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Archaeological ceramics are of heritage significance, but their biodeterioration has been poorly explored. This study examines the damage resulting from the biodeterioration of such material at an arid site in La Rioja, a Province of northern Argentina. The microbial colonization of two styles of ceramics, Aguada and Rustic, was assessed by different microscopies and spectroscopy techniques and laboratory assays. Bacteria, fungi and cyanolichens have been typified. It is noteworthy the isolation of one strain of Pseudomonas sp. due to their adhesive potential and ability to form biofilms in all materials studied. The confirmation of biodeterioration processes involving mechanical damage and potential chemical changes was observed. Bacteria and fungi developed in cracks causing a breakdown of the material while cyanolichens grew on surfaces and edges of ceramics, producing a severe deterioration. Fil: Guiamet, Patricia Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina Fil: Soto, Daiana Marilé. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Arqueología; Argentina Fil: Schultz, Matthias. Universitat Hamburg; Alemania

Fungi produce pigments and acids, generating particular local conditions which modify the physicochemical properties of materials. The aims of this work are (i) to investigate bioadhesion, foxing production and biofilm formation by Scopulariopsis sp. and Fusarium sp. isolated from document collections under laboratory conditions; (ii) to verify attack on cellulose fibres and (iii) to study the possibility of reducing fungal growth using natural products. Biofilm formation and extracellular polymeric substance (EPS) production by fungi were demonstrated in laboratory assays and by scanning electron microscopy (SEM) observations. The biocidal activity of two essential oils of Origanum vulgare L. and Thymus vulgaris L. was evaluated using the microatmosphere method. SEM observations showed that these strains were able to attach to paper and form biofilms, causing damage on them, which demonstrates the biodeterioration ability of these microorganisms. Scopulariopsis sp. and Fusarium sp. isolated from paper books showed the formation of fox-like reddish-brown colour spots, attack to the paper structure and pigment production on aged paper samples. The strains tested produced a decrease in the pH of one unit. This would substantiate the effect of the strains in paper biodeterioration. The microatmosphere method showed that volatile compounds of the essential oils have antifungal activity., Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Facultad de Ciencias Veterinarias, Facultad de Ciencias Naturales y Museo

Comparative assessment of atmospheric and microbiological deterioration of constructional material of a church, which is part of the Colombian cultural heritage was made using different microbiological and surface analytical techniques complemented by electron microscopy. The main constructional material of the church of Veracruz in the urban area of the city of Medellin is peridotite, an ultramafic igneous rock containing >90% of iron and magnesium minerals such as olivine and pyroxene. Assessment showed that the atmospheric characteristics in the city of Medellin are only slightly aggressive, suggesting that weathering would not be the main cause of decay of the structural material. The main microorganisms isolated from the facade of the church were heterotrophic bacteria and fungi, and phototrophic microalgae and cyanobacteria. Lichens and mosses were also found colonizing the rock. Experimental evidence suggests that deterioration of the peridotite is mainly due to acidifying bacteria and other microbial contaminants and that atmospheric factors would only play a secondary role in the decay.

Experiments were designed (1) to investigate the bioadhesion, biofilm formation, foxing, and micropitting in documentary collections, (2) to assess the risk of biodeterioration, (3) to investigate the environmental microbial concentration, and (4) to study the influence of environmental factors in biodeterioration of documentary heritage in three archives. The importance of this work in the field of biodeterioration of documentary heritage was verified by bioadhesion and biofilm formation by microorganisms isolated from the collections under study. Bacillus sp. and Scopulariopsis sp. isolated from paper books showed considerable evidence of attacking the paper structure and of pigment production, constituting a hazard to the loss of documentary heritage. Fil: Lavin, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentina Fil: Gómez de Saravia, Sandra Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentina Fil: Guiamet, Patricia Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentina

Many of the monuments of the Mayan civilization are suffering deterioration caused by environmental factors (high temperatures and relative humidities), increasing contamination from natural and anthropogenic sources, and by the action of micro- and macro-biological communities. Archaeological sites and historical monuments in the Mayan area were constructed with different limestones which offer different resistances to degradation by the various types of contamination. Two different sampling sites were chosen at the archaeological site of Uxmal in the Yucatan Peninsula, Mexico. Heterotrophic bacteria, cyanobacteria and different fungi were isolated and classified taxonomically. The other archaeological site chosen for this study was the fortress of Tulum, located at the side of the Caribbean Sea and exposed to chloride of marine spray and sand erosion. In this case, heterotrophic aerobic and anaerobic bacteria, cyanobacteria and fungi were isolated from the four sampling areas selected. In both archaeological sites crust deposits were observed by using light microscopy, SEM and ESEM. Surface analyses were made by means of EDAX and electron microprobe. Possible mechanisms of stone decay, based on the type of microorganisms isolated, the physico-chemical characteristics of the constructional materials and environmental factors are discussed.

Cooling water treatment requires effective, environmentally-safe biocides compatible with system operation. The unique combination of high biocidal activity during use with no toxic discharge, could render dissolved ozone a safe biocide for cooling water treatment. Planktonic and sessile cells of Pseudomonas fluorescens (a frequent microbial contaminant of industrial systems) were used in this work to assess the biocidal effectiveness of ozone. Dissolved ozone showed to be effective at concentrations between 0.1 and 0.3 ppm, to eliminate completely the levels of planktonic cells used in this paper (10 7 –10 8 cell/ml) within a range of contact times between 10 and 30 min. However, ozone at 0.15 ppm was only able to diminish sessile cell population by two or three orders of magnitude. This minor biocidal effectiveness of ozone against bacterial biofilms is discussed in this paper, taking into account recent concepts on structure and dynamics of biofilms. Different metallic substrata were assayed to verify if there was any effect of metal nature on the biocidal action. Open circuit potentials vs. time experiments and potentiodynamic polarization curves were made for assessing the effect of dissolved ozone on the corrosion behavior of the metals tested.

Cemeteries are part of the cultural heritage of urban communities, containing funerary crypts and monuments of historical and architectural interest. Efforts aimed at the conservation of these structures must target not only the abiotic stresses that cause their destruction, such as light and humidity, but also biofouling by biotic agents. The purpose of this study was to assess the development of biofouling of several historically and architecturally valuable crypts at La Plata Cemetery (Argentina). Samples obtained from the biofilms, lichens, and fungal colonies that had developed on the marble surfaces and cement mortar of these crypts were analyzed by conventional microbiological techniques and by scanning electron microscopy. The lichens were identified as Caloplaca austrocitrina, Lecanora albescens, Xanthoparmelia farinosa and Xanthoria candelaria, the fungi as Aspergillus sp., Penicillium sp., Fusarium sp., Candida sp. and Rhodotorula sp., and the bacteria as Bacillus sp. and Pseudomonas sp. The mechanisms by which these microorganisms cause the aesthetic and biochemical deterioration of the crypts are discussed. © 2011 Elsevier Masson SAS. Fil: Guiamet, Patricia Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina Fil: Rosato, Vilma Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica, La Plata; Argentina. Universidad Tecnológica Nacional; Argentina Fil: Gómez de Saravia, Sandra Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina Fil: Coto García, Ana María. Universidad Politécnica de Madrid; España Fil: Moreno, Diego A.. Universidad Politécnica de Madrid; España

The aims of this paper were to study the biofouling and biodeterioration of photos and maps stored at Historical Archive of the Museum of La Plata (HAMP), Argentine, and two repositories of the National Archive of Cuba Republic (NARC) and to carry out the physiological characterization of the isolated fungi and bacteria. The role of the environmental microbiota in the biofouling formation was also studied. Microbial assemblages in the air were sampled by sedimentation technique while those on documents were sampled by swabbering. Biofilm formation and biofouling were monitored by scanning electron microscope (SEM). Large microbial assemblages were found at NARC archives with the prevalence of genera Aspergillus, Cladosporium and Penicillium, whereas at HAMP these values were lower, Penicillium was the only fungal genus detected. Most of the fungi degraded cellulose and produced pigments and acids, and all of the isolated bacteria had proteolytic and/or cellulolytic activity. In all cases, a higher concentration of viable bacteria than of fungi was isolated from documents. These results correlated with bacterial values detected in air at NARC repositories. However, this correlation cannot be observed at HAMP where Aspergillus, Penicillium and Talaromyces helicus (teleomorph of Penicillium) were isolated. It is the first time that the last genus is reported in documents.