Recolonization of mortars by endolithic organisms on the walls of San Roque church in Campeche (Mexico): A case of tertiary bioreceptivity V. Jurado a,1 , A.Z. Miller b,1 , S. Cuezva c , A. Fernandez-Cortes d , D. Benavente c , M.A. Rogerio-Candelera a , J. Reyes e , J.C. Cañaveras c , S. Sanchez-Moral d , C. Saiz-Jimenez a,⇑ a Instituto de Recursos Naturales y Agrobiologia, IRNAS-CSIC, Av. Reina Mercedes 10, 41012 Sevilla, Spain b Centro de Petrologia e Geoquimica/CERENA, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal c Laboratorio de Petrologia Aplicada, Unidad Asociada CSIC-Universidad de Alicante, 03690 San Vicente del Raspeig, Spain d Museo Nacional de Ciencias Naturales, MNCN-CSIC, 28006 Madrid, Spain e Centro de Investigacion en Corrosion, Universidad Autonoma de Campeche, Campeche, Mexico highlights  Biodeterioration of San Roque church, Campeche, Mexico, in a tropical climate.  Restoration works increased tertiary bioreceptivity of mortars.  Early colonization by endolithic phototrophic microorganisms was promoted on the restored church façades. article info Article history: Received 7 January 2013 Received in revised form 18 November 2013 Accepted 26 November 2013 Available online 23 December 2013 Keywords: Biodeterioration Biofilm Cyanobacteria Tertiary bioreceptivity Recolonization Mortar abstract San Roque church (Campeche, Mexico) was built at the end of the 17th century with a micritic limestone and lime mortar in baroque style. In 2005 the church exhibited heavy biodeterioration associated with the development of extensive dark green phototrophic-based biofilms. Several cyanobacteria belonging to the order Chroococcales and lichenized fungi (Toninia nordlandica, Lobaria quercizans, Lecanora subcar- nea, Cystocoleus ebeneus) were predominant in the dark biofilm samples, as revealed by DNA-based molecular techniques. In 2009, a cleaning and restoration intervention was adopted; however, after few months, microbial recolonization started to be noticeable on the painted church walls, representing an early phototrophic-based recolonization. According to molecular analysis, scanning electron micros- copy observations and digital image analysis of cross sections, new phototrophic-based colonization, composed of cyanobacteria and bryophytes, developed mainly beneath the restored mortars. The intrin- sic properties of the mortars, the tropical climate of Campeche and the absence of a biocide treatment in the restoration protocol influenced the recolonization of the church façades and enhanced the overall rate of deterioration in a short-term period. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction The historical center of Campeche, in Yucatan peninsula, Mex- ico (Fig. 1A), is enshrined in the UNESCO World Heritage List. This coastal city is a model of Baroque colonial urbanism, where the defensive walls reflect the influence of the Spanish architecture in the Caribbean. The fortification system of Campeche, an eminent example of the military architecture of the 17th and 18th centu- ries, is part of an overall defensive system set up to protect the Caribbean ports from pirate attacks. By the end of the 17th century, San Roque church (Fig. 1B) was built with hard limestone quarried in the region, like most build- ings in the Campeche city. The stone is a micritic limestone with small calcite fragments, scarce particles of quartz and carbonate content higher than 96%. As mortars, a double solution was adopted: lime mortar and sahcab (a calcareous white earth abun- dant in the subsoil of Yucatan, which is mixed with lime, and tra- ditionally used in the construction of ancient Maya buildings). The same materials were used for the flattening of the external and in- ner surfaces, which were finished with lime paint. The roofs, in flat shape, were built with limestone masonry, known in the region as bahpek system. In 2005 the church exhibited heavy biodeterioration associated with the development of dark green biofilms (Figs. 2A and 3A), as some other limestone monuments in the area. The biodeterioration 0950-0618/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.conbuildmat.2013.11.114 ⇑ Corresponding author. Tel.: +34 95 462 4711. E-mail address: saiz@irnase.csic.es (C. Saiz-Jimenez). 1 These authors contributed equally to this work. Construction and Building Materials 53 (2014) 348–359 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat