Biodiversity of Phototrophic Biofilms Dwelling on Monumental Fountains

Abstract

Among the stone monumental assets, artistic fountains are particularly affected by microbial colonization due to constant contact with water, giving rise to biodegradation processes related with physical-chemical and aesthetical alterations. In this paper, we make an overview of reported biodiversity of the phototrophic patina developed in various fountains of Italy and Spain. The microbial composition of four fountains (two from Florence, Italy and two from Granada, Spain) was investigated using traditional and/or molecular techniques. The results indicated many common similarities with regard the phototrophic biodiversity for all the investigated fountains. Automated ribosomal RNA intergenic spacer analysis (ARISA), a molecular fingerprint tool, was used to examine the eubacterial and cyanobacterial community for two of the investigated fountains. The principal component analysis of ARISA profiles strengthens the results obtained by traditional methods and revealed separate clusters, as a consequence of the differences of micro-environmental conditions for each fountain.

Microbially induced deterioration of architectural heritages: routes and mechanisms involved

“…These historic building and artworks are our heritage which tells us about the past art, architecture and enriches us with cultural values. Stones used in making these sculptural monuments were highly consolidated and [17] Granada, Spain Green patina and Biofilm [31] durable and were obtained from naturally occurring sedimentary rocks which are composed of one or more minerals. These monuments and artworks exposed to polluted air and corrosive acid rain water and are now at risk of degradation and deterioration.…”

“…Due to their phototrophic nature, they easily grow on the stone forming colored patinas and incrustations [22]. Their association with substrate in the presence of water makes their growth predominates over other organisms and accelerates the formation of biofilms which facilitates attachment and serves as a mechanism for resisting adverse abiotic conditions [17,81]. Biofilm act as precursor for the physical damage to the stone leading to its biodeterioration [21,48] and discoloration [20].…”

A fluid dynamics model of the growth of phototrophic biofilms

“…: on stone substrates and under a water layer. The colonization of external surfaces of buildings, monuments and archaeological sites by microorganisms creates an unaesthetically appearance of staining of the stone surfaces [10,11]. It produces also extracellular polymeric substances that cause mechanical stresses to the mineral structure inside the pore system.…”

Biodiversity on Stone Artifacts

“…Biofilms are aggregates of microorganisms embedded in a mucilaginous organic matrix (EPS) found in aqueous environments, usually intended as a spread microbial growth at the water-substratum interface, such as the basins and artistic fountains pools or the architectural elements under a continuous water flow (Cuzman et al, 2010). According to the quantity, turbulence and water spraying the stone surface can partially or totally in direct contact with the air as well.…”