2009;Qi-Wang et al, 2011;Piñar et al, 2013;Otlewska et al, 2014). However, DNA can persist undamaged after cell death, and consequently DNA-based methods do not provide a differentiation between viable and nonviable cells.…”

An integrated approach for assessing the bioreceptivity of glazed tiles to phototrophic microorganisms

“…Most of these studies relied on the artificial inoculation of organisms on a substrate under controlled environmental conditions (e.g. Tiano et al 1995;Miller et al 2008Miller et al , 2009aMarques et al 2015). These approaches were developed for stone, glass, unglazed ceramics and concrete materials, providing important data on their bioreceptivity and mechanisms of biodeterioration (Ranogajec et al 2008;Miller et al 2009b;Herisson et al 2013;Rodrigues et al 2014).…”