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Even when Pseudomonas aeruginosa pathogenicity has been well recognized by clinic medicine and vet literature, few it is known regarding to strains isolated from archaeological materials. Recent studies have demonstrated that strains of P. aeruginosa with a high adaptive ability to colonize and develop biofilm in inorganic surfaces of archaeological ceramics exist. The potsherds samples from which P. aeruginosa was isolated are of Rustic pottery, usually for domestic, and they came from the archaeological site La Cuestecilla, Northern of La Rioja province, Argentina. To assess the bioadhesión and biofilm formation ability of this strain adapted to inorganic materials, experimental assays were performed with samples of the same ceramic type from which they were identify. Firstly, the strain was seeded on solid mineral medium and then in contact with archaeological ceramics samples. The bioadhesion and biofilm formation was assessed after an incubation time by scanning electron miscroscopy (SEM-EDAX Fem Quanta 200 TM – LIMF, UNLP). The samples were kept in a closed chamber with ethanol (100%) for 24 h. Previously to observation by scanning electron microscopy, a part of the samples were cleaned by utrasonic to evaluate biodeterioration processes in its surface, while the other were metalized with Au to increase image resolution to observe bioadhesion and biofilm formation. Potsherds without treatment were used as control samples and were analysed by stereomicroscopy (Olympus BH2, INIFTA-CONICET) and SEM. Cyanolichens colonized weakened ceramics surfaces by weathering and erosion processes. The results proved that cyanolichens left biopits of subcircular shapes of approximated 0,5-1,5 mm that later are used, along with surface irregularities, by P. aeruginosa to develop. Even though archaeological potsherds did not have clearly defined biofilms such as those obtained by experimentation, the production of exopolimeric substances (EPS) and biofilm formation by P. aeruginosa it is corroborate, such as its pathogenicity and risk in the handling of such cultural objects., Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Facultad de Ciencias Veterinarias

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

Background: Metal surface immersed in natural or industrial waters undergo a sequence of processes in time and space that lead to the formation of biological and inorganic (scaling) deposit adhesion of different microorganisms (bacteria, microalgae, fungi) on the metal surface through extracellular polymeric substances, causing microbiologically influenced corrosion. The biofilm formation and microbiologically influenced corrosion impact on economic interests and after inorganic corrosion they are the most important problems affecting different industries. The eradication of biofilm in the industry is difficult and costly. Technological importance in the thermoelectric industry by biofilm and biofouling formation lies in energy losses in heat exchanger systems. In the oil industry, problems derived from the presence of biofilms as filter plugging, corrosion in structures storage and distribution of fuel are presented. The aim of this work is to show the different industry cases of microbiologically influenced corrosion: jet aircraft fuel storage tanks and distribution plant, steel plant, thermoelectric industry. The evaluation of microbiologically influenced corrosion and the biofilm formation are investigated. Methods: Microbial counts were performed by conventional techniques. The formation of the biofilm and the attack on the metal surface were studied through scanning electron microscopic techniques. Results: Different results were obtained for each of the industrial environments studied. Conclusion:Strategies to evaluate corrosion problems systems are proposed through microbiological and physical-chemical studies., Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas

Biodeterioration of archaeological materials contribute to significant economic losses and the destruction of invaluable pieces of cultural heritage. The study materials were 5 pre-Columbian fibres (1250–1450 A.D., Argentina). The microscopic analyses (SEM-EDS) showed that they were made of cotton, sisal and wool, as well as they were contaminated by mineral impurities and dust. So far, no research has been conducted on determining the effectiveness of disinfection with silver nanoparticles (AgNPs) misting of historical textiles. The studies showed that the reduction of microorganism number was between 30.8–99.9%, which depended on the qualitative microbial contamination and its amount. Different AgNPs sensitivity of microorganisms was noted, with the least susceptible being endospore-forming bacteria Bacillus, more easily inhibited were bacterial genus Oceanobacillus, Kocuria, Paracoccus and moulds Cladosporium, Penicillium. AgNPs misting does not adversely influence the pH and chemistry textiles. The presented in this paper disinfection method with AgNPs misting can be used for disinfection of archaeological textiles made of wool, cotton and sisal, as an alternative to the currently available methods. Fil: Pietrzak, Katarzyna. Lodz University of Technology; Polonia Fil: Puchalski, Michal. Lodz University of Technology; Polonia Fil: Otlewska, Anna. Lodz University of Technology; Polonia Fil: Wrzosek, Henryk. Lodz University of Technology; Polonia 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: Piotrowska, Ma?gorzata. Lodz University of Technology; Polonia Fil: Gutarowska, Beata. Lodz University of Technology; Polonia

The aims of this work were to: (i) microscopically analyse the pre- and post-Columbian archaeological textiles using Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDX); (ii) microbiologically analyse the archaeological textiles (from the Southern Andean Area, La Plata Museum); (iii) determine the ability of Pseudomonas sp. isolates from archaeological textiles to biofilm formation by SEM; (iv) assess the anti-biofilm properties of AgNPs protecting cotton against Pseudomonas sp. Results showed the presence of bacteria with proteolytic and lipolytic activities on archaeological textiles, including Clostridium sp. and Pseudomonas aeruginosa. Two nucleotide sequences of 16S ribosomal RNA gene of P. aeruginosa strains were deposited in GeneBank NCBI database with accession numbers: KP842564 (strain 1) and KP842565 (strain 2). Those strains exhibited different morphological and growth characteristics: strain 1 with ability to form biofilms on archaeological textiles was rod-shaped, produced bluish-green pigment, and smaller than strain 2; and strain 2 was pleomorphic and produced brown pigment. The use of silver nanoparticles (90 ppm, φ 10–80 nm) allowed to protecting textiles against P. aeruginosa growth by 63%–97%, depending on the strain and exposition time., Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas

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

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 Aplicadas, Facultad de Ciencias Exactas, Facultad de Ciencias Veterinarias