title: Characterizing the microbial colonization of a dolostone quarry: implications for stone biodeterioration and response to biocide treatments.
abstract: This study examines the microbial colonization of three fronts of an abandoned dolostone quarry (Redueña, Madrid, Spain) exposed to atmospheric conditions for different time periods since Roman times to the present. Through scanning electron microscopy in backscattered electron mode (SEM-BSE), endolithic colonization was predominantly detected in the most recently exposed front, while in the longer exposed quarry fronts, epilithic forms of growth were most often observed. These observations were confirmed by denaturing gradient gel electrophoresis (DGGE) analysis. Based on the distribution pattern of microbial colonization in the different quarry fronts, we then established a sequence of colonization events that took place over this long time frame. Bioalteration processes related to this sequential colonization were also identified. Characterizing these sequential processes can be useful for interpreting biodeterioration processes in historic dolostone monuments, especially those affecting constructions in the area of the Redueña stone quarry. In a second experimental stage, different biocide treatments were tested on this quarry rock to find the best way to avoid the microbial colonization effects identified. Through combined SEM-BSE/DGGE analysis, the efficacy of several biocides against the microorganisms inhabiting the dolostones was assessed after 4 and 16 months treatment. In general, all treatments were effective at reducing around 80% of the lichen cover, although effects on endolithic lithobiontic communities were dependent on how well the rock surface had been mechanically cleaned prior to treatment and gradually disappeared over time.
authors.affiliation: Museo Nacional de Ciencias Naturales, CSIC, C/Serrano 115 Dpdo, 28006, Madrid, Spain. bcamara@ccma.csic.es
authors.forename: Beatriz
authors.initials: B
authors.lastname: Cámara
authors.forename: Asuncion
authors.initials: A
authors.lastname: De los Ríos
authors.forename: Marta
authors.initials: M
authors.lastname: Urizal
authors.forename: Mónica Alvarez
authors.initials: MA
authors.lastname: de Buergo
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Varas
authors.forename: Rafael
authors.initials: R
authors.lastname: Fort
authors.forename: Carmen
authors.initials: C
authors.lastname: Ascaso
mesh_terms: D058448:Biota; D001711:Biotransformation; D002119:Calcium Carbonate / Q000737:chemistry*; D003124:Colorimetry; D003252:Construction Materials / Q000382:microbiology*; D004271:DNA, Fungal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D004202:Disinfectants / Q000494:pharmacology*; D020459:Genes, rRNA; D008011:Lichens / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification; D008274:Magnesium / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D013030:Spain
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D004202:Disinfectants; D002119:Calcium Carbonate; D008274:Magnesium; C028042:calcium magnesium carbonate