Reproducing stone monument photosynthetic-based colonization under laboratory conditions

• Published in: The Science of the total environment 2008-11, Vol.405 (1), p.278-285
• Main Authors: Miller, Ana Zélia, Laiz, Leonila, Gonzalez, Juan Miguel, Dionísio, Amélia, Macedo, Maria Filomena, Saiz-Jimenez, Cesareo
• Format: Article
• Language: English
• Subjects: aerosols; air pollution; Animal and plant ecology; Animal, plant and microbial ecology; Ascomycota; Biodeterioration; Biofilms; Biological and medical sciences; Calcium Carbonate; carbon; Chlorella; Chlorophyta - classification; Chlorophyta - growth & development; Chlorophyta - physiology; Colonization experiment; Cyanobacteria; Cyanobacteria - classification; Cyanobacteria - growth & development; Cyanobacteria - physiology; Cyanophyta; diesel engines; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Engineering geology; Exact sciences and technology; exhaust systems; Fundamental and applied biological sciences. Psychology; Laboratory chamber; Leptolyngbya; Limestone; Microbiological Techniques; nanotechnology; nitrogen dioxide; oxidation; Photosynthesis; Phototrophic microorganisms; Phylogeny; Pleurocapsa; pollution control; Stichococcus; Synecology; temperature; Terrestrial ecosystems; Trebouxia; Verrucomicrobia
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2008.06.066

In order to understand the biodeterioration process occurring on stone monuments, we analyzed the microbial communities involved in these processes and studied their ability to colonize stones under controlled laboratory experiments. In this study, a natural green biofilm from a limestone monument was cultivated, inoculated on stone probes of the same lithotype and incubated in a laboratory chamber. This incubation system, which exposes stone samples to intermittently sprinkling water, allowed the development of photosynthetic biofilms similar to those occurring on stone monuments. Denaturing gradient gel electrophoresis (DGGE) analysis was used to evaluate the major microbial components of the laboratory biofilms. Cyanobacteria, green microalgae, bacteria and fungi were identified by DNA-based molecular analysis targeting the 16S and 18S ribosomal RNA genes. The natural green biofilm was mainly composed by the Chlorophyta Chlorella, Stichococcus, and Trebouxia, and by Cyanobacteria belonging to the genera Leptolyngbya and Pleurocapsa. A number of bacteria belonging to Alphaproteobacteria, Bacteroidetes and Verrucomicrobia were identified, as well as fungi from the Ascomycota. The laboratory colonization experiment on stone probes showed a colonization pattern similar to that occurring on stone monuments. The methodology described in this paper allowed to reproduce a colonization equivalent to the natural biodeteriorating process.