La medusa Craspedacusta sowerbyi en el embalse Río Tercero III, Córdoba, Argentina

Fil: Boltovskoy, Andrés. Instituto de Limnología Dr. Raúl A. Ringuelet (ILPLA). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Battistoni, Patricia A.. Instituto de Limnología Dr. Raúl A. Ringuelet (ILPLA). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Biofilms fotótrofos sobre muros de ladrillo

Los microorganismos fotótrofos que forman biofilms sobre superficies de ladrillo, como las microalgas, pueden ocasionar ensuciamiento biológico y biodeterioro. Además del efecto antiestético que ocasiona el bioensuciamiento, evidente en muchos edificios y monumentos, debemos también considerar los mecanismos de disolución de materiales, tal es el caso de las cianobacterias epilíticas que puede jugar un papel importante en la disolución del carbonato a través de procesos biogeoquímicos. El bioensuciamiento y el biodeterioro toman dimensiones económicas y sociales importantes cuando los sustratos colonizados tienen importancia patrimonial. En las últimas décadas, los procesos de biodeterioro han aumentado significativamente, especialmente en las zonas urbanas debido al aumento de la contaminación del medio ambiente. Compuestos químicos en la atmósfera en forma de SO3, NO3 y NH3, sirven de nutrientes para las algas. Los objetivos de este trabajo fueron: identificar los taxones de organismos fotótrofos que forman biofilms sobre las paredes de ladrillo de la Catedral de La Plata, Buenos Aires, Argentina con el fin de evaluar el biodeterioro. Fueron muestreadas tres zonas que presentaban biofilms con diferentes coloraciones. Las muestras fueron observadas con diferentes técnicas microscópicas. Se realizaron cultivos en medio BG11 que luego de un mes se inocularon en ladrillos estériles, bajo condiciones de luz, humedad y temperatura controladas para favorecer el desarrollo del biofilm y evaluar el biodeterioro. Los ladrillos se observaron en el microscopio óptico (Olympus BX51), microscopio estereoscópico (Nikon SMZ- 10) y microscopio electrónico de barrido (Jeol 6360LV). La diversidad específica de los microorganismos fotótrofos presentes en los biofilms mostró variaciones relacionadas a los factores ambientales. Se observó biodeterioro del material estructural debido al desarrollo de biofilmsTópico 2: Patrimonio Arquitectónico, Ingenieril y Arqueológico (urbano, rural, industrial, religioso, funerario). Construcciones en Tierra. Intervenciones en construcciones con patologías estructurales (aplicación de refuerzos). Técnicas de limpieza y conservación. Sostenibilidad (iluminación, ventilación, acústica, climatización, etc.) Biodeterioro del Patrimonio y técnicas de intervención sobre distintos sustratos

Phototrophic biofilms on exterior brick substrate

La Plata Cathedral is considered a historical monument and the most important and characteristic building in the city. The aims of this work were: to identify the taxa of phototrophic organisms that inhabit on the brick walls of the Cathedral, in order to investigate phototrophic biofilm formation and to assess the risk of biodeterioration, biopitting, and to relate them to the microclimatic conditions that affect the temple and the characteristics of material. Different types of growth of phototropic biofilms sampled were: i) the green one, which is present on the south-east wall, and had moss, genus Henediella, as an external layer and Chlorophyta (Chlorella sp. and Chlorococcum sp.) joined to Cyanobacteria (Synechococcus sp. and Synechocystis sp.); ii) the black one, which was sampled in several areas of the Cathedral. This phototropic biofilm showed pedominant filament forms; iii) the black muddy one combined with a great amount of muddy material which comes from a conduit; here the predominant forms were Chlorophytes (Trentepohlia sp. and Printzina sp.). The great diversity of Pennales Diatoms was a characteristic shared among all the biofilms. Under laboratory assays we observed grooves and biopitting caused by the attack of phototrophic biofilms on the substrate (brick).Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Phototrophic biofilms on exterior brick substrate

La Plata Cathedral is considered a historical monument and the most important and characteristic building in the city. The aims of this work were: to identify the taxa of phototrophic organisms that inhabit on the brick walls of the Cathedral, in order to investigate phototrophic biofilm formation and to assess the risk of biodeterioration, biopitting, and to relate them to the microclimatic conditions that affect the temple and the characteristics of material. Different types of growth of phototropic biofilms sampled were: i) the green one, which is present on the south-east wall, and had moss, genus Henediella, as an external layer and Chlorophyta (Chlorella sp. and Chlorococcum sp.) joined to Cyanobacteria (Synechococcus sp. and Synechocystis sp.); ii) the black one, which was sampled in several areas of the Cathedral. This phototropic biofilm showed pedominant filament forms; iii) the black muddy one combined with a great amount of muddy material which comes from a conduit; here the predominant forms were Chlorophytes (Trentepohlia sp. and Printzina sp.). The great diversity of Pennales Diatoms was a characteristic shared among all the biofilms. Under laboratory assays we observed grooves and biopitting caused by the attack of phototrophic biofilms on the substrate (brick).Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Estudios de biodeterioro en acervo documental

En este trabajo se presentan los estudios que se llevan a cabo en el Laboratorio de Biodeterioro de Materiales de INIFTA, sobre la contaminación microbiana del ambiente y el biodeterioro de materiales almacenados en diferentes archivos: Archivo Histórico del Museo de La Plata; Archivo Histórico y Cartográfico de Geodesia del Ministerio de Obras Públicas de la Provincia de Buenos Aires y Archivo del Colegio de Escribanos de la Provincia de Buenos Aires; Archivo Nacional de La Habana, Cuba.\n\n(Párrafo extraído del texto a modo de resumen)Eje 3: Exhibición y Conservació

Hongos y bacterias en el biodeterioro de fibras arqueológicas. Análisis con diferentes técnicas microscópicas

Pre and post-Columbian archeological textiles from the Southern Andean area, sheltered in Deposit 25 at La Plata Museum (Fig. 1), were analyzed by Olympus BX51optical microscopy (OM), FEI Quanta 200 scanning electron microscopy (SEM) and Leica SP5 confocal laser scanning microscopy (CLSM) with the aim of studying their biodeterioration3 . For over 120 years, these textiles have provided information to archeologists around the world, and it was through the study of many pieces that we now know in detail the characteristics of the material culture of the various groups that inhabited the territory during the national Holocene period.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias ExactasFacultad de Ciencias Veterinaria

Hongos y bacterias en el biodeterioro de fibras arqueológicas. Análisis con diferentes técnicas microscópicas

Pre and post-Columbian archeological textiles from the Southern Andean area, sheltered in Deposit 25 at La Plata Museum (Fig. 1), were analyzed by Olympus BX51optical microscopy (OM) (Fig. 2A and 3A), FEI Quanta 200 scanning electron microscopy (SEM) (Figs. 2B and 3C) and Leica SP5 confocal laser scanning microscopy (CLSM) (Fig. 3B) with the aim of studying their biodeterioration3. For over 120 years, these textiles have provided information to archeologists around the world, and it was through the study of many pieces that we now know in detail the characteristics of the material culture of the various groups that inhabited the territory during the national Holocene period. Textiles containing natural fibers, and cotton fabrics can present problems when exposed to unfavorable external conditions. High humidity and temperature and insufficient air circulation result in enhanced growth of microorganisms, especially fungi2. Uncontrolled fungi growth leads to the complete deterioration of archeological fibers. Microorganisms such as fungi and bacteria (ie. Cladosporium sp. and Pseudomonas sp.) (Fig. 3) cause the biodeterioration of cellulose, which is the main component of natural fibers such as flax and cotton4. This leads to loss of strength of the natural fibers, causing odor emission, esthetic damage, the presence of staining, discoloration (foxing) and finally loss of fiber structure5, and giving rise to significant losses at economic and cultural levels. Proper storage of textiles susceptible to biodeterioration in special containers under conditions of temperature and relative humidity suitable are effective preventive measures to avoid undesirable results. Essential oils and silver nanoparticles1, among others, can be used as disinfectants for the surface of archeological fibers, historical objects and archival documents. It is essential that all tasks and strategies used in the preservation of the material be written and documented photographically, so as to keep a record for regularly assessing changes of microorganism activity leading to textile damage.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. Facultad de Ciencias Veterinarias; ArgentinaFil: Igareta, Ana Teresa. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Arqueologia; ArgentinaFil: Battistoni, Patricia Adriana. 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; ArgentinaFil: 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. Facultad de Ciencias Naturales y Museo; Argentin

Aceites esenciales y extractos vegetales en el control del biodeterioro del patrimonio documental argentino y cubano

Tópico 2: Conservación y restauración de pinturas, cueros, textiles, papel y metales. Técnicas de limpieza y restauración

BIODETERIORO, ¿DÓNDE ESTÁS?

Muchas veces hemos escuchado hablar de biodeterioro, y no siempre es fácil comprender ¿de qué se trata? Éstas son algunas de las preguntas que nos han hecho en muchas circunstancias y distintos lugares a lo largo de los años de trabajo

Biocidal activity of two essential oils on fungi that cause degradation of paper documents

The aim of this study was to evaluate the biocidal activity of essential oils of Syzygium aromaticum (L.) Merr. and L. M. Perry (nail) and Allium sativum L. (garlic) against different fungal species producing paper degradation and deterioration. Essential oils (EOs) were obtained from harvested plants in their natural habitat in Cuba, and were tested against the species Aspergillus niger, Aspergillus flavus and Penicillium sp. which were isolated from archival indoor environments and documents with patrimonial value The biocidal activity was studied at different concentrations (70, 50, 25, 12.5 and 7.5%) using the agar diffusion method. The effect of extracts on paper alterations was studied through different techniques including determination of pH and number of copper and scanning electron microscopy (SEM) observations. EOs were analyzed by gas chromatography coupled to mass spectroscopy (GC/MS). The determination of inhibition zones by the agar diffusion method of the tested EOs showed a moderate and/or positive effect. The study of the antifungal activity on paper (“in vivo”) shows that both clove and garlic oils were potent biocides. Although the paper structure was not affected by EOs pure, some molecular damages were observed at lower concentrations across determinations of the pH and copper number.Facultad de Ciencias Exacta