WorldWideScience

Sample records for biodeterioration

  1. Biodeterioration of wood in estuarine ecosystem of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Yennawar, P.L; Thakur, N.L; Venkat, K.; Anil, A.C.; Wagh, A.B.

    community was dominated by Martesia striata in pre-monsoon and post-monsoon seasons and by L. pedicellatus in monsoon. The macrofouling and wood boring communities which mainly contributes in biodeterioration of wood is discussed in this paper...

  2. Non-destructive testing of stone biodeterioration and biocleaning effectiveness

    OpenAIRE

    Sasso, S.; Miller, A. Z.; Rogerio Candelera, Miguel A.; Cubero, Beatriz; Scrano, Laura; Bufo, Sabino A.; Sáiz-Jiménez, Cesáreo

    2015-01-01

    Microorganisms (bacteria, green algae and fungi) may lead to complex problems in the conservation of cultural heritage assets due to their biodeteriorative potential. The biodeterioration phenomena observed on materials of cultural heritage is determined by several factors, such as climatic conditions, chemical composition and nature of the material itself, as well as biological colonizers. The combination of several non-destructive techniques is compulsory in the field of cultural herit...

  3. Fungal Biodeterioration, Aflatoxin Contamination, and Nutrient Value of "Suya Spices".

    Science.gov (United States)

    Jonathan, Segun Gbolagade; Adeniyi, Mary Adejoke; Asemoloye, Michael Dare

    2016-01-01

    This work aimed to analyze the nutrient values, examine the biodeteriorating fungi biota, and analyze the mycotoxin contents of "Suya spices." Fungi with highest percentage occurrence on all the samples are Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Fusarium sp., Rhizopus stolonifer, yeast, and Trichoderma koningii. Nutrient composition of the samples is significantly different statistically (P Aflatoxin analysis of the samples revealed that they all contain aflatoxin in varying amount but no detectible aflatoxin content in the control. 59.54% of the detected aflatoxin is aflatoxin B1 with highest recorded in Agbowo, Mokola, and Sango samples (i.e., 28.03, 22.44, and 13.8 μg/kg, resp.). 4.78% of the aflatoxin is aflatoxin B2 which is only found in Sango and Mokola samples (3.59 and 2.6 μg/kg, resp.). 32.76% of aflatoxin is aflatoxin G1 with the highest found in Agbowo and Mokola samples (i.e., 18.63 and 10.41 μg/kg, resp.). 2.93% of the aflatoxin is aflatoxin G2 which is only detected in Sango and Agbowo samples (i.e., 1.19 and 2.65 μg/kg, resp.). PMID:27092289

  4. Biodeterioration studies of thermoplastics in nature using indigenous bacterial consortium

    Directory of Open Access Journals (Sweden)

    Mohd. Shahbaz Anwar

    2013-06-01

    Full Text Available Thermoplastics, poly vinyl chloride and low-density polyethylene were treated in the presence of indigenously developed bacterial consortium in laboratory and natural conditions. The consortium was developed using four bacteria, selected on the basis of utilization of PVC as primary carbon source, namely P. otitidis, B. aerius, B. cereus and A. pedis isolated from the plastic waste disposal sites in Northern India. The comparative in-vitro treatment studies as revealed by the spectral and thermal data, illustrated the relatively better biodegradation potential of developed consortium for PVC than the LDPE. Further, the progressive treatments of both the thermoplastics were conducted for three months under natural conditions. For this purpose, bioformulation of consortium was prepared and characterized for the viability up to 70 days of storage at 25±1ºC. The consortium treated polymer samples were monitored through SEM and FT-IR spectroscopy. Analytical data revealed the biodeterioration potential of the developed consortium for PVC and LDPE, which could help in disposing the plastic waste.

  5. BIODETERIORATION AND PRESERVATION OF SITA DEVI TEMPLE, DEORBIJA, CHHATTISGARH, INDIA

    Directory of Open Access Journals (Sweden)

    Sanjay Prasad GUPTA

    2011-06-01

    Full Text Available Chhattisgarh is a land of ancient culture, with many ancient monuments, temples and forts. Every nook and corner of Chhattisgarh has traditional heritage. There are numerous factors that affect the durability of stone. Stone surfaces are continuously exposed to physical, chemical and biological degradation. Physical, chemical, and biological agents act in co-association, ranging from synergistic to antagonistic and leading to deterioration. Among biological agents, micro-organisms are of critical importance in stone deterioration. They can cause various damages on the stone surface. Biodeterioration processes result from complex interactions of surface-invading microbes with each other, as well as with the surface material. The ability of fungi to produce pigments and organic acids is crucial for the discoloration and degradation of monuments. Air acts as a vehicle for the dispersion of microorganisms. They are introduced into air from different sources: soil, water, organic waste, plant leaves, sneezes and cough. This investigation focuses on the scientific conservation of The Sita Devi Temple of Deorbija DistricDurg, [Chhattisgarh]. The stone surface of the temple grew dark due to deposits of dust, dirt, dried vegetation and the growth of micro vegetation on the exterior as well as the interior portions.

  6. Combining Statistical Tools and Ecological Assessments in the Study of Biodeterioration Patterns of Stone Temples in Angkor (Cambodia)

    Science.gov (United States)

    Caneva, G.; Bartoli, F.; Savo, V.; Futagami, Y.; Strona, G.

    2016-01-01

    Biodeterioration is a major problem for the conservation of cultural heritage materials. We provide a new and original approach to analyzing changes in patterns of colonization (Biodeterioration patterns, BPs) by biological agents responsible for the deterioration of outdoor stone materials. Here we analyzed BPs of four Khmer temples in Angkor (Cambodia) exposed to variable environmental conditions, using qualitative ecological assessments and statistical approaches. The statistical analyses supported the findings obtained with the qualitative approach. Both approaches provided additional information not otherwise available using one single method. Our results indicate that studies on biodeterioration can benefit from integrating diverse methods so that conservation efforts might become more precise and effective. PMID:27597658

  7. Combining Statistical Tools and Ecological Assessments in the Study of Biodeterioration Patterns of Stone Temples in Angkor (Cambodia).

    Science.gov (United States)

    Caneva, G; Bartoli, F; Savo, V; Futagami, Y; Strona, G

    2016-01-01

    Biodeterioration is a major problem for the conservation of cultural heritage materials. We provide a new and original approach to analyzing changes in patterns of colonization (Biodeterioration patterns, BPs) by biological agents responsible for the deterioration of outdoor stone materials. Here we analyzed BPs of four Khmer temples in Angkor (Cambodia) exposed to variable environmental conditions, using qualitative ecological assessments and statistical approaches. The statistical analyses supported the findings obtained with the qualitative approach. Both approaches provided additional information not otherwise available using one single method. Our results indicate that studies on biodeterioration can benefit from integrating diverse methods so that conservation efforts might become more precise and effective. PMID:27597658

  8. Biodeterioration of the Lions Fountain at the Alhambra Palace, Granada (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Sarro, M. Isabel; Garcia, Ana M.; Rivalta, Victor M.; Moreno, Diego A. [Universidad Politecnica de Madrid, Escuela Tecnica Superior de Ingenieros Industriales, Jose Gutierrez Abascal, Madrid (Spain). Departamento de Ingenieria y Ciencia de los Materiales; Arroyo, Irene [Instituto del Patrimonio Historico Espanol, Ministerio de Cultura, El Greco, Madrid (Spain)

    2006-12-15

    Stone works of art exposed to the environment are liable to be deteriorated by the action of biological agents such as bacteria, fungi, mosses, etc. In ornamental fountains, the microorganisms present in water can contribute to these biodeterioration processes. This paper assesses the biodeterioration experienced by the Lions Fountain at the Alhambra Palace in Granada (Spain). Analyses have been made of the biodeterioration of Lions 4, 5 and 9, the biofouling of the fountain basin, and the water supply system. Conventional and molecular biology techniques have identified microorganisms belonging to various microbial groups ({alpha}-, {beta}- and {gamma}-Protebacteria, Chlamydiae/Verrucomicrobia and Eukaryota). Additionally, on the mortar in the sculptures the presence of algae and bryophytes has been observed. X-ray diffraction allowed both the detection of neoformation mineral products that can be related with the presence of microorganisms and the corrosion products in the Lions Fountain. A number of recommendations are made regarding the prevention and control of biodeterioration in this important work of art. (author)

  9. Fungal Biodeterioration, Aflatoxin Contamination, and Nutrient Value of “Suya Spices”

    OpenAIRE

    Segun Gbolagade Jonathan; Mary Adejoke Adeniyi; Michael Dare Asemoloye

    2016-01-01

    This work aimed to analyze the nutrient values, examine the biodeteriorating fungi biota, and analyze the mycotoxin contents of “Suya spices.” Fungi with highest percentage occurrence on all the samples are Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Fusarium sp., Rhizopus stolonifer, yeast, and Trichoderma koningii. Nutrient composition of the samples is significantly different statistically (P < 0.05) with high protein (9.53% to 13.17%), fiber (9.2...

  10. Lichen biodeterioration of the Convento de la Peregrina, Sahagún, Spain.

    Science.gov (United States)

    Edwards, H G; Perez, F R

    1999-01-01

    Lichen encrustations from Diploschistes scruposus involved in the biodeterioration of the 13th Century Convento de la Peregrina in Sahagún Spain, have been analyzed using Raman spectroscopy. The vibrational spectra are characteristic of calcium oxalate monohydrate, beta-carotene, chlorophyll, and para-depside phenolic acids such as atranorin, lecanoric acid, and diploschistesic acid. The destructive colonization of the monumental stonework is highlighted and evidence presented for deleterious lichen invasion of the wall paintings inside the Convent. PMID:10219880

  11. Coupled reliability model of biodeterioration, chloride ingress and cracking for reinforced concrete structures

    OpenAIRE

    Bastidas-Arteaga, Emilio; Sánchez-Silva, Mauricio; CHATEAUNEUF, Alaa; Ribas Silva, Moema

    2008-01-01

    International audience; Maintaining and operating civil infrastructure systems has been recognized as a critical issue worldwide. Among all possible causes of safety reduction during the structural lifetime, deteriora- tion is particularly important. Structural deterioration is usually a slow time-dependent process controlled by safety and operation threshold specifications. This paper presents a model of RC deterioration by coupling biodeterioration (i.e., chemical, physical and mechanical a...

  12. Fungal Biodeterioration, Aflatoxin Contamination, and Nutrient Value of “Suya Spices”

    Science.gov (United States)

    Jonathan, Segun Gbolagade; Adeniyi, Mary Adejoke; Asemoloye, Michael Dare

    2016-01-01

    This work aimed to analyze the nutrient values, examine the biodeteriorating fungi biota, and analyze the mycotoxin contents of “Suya spices.” Fungi with highest percentage occurrence on all the samples are Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Fusarium sp., Rhizopus stolonifer, yeast, and Trichoderma koningii. Nutrient composition of the samples is significantly different statistically (P Aflatoxin analysis of the samples revealed that they all contain aflatoxin in varying amount but no detectible aflatoxin content in the control. 59.54% of the detected aflatoxin is aflatoxin B1 with highest recorded in Agbowo, Mokola, and Sango samples (i.e., 28.03, 22.44, and 13.8 μg/kg, resp.). 4.78% of the aflatoxin is aflatoxin B2 which is only found in Sango and Mokola samples (3.59 and 2.6 μg/kg, resp.). 32.76% of aflatoxin is aflatoxin G1 with the highest found in Agbowo and Mokola samples (i.e., 18.63 and 10.41 μg/kg, resp.). 2.93% of the aflatoxin is aflatoxin G2 which is only detected in Sango and Agbowo samples (i.e., 1.19 and 2.65 μg/kg, resp.). PMID:27092289

  13. Bacterially mediated mineralisation processes lead to biodeterioration of artworks in Maltese catacombs

    Energy Technology Data Exchange (ETDEWEB)

    Zammit, Gabrielle, E-mail: gabrielle.zammit@gmail.com [Dept. of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta (Malta); Sanchez-Moral, Sergio [Dept. de Geologia, Museo Nacional de Ciencias Naturales, CSIC, Madrid (Spain); Albertano, Patrizia [Dept. of Biology, Faculty of Science, University of Rome ' Tor Vergata' , Rome (Italy)

    2011-06-15

    Mineral structures formed by bacterial and microalgal biofilms growing on the archaeological surface in Maltese hypogea were studied using Energy Dispersive X-Ray Spectroscopy (EDS) coupled to Environmental Scanning Electron Microscopy (ESEM), X-ray micro-diffraction (XRD) and X-ray fluorescence (XRF). These techniques have shown that mineral structures having different morphologies and chemical composition were associated with the microorganisms in the subaerophytic biofilm. Salt efflorescences and mineral deposits on the archaeological surface were often formed from gypsum (CaSO{sub 4}{center_dot} 2H{sub 2}O), halite (NaCl) and calcite (CaCO{sub 3}). Biogenic carbonates produced by microbial activities were a common occurrence. These assumed different forms, such as the production of mineral coats around cyanobacterial sheaths and the occurrence of calcite fibres with different morphologies on the surface of the biofilms. Moreover, vaterite (CaCO{sub 3}) spherulites which appeared hollow in cross-section were observed. The presence of struvite was recorded from one catacomb site. These investigations have facilitated the study of the neoformation of metastable minerals by microbially mediated processes, which potentially contribute to a better understanding of the biodeterioration of artworks in Maltese palaeo-Christian catacombs. - Research highlights: {yields} Mineral structures formed by subaerial biofilms growing in hypogea were examined. {yields} Efflorescences and mineral deposits were often formed from gypsum, halite, and calcite. {yields} Biogenic carbonates assumed different forms e.g. vaterite spherulite, calcite fibres. {yields} The formation of rare minerals e.g. struvite was mediated by bacteria. {yields} Understanding biomineralisation processes facilitates the conservation of artworks.

  14. Fungal Biodeterioration, Aflatoxin Contamination, and Nutrient Value of “Suya Spices”

    Directory of Open Access Journals (Sweden)

    Segun Gbolagade Jonathan

    2016-01-01

    Full Text Available This work aimed to analyze the nutrient values, examine the biodeteriorating fungi biota, and analyze the mycotoxin contents of “Suya spices.” Fungi with highest percentage occurrence on all the samples are Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Fusarium sp., Rhizopus stolonifer, yeast, and Trichoderma koningii. Nutrient composition of the samples is significantly different statistically (P<0.05 with high protein (9.53% to 13.17%, fiber (9.27 to 13.17%, carbohydrate (46.27% to 50.90%, and ash (8.47% to 9.70% contents but low moisture (9.03% to 9.47% and fat (9.77% to 13.53% contents. Aflatoxin analysis of the samples revealed that they all contain aflatoxin in varying amount but no detectible aflatoxin content in the control. 59.54% of the detected aflatoxin is aflatoxin B1 with highest recorded in Agbowo, Mokola, and Sango samples (i.e., 28.03, 22.44, and 13.8 μg/kg, resp.. 4.78% of the aflatoxin is aflatoxin B2 which is only found in Sango and Mokola samples (3.59 and 2.6 μg/kg, resp.. 32.76% of aflatoxin is aflatoxin G1 with the highest found in Agbowo and Mokola samples (i.e., 18.63 and 10.41 μg/kg, resp.. 2.93% of the aflatoxin is aflatoxin G2 which is only detected in Sango and Agbowo samples (i.e., 1.19 and 2.65 μg/kg, resp..

  15. Abiotic determinants of the historical buildings biodeterioration in the former Auschwitz II-Birkenau concentration and extermination camp.

    Directory of Open Access Journals (Sweden)

    Małgorzata Piotrowska

    Full Text Available The paper presents the results of a study conducted at the Auschwitz-Birkenau State Museum in Oświęcim on the occurrence of biodeterioration. Visual assessment of the buildings revealed signs of deterioration of the buildings in the form of dampness, bulging and crumbling plaster, and wood fiber splitting. The external surfaces, and especially the concrete strips and ground immediately adjoining the buildings, were colonized by bryophytes, lichens, and algae. These organisms developed most intensively close to the ground on the northern sides of the buildings. Inside the buildings, molds and bacteria were not found to develop actively, while algae and wood-decaying fungi occurred locally. The factors conducive to biological corrosion in the studied buildings were excessive dampness of structural partitions close to the ground and a relative air humidity of above 70%, which was connected to ineffective moisture insulation. The influence of temperature was smaller, as it mostly affected the quantitative composition of the microorganisms and the qualitative composition of the algae. Also the impact of light was not very strong, but it was conducive to algae growth.

  16. Characterizing the microbial colonization of a dolostone quarry: implications for stone biodeterioration and response to biocide treatments.

    Science.gov (United States)

    Cámara, Beatriz; De los Ríos, Asuncion; Urizal, Marta; de Buergo, Mónica Alvarez; Varas, Maria Jose; Fort, Rafael; Ascaso, Carmen

    2011-08-01

    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.

  17. Abiotic determinants of the historical buildings biodeterioration in the former Auschwitz II-Birkenau concentration and extermination camp.

    Science.gov (United States)

    Piotrowska, Małgorzata; Otlewska, Anna; Rajkowska, Katarzyna; Koziróg, Anna; Hachułka, Mariusz; Nowicka-Krawczyk, Paulina; Wolski, Grzegorz J; Gutarowska, Beata; Kunicka-Styczyńska, Alina; Zydzik-Białek, Agnieszka

    2014-01-01

    The paper presents the results of a study conducted at the Auschwitz-Birkenau State Museum in Oświęcim on the occurrence of biodeterioration. Visual assessment of the buildings revealed signs of deterioration of the buildings in the form of dampness, bulging and crumbling plaster, and wood fiber splitting. The external surfaces, and especially the concrete strips and ground immediately adjoining the buildings, were colonized by bryophytes, lichens, and algae. These organisms developed most intensively close to the ground on the northern sides of the buildings. Inside the buildings, molds and bacteria were not found to develop actively, while algae and wood-decaying fungi occurred locally. The factors conducive to biological corrosion in the studied buildings were excessive dampness of structural partitions close to the ground and a relative air humidity of above 70%, which was connected to ineffective moisture insulation. The influence of temperature was smaller, as it mostly affected the quantitative composition of the microorganisms and the qualitative composition of the algae. Also the impact of light was not very strong, but it was conducive to algae growth. PMID:25279789

  18. Microbial survey of the mummies from the Capuchin Catacombs of Palermo, Italy: biodeterioration risk and contamination of the indoor air.

    Science.gov (United States)

    Piñar, Guadalupe; Piombino-Mascali, Dario; Maixner, Frank; Zink, Albert; Sterflinger, Katja

    2013-11-01

    The Capuchin Catacombs of Palermo contain over 1800 preserved bodies dating from the 16th to 20th centuries AD and showing evidence of biodeterioration. An extensive microbiological and molecular investigation was recently performed. Samples were taken from skin, muscle, hair, bone, stuffing materials, clothes, and surrounding walls as well as from the indoor air. In this study, we witnessed that the different degradation phenomena observed on the variety of materials located at the Capuchin Catacombs of Palermo are biological in origin. Molecular techniques showed the dominance of halophilic species of the domains Bacteria and Archaea on the walls and - as a result of salt emanating from the walls - on the mummies themselves. Nevertheless, specialized microorganisms belonging to taxa well-known for their cellulolytic and proteolytic activities were detected on clothes and stuffing material, and on skin, muscle, hair, and bone, respectively. This specialized microbiota is threatening the conservation of the mummies themselves. Additionally, sequences related to the human skin microbiome and to some pathogenic Bacteria (order Clostridiales) and fungi (genus Phialosimplex) were identified on samples derived from the mummies. Furthermore, a phosphate-reducing fungus, Penicillium radicum, was detected on bone. Finally, the high concentration of airborne fungal spores is not conducive to the conservation of the human remains and is posing a potential health risk for visitors.

  19. Metabolomic and high-throughput sequencing analysis – modern approach for the assessment of biodeterioration of materials from historic buildings

    Directory of Open Access Journals (Sweden)

    Beata eGutarowska

    2015-09-01

    microbial communities and to shed new light on biodeterioration processes.

  20. Metabolomic and high-throughput sequencing analysis-modern approach for the assessment of biodeterioration of materials from historic buildings.

    Science.gov (United States)

    Gutarowska, Beata; Celikkol-Aydin, Sukriye; Bonifay, Vincent; Otlewska, Anna; Aydin, Egemen; Oldham, Athenia L; Brauer, Jonathan I; Duncan, Kathleen E; Adamiak, Justyna; Sunner, Jan A; Beech, Iwona B

    2015-01-01

    and to shed new light on biodeterioration processes. PMID:26483760

  1. Scopulariopsis sp. and Fusarium sp. in the Documentary Heritage: Evaluation of Their Biodeterioration Ability and Antifungal Effect of Two Essential Oils.

    Science.gov (United States)

    Lavin, Paola; de Saravia, Sandra Gómez; Guiamet, Patricia

    2016-04-01

    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. PMID:26500067

  2. The accelerating effects of the microorganisms on biodeterioration of stone monuments under air pollution and continental-cold climatic conditions in Erzurum, Turkey

    International Nuclear Information System (INIS)

    The aim of this research was to determine the accelerating effects of microorganisms on the biodeterioration of stone under air pollution and continental-cold climatic region in Erzurum, Turkey. Studies have been carried out on specimens of the Rustempasa Bazaar, the Lalapasa Mosque, the Erzurum Castle Mosque, the Double Minarets-Madrasah, the Great Mosque and the Haji Mehmet Fountain aged from 441 to 823 years old. The results showed that vegetative and reproductive (generative) forms of the microorganisms could develop during the winter months when the night time average temperature was even - 25 deg. C. Also the reproductive forms had developed and the whole stone surface was covered with a biofilm caused by the microorganisms. Silicon, aluminum, calcium, potassium, titanium, magnesium, zinc, sulfur, iron, sodium, and niobium were found in the stones of the historical buildings with varying amounts through the SEM-EDS analysis. Some of these elements could be used as an energy resource for the microorganisms together with the air pollutants such as sulfur dioxide, nitrogen oxides and particles on the stone surfaces. Of 21 isolates, 15 species from 6 bacterium genera and 5 species from 5 fungi genera plus 1 fungi genera were identified on the deteriorated stone surfaces even during the coldest months by microbial identification system (MIS) and these findings were tested by SEM investigations

  3. The accelerating effects of the microorganisms on biodeterioration of stone monuments under air pollution and continental-cold climatic conditions in Erzurum, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Nuhoglu, Y.; Oguz, E. [Atatuerk University, Department of Environmental Engineering, Engineering Faculty, 25240, Erzurum (Turkey); Uslu, H.; Ozbek, A. [Atatuerk University, Department of Clinical Microbiology, Medicine Faculty, 25240, Erzurum (Turkey); Ipekoglu, B. [Izmir Institute of Technology, Faculty of Architecture, Department of Architectural Restoration 35430, Izmir (Turkey); Ocak, I.; Hasenekoglu, I. [Atatuerk University, Department of Biology, K.K Education Faculty, 25240 Erzurum (Turkey)

    2006-07-01

    The aim of this research was to determine the accelerating effects of microorganisms on the biodeterioration of stone under air pollution and continental-cold climatic region in Erzurum, Turkey. Studies have been carried out on specimens of the Rustempasa Bazaar, the Lalapasa Mosque, the Erzurum Castle Mosque, the Double Minarets-Madrasah, the Great Mosque and the Haji Mehmet Fountain aged from 441 to 823 years old. The results showed that vegetative and reproductive (generative) forms of the microorganisms could develop during the winter months when the night time average temperature was even -25 {sup o}C. Also the reproductive forms had developed and the whole stone surface was covered with a biofilm caused by the microorganisms. Silicon, aluminum, calcium, potassium, titanium, magnesium, zinc, sulfur, iron, sodium, and niobium were found in the stones of the historical buildings with varying amounts through the SEM-EDS analysis. Some of these elements could be used as an energy resource for the microorganisms together with the air pollutants such as sulfur dioxide, nitrogen oxides and particles on the stone surfaces. Of 21 isolates, 15 species from 6 bacterium genera and 5 species from 5 fungi genera plus 1 fungi genera were identified on the deteriorated stone surfaces even during the coldest months by microbial identification system (MIS) and these findings were tested by SEM investigations. (author)

  4. Bio-films and processes of bio-corrosion and bio-deterioration in oil-and gas-processing industry

    Energy Technology Data Exchange (ETDEWEB)

    Kholodenko, V.P.; Irkhina, I.A.; Chugunov, V.A.; Rodin, V.B.; Zhigletsova, S.K.; Yermolenko, Z.M.; Rudavin, V.V. [State Research Center for Applied Microbiology, Obolensk, Moscow region (Russian Federation)

    2004-07-01

    As a rule, oil- and gas-processing equipment and pipelines are attacked by different microorganisms. Their vital ability determines processes of bio-deterioration and bio-corrosion that lead often to technological accidents and severe environmental contamination. Bio-films presenting a complex association of different microorganisms and their metabolites are responsible for most of damages. In this context, to study the role bio-films may play in processes of bio-damages and in efficacy of protective measures is important. We have developed method of culturing bio-films on the surface of metal coupons by using a natural microbial association isolated from oil-processing sites. Simple and informative methods of determining microbiological parameters of bio-films required to study bio-corrosion processes are also developed. In addition, a method of electron microscopic analysis of bio-films and pitting corrosion is offered. Using these methods, we conducted model experiments to determine the dynamics of corrosion processes depending on qualitative and quantitative composition of bio-films, aeration conditions and duration of the experiment. A harmful effect of soil bacteria and micro-mycetes on different pipeline coatings was also investigated. Experiments were conducted within 3-6 months and revealed degrading action of microorganisms. This was confirmed by axial tension testing of coatings. All these approaches will be used for further development of measures to protect gas- and oil-processing equipment and pipelines against bio-corrosion and bio-damages (first of all biocides). (authors)

  5. Clone-based comparative sequence analysis of 16S rRNA genes retrieved from biodeteriorating brick buildings of the former Auschwitz II-Birkenau concentration and extermination camp.

    Science.gov (United States)

    Otlewska, Anna; Adamiak, Justyna; Gutarowska, Beata

    2015-02-01

    The aim of this work was to analyze the bacterial communities in four samples of historical materials (plaster, brick, and wood) derived from buildings located in the former Auschwitz II-Birkenau concentration and extermination camp in Brzezinka, Poland. For this purpose a molecular strategy based on the construction of 16S rRNA clone libraries was used. In total, 138 partial 16S rRNA gene sequences (∼600bp) were obtained and compared. The clones belonged to phyla Proteobacteria (classes: Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria), Actinobacteria, Firmicutes, and Bacteroidetes. The plaster samples predominantly contained clones closely related to Actinobacteria and Alphaproteobacteria, brick samples contained Gammaproteobacteria, while wood samples had Actinobacteria clones. Interestingly, the historic plaster and brick samples contained the following bacteria with known and described biodeterioration potential: chemoorganotrophic Streptomyces sp. and Pseudonocardia sp., halotolerant or halophilic Rubrobacter sp., Salinisphaera sp. and Halomonas sp. Principal component analysis (PCA) showed that amongst the bacterial species detected and identified none occurred on all the tested historical materials. The 16S rRNA clone library construction method was successfully used for the detection and diversity determination of bacterial communities inhabiting brick barracks located in the former Auschwitz II-Birkenau concentration and extermination camp in Brzezinka.

  6. Biodeterioration of cementitious materials in biogas digester

    OpenAIRE

    Voegel, C.; Bertron, A.; Erable, B

    2015-01-01

    In biogas production plants, concrete structures suffer chemical and biological attacks during the anaerobic digestion process. The attack on concrete may be linked to the effects of (i) organic acids; (ii) ammonium and CO2 co-produced by the microorganisms’ metabolisms; and (iii) the bacteria’s ability to form biofilms on the concrete surface. In a context of biogas industry expansion, the mechanisms of concrete deterioration need to be better understood in order to propose innovative, effic...

  7. Review of concrete biodeterioration in relation to nuclear waste.

    Science.gov (United States)

    Turick, Charles E; Berry, Christopher J

    2016-01-01

    Storage of radioactive waste in concrete structures is a means of containing wastes and related radionuclides generated from nuclear operations in many countries. Previous efforts related to microbial impacts on concrete structures that are used to contain radioactive waste showed that microbial activity can play a significant role in the process of concrete degradation and ultimately structural deterioration. This literature review examines the research in this field and is focused on specific parameters that are applicable to modeling and prediction of the fate of concrete structures used to store or dispose of radioactive waste. Rates of concrete biodegradation vary with the environmental conditions, illustrating a need to understand the bioavailability of key compounds involved in microbial activity. Specific parameters require pH and osmotic pressure to be within a certain range to allow for microbial growth as well as the availability and abundance of energy sources such as components involved in sulfur, iron and nitrogen oxidation. Carbon flow and availability are also factors to consider in predicting concrete biodegradation. The microbial contribution to degradation of the concrete structures containing radioactive waste is a constant possibility. The rate and degree of concrete biodegradation is dependent on numerous physical, chemical and biological parameters. Parameters to focus on for modeling activities and possible options for mitigation that would minimize concrete biodegradation are discussed and include key conditions that drive microbial activity on concrete surfaces. PMID:26397745

  8. Lichen biodeterioration of ecclesiastical monuments in northern Spain

    Science.gov (United States)

    Villar, Susana E. Jorge; Edwards, Howell G. M.; Seaward, Mark R. D.

    2004-04-01

    Seven highly-coloured lichen species belonging to the genera Caloplaca, Candelariella, Aspicilia and Xanthoria from ecclesiastical buildings in northern Spain have been analysed non-destructively by FT-Raman spectroscopy. The vibrational band assignments in the spectra of the specimens, which were still attached to their limestone or sandstone substrata, were accomplished with the assistance of the chemical compositions obtained from wet chemical extraction methods. β-Carotene was found in all specimens as the major pigment, and the characteristic spectral signatures of calcium oxalate monohydrate (whewellite) and dihydrate (weddelite) could be identified; chemical signatures were found for these materials even in lichen thalli growing the non-calcareous substrata, indicating, probably, that the calcium was provided here from wind-or-rain-borne sources. The Raman spectral biomarkers found in the lichens broadly agreed with the chemical extraction profiles as expected, but the present study indicates that some form of non-destructive taxonomic identification based on Raman spectroscopy was possible.

  9. Review of concrete biodeterioration in relation to nuclear waste.

    Science.gov (United States)

    Turick, Charles E; Berry, Christopher J

    2016-01-01

    Storage of radioactive waste in concrete structures is a means of containing wastes and related radionuclides generated from nuclear operations in many countries. Previous efforts related to microbial impacts on concrete structures that are used to contain radioactive waste showed that microbial activity can play a significant role in the process of concrete degradation and ultimately structural deterioration. This literature review examines the research in this field and is focused on specific parameters that are applicable to modeling and prediction of the fate of concrete structures used to store or dispose of radioactive waste. Rates of concrete biodegradation vary with the environmental conditions, illustrating a need to understand the bioavailability of key compounds involved in microbial activity. Specific parameters require pH and osmotic pressure to be within a certain range to allow for microbial growth as well as the availability and abundance of energy sources such as components involved in sulfur, iron and nitrogen oxidation. Carbon flow and availability are also factors to consider in predicting concrete biodegradation. The microbial contribution to degradation of the concrete structures containing radioactive waste is a constant possibility. The rate and degree of concrete biodegradation is dependent on numerous physical, chemical and biological parameters. Parameters to focus on for modeling activities and possible options for mitigation that would minimize concrete biodegradation are discussed and include key conditions that drive microbial activity on concrete surfaces.

  10. Review of Concrete Biodeterioration in Relation to Buried Nuclear Waste

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C; Berry, C.

    2012-10-15

    Long-term storage of low level radioactive material in below ground concrete disposal units (DUs) (Saltstone Disposal Facility) is a means of depositing wastes generated from nuclear operations of the U.S. Department of Energy. Based on the currently modeled degradation mechanisms, possible microbial induced effects on the structural integrity of buried low level wastes must be addressed. Previous international efforts related to microbial impacts on concrete structures that house low level radioactive waste showed that microbial activity can play a significant role in the process of concrete degradation and ultimately structural deterioration. This literature review examines the recent research in this field and is focused on specific parameters that are applicable to modeling and prediction of the fate of concrete vaults housing stored wastes and the wastes themselves. Rates of concrete biodegradation vary with the environmental conditions, illustrating a need to understand the bioavailability of key compounds involved in microbial activity. Specific parameters require pH and osmotic pressure to be within a certain range to allow for microbial growth as well as the availability and abundance of energy sources like components involved in sulfur, iron and nitrogen oxidation. Carbon flow and availability are also factors to consider in predicting concrete biodegradation. The results of this review suggest that microbial activity in Saltstone, (grouted low level radioactive waste) is unlikely due to very high pH and osmotic pressure. Biodegradation of the concrete vaults housing the radioactive waste however, is a possibility. The rate and degree of concrete biodegradation is dependent on numerous physical, chemical and biological parameters. Results from this review point to parameters to focus on for modeling activities and also, possible options for mitigation that would minimize concrete biodegradation. In addition, key chemical components that drive microbial activity on concrete surfaces are discussed.

  11. Biodeterioration of oil spills. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The bibliography contains citations concerning the biodegradation, bioremediation, and bioreclamation of oil spills. Effectiveness and regulatory issues in oil spill control on lands, on water surface, and underwater are discussed. Topics include in-situ bioremediation, dispersants, gasoline spills from underground storage tanks, beach and harbor clean-up, groundwater pollution, and soil pollution. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  12. Investigation of the effects of plasma treatments on biodeteriorated ancient paper

    Science.gov (United States)

    Laguardia, L.; Vassallo, E.; Cappitelli, F.; Mesto, E.; Cremona, A.; Sorlini, C.; Bonizzoni, G.

    2005-11-01

    Deterioration of paper-based materials is mainly due to the degradation of cellulose caused by a lot of factors such as chemical attack due to acidic hydrolysis, oxidative agent, light, air pollution and biological attack and also due to the presence of microorganisms like bacteria and fungi. It is therefore desirable to focus the research activities on restoration and conservation techniques to develop appropriate treatments. The aim of this paper is the removal or reduction of the microbial contamination and paper consolidation by means of plasma treatment. For plasma processes, different gas mixtures are utilised, and the different gas mixtures are compared as a function of pressure, power, and treatment time. To demonstrate the efficiency of the sterilisation treatment, two fungi: Aspergillus niger and Penicillium funiculosum, commonly found in libraries and archives were spread on naturally aged paper (19th century). Microorganisms were let to grow by using the organic compounds found in the historical records as a sole source of carbon and energy. The microbial abatement was measured before and after the plasma treatment by using the standard plate count method. Surface chemical and morphological characterisation of paper before and after plasma treatment has been carried out by X-ray photoelectron spectroscopy (XPS) and ATR infrared spectroscopy (ATR FTIR). The tensile strength of the plasma-treated papers was also determined. CNR Patent, n° Mi2004A000068, 21/01/2004.

  13. BIODETERIORATION OF CHEMICAL CONSTITUENTS IN DRUG TRIBULUS TERRESTRIS LINN. ROOTS DUE TO SPOILAGE OF FUNGI

    Directory of Open Access Journals (Sweden)

    M. Rashidi

    2012-11-01

    Full Text Available Total 15 fungi were obtained to be associated with the roots of Tribulus terrestris Linn. Roots stored at different relative humidities 30, 50, 75, 96 and 100% RH for 90 days. Quantitative estimation of main chemical constituents such as phenols, proteins, alkaloids, glycosides and sugars in relation to association of fungi were done. The drug stored at above 75% relative humidity showed maximum percentage incidence of fungi as well as deterioration of chemical constituents.

  14. BIODETERIORATION OF CHEMICAL CONSTITUENTS IN DRUG TRIBULUS TERRESTRIS LINN. ROOTS DUE TO SPOILAGE OF FUNGI

    OpenAIRE

    M Rashidi; Deokule, S.S.

    2012-01-01

    Total 15 fungi were obtained to be associated with the roots of Tribulus terrestris Linn. Roots stored at different relative humidities 30, 50, 75, 96 and 100% RH for 90 days. Quantitative estimation of main chemical constituents such as phenols, proteins, alkaloids, glycosides and sugars in relation to association of fungi were done. The drug stored at above 75% relative humidity showed maximum percentage incidence of fungi as well as deterioration of chemical constituents.

  15. Biodeterioration of products made from australian cedar (Toona ciliata M. Roem. var. australis

    Directory of Open Access Journals (Sweden)

    Natália Amarante Almeida

    2012-03-01

    Full Text Available The objectives of this study were to evaluate the natural resistance of composite and solid wood panels from Toona ciliata to fungal attack through accelerated laboratory testing, to characterize the anatomical components of the wood according to IAWA, to quantify the soluble and insoluble lignin contents by acid hydrolysis and to determine the colorimetric parameters before and after fungal attack by using the CIE-L*a*b*(1976 system. Solid wood was classified as moderately and highly resistant to white-rot fungus (Trametes versicolor and to brown-rot fungus (Gloeophyllum trabeum. OSB panels were found to be resistant and moderately resistant to white-rot fungus and highly resistant to brown-rot fungus. Variation in species and particle type did not have a positive effect on the treatments. As regards the wood, both fungi were inhibited by the presence of phenolic resin. Particleboard panels were classified as moderately resistant to white-rot fungus. Treatments T2 (cedar and T4 (cedar-eucalyptus were resistant while treatment T3 (cedar-pine was not resistant to attack by brown-rot fungus. The urea-formaldehyde resin failed to inhibit attack in the same way the phenolic resin did. Anatomically, the species was found to have medium texture, straight vessel lines, pleasant smell after incision and poor luster on the radial surface. Its anatomical structure favored colonization by the threadlike filaments of the fungi. All treatments caused wood darkening after attack by the G. trabeum fungus, with total variation in color. It was observed that with weight loss an increase followed in insoluble lignin contents, in all treatments, indicating that this chemical property is a determining factor in wood resistance to the attack of the fungi being evaluated.

  16. ASPECTS OF BIODETERIORATION OF LAPIDEOUS SUBMERGED ARTEFACTS: 3D METHODOLOGIES APPLICATION

    Directory of Open Access Journals (Sweden)

    S. Ricci

    2015-04-01

    Full Text Available Submerged stone archaeological artefacts are bioeroded by endolithic microbiota (cyanobacteria, algae and fungi and macroborers (Porifera, Bivalvia and Sipuncula. Optical microscope and SEM observations permit to analyse the bioerosion traces and to identify bioeroders. Data obtained with these techniques cannot be used to estimate volumes of material bioeroded. This aspect require the need to collect three-dimensional, close-range data from artefact. In this work we illustrate two 3D imaging techniques used to study bioerosion phenomena of underwater Cultural Heritage. In particular Digital Video Microscope permit the elaboration of 3D images, which are widely employed for close-range acquisitions. Underwater Laser Scanner documents the in situ degradation of submerged artefacts. This research aims to sensitize specialist figures in the study 3D offering a starting point for future collaborations that could lead to interesting results.

  17. BIODETERIORATION OF MEDICAL-GRADE SILICONE-RUBBER USED FOR VOICE PROSTHESES - A SEM STUDY

    NARCIS (Netherlands)

    NEU, TR; VANDERMEI, HC; BUSSCHER, HJ; DIJK, F; VERKERKE, GJ

    1993-01-01

    Silicone voice prostheses used for rehabilitation of speech after total laryngectomy are inserted in an non-sterile habitat. Deposits on explanted Groningen Button voice prostheses revealed a biofilm, due to heavy colonization of the silicone surface by bacteria and yeasts. Furthermore, it was demon

  18. Biodeterioration of cardboard-based liquid containers collected for fibre reuse.

    Science.gov (United States)

    Koivula, N; Hänninen, K

    1999-04-01

    Liquid packaging board (LPB) collected in Germany is processed in Finland as recycled fibre and as plastic reject for incineration. The chemical, biological and physical changes occurring in recycled LPB bales were monitored during storage of six and 18 months. The moisture content in the core of the bales ranged from 7% to 53%, and pH values varied from 6.0 to 8.5. The average amount of mesophilic bacteria per container was 1.5 x 10(7) - 5 x 10(8), which means that recycled LPB pulp cannot be recommended for sanitary use. The concentration of CO2 inside the bale is an indicator of the activity of aerobic microorganisms and might be suitable for identifying deteriorated bales and removing them from the production line. Insects were found in some bales and the more deteriorated the bale was the more species of insects were found. The results showed the conversion of cellulose into humic acids to be clearly underway in some recycled LPB bales. The bale samples were extracted into hot water and into fulvic acids and humic acid (HA) fractions. The concentration of the humic acid fraction varied in the range 0.3-0.6% of the organic matter in fresh bales and 2.2% in one old bale. During aging nitrogen was enriched in all fractions. PMID:10101851

  19. Biodeterioration Risk Threatens the 3100 Year Old Staircase of Hallstatt (Austria: Possible Involvement of Halophilic Microorganisms.

    Directory of Open Access Journals (Sweden)

    Guadalupe Piñar

    Full Text Available The prosperity of Hallstatt (Salzkammergut region, Austria is based on the richness of salt in the surrounding mountains and salt mining, which is documented as far back as 1500 years B.C. Substantial archaeological evidence of Bronze and Iron Age salt mining has been discovered, with a wooden staircase (1108 B.C. being one of the most impressive and well preserved finds. However, after its discovery, fungal mycelia have been observed on the surface of the staircase, most probably due to airborne contamination after its find.As a basis for the further preservation of this valuable object, the active micro-flora was examined to investigate the presence of potentially biodegradative microorganisms.Most of the strains isolated from the staircase showed to be halotolerant and halophilic microorganisms, due to the saline environment of the mine. Results derived from culture-dependent assays revealed a high fungal diversity, including both halotolerant and halophilic fungi, the most dominant strains being members of the genus Phialosimplex (synonym: Aspergillus. Additionally, some typical cellulose degraders, namely Stachybotrys sp. and Cladosporium sp. were detected. Numerous bacterial strains were isolated and identified as members of 12 different genera, most of them being moderately halophilic species. The most dominant isolates affiliated with species of the genera Halovibrio and Marinococcus. Halophilic archaea were also isolated and identified as species of the genera Halococcus and Halorubrum. Molecular analyses complemented the cultivation assays, enabling the identification of some uncultivable archaea of the genera Halolamina, Haloplanus and Halobacterium. Results derived from fungi and bacteria supported those obtained by cultivation methods, exhibiting the same dominant members in the communities.The results clearly showed the presence of some cellulose degraders that may become active if the requirements for growth and the environmental conditions turn suitable; therefore, these microorganisms must be regarded as a threat to the wood.

  20. Los biocidas vegetales en el control del biodeterior o del patrimonio documental. Perspectivas e impacto

    Directory of Open Access Journals (Sweden)

    Sofía Borrego-Alonso

    2015-01-01

    Full Text Available Los procesos de biodeterioro afectan a los sistemas industriales de d istintos sectores productivos (industrias del petróleo, del papel, energética, etc., a los biomateriales y al patrimonio cultural de cada nación. Los principales agentes que causan el biodeterioro del patrimonio documental son los microorganismos y los in sectos que utilizan el papel , como fuente nutritiva y junto a las condiciones ambientales inadecuadas, aceleran el deterioro de los diferentes soportes documentales llegando incluso a generar plagas. En el control de plagas se utilizan los biocidas, que gen eralmente son sustancias químicas costosas, tienen efectos nocivos sobre las personas que los usan, sobre el medio ambiente y aceleran el deterioro de los materiales. De ahí que la elección de un producto biocida sea cada vez más difícil ya que debe cumplir con requerimientos estrictos de control. Sin embargo, la búsqueda de alternativas como es el uso racional de productos naturales provenientes de plantas, puede incidir, positivamente en la solución de estos problemas. El objetivo de este trabajo es realiz ar una disertación sobre los biocidas, su concepto, los distintos tipos y la importancia de los productos naturales provenientes de plantas como biocidas para el control del biodeterioro por microorganismos e insectos, así como las perspectivas y el impact o que pudieran tener en su aplicación sobre el patrimonio documental.

  1. Microbiological Analysis of Surfaces of Leonardo Da Vinci’s Atlantic Codex: Biodeterioration Risk

    Directory of Open Access Journals (Sweden)

    Gianfranco Tarsitani

    2014-01-01

    Full Text Available Following the discovery of discoloration on some pages of the Atlantic Codex (AC of Leonardo da Vinci kept in the Biblioteca Ambrosiana in Milan, some investigations have been carried out to verify the presence of microorganisms, such as bacteria and fungi. To verify the presence of microorganisms a noninvasive method of sampling has been used that was efficient and allowed us to highlight the microbial facies of the material that was examined using conventional microbiological techniques. The microclimatic conditions in the storage room as well as the water content of the volume were also assessed. The combined observations allowed the conclusion that the discoloration of suspected biological origin on some pages of AC is not related to the presence or current attack of microbial agents.

  2. Microbiological Analysis of Surfaces of Leonardo Da Vinci's Atlantic Codex: Biodeterioration Risk

    Science.gov (United States)

    Moroni, Catia; Pasquariello, Giovanna; Maggi, Oriana

    2014-01-01

    Following the discovery of discoloration on some pages of the Atlantic Codex (AC) of Leonardo da Vinci kept in the Biblioteca Ambrosiana in Milan, some investigations have been carried out to verify the presence of microorganisms, such as bacteria and fungi. To verify the presence of microorganisms a noninvasive method of sampling has been used that was efficient and allowed us to highlight the microbial facies of the material that was examined using conventional microbiological techniques. The microclimatic conditions in the storage room as well as the water content of the volume were also assessed. The combined observations allowed the conclusion that the discoloration of suspected biological origin on some pages of AC is not related to the presence or current attack of microbial agents. PMID:25574171

  3. Aspects of Biodeterioration of Lapideous Submerged Artefacts: 3d Methodologies Application

    Science.gov (United States)

    Ricci, S.; Antonelli, F.; Sacco Perasso, C.

    2015-04-01

    Submerged stone archaeological artefacts are bioeroded by endolithic microbiota (cyanobacteria, algae and fungi) and macroborers (Porifera, Bivalvia and Sipuncula). Optical microscope and SEM observations permit to analyse the bioerosion traces and to identify bioeroders. Data obtained with these techniques cannot be used to estimate volumes of material bioeroded. This aspect require the need to collect three-dimensional, close-range data from artefact. In this work we illustrate two 3D imaging techniques used to study bioerosion phenomena of underwater Cultural Heritage. In particular Digital Video Microscope permit the elaboration of 3D images, which are widely employed for close-range acquisitions. Underwater Laser Scanner documents the in situ degradation of submerged artefacts. This research aims to sensitize specialist figures in the study 3D offering a starting point for future collaborations that could lead to interesting results.

  4. Microbiological Analysis of Surfaces of Leonardo Da Vinci's Atlantic Codex: Biodeterioration Risk.

    Science.gov (United States)

    Tarsitani, Gianfranco; Moroni, Catia; Cappitelli, Francesca; Pasquariello, Giovanna; Maggi, Oriana

    2014-01-01

    Following the discovery of discoloration on some pages of the Atlantic Codex (AC) of Leonardo da Vinci kept in the Biblioteca Ambrosiana in Milan, some investigations have been carried out to verify the presence of microorganisms, such as bacteria and fungi. To verify the presence of microorganisms a noninvasive method of sampling has been used that was efficient and allowed us to highlight the microbial facies of the material that was examined using conventional microbiological techniques. The microclimatic conditions in the storage room as well as the water content of the volume were also assessed. The combined observations allowed the conclusion that the discoloration of suspected biological origin on some pages of AC is not related to the presence or current attack of microbial agents.

  5. Culture-independent methods to study subaerial biofilm growing on biodeteriorated surfaces of stone cultural heritage and frescoes.

    Science.gov (United States)

    Cappitelli, Francesca; Villa, Federica; Polo, Andrea

    2014-01-01

    Actinobacteria, cyanobacteria, algae, and fungi form subaerial biofilm (SAB) that can lead to material deterioration on artistic stone and frescoes. In studying SAB on cultural heritage surfaces, a general approach is to combine microscopy observations and molecular analyses. Sampling of biofilm is performed using specific adhesive tape and sampling of SAB and the substrate with sterile scalpels and chisels. Biofilm observations are carried out using optical and scanning electron microscopy. Specific taxa and EPS in biofilm can be readily visualized by fluorochrome staining and subsequent observation using fluorescence or confocal laser scanning microscopy. The observation of cross sections containing both SAB and the substrate shows if biofilm has developed not only on the surface but also underneath. Following nucleic acid extraction, 16S rRNA gene sequencing is used to identify bacterial taxa, while 18S rRNA gene and internal transcribed spacer (ITS) sequence analysis is used to study eukaryotic groups. In this chapter, we illustrate the protocols related to fluorescence in situ hybridization (FISH), scanning electron microscopy (SEM), and denaturing gradient gel electrophoresis (DGGE).

  6. BIODETERIORATION OF CHEMICAL CONSTITUENTS IN DRUG GMELINA ARBOREA LINN. UNDER STORAGE OF DIFFERENT RELATIVE HUMIDITIES DUE TO SPOILAGE OF FUNGI

    Directory of Open Access Journals (Sweden)

    M Rashidi

    2012-12-01

    Full Text Available The roots of plant Gmelina arborea Linn. were selected for the present investigation. The roots were stored at different relative humidities 30, 50, 75, 96 and 100% RH for 90 days. Total 15 fungal species were isolated from these roots. Quantitative estimation of phenols, proteins, alkaloids, glycosides and sugars in relation to fungi were done. Maximum percentage incidence of storage fungi as well as deterioration of chemical constituents in the roots was showed at above 75% RH.

  7. A multianalytical approach to investigate stone biodeterioration at a UNESCO world heritage site: the volcanic rock-hewn churches of Lalibela, Northern Ethiopia

    Science.gov (United States)

    Schiavon, Nick; De Caro, Tilde; Kiros, Alemayehu; Caldeira, Ana Teresa; Parisi, Isabella Erica; Riccucci, Cristina; Gigante, Giovanni Ettore

    2013-12-01

    A multianalytical approach combining Optical Microscopy (OM), Backscattered Variable Pressure Scanning Electron Microscopy + Energy Dispersive X-ray Spectroscopy (VP-BSEM + EDS), Powder X-ray Diffractometry (PXRD), Raman Spectroscopy, and Microbiological techniques has been applied to characterize decay products and processes occurring at the surface of two rock-hewn churches ( Bete Gyorgis and Bete Amanuel) at the UNESCO's World Heritage site of Lalibela, Northern Ethiopia. The two churches were carved into volcanic scoria deposits of basaltic composition. In their geological history, the Lalibela volcanic rocks underwent late to post-magmatic hydrothermal alteration together with partial laterization and are therefore characterized by a decay-prone highly vesicular microtexture with late stage to post-magmatic precipitation of secondary mineral phases (calcite-zeolite-smectite). The main objective of the study was to gain a better insight into the weathering products and mechanisms affecting the surface of the stone monuments and to assess the relative contribution of natural "geological" weathering processes versus biological/salt attack in stone decay at this unique heritage site. Results indicate that while the main cause of bulk rock deterioration and structural failure could be related to the stone inherited "geological" features, biological attack by micro- (bacteria) and/or macro- (lichens) organisms is currently responsible for severe stone surface physical and chemical weathering leading to significant weakening of the stone texture and to material loss at the surface of the churches walls. A prompt and careful removal of the biological patinas with the correct biocidal treatment is therefore recommended.

  8. Biofouling e biodeterioração química de argamassa de cimento portland em reservatório de usina hidroelétrica Biofouling and chemical biodeterioration in hydroeletric power plant portland cement mortar

    Directory of Open Access Journals (Sweden)

    Kleber Franke Portella

    2009-01-01

    Full Text Available Last decade Brazilian rivers experimented progressive biofouling of Limnoperna fortunei communities and Cordylophora caspia hydroids. The microhabitat is so favorable that in around 1.5 years L. fortunei increased from 0.39 to nearby 149,000 units/m². Ten Portland cement mortar samples were produced with 1: 3.5: 0.4 dosages and installed for 1 year at Salto Caxias Brazilian Power Plant reservoir in 0.5 m and 1.0 m deep to investigate the biofouling influence on hydraulic civil structures. SEM, EDS, visual investigation and XRF results indicate none direct chemical interrelationships between L. fortunei and the mortar samples. However C. caspia diminished the mortar surface resistance and caused cement paste leaching.

  9. Fungal decay of traditional fishing craft

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, R.

    , their role in the biodeterioration process, traditional and modern preventive methods, their economics with suggestions for future work. This study becomes important in view of the fishing industry turning towards traditional fishing craft for low energy...

  10. Deterioration of polymethyl methacrylate dentures in the oral cavity.

    Science.gov (United States)

    Matsuo, Hiroshi; Suenaga, Hanako; Takahashi, Masatoshi; Suzuki, Osamu; Sasaki, Keiichi; Takahashi, Nobuhiro

    2015-01-01

    Polymethyl methacrylate (PMMA)-made prostheses used in the oral cavity were evaluated by multimodal assessment in order to elucidate the biodeterioration of PMMA. In used dentures (UD), the micro-Vickers hardness of the polished denture surface and denture basal surface was lower than that of the torn surface (pPMMA deteriorated during long-term use in the oral cavity in terms of hardness and volatile content with component alteration, and suggests the involvement of biodeterioration, possibly due to saliva and oral microbiota.

  11. Microbial deterioration of cultural heritage and works of art--tilting at windmills?

    Science.gov (United States)

    Sterflinger, Katja; Piñar, Guadalupe

    2013-11-01

    Microorganisms (bacteria, archaea and fungi), in addition to lichens and insect pests, cause problems in the conservation of cultural heritage because of their biodeteriorative potential. This holds true for all types of historic artefacts, and even for art made of modern materials, in public buildings, museums and private art collections. The variety of biodeterioration phenomena observed on materials of cultural heritage is determined by several factors, such as the chemical composition and nature of the material itself, the climate and exposure of the object, in addition to the manner and frequency of surface cleaning and housekeeping in museums. This study offers a review of a variety of well-known biodeterioration phenomena observed on different materials, such as stone and building materials, objects exhibited in museums and libraries, as well as human remains and burial-related materials. The decontamination of infected artefacts, exhibition rooms and depots incurs high expenditure for museums. Nevertheless, the question has to be raised: whether the process of biodeterioration of cultural heritage can or should be stopped under all circumstances, or whether we have to accept it as a natural and an implicit consecution of its creation. This study also highlights critically the pros and cons of biocide treatments and gives some prominent examples of successful and unsuccessful conservation treatments. Furthermore, an outlook on the future research needs and developments in this highly interesting field is given.

  12. Adhesion to silicone rubber of yeasts and bacteria isolated from voice prostheses : Influence of salivary conditioning films

    NARCIS (Netherlands)

    Busscher, HJ; GeertsemaDoornbusch, GI; vanderMei, HC

    1997-01-01

    Adhesion of yeasts and bacteria to silicone rubber is one of the first steps in the biodeterioration of silicone rubber voice prostheses. In this paper, adhesion of two streptococcal, staphylococcal, Candida albicans and Candida tropicalis strains, isolated from explanted voice prostheses was invest

  13. Plasticizers increase adhesion of the deteriogenic fungus Aureobasidium pullulans to polyvinyl chloride

    NARCIS (Netherlands)

    Webb, JS; Van der Mei, HC; Nixon, M; Eastwood, IM; Greenhalgh, M; Read, SJ; Robson, GD; Handley, PS

    1999-01-01

    Initial adhesion of fungi to plasticized polyvinyl chloride (pPVC) may determine subsequent colonization and biodeterioration processes. The deteriogenic fungus Aureobasidium pullulans was used to investigate the physicochemical nature of adhesion to both unplasticized PVC (uPVC) and pPVC containing

  14. A conductive polymer based electronic nose for early detection of Penicillium digitatum in post-harvest oranges

    International Nuclear Information System (INIS)

    We describe the construction of an electronic nose, comprising four chemiresistive sensors formed by the deposition of thin conductive polymer films onto interdigitated electrodes, attached to a personal computer via a data acquisition board. This e-nose was used to detect biodeterioration of oranges colonized by Penicillium digitatum. Significant responses were obtained after only 24 h of incubation i.e. at an early stage of biodeterioration, enabling remedial measures to be taken in storage facilities and efficiently distinguishing between good and poor quality fruits. The instrument has a very low analysis time of 40 s. - Highlights: • Early detection of Penicillium digitatum in oranges • Low cost electronic nose based on conductive polymers • Efficient distinction between good and poor quality fruits

  15. A conductive polymer based electronic nose for early detection of Penicillium digitatum in post-harvest oranges

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, Jonas, E-mail: jogruber@iq.usp.br [Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, CEP 05508-000 São Paulo, SP (Brazil); Nascimento, Henry M. [Sociedade Brasileira de Microbiologia, São Paulo, SP (Brazil); Yamauchi, Elaine Y. [Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, CEP 05508-000 São Paulo, SP (Brazil); Li, Rosamaria W.C. [Centro Universitário Estácio Radial São Paulo, São Paulo, SP (Brazil); Esteves, Carlos H.A. [Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, CEP 05508-000 São Paulo, SP (Brazil); Rehder, Gustavo P. [Escola Politécnica, Universidade de São Paulo, São Paulo, SP (Brazil); Gaylarde, Christine C. [University of Portsmouth, Portsmouth (United Kingdom); Shirakawa, Márcia A. [Escola Politécnica, Universidade de São Paulo, São Paulo, SP (Brazil)

    2013-07-01

    We describe the construction of an electronic nose, comprising four chemiresistive sensors formed by the deposition of thin conductive polymer films onto interdigitated electrodes, attached to a personal computer via a data acquisition board. This e-nose was used to detect biodeterioration of oranges colonized by Penicillium digitatum. Significant responses were obtained after only 24 h of incubation i.e. at an early stage of biodeterioration, enabling remedial measures to be taken in storage facilities and efficiently distinguishing between good and poor quality fruits. The instrument has a very low analysis time of 40 s. - Highlights: • Early detection of Penicillium digitatum in oranges • Low cost electronic nose based on conductive polymers • Efficient distinction between good and poor quality fruits.

  16. Microbial life in geothermal waters

    Energy Technology Data Exchange (ETDEWEB)

    Sand, W. [Universitaet Hamburg (Germany). Mikrobiologie

    2003-12-01

    Geothermal waters usually contain many salts, often in varying concentrations. Some of these salts, especially if they are oxidizable or reducible, may be subject to microbial conversion and/or (bio)precipitation. Microorganisms can oxidize, sometimes even under anoxic (absence of oxygen) conditions, reduced sulfur compounds, iron (II) ions, and manganese (II) ions, to mention just a few of the most important. On the other hand, partially or fully oxidized compounds can be reduced by microorganisms, for example sulfur compounds, iron (III) ions, manganese (IV) ions, nitrogen oxides such as nitrite and nitrate, and, finally, bicarbonate and carbonate ions. If organic compounds are present, these may also be oxidized or reduced. A multitude of these microorganisms are able to perform such a metabolism under aerobic or anoxic conditions. All these (bio)processes allow bacteria to grow and proliferate. The consequences include biocorrosion and biodeterioration. The growth requirements and the biodeterioration mechanisms will be discussed in this review. (author)

  17. Microbial communities adhering to the obverse and reverse sides of an oil painting on canvas: identification and evaluation of their biodegradative potential

    OpenAIRE

    López-Miras, M.; Piñar, G.; Romero-Noguera, J.; Bolívar-Galiano, F. C.; Ettenauer, J.; Sterflinger, K.; Martín-Sánchez, I. (Isidoro)

    2012-01-01

    In this study, we investigated and compared the microbial communities adhering to the obverse and the reverse sides of an oil painting on canvas exhibiting signs of biodeterioration. Samples showing no visible damage were investigated as controls. Air samples were also analysed, in order to investigate the presence of airborne microorganisms suspended in the indoor atmosphere. The diversity of the cultivable microorganisms adhering to the surface was analysed by molecular techniques, such as ...

  18. Degradation modelling of concrete submitted to sulfuric acid attack

    OpenAIRE

    Yuan, Haifeng; Dangla, Patrick; Chatellier, Patrice; Chaussadent, Thierry

    2013-01-01

    Bio-deterioration of concrete,which is very common in sewer system and waste water treatment plant, results in significant structure degradation. Normally, the process can be described by the two following steps: Biochemical reactions producing biogenic aggressive species (H2SO4 is one of the most significant biogenic acid in sewer pipes), and chemical reactions between biogenic aggressive species and cement hydration products which is responsible for concrete degradation. A reactive transpor...

  19. The Fungi and Insects Which Attack Rubberwood%危害橡胶木的真菌和昆虫

    Institute of Scientific and Technical Information of China (English)

    邢嘉琪

    2001-01-01

    The biological characteristics of the insects and fungi which seriously attack rubberwood and the present state of rubberwood biodeterioration in China were described. The fungi attaching rubberwood consist mainly of blue-stain fungi, moulds and rotting fungi. The insects include beetle borers, termites and some other Coleopteran species, such as longicorns and snout beetles etc., the total insect species are near to one hundred. The stain fungi, moulds and beetles should be paid more attention to in rubberwood preservation.

  20. Modélisation de la dégradation du béton due aux attaques acidesbiogéniques.

    OpenAIRE

    Yuan, Haifeng

    2013-01-01

    Bio-deterioration of concrete, which is very common in sewer system and waste water treatment plant, results in significant structure degradation. Normally, the process can be described by the two following parts: 1) Biochemistry reactions producing biogenic aggressive species in biofilms which are spread on the surface of concrete. As one of the most significant biogenic acid in sewer pipes, sulfuric acid (H2SO4) is produced by sulfur oxidizing bacteria (SOB). 2) Chemical reactions between b...

  1. Deteriorating effects of lichen and microbial colonization of carbonate building rocks in the Romanesque churches of Segovia (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Asuncion de los [Instituto de Recursos Naturales, Centro de Ciencias Medioambientales (CSIC), Serrano 115 dpdo., 28006 Madrid (Spain)], E-mail: arios@ccma.csic.es; Camara, Beatriz [Instituto de Recursos Naturales, Centro de Ciencias Medioambientales (CSIC), Serrano 115 dpdo., 28006 Madrid (Spain); Garcia del Cura, Ma Angeles [Instituto de Geologia Economica CSIC-UCM, Laboratorio de Petrologia Aplicada, Unidad Asociada CSIC-UA, Alicante (Spain); Rico, Victor J. [Departamento de Biologia Vegetal II, Facultad de Farmacia, Universidad Complutense, 28040 Madrid (Spain); Galvan, Virginia [Facultad Patrimonio Cultural, Universidad SEK, Convento de Santa Cruz la Real, 40003 Segovia (Spain); Ascaso, Carmen [Instituto de Recursos Naturales, Centro de Ciencias Medioambientales (CSIC), Serrano 115 dpdo., 28006 Madrid (Spain)

    2009-01-15

    In this study, the deterioration effects of lichens and other lithobionts in a temperate mesothermal climate were explored. We examined samples of dolostone and limestone rocks with visible signs of biodeterioration taken from the exterior wall surfaces of four Romanesque churches in Segovia (Spain): San Lorenzo, San Martin, San Millan and La Vera Cruz. Biofilms developing on the lithic substrate were analyzed by scanning electron microscopy. The most common lichen species found in the samples were recorded. Fungal cultures were then obtained from these carbonate rocks and characterized by sequencing Internal Transcribed Spacers (ITS). Through scanning electron microscopy in back-scattered electron mode, fungi (lichenized and non-lichenized) were observed as the most frequent microorganisms occurring at sites showing signs of biodeterioration. The colonization process was especially conditioned by the porosity characteristics of the stone used in these buildings. While in dolostones, microorganisms mainly occupied spaces comprising the rock's intercrystalline porosity, in bioclastic dolomitized limestones, fungal colonization seemed to be more associated with moldic porosity. Microbial biofilms make close contact with the substrate, and thus probably cause significant deterioration of the underlying materials. We describe the different processes of stone alteration induced by fungal colonization and discuss the implications of these processes for the design of treatments to prevent biodeterioration.

  2. Microbial community analysis of fresh and old microbial biofilms on Bayon temple sandstone of Angkor Thom, Cambodia.

    Science.gov (United States)

    Lan, Wensheng; Li, Hui; Wang, Wei-Dong; Katayama, Yoko; Gu, Ji-Dong

    2010-07-01

    The temples of Angkor monuments including Angkor Thom and Bayon in Cambodia and surrounding countries were exclusively constructed using sandstone. They are severely threatened by biodeterioration caused by active growth of different microorganisms on the sandstone surfaces, but knowledge on the microbial community and composition of the biofilms on the sandstone is not available from this region. This study investigated the microbial community diversity by examining the fresh and old biofilms of the biodeteriorated bas-relief wall surfaces of the Bayon Temple by analysis of 16S and 18S rRNA gene sequences. The results showed that the retrieved sequences were clustered in 11 bacterial, 11 eukaryotic and two archaeal divisions with disparate communities (Acidobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Proteobacteria; Alveolata, Fungi, Metazoa, Viridiplantae; Crenarchaeote, and Euyarchaeota). A comparison of the microbial communities between the fresh and old biofilms revealed that the bacterial community of old biofilm was very similar to the newly formed fresh biofilm in terms of bacterial composition, but the eukaryotic communities were distinctly different between these two. This information has important implications for understanding the formation process and development of the microbial diversity on the sandstone surfaces, and furthermore to the relationship between the extent of biodeterioration and succession of microbial communities on sandstone in tropic region.

  3. Molecular biotechnologies for the characterization and the evaluation of microorganisms in degradation processes of manufactures which are of historical artistic interest

    Directory of Open Access Journals (Sweden)

    Franco Palla

    2004-02-01

    Full Text Available This work presents the application of some molecular biology techniques with high interest in cultural heritage field. These methodologies have proved to be extremely useful to characterize microbial communities colonization and their potential involvement in deterioration processes, mainly because it become possible curried out cultural-independent studies of microorganisms in both organic or inorganic substrates. These methods can be easily suited to study the biodeterioration of cultural heritage and, in the future, their application will be essential in conservation and/or restoration projects.

  4. Antibiotic Extraction as a Recent Biocontrol Method for Aspergillus Niger andAspergillus Flavus Fungi in Ancient Egyptian mural paintings

    Science.gov (United States)

    Hemdan, R. Elmitwalli; Fatma, Helmi M.; Rizk, Mohammed A.; Hagrassy, Abeer F.

    Biodeterioration of mural paintings by Aspergillus niger and Aspergillus flavus Fungi has been proved in different mural paintings in Egypt nowadays. Several researches have studied the effect of fungi on mural paintings, the mechanism of interaction and methods of control. But none of these researches gives us the solution without causing a side effect. In this paper, for the first time, a recent treatment by antibiotic "6 penthyl α pyrone phenol" was applied as a successful technique for elimination of Aspergillus niger and Aspergillus flavus. On the other hand, it is favorable for cleaning Surfaces of Murals executed by tembera technique from the fungi metabolism which caused a black pigments on surfaces.

  5. Actinomycetes in Karstic caves of northern Spain (Altamira and Tito Bustillo).

    Science.gov (United States)

    Groth, I; Vettermann, R; Schuetze, B; Schumann, P; Saiz-Jimenez, C

    1999-05-01

    A variety of isolation procedures were carried out to study the involvement of bacteria in the colonisation and biodeterioration of Spanish caves with paleolithic rock art (Altamira and Tito Bustillo). The applied techniques mainly aimed to isolate heterotrophic bacteria such as streptomycetes, nocardioform and coryneform actinomycetes, and other gram-positive and gram-negative bacteria. The results demonstrated that actinomycetes were the most abundant gram-positive bacteria in the caves. Actinomycetes revealed a great taxonomic diversity with the predominant isolates belonging to the genus Streptomyces. Members of the genera Nocardia, Rhodococcus, Nocardioides, Amycolatopsis, Saccharothrix, Brevibacterium, Microbacterium, and coccoid actinomycetes (family Micrococcaceae) were also found. PMID:10353805

  6. Aislamiento e identificación de microorganismos en biopelículas provenientes del Castillo de Chapultepec, Ciudad de México.

    Directory of Open Access Journals (Sweden)

    E de la Cruz

    2011-12-01

    Full Text Available Today microbiology is based on pure cultures and separate microorganisms, pure cultures really do not exist in nature, because that microorganism are combined into large colonies slimy (biofilms in which the various individuals establish relationships and dependencies. Only in the United State of America is estimated that biofilms cause billions of dollars in energy losses, equipment damage, product contamination and medical infections. This paper presents the results of the isolation of microorganisms by microbiological and molecular methods, from biofilms located in the Castle of Chapultepec in Mexico City. In the biofilm coexist different genres of filamentous fungi such as Cladosporium, Mucor, Alternaria, Aspergillus, Aureobasidium, Rhodotorula and others in those biofilms; besides bacterial genera as Bacillus, Pantoea, Kokuria, etc. Many of these microbial genera have been widely reported as a participating in biodeterioration processes to monuments and others are reported as contributing to its restoration, so this work opens the door to future researches that allow biological restoration of monuments, conservation and development of new biotechnological processes.   Keywords: Microbiology; pure cultures; biofilms; isolation of microorganism; microbiological methods; biodeterioration processes. 

  7. Reproducing stone monument photosynthetic-based colonization under laboratory conditions.

    Science.gov (United States)

    Miller, Ana Zélia; Laiz, Leonila; Gonzalez, Juan Miguel; Dionísio, Amélia; Macedo, Maria Filomena; Saiz-Jimenez, Cesareo

    2008-11-01

    In order to understand the biodeterioration process occurring on stone monuments, we analyzed the microbial communities involved in these processes and studied their ability to colonize stones under controlled laboratory experiments. In this study, a natural green biofilm from a limestone monument was cultivated, inoculated on stone probes of the same lithotype and incubated in a laboratory chamber. This incubation system, which exposes stone samples to intermittently sprinkling water, allowed the development of photosynthetic biofilms similar to those occurring on stone monuments. Denaturing gradient gel electrophoresis (DGGE) analysis was used to evaluate the major microbial components of the laboratory biofilms. Cyanobacteria, green microalgae, bacteria and fungi were identified by DNA-based molecular analysis targeting the 16S and 18S ribosomal RNA genes. The natural green biofilm was mainly composed by the Chlorophyta Chlorella, Stichococcus, and Trebouxia, and by Cyanobacteria belonging to the genera Leptolyngbya and Pleurocapsa. A number of bacteria belonging to Alphaproteobacteria, Bacteroidetes and Verrucomicrobia were identified, as well as fungi from the Ascomycota. The laboratory colonization experiment on stone probes showed a colonization pattern similar to that occurring on stone monuments. The methodology described in this paper allowed to reproduce a colonization equivalent to the natural biodeteriorating process.

  8. Microbial communities adhering to the obverse and reverse sides of an oil painting on canvas: identification and evaluation of their biodegradative potential.

    Science.gov (United States)

    López-Miras, M; Piñar, G; Romero-Noguera, J; Bolívar-Galiano, F C; Ettenauer, J; Sterflinger, K; Martín-Sánchez, I

    2013-06-01

    In this study, we investigated and compared the microbial communities adhering to the obverse and the reverse sides of an oil painting on canvas exhibiting signs of biodeterioration. Samples showing no visible damage were investigated as controls. Air samples were also analysed, in order to investigate the presence of airborne microorganisms suspended in the indoor atmosphere. The diversity of the cultivable microorganisms adhering to the surface was analysed by molecular techniques, such as RAPD analysis and gene sequencing. DGGE fingerprints derived from DNA directly extracted from canvas material in combination with clone libraries and sequencing were used to evaluate the non-cultivable fraction of the microbial communities associated with the material. By using culture-dependent methods, most of the bacterial strains were found to be common airborne, spore-forming microorganisms and belonged to the phyla Actinobacteria and Firmicutes, whereas culture-independent techniques identified sequenced clones affiliated with members of the phyla Actinobacteria and Proteobacteria. The diversity of fungi was shown to be much lower than that observed for bacteria, and only species of Penicillium spp. could be detected by cultivation techniques. The selected strategy revealed a higher microbial diversity on the obverse than on the reverse side of the painting and the near absence of actively growing microorganisms on areas showing no visible damage. Furthermore, enzymatic activity tests revealed that the most widespread activities involved in biodeterioration were esterase and esterase lipase among the isolated bacterial strains, and esterase and N-acetyl-β-glucosaminidase among fungi strains. PMID:23576841

  9. L’impoverimento delle risorse storiche e culturali siciliane (Italia a causa di specie aliene di insetti: il caso del Punteruolo rosso delle palme

    Directory of Open Access Journals (Sweden)

    Barbara Manachini

    2012-12-01

    Full Text Available Stone cultural heritage materials are at risk of bio-deterioration caused by diverse populations of microorganisms living in biofilms. The microbial metabolites of these biofilms are responsible for the deterioration of the underlying substratum and may lead to physical weakening and discoloration of stone [1,18]. Fungal ability in producing pigments and organic acids have a crucial role in the discoloration and degradation of different types of stone in cultural heritage objects. Additionally, stone objects may support the communities of microorganisms that are active in the biodeterioration process. This investigation focuses on the mycological analyses of microbial biofilm from the Bhimkichak temple, in Malhar of Bilaspur District of Chhattisgarh state which is made of sandstone, and is heavily colonized by fungi. Eight fungal species on the sandstone were isolated. Aspergillus sp. was observed, a common species in the stone structure of this monument. The identified micro fungi cause discoloration as well as mechanical exfoliation of the building stone material which was analyzed through mechanical hyphae penetration and production of dark pigments and organic acids.

  10. Art collection preservation: gamma radiation application for decontaminating objects in the Instituto de Estudos Brasileiros from Universidade de Sao Paulo (USP), SP, Brazil

    International Nuclear Information System (INIS)

    The Instituto de Estudos Brasileiros (IEB) from the University of Sao Paulo received the charge from Sao Paulo's Federal Justice to take care of part of the collection from Banco Santos that was severely attacked by insects and micro-organisms (moulds) when stored in a warehouse that was flooded by intense rainfall. A chemical treatment to eliminate the biodeterioration agents was tried but it was not effective. As the heap has a large amount of Xylograph wood dye, printings and manuscripts from cordel literature an urgent way to treat was searched and after the study and previous experience on wood irradiation process it was decided to submit promptly the heap to gamma irradiation. After the treatment the art pieces were restored by IEB staff and now is being part of IEB collection and available for the scientific research community (author)

  11. Bacteria, fungi and arthropod pests collected on modern human mummies

    Directory of Open Access Journals (Sweden)

    F. Palla

    2011-08-01

    Full Text Available A survey of opportunistic biocenosis (macro and micro organisms associated with a rest of human mummy samples was carried out to characterise the biocenosis and to detect the potential of biodeteriogens. The rests of the human modern mummies come from a hypogeic site. Since mummies are relevant from a historic-artistic-scientific point of view, an aspect of this study was the identification and characterization of the biological systems related with biodeterioration of organic matter. In a first step, different sampling methods, according to the taxa, were applied. Technological procedures were combined in order to have an interdisciplinary approach to the conservation actions for testing future restoration protocols. Specimens were collected, identified and characterized by Microscopy (light, SEM, CLSM and molecular analyses (DNA extraction, in vitro target sequence amplification, sequencing, sequence analysis. The results highlight a rather complex biocenonsis consisting of fungi, cyanobacteria, several insects and other arthropods.

  12. Resistance of particleboard panels made of agricultural residues and bonded with synthetic resins or PVC plastic to wood-rotting fungi

    Directory of Open Access Journals (Sweden)

    Divino Eterno Teixeira

    2009-12-01

    Full Text Available This study aims to evaluate the resistance of three types of particleboard panel to biodeterioration, two of which bonded with synthetic resins and one bonded with PVC plastic. Composite panels were made using sugar cane straw particles as raw material which were bonded together with urea-formaldehyde (UF, tannin-formaldehyde (TANI and PVC plastic (PVC resins. Decay tests were performed following procedures outlined in the ASTM D2017-81/1994 standard, whereby sample specimens were subjected to attack by white rot fungus Trametes versicolor and brown rot fungus Gloeophyllum trabeum using pine (Pinus sp. and embaúba (Cecropia sp. as reference timber. Panels bonded with PVC resin were rated ‘resistant’ to attack by both fungi while those bonded with UF and TANI resins were rated ‘slightly resistant’ to their attack.

  13. [Mechanisms of microbial corrosion on petrous materials].

    Science.gov (United States)

    Gómez-Alarcón, G; de la Torre, M A

    1994-01-01

    Present studies related to stone weathering demonstrate that the biological activity of bacteria, algae, fungi and lichens play an important role in the biodegradative processes implied in stone building decay. In natural environments is not possible to separate the damage provoked by microorganisms from damage caused by physical and chemical agents. In vitro assays carried out with microbes isolated from weathered stones are required in order to understand the biological mechanisms involved in stone deterioration. We have demonstrated, by means of different techniques as commented in the text, that filamentous fungi contribute greatly to stone biodeterioration by using different mechanisms: (a) mechanical (hyphae growth and penetration in stony substrate); and (b) biochemical (organic acid excretion, cation release, chelation and deposition of organic salts, precipitation of neoformation salts and metals oxidation). PMID:7946114

  14. A review of microbiological studies. Pt. 1

    International Nuclear Information System (INIS)

    Safety assessment research programmes in the UK and other countries are considering the possible effect of microorganisms on waste and waste isolation materials in deep geological environments, including the degradation of organic wastes producing chelating/complexing agents capable of solubilising radionuclides making them more mobile; corrosion of steel and concrete isolation materials; alteration of groundwater chemistry; microbial gas generation and movement of radionuclides after sorption onto motile microorganisms. Early studies concentrated on reviewing the potential role of microorganisms in nuclear waste disposal, followed by an examination of relevant groundwater and sediment samples for microorganisms and microbial activity. A range of laboratory experiments have been devised to determine the biodegradation of organic wastes and the biodeterioration of waste isolation materials particularly steel, and have been supplemented with examination of relevant natural analogue sites. Such studies have shown that microorganisms will be most important in ILW and LLW repositories. (Author)

  15. Corrosion inhibition in the presence of microbial corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Videla, H.A. [Univ. of La Plata (Argentina). Dept. of Chemistry

    1996-12-01

    Microorganisms influence corrosion by changing the electrochemical conditions at the metal/solution interface. These changes may have different effects, ranging from the induction of localized corrosion to corrosion inhibition. The key to the alteration of conditions at a metal surface and hence, the enhancement or inhibition of corrosion is the formation of a biofilm. On a biologically conditioned metal surface microorganisms can induce corrosion inhibition in several ways: (a) by neutralizing the action of a corrosive substance already present in the medium; (b) by stabilizing a protective film on a metal surface or (c) by inducing a decrease in the medium aggressiveness. Seldomly mentioned in the literature, microbial inhibition of corrosion could be a potentially useful tool to counteract many of the biodeterioration cases encountered in practice.

  16. Biofilms affecting progression of mild steel corrosion by Gram positive Bacillus sp.

    Science.gov (United States)

    Lin, Johnson; Madida, Bafana B

    2015-10-01

    The biodeterioration of metals have detrimental effects on the environment with economic implications. The deterioration of metals is of great concern to industry. In this study, mild steel coupons which were immersed in a medium containing Gram-positive Bacillus spp. and different nutrient sources were compared with the control in sterile deionized water. The weight loss of the coupons in the presence of Bacillus spp. alone was lower than the control and was further reduced when additional carbon sources, especially fructose, were added. The level of metal corrosion was significantly increased in the presence of nitrate with or without bacteria. There was a significant strong correlation between the weight loss and biofilm level (r =  0.64; p level of metal corrosion under different environmental conditions, thereby, supporting the development of a preventive strategy against corrosion. PMID:25847372

  17. Epilithic and endolithic bacterial communities in limestone from a Maya archaeological site.

    Science.gov (United States)

    McNamara, Christopher J; Perry, Thomas D; Bearce, Kristen A; Hernandez-Duque, Guillermo; Mitchell, Ralph

    2006-01-01

    Biodeterioration of archaeological sites and historic buildings is a major concern for conservators, archaeologists, and scientists involved in preservation of the world's cultural heritage. The Maya archaeological sites in southern Mexico, some of the most important cultural artifacts in the Western Hemisphere, are constructed of limestone. High temperature and humidity have resulted in substantial microbial growth on stone surfaces at many of the sites. Despite the porous nature of limestone and the common occurrence of endolithic microorganisms in many habitats, little is known about the microbial flora living inside the stone. We found a large endolithic bacterial community in limestone from the interior of the Maya archaeological site Ek' Balam. Analysis of 16S rDNA clones demonstrated disparate communities (endolithic: >80% Actinobacteria, Acidobacteria, and Low GC Firmicutes; epilithic: >50% Proteobacteria). The presence of differing epilithic and endolithic bacterial communities may be a significant factor for conservation of stone cultural heritage materials and quantitative prediction of carbonate weathering. PMID:16391878

  18. Biotechnology/materials: The growing interface

    Science.gov (United States)

    Decker, Raymond F.

    1986-01-01

    The biotechnology/materials interaction dates back 3.5 billion years, yet today offers novel challenges for human creativity. The materials cycle practiced by microorganisms is compared to that recently practiced by humans. The processes of the biotechnology materials cycle are biogenesis, bioleaching, biofouling, biocorrosion, biodeterioration, and bioaccumulation. Each process is examined for mechanisms, scale of effect, and opportunity for creative human intervention or utilization. More than 50 of our metallic elements are bio-processed in nature. A like number of biogenic materials have been identified, with some at production rates of trillions of kg per annum (p.a.). Microorganisms can substitute for energy, capital, and labor. Over the eons, microorganisms have gained special attributes that now offer creative humans a new era of partnership in materials processing.

  19. Efficacy of Erythropleum suaveolens (potrodom and Distemonanthus benthamianus (bonsamdua Water Extractives on the Durability of Five Selected Ghanaian Less Used Timber Species

    Directory of Open Access Journals (Sweden)

    *A. Asamoah

    2013-06-01

    Full Text Available Conventional wood preservatives are not only toxic to target bio-deterioration organisms but also to man, other organisms and the environment. In an effort to find preservatives that are less or non- toxic to man, other organisms and the environment, efficacy of branch bark and heartwood water extracts (0.65g/ml of Erythropleum suaveolens (potrodom and Distemonanthus benthamianus (bonsamdua respectively were tested on five selected less used timer species (LUS: Sterculia oblonga (ohaa, Antiaris toxicaria (kyenkyen, Canarium schweinfurthii (bediwonua, Celtis zenkeri (esa-kokoo and Cola gigantea (watapuo following a modified EN 252. Regardless of extract retention in selected LUS, potrodom extract improved their durability more than that of bonsamdua. Improved durability of immersed and brushed selected LUS was ranked as follows: C. gigantea > C. zenkeri > S. oblonga > A. toxicaria > C. schweinfurthii. Though extracts showed reduced efficacy with time, indications were that they could be employed to control pests in low durability woods.

  20. Anti-Fungal Laser Treatment of Paper: A Model Study with a Laser Wavelength of 532 nm

    Science.gov (United States)

    Pilch, E.; Pentzien, S.; Mädebach, H.; Kautek, W.

    Biodeterioration of organic cultural heritage materials is a common problem. Particularly the removal of discoloration caused by fungal pigments is yet an unsolved problem in paper conservation. In the present study, cellulose (cotton and linters) and 16th century paper (rag), were incubated with several fungi types, such as Cladosporium, Epicoccum, Alternaria, Chaetomium, Aspergillus, Trichophyton, and Penicillium on agar for three weeks. Then they were immersed in 70% Ethanol for removal of hyphae and mycelia and deactivation of the remaining conidia. These specimens were laser-treated in a computer-controlled laser cleaning system with a high pulse energy diode pumped Q-switched Nd:YAG laser operating at 532 nm and a pulse duration of 8 ns. Colour differences were determined spectrophotometrically. Best cleaning results were observed with fungi such as Penicillium and Alternaria. Dry laser cleaning generally turned out to be superb over wet bleaching approaches.

  1. Inhibition of microorganisms involved in deterioration of an archaeological site by silver nanoparticles produced by a green synthesis method.

    Science.gov (United States)

    Carrillo-González, Rogelio; Martínez-Gómez, Miriam Araceli; González-Chávez, Ma Del Carmen A; Mendoza Hernández, José Carlos

    2016-09-15

    The Citadel, part of the pre-Hispanic city of Teotihuacan and listed as a World Heritage Site, harbors irreplaceable archaeological walls and murals. This city was abandoned by the 7th century and its potential deterioration represents a noteworthy loss of the world's cultural heritage. This research consisted of isolation and identification of bacteria and fungi contributing to this deterioration from walls of a pre-Hispanic city. In addition, silver nanoparticles (AgNP) produced, using a green synthesis method, were tested as potential inhibitors of microbes. AgNP of different sizes and concentrations were tested using in situ assays. Leaf aqueous extracts from two plants species (Foeniculum vulgare and Tecoma stans) and two extraction procedures were used in the NP synthesis. The potential of AgNP as preventive/corrective treatments to protect stucco materials from biodeterioration, as well as the microbial inhibition on three stone materials (stucco, basalt and calcite) was analyzed. Twenty-three bacterial species belonging to eight genera and fourteen fungal species belonging to seven genera were isolated from colored stains, patinas and biofilms produced on the surfaces of archaeological walls from the pre-Hispanic city, Teotihuacan. AgNP from F. vulgare were more effective for in vitro microbial growth inhibition than those from T. stans. Bacteria were less sensitive to AgNP than fungi; however, sensitivity mainly depended on the microbial strain and the plant extract used to prepare AgNP. The use of AgNP as a preventive or corrective treatment to decrease microbial colonization in three kinds of stone used in historical walls was successful. Calcite was more colonized by Alternaria alternata, but less by Pectobacterium carotovorum. This is the first study at different scales (in vitro and tests on different stone types) of inhibition of biodeterioration-causing microorganisms isolated from an archaeological site by green synthesized AgNP. PMID:27015961

  2. Mechanical and physical properties of Tipuana tipu Wood deteriorated by decaying fungi

    Directory of Open Access Journals (Sweden)

    Sergio Brazolin

    2014-06-01

    Full Text Available The tipuana was widely used in urban arborization. In general, inadequate management exposes the wood to the action of wood decaying fungi and insects, often associated with the fall of the trees. The aim of this study was to evaluate the physical and mechanical properties of sound and rotten tipuana wood from São Paulo City´s afforestation. Thirteen old trees with symptoms of wood deterioration were removed. From the basal region of the trunk were cut 1 m-length stem segments, to characterize the physical and mechanical properties of sound and decayed wood. The results indicated that through the radial wood density profile by X-ray densitometry were classified seven pattern of wood biodeterioration, named (EXS with accumulation of extractives and sound, (ZR with the reaction zone and sound, (NS normal and sound, (PBINC; PBINT incipient and intense white rot (PMINC; PMINT incipient and intense soft rot, with apparent densities of 0.94, 0.92, 0.82, 0.66, 0.41, 0.67 and 0.44 g.cm-3, respectively. The mechanical tests showed that wood classified as (ZR (EXS presented the highest values of strength and stiffness of 84 and 80 MPa and 6461 MPa and 5826, respectively; the (NS showed values of 62 and 4642 MPa, and the (PBINC (PMINTthe significant and lowest values of strength and stiffness, enhancing (PBINT with values of 5 and 571 MPa. The reduction of density, strength and stiffness of wood is related to the biodeterioration of wood cell walls of trees tipuana by decaying fungi.

  3. Resource potential of bamboo, challenges and future directions towards sustainable management and utilization in Ethiopia

    Directory of Open Access Journals (Sweden)

    Getachew Desalegn

    2014-08-01

    Full Text Available Aim of study: Bamboo, the fastest growing and high yielding perennial plant of the world has more than 1500 species and 1500 versatile socio-economic uses and ecological services. Ethiopia has two indigenous bamboo species namely Yushania alpina and Oxytenantheria abyssinica, covering about one million ha with a wide distribution. The objective of this paper is to highlight the potential of bamboo resources, challenges including biodeterioration damage, opportunities and future research directions towards its sustainable management and rational utilization.Area of study: Bamboo resources of EthiopiaMaterial and Methods: Reconnaissance survey was done to some parts of the bamboo growing potential areas in Ethiopia besides the literature review. Main results: The bamboo resource, despite its socio-economic and environmental benefits, currently, in most areas has been under high pressure due to land use changes, bamboo mass- flowering, poor processing with low value addition, and damage by biodeteriorating agents (termites, beetles and fungi. The preservative tests on Ethiopian bamboos revealed low natural durability and highlighted the paramount importance of appropriate protection measures such as Tanalith and vehicles used motor oil to increase durability, service life and rational utilization of bamboo-based products and structures as potential alternative construction and furniture material.Research highlights: Therefore, integrated research and development interventions involving different propagation and managements techniques, harvesting season, processing, value addition including proper seasoning and preservation technologies and marketing are recommended to fill the information and technological gaps on sustainable management and rational utilization of this fast growing and multipurpose bamboo resources in Ethiopia.Key words: Bamboo; challenges; management; socio-economic and environmental significance; utilization.

  4. Dureza Rockwell da madeira de três espécies amazônicas submetidas a ensaios de apodrecimento acelerado Rockwell hardness of the wood of three Amazon species submitted to decay accelerated tests

    Directory of Open Access Journals (Sweden)

    Diego Martins Stangerlin

    2013-04-01

    Full Text Available Objetivou-se avaliar o emprego de ensaios de dureza Rockwell na caracterização da biodeterioração das madeiras de Simarouba amara (marupá, Cariniana micrantha (jequitibá e Dipteryx odorata (cumaru, submetidas ao ataque dos fungos apodrecedores Trametes versicolor (podridão branca e Gloeophyllum trabeum (podridão parda. Para tanto, corpos de prova de cada espécie amazônica foram submetidos a ensaios de apodrecimento acelerado, de acordo com a ASTM D2017 (2005, durante 20 semanas. A caracterização da dureza Rockwell foi realizada semanalmente até a 4ª semana e, posteriormente, a cada duas semanas, até a 20ª semana. Adicionalmente, foram determinadas as perdas de massa, conforme critérios estabelecidos pela ASTM D2017 (2005. Quanto aos resultados, destaca-se que a dureza Rockwell pode ser empregada como ferramenta principal na caracterização da biodeterioração da madeira, sendo sensível na predição dos estágios iniciais. Dentre as madeiras amazônicas, o cumaru apresentou a maior resistência natural aos fungos apodrecedores. Com relação aos fungos, a podridão parda atacou mais intensamente as três madeiras amazônicas.This study aimed to evaluate the use of Rockwell hardness in the characterization of the biodeterioration of Simarouba amara (marupá, Cariniana micrantha (jequitibá e Dipteryx odorata (cumaru woods, which were submitted to decay fungi Trametes versicolor (white rot and Gloeophyllum trabeum (brown rot. For this purpose, specimens of each Amazon species were submitted to decay fungi, according to ASTM D2017 (2005. The characterization of the Rockwell hardness was performed weekly until the fourth week, and then every two weeks until the twentieth week. Additionally, it was determined the mass loss, according to criteria established by ASTM D2017 (2005. The results indicated that the Rockwell hardness can be used as a primary tool in the characterization of the biodeterioration of wood, being sensitive in

  5. Towards a more realistic picture of in situ biocide actions: Combining physiological and microscopy techniques

    Energy Technology Data Exchange (ETDEWEB)

    Speranza, M., E-mail: speranzamariela@gmail.com [Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 bis, 28006 Madrid (Spain); Wierzchos, J.; De Los Rios, A.; Perez-Ortega, S. [Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 bis, 28006 Madrid (Spain); Souza-Egipsy, V. [Instituto de Ciencias Agrarias, ICA-CSIC, Serrano 115 bis, 28006 Madrid (Spain); Ascaso, C., E-mail: ascaso@mncn.csic.es [Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 bis, 28006 Madrid (Spain)

    2012-11-15

    In this study, we combined chlorophyll a fluorescence (ChlaF) measurements, using pulse-amplitude-modulate (PAM) equipment, with scanning electron microscopy in backscattered electron mode (SEM-BSE) and transmission electron microscopy (TEM) images to evaluate the actions of Koretrel at lower concentrations on Verrucaria nigrescens colonising a dolostone. ChlaF measurements are good indicators of the damaging effects of biocides. However, these indicators only provide an incomplete view of the mechanism of biocides used to control biodeterioration agents. The death of the V. nigrescens photobiont at two biocide concentrations was revealed by PAM, SEM-BSE and TEM. Once Koretrel was applied, the Fv/Fm ratios markedly fell in the first few hours after the 1.5% treatment, and ratios for the 3% dilution remained close to zero throughout the study. The algal zone shows the plasmolysed appearance of the photobiont cells, and important aspects related to the action of the biocide on free and lichenised fungi were also detected using SEM-BSE. Many of the mycobiont cells had only their cell walls preserved; although, some fungal hyphae in lichen thalli and some microorganisms in endolithic clusters maintained lipid storage in their cytoplasm. These results indicated that the combination of physiological and microscopy techniques improves the assessment of biocide action in situ and this will help to optimize protocols in order to reduce the emission of these compounds to the environment. -- Highlights: Black-Right-Pointing-Pointer We combined ChlaF measurements with EM images to analyses the biocides action on stone biodeterioration agents. Black-Right-Pointing-Pointer At lower biocide concentrations damage to photobiont and mycobiont cells integrity, ultrastructure and vitality were observed. Black-Right-Pointing-Pointer The limited action of biocides on fungi and algae were detected using SEM-BSE. Black-Right-Pointing-Pointer The combination of physiological and microscopy

  6. Life in extreme environments: survival strategy of the endolithic desert lichen Verrucaria rubrocincta

    Science.gov (United States)

    Garvie, Laurence A. J.; Knauth, L. Paul; Bungartz, Frank; Klonowski, Stan; Nash, Thomas H.

    2008-08-01

    Verrucaria rubrocincta Breuss is an endolithic lichen that inhabits caliche plates exposed on the surface of the Sonoran Desert. Caliche surface temperatures are regularly in excess of 60°C during the summer and approach 0°C in the winter. Incident light intensities are high, with photosynthetically active radiation levels typically to 2,600 μmol/m2 s-1 during the summer. A cross-section of rock inhabited by V. rubrocincta shows an anatomical zonation comprising an upper micrite layer, a photobiont layer containing clusters of algal cells, and a pseudomedulla embedded in the caliche. Hyphae of the pseudomedulla become less numerous with depth below the rock surface. Stable carbon and oxygen isotopic data for the caliche and micrite fall into two sloping, well-separated arrays on a δ13C δ18O plot. The δ13CPDB of the micrite ranges from 2.1 to 8.1 and δ18OSMOW from 25.4 to 28.9, whereas δ13CPDB of the caliche ranges from -4.7 to 0.7 and δ18OSMOW from 23.7 to 29.2. The isotopic data of the micrite can be explained by preferential fixing of 12C into the alga, leaving local 13C enrichment and evaporative enrichment of 18O in the water. The 14C dates of the micrite range from recent to 884 years b.p., indicating that “dead” carbon from the caliche is not a significant source for the lichen-precipitated micrite. The endolithic growth is an adaptation to the environmental extremes of exposed rock surfaces in the hot desert. The micrite layer is highly reflective and reduces light intensity to the algae below and acts as an efficient sunscreen that blocks harmful UV radiation. The micrite also acts as a cap to the lichen and helps trap moisture. The lichen survives by the combined effects of biodeterioration and biomineralization. Biodeterioration of the caliche concomitant with biomineralization of a protective surface coating of micrite results in the distinctive anatomy of V. rubrocincta.

  7. Microbial deterioration of artistic tiles from the façade of the Grande Albergo Ausonia & Hungaria (Venice, Italy).

    Science.gov (United States)

    Giacomucci, Lucia; Bertoncello, Renzo; Salvadori, Ornella; Martini, Ilaria; Favaro, Monica; Villa, Federica; Sorlini, Claudia; Cappitelli, Francesca

    2011-08-01

    The Grande Albergo Ausonia & Hungaria (Venice Lido, Italy) has an Art Nouveau polychrome ceramic coating on its façade, which was restored in 2007. Soon after the conservation treatment, many tiles of the façade decoration showed coloured alterations putatively attributed to the presence of microbial communities. To confirm the presence of the biological deposit and the stratigraphy of the Hungaria tiles, stereomicroscope, optical and environmental scanning electron microscope observations were made. The characterisation of the microbial community was performed using a PCR-DGGE approach. This study reported the first use of a culture-independent approach to identify the total community present in biodeteriorated artistic tiles. The case study examined here reveals that the coloured alterations on the tiles were mainly due to the presence of cryptoendolithic cyanobacteria. In addition, we proved that the microflora present on the tiles was generally greatly influenced by the environment of the Hungaria hotel. We found several microorganisms related to the alkaline environment, which is in the range of the tile pH, and related to the aquatic environment, the presence of the acrylic resin Paraloid B72® used during the 2007 treatment and the pollutants of the Venice lagoon. PMID:21286701

  8. Effect of Plectranthus glandulosus and Ocimum gratissimum Essential Oils on Growth of Aspergillus flavus and Aflatoxin B1 Production

    Directory of Open Access Journals (Sweden)

    Mbofung, CMF.

    2008-01-01

    Full Text Available Essential oils of Ocimum gratissimum and Plectranthus glandulosus leaves were extracted by steam distillation and analysed by GC-MS, and their effects on growth and aflatoxin B1 production by Aspergillus flavus were tested at five levels (i.e 200, 400, 600, 800 and 1000 mg/l using SMKY agar medium. The main components of O. gratissimum were thymol (47.7% and -terpinene (14.3% whereas those of P. glandulosus were represented by -terpinene (30.8% and terpinolene (25.2%. After 8 days of incubation on essential oil-supplemented medium, growth of A. flavus was totally inhibited by 800 mg/l of O. gratissimum essential oil and by 1000 mg/l of P. glandulosus essential oil. The effect of essential oils on aflatoxin B1 synthesis was evaluated in SMKY broth. The medium supplemented with different essential oil concentrations, was inoculated with A. flavus mycelium and incubated at 25 °C. At 2, 4, 6 and 8 days, aflatoxin B1 concentrations in the supernatant were estimated using Enzyme Linked Immuno-Sorbent Assay (ELISA. Results showed that aflatoxin B1 synthesis was inhibited by 1000 mg/l of both essential oils of O. gratissimum and P. glandulosus after 8 days of incubation. Results obtained in the present study indicate the possibility of exploiting O. gratissimum and P. glandulosus essential oils in the fight against strains of A. flavus responsible for biodeterioration of stored food products.

  9. Efficacy of corn and rice seed-borne mycoflora in controlling aflatoxigenic Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Adel K. Madbouly

    2014-02-01

    Full Text Available Food commodities such as cereals are subjected to spoilage and bio-deterioration during storage by mycotoxigenic fungi such as Aspergillus flavus. Efforts are done to biologically control toxigenic A. flavus and subsequently prevent or at least minimize its aflatoxin production ability, without the need of using synthetic fungicides. Antifungal activity of corn and rice seed-borne mycoflora was tested against aflatoxigenic A. flavus in vitro, using bioassays such as dual culture technique; ability to produce volatile and non-volatile metabolites; ability to inhibit germination and reduce germ tube length of A. flavus conidia; in vivo reduction of aflatoxins level in corn seeds co-inoculated with the pathogen and antagonists. Penicillum crustosum, Aspergillus giganteus, Fusarium verticillioides and Aspergillus fumigatus isolates showed promising antifungal activities and varying efficiencies of reducing aflatoxins level; however, only A. fumigatus isolate was non-aflatoxigenic. It could be concluded that A. fumigatus could be used effectively as a biopreservative to increase shelf life of cereals during storage, but after testing its tendency to produce other mycotoxins or causing human Aspergillosis.

  10. Microbial deterioration of artistic tiles from the façade of the Grande Albergo Ausonia & Hungaria (Venice, Italy).

    Science.gov (United States)

    Giacomucci, Lucia; Bertoncello, Renzo; Salvadori, Ornella; Martini, Ilaria; Favaro, Monica; Villa, Federica; Sorlini, Claudia; Cappitelli, Francesca

    2011-08-01

    The Grande Albergo Ausonia & Hungaria (Venice Lido, Italy) has an Art Nouveau polychrome ceramic coating on its façade, which was restored in 2007. Soon after the conservation treatment, many tiles of the façade decoration showed coloured alterations putatively attributed to the presence of microbial communities. To confirm the presence of the biological deposit and the stratigraphy of the Hungaria tiles, stereomicroscope, optical and environmental scanning electron microscope observations were made. The characterisation of the microbial community was performed using a PCR-DGGE approach. This study reported the first use of a culture-independent approach to identify the total community present in biodeteriorated artistic tiles. The case study examined here reveals that the coloured alterations on the tiles were mainly due to the presence of cryptoendolithic cyanobacteria. In addition, we proved that the microflora present on the tiles was generally greatly influenced by the environment of the Hungaria hotel. We found several microorganisms related to the alkaline environment, which is in the range of the tile pH, and related to the aquatic environment, the presence of the acrylic resin Paraloid B72® used during the 2007 treatment and the pollutants of the Venice lagoon.

  11. Application of molecular techniques for the assessment of microorganism diversity on cultural heritage objects.

    Science.gov (United States)

    Otlewska, Anna; Adamiak, Justyna; Gutarowska, Beata

    2014-01-01

    As a result of their unpredictable ability to adapt to varying environmental conditions, microorganisms inhabit different types of biological niches on Earth. Owing to the key role of microorganisms in many biogeochemical processes, trends in modern microbiology emphasize the need to know and understand the structure and function of complex microbial communities. This is particularly important if the strategy relates to microbial communities that cause biodeterioration of materials that constitute our cultural heritage. Until recently, the detection and identification of microorganisms inhabiting objects of cultural value was based only on cultivation-dependent methods. In spite of many advantages, these methods provide limited information because they identify only viable organisms capable of growth under standard laboratory conditions. However, in order to carry out proper conservation and renovation, it is necessary to know the complete composition of microbial communities and their activity. This paper presents and characterizes modern techniques such as genetic fingerprinting and clone library construction for the assessment of microbial diversity based on molecular biology. Molecular methods represent a favourable alternative to culture-dependent methods and make it possible to assess the biodiversity of microorganisms inhabiting technical materials and cultural heritage objects.

  12. Photoinhibition of cyanobacteria and its application in cultural heritage conservation.

    Science.gov (United States)

    Hsieh, Paul; Pedersen, Jens Z; Bruno, Laura

    2014-01-01

    Light has bilateral effects on phototrophic organisms. As cyanobacteria in Roman hypogea are long acclimatized to dim environment, moderate intensity of illumination can be used to alleviate biodeterioration problems on the stone substrata. Moderate intensity of light inactivates cyanobacteria by causing photoinhibition, photobleaching and photodamage to the cells. The effectiveness of light depends not only on its intensity but also on the composition and pigmentation of the component cyanobacteria in the biofilms. Red light is the most effective for the species rich in phycocyanin and allophycocyanin, such as Leptolyngbya sp. and Scytonema julianum, whereas green light is effective to inhibit the species rich in phycoerythrin, like Oculatella subterranea. White light is effective to control the grayish and the black cyanobacteria, such as Symphyonemopsis sp. and Eucapsis sp. abundant in all of these pigments. Blue light is the least effective. 150 μmol photons m(-2)  s(-1) of blue light cannot cause biofilm damage while the same intensity of red, green or white irradiation for 14 days can severely damage the cyanobacterial cells in the biofilms due to ROS formation. Electron spin resonance spectroscopy detected the formation of radicals in different cyanobacterial cellular extracts exposed to 80 μmol photons m(-2)  s(-1) of light.

  13. Synthesis and analytical characterisation of copper-based nanocoatings for bioactive stone artworks treatment.

    Science.gov (United States)

    Ditaranto, Nicoletta; Loperfido, Sabrina; van der Werf, Inez; Mangone, Annarosa; Cioffi, Nicola; Sabbatini, Luigia

    2011-01-01

    Biological agents play an important role in the deterioration of cultural heritage causing aesthetic, biogeophysical and biogeochemical damages. Conservation is based on the use of preventive and remedial methods. The former aims at inhibiting biological attack, and the latter aims at eradicating the biological agents responsible for biodeterioration. Here, we propose the preparation and the analytical characterisation of copper-based nanocoating, capable of acting both as a remedy and to prevent microbial proliferation. Core-shell CuNPs are mixed with a silicon-based product, commonly used as a water-repellent/consolidant, to obtain a combined bioactive system to be applied on stone substrates. The resulting coatings exert a marked biological activity over a long period of time due to the continuous and controlled release of copper ions acting as biocides. To the best of our knowledge, this is the first time that a multifunctional material is proposed, combining the antimicrobial properties of nanostructured coatings with those of the formulations applied to the restoration of stone artworks. A complete characterisation based on a multi-technique analytical approach is presented. PMID:20972773

  14. Metabolic activity of moulds as a factor of building materials biodegradation.

    Science.gov (United States)

    Gutarowska, Beata

    2010-01-01

    This paper presents the effect of building materials on the growth and metabolic activity of moulds. In cultures of Aspergillus and Penicillium moulds grown on a model medium with the addition of building materials, the biomass of mycelium, its cellular components--glucan, chitin, ergosterol and the spectrum of enzymes and organic acids produced in the medium were investigated. It was found that on the medium with wallpaper moulds produced more biomass and extracellular enzymes, mainly glycolytic ones. On medium with mortar the growth of mycelium was impeded, production of biomass was 60% smaller, the quantity of chitin, glucan and ergosterol decreased 13-41%, and the activity of most enzymes was reduced; however the moulds intensively produced organic acids: malic, succinic and oxalic acid. The largest acid production activity was found in medium with addition of mortar; moulds produced the greatest variety of acids and in greater quantities than in the control medium. Metabolic activity of the moulds depends on the type of building material, and may lead to biodeterioration of these materials.

  15. Characterization of three antifungal calcite-forming bacteria, Arthrobacter nicotianae KNUC2100, Bacillus thuringiensis KNUC2103, and Stenotrophomonas maltophilia KNUC2106, derived from the Korean islands, Dokdo and their application on mortar.

    Science.gov (United States)

    Park, Jong-Myong; Park, Sung-Jin; Ghim, Sa-Youl

    2013-09-28

    Crack remediation on the surface of cement mortar using microbiological calcium carbonate (CaCO3) precipitation (MICP) has been investigated as a microbial sealing agent on construction materials. However, MICP research has never acknowledged the antifungal properties of calcite-forming bacteria (CFB). Since fungal colonization on concrete surfaces can trigger biodeterioration processes, fungi on concrete buildings have to be prevented. Therefore, to develop a microbial sealing agent that has antifungal properties to remediate cement cracks without deteriorative fungal colonization, we introduced an antifungal CFB isolated from oceanic islands (Dokdo islands, territory of South Korea, located at the edge of the East Sea in Korea.). The isolation of CFB was done using B4 or urea-CaCl2 media. Furthermore, antifungal assays were done using the pairing culture and disk diffusion methods. Five isolated CFB showed CaCO3 precipitation and antifungal activities against deteriorative fungal strains. Subsequently, five candidate bacteria were identified using 16S rDNA sequence analysis. Crack remediation, fungi growth inhibition, and water permeability reduction of antifungal CFB-treated cement surfaces were tested. All antifungal CFB showed crack remediation abilities, but only three strains (KNUC2100, 2103, and 2106) reduced the water permeability. Furthermore, these three strains showed fungi growth inhibition. This paper is the first application research of CFB that have antifungal activity, for an eco-friendly improvement of construction materials.

  16. Fungi from a Groundwater-Fed Drinking Water Supply System in Brazil.

    Science.gov (United States)

    Oliveira, Helena M B; Santos, Cledir; Paterson, R Russell M; Gusmão, Norma B; Lima, Nelson

    2016-03-09

    Filamentous fungi in drinking water distribution systems are known to (a) block water pipes; (b) cause organoleptic biodeterioration; (c) act as pathogens or allergens and (d) cause mycotoxin contamination. Yeasts might also cause problems. This study describes the occurrence of several fungal species in a water distribution system supplied by groundwater in Recife-Pernambuco, Brazil. Water samples were collected from four sampling sites from which fungi were recovered by membrane filtration. The numbers in all sampling sites ranged from 5 to 207 colony forming units (CFU)/100 mL with a mean value of 53 CFU/100 mL. In total, 859 isolates were identified morphologically, with Aspergillus and Penicillium the most representative genera (37% and 25% respectively), followed by Trichoderma and Fusarium (9% each), Curvularia (5%) and finally the species Pestalotiopsis karstenii (2%). Ramichloridium and Leptodontium were isolated and are black yeasts, a group that include emergent pathogens. The drinking water system in Recife may play a role in fungal dissemination, including opportunistic pathogens.

  17. Gamma radiation effects on physical properties of parchment documents: Assessment of Dmax

    International Nuclear Information System (INIS)

    Parchments are important documents that give testimony for History; therefore these materials should be respected and preserved. Considering incremental biodeterioration problems that have to be faced daily, the Archive of the University of Coimbra (AUC) is involved in different scientific projects in order to evaluate and determine new methods for document decontamination and preservation. The aim of this study was to evaluate gamma radiation effects on the colour and texture of the AUC parchment documents. The assessment of these effects was used to estimate the maximum gamma radiation dose (Dmax) that could guarantee parchment documents′ decontamination treatment, without significant alteration of their physical properties. Parchment samples were exposed to gamma radiation doses ranging from 10 to 30 kGy. The texture and colour of samples were assessed before and after the irradiation procedure, using a texture analyser and an electronic colorimeter. Hardness and springiness were determined based on texture spectra. Lightness (L⁎), Chroma (C), greenness vs. redness (a*) and yellowness vs. blueness (b*) values were obtained from colorimetric measures. Results indicate no significant effects of gamma radiation on the texture and colour of parchment for the studied doses. - Highlights: ► Study on the effects of gamma radiation in parchment physical properties. ► Evaluation of the uniformity of parchment samples′ physical parameters. ► Proposal of a maximum gamma radiation dose for parchment decontamination treatment.

  18. The effect of spaceflight on growth of Ulocladium chartarum colonies on the international space station.

    Science.gov (United States)

    Gomoiu, Ioana; Chatzitheodoridis, Elias; Vadrucci, Sonia; Walther, Isabelle

    2013-01-01

    The objectives of this 14 days experiment were to investigate the effect of spaceflight on the growth of Ulocladium chartarum, to study the viability of the aerial and submerged mycelium and to put in evidence changes at the cellular level. U. chartarum was chosen for the spaceflight experiment because it is well known to be involved in biodeterioration of organic and inorganic substrates covered with organic deposits and expected to be a possible contaminant in Spaceships. Colonies grown on the International Space Station (ISS) and on Earth were analysed post-flight. This study clearly indicates that U. chartarum is able to grow under spaceflight conditions developing, as a response, a complex colony morphotype never mentioned previously. We observed that spaceflight reduced the rate of growth of aerial mycelium, but stimulated the growth of submerged mycelium and of new microcolonies. In Spaceships and Space Stations U. chartarum and other fungal species could find a favourable environment to grow invasively unnoticed in the depth of surfaces containing very small amount of substrate, posing a risk factor for biodegradation of structural components, as well as a direct threat for crew health. The colony growth cycle of U. chartarum provides a useful eukaryotic system for the study of fungal growth under spaceflight conditions. PMID:23637980

  19. Dust particulate absorption by ivy (Hedera helix L) on historic walls in urban environments

    Energy Technology Data Exchange (ETDEWEB)

    Sternberg, Troy, E-mail: troy.sternberg@geog.ox.ac.uk [School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY UK (United Kingdom); Viles, Heather, E-mail: heather.viles@ouce.ox.ac.uk [School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY UK (United Kingdom); Cathersides, Alan, E-mail: alan.cathersides@english-heritage.org.uk [Conservation Department, English Heritage, Kemble Drive, Swindon, SN2 2GZ UK (United Kingdom); Edwards, Mona, E-mail: mona.edwards@ouce.ox.ac.uk [School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY UK (United Kingdom)

    2010-12-01

    The potential bio-protective role of urban greenery and how it interacts with airborne dust and pollutants has been the subject of much recent research. As particulate pollution has been implicated in both the deterioration of building materials and in damaging human health, understanding how it interacts with urban greenery is of great applied interest. Common or English Ivy (Hedera helix L) grows widely on urban walls in many parts of the world, and thus any bio-protective role it might play is of broad relevance. Using Scanning Electron Microscopy ivy leaves collected on roadways were examined to determine if ivy can absorb dust and pollutants that can instigate decay processes on stone walls and impact human health in urban environments. Results showed that ivy acts as a 'particle sink', absorbing particulate matter, particularly in high-traffic areas. It was effective in adhering fine (< 2.5 {mu}m) and ultra-fine (< 1 {mu}m) particles at densities of up to 2.9 x 10{sup 10} per m{sup 2}. Our findings suggest that through absorbing pollutant particles ivy can retard bio-deteriorative processes on historic walls and reduce human exposure to respiratory problems caused by vehicle pollutants.

  20. The effect of spaceflight on growth of Ulocladium chartarum colonies on the international space station.

    Science.gov (United States)

    Gomoiu, Ioana; Chatzitheodoridis, Elias; Vadrucci, Sonia; Walther, Isabelle

    2013-01-01

    The objectives of this 14 days experiment were to investigate the effect of spaceflight on the growth of Ulocladium chartarum, to study the viability of the aerial and submerged mycelium and to put in evidence changes at the cellular level. U. chartarum was chosen for the spaceflight experiment because it is well known to be involved in biodeterioration of organic and inorganic substrates covered with organic deposits and expected to be a possible contaminant in Spaceships. Colonies grown on the International Space Station (ISS) and on Earth were analysed post-flight. This study clearly indicates that U. chartarum is able to grow under spaceflight conditions developing, as a response, a complex colony morphotype never mentioned previously. We observed that spaceflight reduced the rate of growth of aerial mycelium, but stimulated the growth of submerged mycelium and of new microcolonies. In Spaceships and Space Stations U. chartarum and other fungal species could find a favourable environment to grow invasively unnoticed in the depth of surfaces containing very small amount of substrate, posing a risk factor for biodegradation of structural components, as well as a direct threat for crew health. The colony growth cycle of U. chartarum provides a useful eukaryotic system for the study of fungal growth under spaceflight conditions.

  1. The effect of spaceflight on growth of Ulocladium chartarum colonies on the international space station.

    Directory of Open Access Journals (Sweden)

    Ioana Gomoiu

    Full Text Available The objectives of this 14 days experiment were to investigate the effect of spaceflight on the growth of Ulocladium chartarum, to study the viability of the aerial and submerged mycelium and to put in evidence changes at the cellular level. U. chartarum was chosen for the spaceflight experiment because it is well known to be involved in biodeterioration of organic and inorganic substrates covered with organic deposits and expected to be a possible contaminant in Spaceships. Colonies grown on the International Space Station (ISS and on Earth were analysed post-flight. This study clearly indicates that U. chartarum is able to grow under spaceflight conditions developing, as a response, a complex colony morphotype never mentioned previously. We observed that spaceflight reduced the rate of growth of aerial mycelium, but stimulated the growth of submerged mycelium and of new microcolonies. In Spaceships and Space Stations U. chartarum and other fungal species could find a favourable environment to grow invasively unnoticed in the depth of surfaces containing very small amount of substrate, posing a risk factor for biodegradation of structural components, as well as a direct threat for crew health. The colony growth cycle of U. chartarum provides a useful eukaryotic system for the study of fungal growth under spaceflight conditions.

  2. Fungi from a Groundwater-Fed Drinking Water Supply System in Brazil

    Science.gov (United States)

    Oliveira, Helena M.B.; Santos, Cledir; Paterson, R. Russell M.; Gusmão, Norma B.; Lima, Nelson

    2016-01-01

    Filamentous fungi in drinking water distribution systems are known to (a) block water pipes; (b) cause organoleptic biodeterioration; (c) act as pathogens or allergens and (d) cause mycotoxin contamination. Yeasts might also cause problems. This study describes the occurrence of several fungal species in a water distribution system supplied by groundwater in Recife—Pernambuco, Brazil. Water samples were collected from four sampling sites from which fungi were recovered by membrane filtration. The numbers in all sampling sites ranged from 5 to 207 colony forming units (CFU)/100 mL with a mean value of 53 CFU/100 mL. In total, 859 isolates were identified morphologically, with Aspergillus and Penicillium the most representative genera (37% and 25% respectively), followed by Trichoderma and Fusarium (9% each), Curvularia (5%) and finally the species Pestalotiopsis karstenii (2%). Ramichloridium and Leptodontium were isolated and are black yeasts, a group that include emergent pathogens. The drinking water system in Recife may play a role in fungal dissemination, including opportunistic pathogens. PMID:27005653

  3. The application of bioactive compounds from the food industry to control mold growth in indoor waterborne coatings.

    Science.gov (United States)

    Bellotti, N; Salvatore, L; Deyá, C; Del Panno, M T; del Amo, B; Romagnoli, R

    2013-04-01

    Microbial growth in indoor environments creates health problems, especially in people with asthma; approximately 80% of these patients are allergic to mold. Antimicrobial coatings are formulated to generate surfaces that are easy to clean and may also incorporate active agents, commonly called biocides, which inhibit microbial colonization, subsequent growth and bio-deterioration of the substrates. Some research lines seek to replace traditional organometallic and organochlorines biocides with environmentally acceptable ones. The aim of this research was, primarily, to explore the possible application of different compounds used in food industry like preservatives to be used as antimicrobial additives for antimicrobial coatings. Four biocides were tested against two different ambient molds isolated from an interior painted wall (Chaetomium globosum and Alternaria alternate). The selected biocides were zinc salicylate, zinc benzoate, calcium benzoate and potassium sorbate. The resulting paints were subjected to biological and physical tests (viscosity, hiding power, humidity absorption and biocides leaching rate). Bioassays revealed that zinc benzoate and zinc salicylate resulted active against both fungi. PMID:23298599

  4. Investigations of the populations of introduced and resident micro-organisms in deep repositories and their effects on containment of radioactive wastes

    International Nuclear Information System (INIS)

    The potential role of microbes in the containment of radioactive waste has been described in several papers but can be briefly summarised as: (1) near field effects ((a) biodeterioration of repository structural materials; (b) mobilisation of waste); (2) far field effects ((a) change in ground water chemistry eg pH, Eh; (b) changes in radionuclide sorption characteristics (speciation, retardation)). The present study has sought to establish the presence of microbes in relevant formations, determine their potential role in disposal and make preliminary investigations on their ability to tolerate extreme environmental conditions and change migration characteristics. As the ultimate goal of this work is to try and model the effect of microorganisms on containment and radionuclide migration, an attempt to define the geochemical constraints on their growth has been attempted within the present study. Several sites of relevance to radioactive waste disposal have been sampled for microbiological content according to a protocol defined in pilot studies. These sites have been in Britain and in mainland Europe. Results have shown that the microbiota of each site is unique but that certain groups are of more importance eg sulphate reducing bacteria, sulphur oxidisers, and that their presence in future sampling should be ascertained as a first priority. (author)

  5. Protection of Historical Wood against Microbial Degradation—Selection and Application of Microbiocides

    Directory of Open Access Journals (Sweden)

    Anna Koziróg

    2016-08-01

    Full Text Available The aim of this study was to select effective and safe microbiocides for the disinfection and protection of historical wooden surfaces at the former Auschwitz II-Birkenau concentration and extermination camp. We tested seven active compounds against bacteria and moulds, of which didecyldimethylammonium chloride and N-(3-aminopropyl-N-dodecylpropane-1,3-diamine were effective even at 0.02%–2%. Subsequently, eight microbiocides containing the selected active ingredients were chosen and applied three times on the surface of wood samples colonized by bacteria and moulds. ABM-1 and ABM-2—6% solution; Rocima 101—8%; Preventol R 80—12%; Acticide 706 LV—15% and Boramon—30% were the most effective disinfectants. Under laboratory conditions, ABM-1, Boramon and Rocima 101 ensured antimicrobial protection of new wood samples for six months. In situ, 30% Boramon and 8% Rocima 101 applied by spraying effectively protected the historical wood from bacterial and mould growth for 12 and 3 months, respectively. Colour and luminance of the new wood were not altered after exposure to the biocides. Boramon and Rocima 101, applied by the spraying method, caused no significant change in the colour of the historical wood. Results from this study were used to develop a procedure for the protection of wood in historical buildings against biodeterioration.

  6. Impact of fixation/drying conditions on fixation rate, leachability and bioefficacy in CCA-C treated red pine and southern pine

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Red pine (Pinus resinosia Ait) and southern pine (Pinus spp.) sapwood blocks were pressure treated with CCA-C at retention of 6.4, 2.0, 1.5 kg?m-3 followed by fixation using 11 post-treatment schedules ranging from 50-70 °C and 5 different relative humidity conditions. The effect of these post-treatment schedules on fixation rate, chemical leachability and decay resistant once were evaluated to better understand the effects of fixation/drying conditions on leachability and biodeterioration. Southern pine blocks fixes slightly slower than red pine. Fixation of CCA at high temperature high humidity, essential initially fixation at high humidity for fixation/drying schedules, resulted in lower leaching of chromium and arsenic elements than high temperature low humidity or initially fixation at the high temperature low humidity conditions. Copper leaching was indicated no significant difference under 11 fixation/drying conditions for both species. Weight losses for southern pine by Chaetomium globosum was lower than red pine by Gloeophyllom trabeum. There were some different capacities of decay resistance for both species under those post treatment conditions.

  7. Studies On Marine Wood-Borers Of Kali Estuary, Karwar, Karnataka, India

    Science.gov (United States)

    Sanagoudra, S. N.; Neelakanton, K. B.

    2008-05-01

    The damage caused to underwater timber construction in Marine environment by Molluscan and Crustaceans borers is well known and is of great economic significance to all maritime countries having an expanding shipping and fishing industry. Biodeterioration of marine structure, fishing crafts and living in mangrove vegetation is quite severe along the Karwar coast. The destruction is caused by atleast 14 species and 1 variety of borers belonging to the moluscan and crustacean families of the Teredinidae, Pholadidae and Sphaeromatidae. The following species have been so far recorded: Dicyathifer manni, Lyrodus pedicellaatus, L.Massa, Bankia rochi, B. campanellata, Mausitora hedleyi,Martesia striata, M.NMairi,Sphaeroma terebrans, S.annandalei, S. annandalei travancorensis. These borers, particularly, the molluscs have prodigenous fecundity producing enormous number of young ones in one brood. They have unlimited appetite attacking any type woodly materials exposed in the sea. They attack in heavy intensity and, because of their fast rate of growth, destroy timber with in a short time of few months. All this together with their other highly specialized. Adaptations make marine wood borers man's number one enemy in the sea. Along Karwar costs borer damage to timber structure is heavy throughout the year, highest in September to November and lowest in June and July. Ecological and biological aspects of the borers are also discussed. Ref: L.N.Shantakumaran, Sawant S.G., Nair N.B., Anil Angre, Nagabhushanan R. STUDIES ON MARINE WOOD-BORERS OF KALI ESTUARY, KARWAR, KARNATAKA, INDIA

  8. à base de água por fungos

    Directory of Open Access Journals (Sweden)

    Erna Elisabeth Bach

    2005-01-01

    Full Text Available The aqueous inks are subjected to microbiological contaminations that happen in humid or dry state and provoke biodeterioration. Some species of fungi grow and colonize the surface promoting a darkened color and destroying the film of the ink. Biocides are products incorporated to the ink, whose function is to protect the film both in the humid and in the dry state, aiming the inhibition of the growth of fungi, guaranteeing a larger durability of the painting. The constant emergence of fungi in walls of the recently painted residences became the objective of research of the present work. During the tests, fungi from contaminated walls of recently painted (eight months residences were isolated and then inoculated in plates containing water-agar (WA culture medium as control and other plates containing biocides or inks with biocides. The results showed that some isolates presented a little development in polyvinyl acrylic (PVA latex-based inks containing biocides while others presented an increase in the development of colonies correlated with greater sporulation. Thus, it can be concluded that the concentration of biocides in the inks was insufficient or presented an inefficiency of the germicidal agents (bactericidal and fungicide, demonstrating that the fungi acquired resistance to the biocides.

  9. Biofouling Prevention of Ancient Brick Surfaces by TiO2-Based Nano-Coatings

    Directory of Open Access Journals (Sweden)

    Lorenzo Graziani

    2015-07-01

    Full Text Available Brick constitutes a significant part of the construction materials used in historic buildings around the world. This material was used in Architectural Heritage for structural scope, and even for building envelopes. Thus, components made of clay brick were subjected to weathering for a long time, and this causes their deterioration. One of the most important causes for deterioration is biodeterioration caused by algae and cyanobacteria. It compromises the aesthetical properties, and, at a later stage, the integrity of the elements. In fact, traditional products used for the remediation/prevention of biofouling do not ensure long-term protection, and they need re-application over time. The use of nanotechnology, especially the use of photocatalytic products for the prevention of organic contamination of building façades is increasing. In this study, TiO2-based photocatalytic nano-coatings were applied to ancient brick, and its efficiency towards biofouling was studied. A composed suspension of algae and cyanobacteria was sprinkled on the bricks’ surface for a duration of twelve weeks. Digital Image Analysis and colorimetric measurements were carried out to evaluate algal growth on specimens’ surfaces. Results show that photocatalytic nano-coating was able to inhibit biofouling on bricks’ surfaces. In addition, substrata (their porosity and roughness clearly influences the adhesion of algal cells.

  10. Contribution to the study of metallic materials bio-corrosion phenomena; Contribution a l'etude des phenomenes de biocorrosion des materiaux metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Feron, D

    2004-05-01

    After having recalled the main electrochemical methods used for the study of metallic materials bio-deterioration phenomena, the corrosion of non or low alloy steels in anaerobic conditions is dealt with: the obtained results reveal a strong interaction between the metallic ions and the growth of sulfato reducing bacteria with inhibiting or accelerating ions of this growth. Concerning the corrosion, the chromium and molybdenum additions have a favourable effect on the resistance of low alloy steels. The sulfides impose the electrochemical behaviour of these materials, whereas the role of hydrogenases on the cathodic reaction is still to be specified to explain the observed localized corrosion, including the pure cultures of sulfato-reducing bacteria. The behaviour of stainless steels in seawater can be explained by an enzymatic catalysis of the cathodic reaction. Such a model takes into account the general behaviour of passivable alloys in natural waters in a general way and has allowed to perfect a synthetic seawater which leads to corrosion phenomena by crevice effect on stainless steels similar to those observed in natural seawater. The coupling of the aerobic conditions with the leading part of the enzymes on the cathodic reaction and of the anaerobic conditions with the presence of sulfides (which decrease the resistance of the passive layer) is the most unfavourable situation for the resistance of passivable alloys. These results lead to the concept of electrochemically activated bio-films which could be used in particular in energy production (fuel cells). (O.M.)

  11. Kinetics of strength gain of biocidal cements

    Directory of Open Access Journals (Sweden)

    Rodin Aleksandr Ivanovich

    Full Text Available Biocorrosion becomes the determinative durability factor of buildings and constructions. Damages of construction materials caused by bacteria, filamentous fungi, actinomycetes constitute a serious danger to the constructions of a building or a structure and to the health of people. Biodeteriorations are typical both in old and new constructions. A great quantity of destruction factors of industrial and residential buildings under the influence of microorganisms was established in practice. Providing products and constructions based on concretes fungicidal and bactericidal properties is an important direction of modern construction material science. The most efficient way to solve this task is creation of biocidal cements. The article presents the results of experimental studies of kinetic dependences of strength gain by biocidal cements by physico-mechanical and physico-chemical analysis methods. The identical velocity character of initial hydration of the developed compositions of biocidal cements is set, as well as a more calm behavior of hardening processes at later terms. It has been established that the compositions of biocidal cements modified by sodium sulfate and sodium fluoride possess the greatest strength.

  12. RESISTÊNCIA BIOLÓGICA DA MADEIRA TRATADA DE Eucalyptus grandis E Eucalyptus cloeziana A FUNGOS APODRECEDORES EM ENSAIOS DE LABORATÓRIO

    Directory of Open Access Journals (Sweden)

    Magnos Alan Vivian

    2015-01-01

    Full Text Available The present study aimed to evaluate the biological resistance of treated wood from Eucalyptus grandis and Eucalyptus cloeziana under the action of biodeteriorative organisms in laboratory testing. Thus, we used trees of Eucalyptus grandis and Eucalyptus cloeziana, both 16 years old, which was converted into planks and subjected to preservative treatment in an autoclave with chromate copper arsenate (CCA. Then, it was made the specimens for the conduct of accelerated decay test, as recommended by ASTM. From the results, it was observed for the fungus Trametes versicolor that the preservative treatment was effective in reducing the biological degradation of the wood of the two species, with reduced mass loss in 35.17 and 82.31% for wood Eucalyptus grandis and Eucalyptus cloeziana, respectively, as for the fungus Gloeophyllum trabeum mass loss was reduced by 6.79 and 96.65%, compared to the control. Based on the conditions of realization of the present study, it was observed that preservative treatment with CCA is effective in the increasing the biological resistance of the wood under the action of fungi Trametes versicolor and Gloeophyllum trabeum.

  13. Studies of detailed biofilm characterization on fly ash concrete in comparison with normal and superplasticizer concrete in seawater environments.

    Science.gov (United States)

    Vishwakarmaa, Vinita; George, R P; Ramachandran, D; Anandkumar, B; Mudalib, U Kamachi

    2014-01-01

    In cooling water systems, many concrete structures in the form of tanks, pillars and reservoirs that come in contact with aggressive seawater are being deteriorated by chemical and biological factors. The nuclear industry has decided to partially replace the Portland cement with appropriate pozzolans such as fly ash, which could densify the matrix and make the concrete impermeable. Three types of concrete mixes, viz., normal concrete (NC), concrete with fly ash and superplasticizer (FA) and concrete with only superplasticizer (SP) were fabricated for short- and long-term exposure studies and for screening out the better concrete in seawater environments. Biofilm characterization studies and microscopic studies showed excellent performance of FA concrete compared to the other two. Laboratory exposure studies in pure cultures of Thiobacillus thiooxidans and Fusarium oxysporum were demonstrated for the inhibition of microbial growth on fly ash. Epifluorescence and scanning electron microscopic studies supported the better performance of the FA specimen. Thus, the present study clearly showed that FA concrete is less prone to biofilm formation and biodeterioration. PMID:24600839

  14. Assessment of the conservation state of stone materials in relation to the level environmental pollution in the conservation place

    Directory of Open Access Journals (Sweden)

    Giovanni Rizzo

    2007-07-01

    Full Text Available The patina represents a superficial natural alteration of the constituting matter of the work of art. It emerges from the natural and usual stabilization process that the materials of the surface undergo because of the interaction with outdoor agents characterizing the surrounding environment. Besides, it is not linked to an obvious phenomenon of degradation that can be noticed through the change in the original colour of the matter. This is what we intend when we talk about biological patina usually generated by macro and/or micro-organic colonization (fungi, bacteria, alga which contributes to surface bio-deterioration and thus lead to the formation of orange, red or even brown and dark pigmented areas. The presence of chromatic alterations (rose-coloured areas, as a consequence of bacterial colonization, was most particularly pointed out in different sites, such as in the marble slabs on the facades of both the Cathedral of Siena (Duomo di Siena and the Certosa of Pavia. The present study shows an example of chromatic alteration of the surface of marble works due to bacterial colonization.

  15. A novel hybrid nano zerovalent iron initiated oxidation--biological degradation approach for remediation of recalcitrant waste metalworking fluids.

    Science.gov (United States)

    Jagadevan, Sheeja; Jayamurthy, Manickam; Dobson, Peter; Thompson, Ian P

    2012-05-01

    Disposal of operationally exhausted metal working fluids (MWF) through a biological route is an attractive option, since it is effective with relatively low energy demands. However, it is enormously challenging since these fluids are chemically complex, including the addition of toxic biocides which are added specifically to retard bio-deterioration whilst the fluids are operational. Nano-sized elemental iron represents a new generation of environmental remediation technologies. Laboratory scale batch studies were performed to test the degradation ability of a semi-synthetic metalworking fluid (MWF) wastewater (which was found to be resistant to initial bacterial treatment in specifically established bioreactors) by employing a novel hybrid approach. The approach was to combine the synergistic effects of nano zerovalent iron (nZVI) induced oxidation, followed by biodegradation, specifically for the remediation of recalcitrant components of MWF effluent. Addition of nZVI particles to oxygenated wastewater resulted in oxidation of organic contaminants present. Our studies confirmed 78% reduction in chemical oxygen demand (COD) by nZVI oxidation at pH 3.0 and 67% reduction in neutral pH (7.5), and 85% concurrent reduction in toxicity. Importantly, this low toxicity made the nZVI treated effluent more amenable for a second stage biological oxidation step. An overall COD reduction of 95.5% was achieved by the novel combined treatment described, demonstrating that nZVI oxidation can be exploited for enhancing the biodegradability of a recalcitrant wastewater in treatment processes. PMID:22365368

  16. Monitoring, Controlling And Prevention Of The Fungal Deterioration Of Textile Artifacts In The Museum Of Jordanian Heritage

    Science.gov (United States)

    Abdel-Kareem, O.

    This study aims at monitoring, controlling and prevention the fungal deterioration of the museum textiles in the museum of Jordanian heritage as a case study. In this study valuable fungal deteriorated textile samples collected from different areas in the storage rooms and the display halls in the selected museum, were used for isolating fungi. Both of the plate method with the manual key and the direct observation method by SEM were used for identification of the fungi. The results show that the most dominant fungi isolated from tested samples belong to Aspergillus, Penicillium, Chaetomium and Alternaria species. The results show that all kinds of textile fibers in both storage room and display halls in the selected museum suffer from fungal attack. This study confirms that the textile collections are displayed and storied in very poor environmental conditions. This study established a strategy for controlling and prevention of the fungal deterioration problem on textile objects in the Museum of Jordanian Heritage and includes disinfection of the biodeteriorated textile objects, and then controlling the environmental conditions surrounding the objects in display showcases and storage cabinets. For disinfection of fungal deteriorated textiles with active fungal infestation the study suggested some fungicides that are safe for both textile objects and conservators.

  17. Chromatic alteration on marble surfaces analysed by molecular biology tools

    Directory of Open Access Journals (Sweden)

    Franco Palla

    2007-07-01

    Full Text Available The patina represents a superficial natural alteration of the constituting matter of the work of art. It emerges from the natural and usual stabilization process that the materials of the surface undergo because of the interaction with outdoor agents characterizing the surrounding environment. Besides, it is not linked to an obvious phenomenon of degradation that can be noticed through the change in the original colour of the matter. This is what we intend when we talk about biological patina usually generated by macro and/or micro-organic colonization (fungi, bacteria, alga which contributes to surface bio-deterioration and thus lead to the formation of orange, red or even brown and dark pigmented areas. The presence of chromatic alterations (rose-coloured areas, as a consequence of bacterial colonization, was most particularly pointed out in different sites, such as in the marble slabs on the facades of both the Cathedral of Siena (Duomo di Siena and the Certosa of Pavia. The present study shows an example of chromatic alteration of the surface of marble works due to bacterial colonization.

  18. Mediaeval cantorals in the Valladolid Biblioteca: FT-Raman spectroscopic study.

    Science.gov (United States)

    Edwards, H G; Farwell, D W; Rull Perez, F; Medina Garcia, J

    2001-03-01

    Raman spectroscopic studies of three mediaeval cantorals in the Biblioteca of the University of Valladolid has revealed information about the pigments used on these large manuscripts. Although executed in a simple colour palette, very pure cinnabar was used as the major colourant, offsetting the carbon black of the verses and script. A dark blue colour was achieved using a mixture of azurite (basic copper carbonate) and carbon, whereas a light blue colour was azurite alone. A grey colour was achieved using azurite, carbon particles and a calcareous 'limewash'. A yellow pigment, used sparely in the cantorals was ascribed to saffron; unusually, there was no evidence for the presence of the yellow mineral pigments orpiment, realgar and massicot. In several regions of the vellum specimens, evidence for biodeterioration was observed through the signatures of hydrated calcium oxalate. We report for the first time the Raman spectra of pigment in situ on a vellum fragment, which also shows evidence of substrate bands; comparison of black and red pigmented regions of vellum specimens has shown the presence of calcium oxalate in the black pigmented script but not in the red pigment regions, which suggests that the cinnabar in the red-pigmented regions acts as a toxic protectant for the vellum substrate against biological colonisation processes.

  19. Polyphasic approach to characterize heterotrophic bacteria of biofilms and patina on walls of the Suburban Bath of the Herculaneum's archaeological excavations in Italy

    Science.gov (United States)

    Ventorino, V.; Pepe, O.; Sannino, L.; Blaiotta, G.; Palomba, S.

    2012-04-01

    Built between the walls of Herculaneum excavations, one of the world's most important archaeological sites, and the sea in the early 1st cent. AD, the Suburban Bath is one of the best thermal complexes better preserved in ancient times. The entrance opens onto a large courtyard that leads into a hallway well lit by a skylight, impluvium, with a portrait of "Apollo". From this room you can access various parts of the thermae, all beautifully preserved. A single room, mostly occupied by the pool, serving both apodyterium (dressing room) that frigidarium. Among tepidarium and frigidarium there's a room elegantly decorated with stucco and marble. The vestibule opens to the right, through a corridor, onto a waiting room with a floor in signinum opus and into a praefurnium (oven for heating). A large pool of tepidarium, connected with laconicum, a small circular room for the baths sweat, is also present. The calidarium, as usual, has a small tank for hot water and a basin for washing in cold water. Behind the calidarium is the praefurnium, an environment with the boiler for heating the bath. Although the suburban baths are well preserved, unfortunately in you can observe the development of visible microbial coatings. During the biodeterioration process, secondary colonization of wall is due to heterotrophic bacteria and fungi that induce deterioration cause structural as well as aesthetic damage such as the discoloration of materials, the formation of crusts on surfaces and the loss of material. This investigation was carried out sampling the surfaces of walls of different rooms in the Suburban Thermae according to Italian legal procedures. Depending on the samples typology, sampling was carry out using sterile nitrocellulose membranes pressed on the surface of the walls, sterile swabs or with sterile tweezers by tearing out surface material. The samples were suspended in physiological solution and immediately refrigerated until analysis. Isolated colonies grown on PCA

  20. Effect of gamma irradiation on Korean traditional multicolored paintwork

    International Nuclear Information System (INIS)

    Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, Sukganju (Hematite; Fe2O3), Jangdan (Minium; Pb3O4), Whangyun (Crocoite; PbCrO4), and Jidang (Rutile; TiO2), were irradiated by gamma radiation at doses of 1, 5, and 20 kGy. After irradiation, changes in Commision Internationale d’Eclairage (CIE) color values (L*, a*, b*) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 dE* unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20 kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20 kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5 kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong. - Highlights: • Effects of gamma irradiation on the Dancheong were evaluated. • We confirmed that optical and structural properties of Dancheong were maintained. • Irradiation can contribute the decontamination for

  1. Biogenic Impact on Materials

    Science.gov (United States)

    Stephan, Ina; Askew, Peter; Gorbushina, Anna; Grinda, Manfred; Hertel, Horst; Krumbein, Wolfgang; Müller, Rolf-Joachim; Pantke, Michael; Plarre, Rüdiger (Rudy); Schmitt, Guenter; Schwibbert, Karin

    Materials as constituents of products or components of technical systems rarely exist in isolation and many must cope with exposure in the natural world. This chapter describes methods that simulate how a material is influenced through contact with living systems such as microorganisms and arthropods. Both unwanted and desirable interactions are considered. This biogenic impact on materials is intimately associated with the environment to which the material is exposed (Materials-Environment Interaction, Chap. 15). Factors such as moisture, temperature and availability of food sources all have a significant influence on biological systems. Corrosion (Chap. 12) and wear (Chap. 13) can also be induced or enhanced in the presence of microorganisms. Section 14.1 introduces the categories between desired (biodegradation) and undesired (biodeterioration) biological effects on materials. It also introduces the role of biocides for the protection of materials. Section 14.2 describes the testing of wood as a building material especially against microorganisms and insects. Section 14.3 characterizes the test methodologies for two other groups of organic materials, namely polymers (Sect. 14.3.1) and paper and textiles (Sect. 14.3.2). Section 14.4 deals with the susceptibility of inorganic materials such as metals (Sect. 14.4.1), concrete (Sect. 14.4.2) and ceramics (Sect. 14.4.3) to biogenic impact. Section 14.5 treats the testing methodology concerned with the performance of coatings and coating materials. In many of these tests specific strains of organisms are employed. It is vital that these strains retain their ability to utilize/attack the substrate from which they were isolated, even when kept for many years in the laboratory. Section 14.6 therefore considers the importance of maintaining robust and representative test organisms that are as capable of utilizing a substrate as their counterparts in nature such that realistic predictions of performance can be made.

  2. Mechanisms of cementitious material deterioration in biogas digester.

    Science.gov (United States)

    Voegel, C; Bertron, A; Erable, B

    2016-11-15

    Digesters produce biogas from organic wastes through anaerobic digestion processes. These digesters, often made of concrete, suffer severe premature deterioration caused mainly by the presence of fermentative microorganisms producing metabolites that are aggressive towards cementitious materials. To clarify the degradation mechanisms in an anaerobic digestion medium, ordinary Portland cement paste specimens were immersed in the liquid fraction of a running, lab-scale digester for 4weeks. The anaerobic digestion medium was a mixture of a biowaste substrate and sludge from municipal wastewater treatment plant used as a source of anaerobic bacteria. The chemical characteristics of the anaerobic digestion liquid phase were monitored over time using a pH metre, high performance liquid chromatography (HPLC) and ion chromatography (HPIC). An initial critical period of low pH in the bioreactors was observed before the pH stabilized around 8. Acetic, propionic and butyric acids were produced during the digestion with a maximum total organic acid concentration of 50mmolL(-1). The maximum ammonium content of the liquid phase was 40mmolL(-1), which was about seven times the upper limit of the highly aggressive chemical environment class (XA3) as defined by the European standard for the specification of concrete design in chemically aggressive environments (EN 206). The changes in the mineralogical, microstructural and chemical characteristics of the cement pastes exposed to the solid and liquid phase of the digesters were analysed at the end of the immersion period by X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDS) and electron-probe micro-analysis (EPMA). A 700-μm thick altered layer was identified in the cement paste specimens. The main biodeterioration patterns in the bioreactors' solid/liquid phase were calcium leaching and carbonation of the cement matrix.

  3. Biogenic Cracks in Porous Rock

    Science.gov (United States)

    Hemmerle, A.; Hartung, J.; Hallatschek, O.; Goehring, L.; Herminghaus, S.

    2014-12-01

    Microorganisms growing on and inside porous rock may fracture it by various processes. Some of the mechanisms of biofouling and bioweathering are today identified and partially understood but most emphasis is on chemical weathering, while mechanical contributions have been neglected. However, as demonstrated by the perseverance of a seed germinating and cracking up a concrete block, the turgor pressure of living organisms can be very significant. Here, we present results of a systematic study of the effects of the mechanical forces of growing microbial populations on the weathering of porous media. We designed a model porous medium made of glass beads held together by polydimethylsiloxane (PDMS), a curable polymer. The rheological properties of the porous medium, whose shape and size are tunable, can be controlled by the ratio of crosslinker to base used in the PDMS (see Fig. 1). Glass and PDMS being inert to most chemicals, we are able to focus on the mechanical processes of biodeterioration, excluding any chemical weathering. Inspired by recent measurements of the high pressure (~0.5 Mpa) exerted by a growing population of yeasts trapped in a microfluidic device, we show that yeast cells can be cultured homogeneously within porous medium until saturation of the porous space. We investigate then the effects of such an inner pressure on the mechanical properties of the sample. Using the same model system, we study also the complex interplay between biofilms and porous media. We focus in particular on the effects of pore size on the penetration of the biofilm within the porous sample, and on the resulting deformations of the matrix, opening new perspectives into the understanding of life in complex geometry. Figure 1. Left : cell culture growing in a model porous medium. The white spheres represent the grains, bonds are displayed in grey, and microbes in green. Right: microscopy picture of glass beads linked by PDMS bridges, scale bar: 100 μm.

  4. Mechanisms of cementitious material deterioration in biogas digester.

    Science.gov (United States)

    Voegel, C; Bertron, A; Erable, B

    2016-11-15

    Digesters produce biogas from organic wastes through anaerobic digestion processes. These digesters, often made of concrete, suffer severe premature deterioration caused mainly by the presence of fermentative microorganisms producing metabolites that are aggressive towards cementitious materials. To clarify the degradation mechanisms in an anaerobic digestion medium, ordinary Portland cement paste specimens were immersed in the liquid fraction of a running, lab-scale digester for 4weeks. The anaerobic digestion medium was a mixture of a biowaste substrate and sludge from municipal wastewater treatment plant used as a source of anaerobic bacteria. The chemical characteristics of the anaerobic digestion liquid phase were monitored over time using a pH metre, high performance liquid chromatography (HPLC) and ion chromatography (HPIC). An initial critical period of low pH in the bioreactors was observed before the pH stabilized around 8. Acetic, propionic and butyric acids were produced during the digestion with a maximum total organic acid concentration of 50mmolL(-1). The maximum ammonium content of the liquid phase was 40mmolL(-1), which was about seven times the upper limit of the highly aggressive chemical environment class (XA3) as defined by the European standard for the specification of concrete design in chemically aggressive environments (EN 206). The changes in the mineralogical, microstructural and chemical characteristics of the cement pastes exposed to the solid and liquid phase of the digesters were analysed at the end of the immersion period by X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDS) and electron-probe micro-analysis (EPMA). A 700-μm thick altered layer was identified in the cement paste specimens. The main biodeterioration patterns in the bioreactors' solid/liquid phase were calcium leaching and carbonation of the cement matrix. PMID:27432729

  5. Effect of gamma irradiation on Korean traditional multicolored paintwork

    Science.gov (United States)

    Yoon, Minchul; Kim, Dae-Woon; Choi, Jong-il; Chung, Yong-Jae; Kang, Dai-Ill; Hoon Kim, Gwang; Son, Kwang-Tae; Park, Hae-Jun; Lee, Ju-Woon

    2015-10-01

    Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, Sukganju (Hematite; Fe2O3), Jangdan (Minium; Pb3O4), Whangyun (Crocoite; PbCrO4), and Jidang (Rutile; TiO2), were irradiated by gamma radiation at doses of 1, 5, and 20 kGy. After irradiation, changes in Commision Internationale d'Eclairage (CIE) color values (L*, a*, b*) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 dE* unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20 kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20 kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5 kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong.

  6. Monitoring the effects of different conservation treatments on paper-infecting fungi

    Science.gov (United States)

    Michaelsen, Astrid; Pinzari, Flavia; Barbabietola, Nicoletta; Piñar, Guadalupe

    2013-01-01

    Fungi are among the most degradative organisms inducing biodeterioration of paper-based items of cultural heritage. Appropriate conservation measures and restoration treatments to deal with fungal infections include mechanical, chemical, and biological methods, which entail effects on the paper itself and health hazards for humans. Three different conservation treatments, namely freeze-drying, gamma rays, and ethylene oxide fumigation, were compared and monitored to assess their short- (one month, T1) and long-term (one year, T2) effectiveness to inhibit fungal growth. After the inoculation with fungi possessing cellulose hydrolysis ability — Chaetomium globosum, Trichoderma viride, and Cladosporium cladosporioides — as single strains or as a mixture, different quality paper samples were treated and screened for fungal viability by culture-dependent and -independent techniques. Results derived from both strategies were contradictory. Both gamma irradiation and EtO fumigation showed full efficacy as disinfecting agents when evaluated with cultivation techniques. However, when using molecular analyses, the application of gamma rays showed a short-term reduction in DNA recovery and DNA fragmentation; the latter phenomenon was also observed in a minor degree in samples treated with freeze-drying. When RNA was used as an indicator of long-term fungal viability, differences in the RNA recovery from samples treated with freeze-drying or gamma rays could be observed in samples inoculated with the mixed culture. Only the treatment with ethylene oxide proved negative for both DNA and RNA recovery. Therefore, DNA fragmentation after an ethylene oxide treatment can hamper future paleogenetic and archaeological molecular studies on the objects. PMID:24092956

  7. Biogeochemical Activity of Siderophilic Cyanobacteria: Implications for Paleobiogeochemistry

    Science.gov (United States)

    Brown, Igor I.; Sarkisova, Svetlana A.; Auyeung, Weng S.; Garrison, Dan; Allen, Carlton C.; McKay, David S.

    2007-01-01

    Understanding the patterns of iron oxidation by cyanobacteria (CB) has tremendous importance for paleobiogeochemistry, since cyanobacteria are presumed to have been involved in the global oxidation of ferrous iron during the Precambrian (Cloud, 1973). B.K. Pierson (1999, 2000) first proposed to study iron deposition in iron-depositing hot springs (ID HS) as a model for Precambrian Fe(2+) oxidation. However, neither the iron-dependent physiology of individual species of CB inhabiting iron-depositing hot springs nor their interactions with minerals enriched with iron have been examined thoroughly. Such study could shed light on ancient iron turnover. Cyanobacterial species isolated from ID HS demonstrate elevated tolerance to colloidal Fe(3+) (= 1 mM), while a concentration of 0.4 mM proved toxic for mesophilic Synechocystis PCC 6803. Isolates from ID HS require 0.4-0.6 mM Fe3+ for maximal growth while the iron requirement for Synechocystis is approximately one order of magnitude lower. We have also demonstrated that thick polysaccharide sheaths around cells of CB isolated from ID HS serve as repositories for precipitated iron. The growth of the mesophilic cyanobacteria Phromidium aa in iron-saturated (0.6 mM) DH medium did not lead to iron precipitation on its filament surfaces. However, a 14.3 fil.2 culture, isolated from an ID HS and incubated under the same conditions, was covered with dense layer of precipitated iron. Our results, taken together with Pierson s data concerning the ability of Fe2+ to stimulate photosynthesis in natural CB mats in ID HS, suggest that CB inhabiting ID HS may constitute a new group of the extremophiles - siderophilic CB. Our recent experiments have revealed for the first time that CB isolates from ID HS are also capable of biodeterioration - the etching of minerals, in particular glasses enriched with Fe, Al, Ti, O, and Si. Thus, Precambrian siderophilic cyanobacteria and their predecessors could have been involved not only in iron

  8. Tortoiseshell or Polymer? Spectroscopic Analysis to Redefine a Purported Tortoiseshell Box with Gold Decorations as a Plastic Box with Brass.

    Science.gov (United States)

    Pereira, António; Caldeira, Ana Teresa; Maduro, Belmira; Vandenabeele, Peter; Candeias, António

    2016-01-01

    possible biofilm composition and understand the role of microorganisms in the biodeterioration process. Using these methodologies, the box was correctly identified as being made of cellulose acetate plastic with brass decorations and the white film was identified as being composed mainly of polymer exudates, namely sulphonamides and triphenyl phosphate.

  9. Fungal Spores Viability on the International Space Station

    Science.gov (United States)

    Gomoiu, I.; Chatzitheodoridis, E.; Vadrucci, S.; Walther, I.; Cojoc, R.

    2016-11-01

    In this study we investigated the security of a spaceflight experiment from two points of view: spreading of dried fungal spores placed on the different wafers and their viability during short and long term missions on the International Space Station (ISS). Microscopic characteristics of spores from dried spores samples were investigated, as well as the morphology of the colonies obtained from spores that survived during mission. The selected fungal species were: Aspergillus niger, Cladosporium herbarum, Ulocladium chartarum, and Basipetospora halophila. They have been chosen mainly based on their involvement in the biodeterioration of different substrate in the ISS as well as their presence as possible contaminants of the ISS. From biological point of view, three of the selected species are black fungi, with high melanin content and therefore highly resistant to space radiation. The visual inspection and analysis of the images taken before and after the short and the long term experiments have shown that all biocontainers were returned to Earth without damages. Microscope images of the lids of the culture plates revealed that the spores of all species were actually not detached from the surface of the wafers and did not contaminate the lids. From the adhesion point of view all types of wafers can be used in space experiments, with a special comment on the viability in the particular case of iron wafers when used for spores that belong to B. halophila (halophilic strain). This is encouraging in performing experiments with fungi without risking contamination. The spore viability was lower in the experiment for long time to ISS conditions than that of the short experiment. From the observations, it is suggested that the environment of the enclosed biocontainer, as well as the species'specific behaviour have an important effect, reducing the viability in time. Even the spores were not detached from the surface of the wafers, it was observed that spores used in the

  10. Microbiological Tests Performed During the Design of the International Space Station Environmental Control and Life Support Systems. Part 1, Bulk Phase. Part 1; Bulk Phase

    Science.gov (United States)

    Roman, Monsi C.; Mittelman, Marc W.

    2010-01-01

    The design and manufacturing of the main Environmental Control and Life Support Systems (ECLSS) for the United States segments of the International Space Station (ISS) was an involved process that started in the mid 1980s, with the assessment and testing of competing technologies that could be used to clean the air and recycle water. It culminated in 2009 with the delivery and successful activation of the Water Recovery System (WRS) water processor (WP). The ECLSS required the work of a team of engineers and scientist working together to develop systems that could clean and/or recycle human metabolic loads to maintain a clean atmosphere and provide the crew clean water. One of the main goals of the ECLSS is to minimize the time spent by the crew worrying about vital resources not available in the vacuum of space, which allows them to spend most of their time learning to live in a microgravity environment many miles from the comforts of Earth and working on science experiments. Microorganisms are a significant part of the human body as well as part of the environment that we live in. Therefore, the ISS ECLSS design had to take into account the effect microorganisms have on the quality of stored water and wastewater, as well as that of the air systems. Hardware performance issues impacted by the accumulation of biofilm and/or microbiologically influenced corrosion were also studied during the ECLSS development stages. Many of the tests that were performed had to take into account the unique aspects of a microgravity environment as well as the challenge of understanding how to design systems that could not be sterilized or maintained in a sterile state. This paper will summarize the work of several studies that were performed to assess the impacts and/or to minimize the effects of microorganisms in open, semi-closed and closed loop life support system. The biofilm and biodeterioration studies that were performed during the design and test periods will be presented in

  11. DEGRADATION AND CONSERVATION OF MARBLE IN THE GREEK ROMAN HADRIANIC BATHS IN LEPTIS MAGNA, LIBYA

    Directory of Open Access Journals (Sweden)

    Nabil.A. ABD EL-TAWAB

    2012-09-01

    Full Text Available The Hadrianic Baths is one of the most important archaeological sites in Leptis Magna- Libya. It was built at the command of Emperor Hadrian in the early 2nd century CE; they represent some of the most lavish structures of Leptis Magna. It is unique in design and building technique. It was built of limestone, marble and brick. This paper mainly describes the deterioration of marble. The marble in the monuments can be classified into several types, based on its color, texture, chemical composition and the constituent mineral. The Hadrianic Baths is subjected to severe degradation, due to the climate, which is typically marine. This site suffered from different weathering forms, for example, disintegration of grains, pitting, chipping, frequent flaking, multiple-flaking, fissures and biodeterioration. These weathering forms were produced by many deterioration factors, such as moisture, salt weathering, biological and micro-biological factors, changes in temperature and wind erosion. The aim of this study is to characterize the building materials at the Hadrianic Baths, especially marble, and to evaluate the role of groundwater and sea weathering on the strength of the marble exposed to the coastline of the Mediterranean. Many samples were collected from limestone, marble, mortar, plaster and salts, for analysis and investigation. Several scientific techniques were used in the study of the morphology and texture. Those methods include microscopy, such as scanning electron microscopy (SEM, polarized light microscopy (PLM and stereo microscopy. A qualitative identification of organic and inorganic chemical species was performed by using techniques such as energy-dispersive spectroscopy (EDS, X-ray diffraction (XRD and microbial investigation were also done. Our results indicated that the deterioration of marble was caused by the aggressive action of environmental agents. SEM observations indicated the occurrence of microcracks and particle aggregates

  12. Evaluating the role of ivy (Hedera helix) in moderating wall surface microclimates and contributing to the bioprotection of historic buildings

    Energy Technology Data Exchange (ETDEWEB)

    Sternberg, Troy; Viles, Heather [Oxford University, School of Geography, South Parks Road, Oxford OX1 3QY (United Kingdom); Cathersides, Alan [English Heritage, Conservation Department, Kemble Drive, Swindon SN2 2GZ (United Kingdom)

    2011-02-15

    The role of ivy (Hedera helix L.) on building walls is much debated, with arguments being put forward for it playing a biodeteriorative role (for example through ivy rootlets exploiting cracks and holes) as well as suggestions that it might provide some bioprotection (for example by the ivy canopy protecting the walls from other agents of deterioration such as frost). We have carried out a year-long study of the influence that ivy canopies play on wall surface microclimates at five sites across a range of climatic settings within England, using iButtons to monitor temperature and relative humidity fluctuations at the wall surface on ivy-covered and exposed walls. Hourly data illustrates a general mediating effect of ivy canopies on both temperature and relative humidity regimes. The ivy reduces extremes of temperature and relative humidity, with the most clearcut differences for temperature. Across all five sites the average daily maximum temperature was 36% higher and the average daily minimum temperature 15% lower on exposed vs ivy-covered surfaces. Differences in the exposure level of studied walls (i.e. whether they are shaded or not by trees or other walls) influenced the degree of microclimatic alteration provided by the ivy canopy. Other important factors influencing the strength of the ivy impact on microclimate were found to be thickness of the canopy and aspect of the wall. A detailed analysis of one site, Byland in North Yorkshire, illustrates the seasonal differences in impact of ivy on microclimates, with insulation against freezing being the dominant effect in January, and the removal of high temperature 'spikes' the dominant effect in July. The observed moderating role of ivy canopies on wall surface microclimates will reduce the likelihood of frost and salt deterioration to the building materials, thus contributing to their conservation. Further research needs to be done on other potentially deteriorative roles of ivy before an overall

  13. Microbes on building materials — Evaluation of DNA extraction protocols as common basis for molecular analysis

    International Nuclear Information System (INIS)

    The study of microbial life in building materials is an emerging topic concerning biodeterioration of materials as well as health risks in houses and at working places. Biodegradation and potential health implications associated with microbial growth in our residues claim for more precise methods for quantification and identification. To date, cultivation experiments are commonly used to gain insight into the microbial diversity. Nowadays, molecular techniques for the identification of microorganisms provide efficient methods that can be applied in this field. The efficiency of DNA extraction is decisive in order to perform a reliable and reproducible quantification of the microorganisms by qPCR or to characterize the structure of the microbial community. In this study we tested thirteen DNA extraction methods and evaluated their efficiency for identifying (1) the quantity of DNA, (2) the quality and purity of DNA and (3) the ability of the DNA to be amplified in a PCR reaction using three universal primer sets for the ITS region of fungi as well as one primer pair targeting the 16S rRNA of bacteria with three typical building materials — common plaster, red brick and gypsum cardboard. DNA concentration measurements showed strong variations among the tested methods and materials. Measurement of the DNA yield showed up to three orders of magnitude variation from the same samples, whereas A260/A280 ratios often prognosticated biases in the PCR amplifications. Visualization of the crude DNA extracts and the comparison of DGGE fingerprints showed additional drawbacks of some methods. The FastDNA Spin kit for soil showed to be the best DNA extraction method and could provide positive results for all tests with the three building materials. Therefore, we suggest this method as a gold standard for quantification of indoor fungi and bacteria in building materials. -- Highlights: ► Up to thirteen extraction methods were evaluated with three building materials.

  14. Phototrophic microorganisms in biofilm samples from Vernjika Cave, Serbia

    Science.gov (United States)

    Popović, Slađana; Jovanović, Jelena; Predojević, Dragana; Trbojević, Ivana; Blagojević, Ana; Subakov Simić, Gordana

    2016-04-01

    Caves represent specific natural monuments in terms of structure, complexity and beauty which can be found worldwide. Even though they are considered extreme environments, they are still a unique habitat for a large number of organisms that grow and proliferate here. Often can be seen that the cave walls are differently coloured as a consequence of the biofilm development. Biofilms represent complex communities of microorganisms that can develop on different kind of surfaces, including various rock surfaces. Each microbe species play a different role in a community, but their development on stone surfaces can cause substantial damage to the substrates through different mechanisms of biodeterioration and degradation. There is an increased interest in the phototrophic component of biofilms (aerophytic cyanobacteria and algae), especially cyanobacteria, an ancient microorganisms capable to survive the most diverse extreme conditions. These phototrophs can easily be found at cave entrances illuminated by direct or indirect sunlight and areas near artificial lights. Cyanobacteria and algae were investigated in biofilm samples taken from the entrance of Vernjika Cave in Eastern Serbia. Cyanobacteria, Chlorophyta and Bacillariophyta were documented, with Cyanobacteria as a group with the highest number of recorded taxa. Chroococcalean species were the most diverse with the most frequently encountered species from the genus Gloeocapsa. Phormidium and Nostoc species were commonly recorded Oscillatoriales and Nostocles, respectively. Among Oscillatoriales species, it was noticed that one Phormidium species precipitates CaCO3 on it's sheats. Trebouxia sp. and Desmococcus olivaceus were frequently documented Chlorophyta, and representatives of Bacillariophyta were exclusively aerophytic taxa, mostly belonging to the genera Luticola and Humidophila. Measured ecological parameters, temperature and relative humidity, were influenced by the external climatic changes, while light

  15. Chemical composition influence of cement based mortars on algal biofouling

    Science.gov (United States)

    Estelle, Dalod; Alexandre, Govin; Philippe, Grosseau; Christine, Lors; René, Guyonnet; Denis, Damidot

    2013-04-01

    The main cause of building-facade biodegradation is the growth of microorganisms. This phenomenon depends on several parameters such as the geographical situation, the environmental conditions and the surface state of the substrate. Several researches have been devoted to the study of the effect of porosity and roughness on the biofouling of stones and mortars. However, none of them have addressed the influence of the mortar chemistry on the microorganism growth kinetic. The main objective of this study is to highlight the influence of the mortar chemistry in relationship with its physical properties on biological weathering. Earlier work showed a good resistance of Calcium Aluminate Cements to biodeterioration by acidogenic bacteria (Thiobacillus) and fungi (Alternaria alternata, Aspergillus Niger and Coniosporium uncinatum). In order to characterize the influence of the mortar chemistry on biofouling, two Portland cements and two alumina cements are used. Among micro-organisms able to grow, green algae are most involved in the aesthetic deterioration of facades. Indeed, they can colonize any type of media and can be a source of nutrients for other micro-organisms such as fungi. The green algae Klebsormidium flaccidum is chosen because of its representativeness. It is indeed the species the most frequently identified and isolated from samples taken on sites. The biofouling kinetic is followed on samples exposed outdoor and on samples tested in a laboratory bench which consists in spraying an algae culture on mortar specimens. The results obtained by in situ trials are compared with the results obtained on the laboratory bench. The microorganism growth kinetic is measured by image analysis. To improve the detection of algae on the surface of the cementitious samples, the raw image is converted in the YIQ color space. Y, I and Q correspond respectively to luminance, in-phase, and quadrature. On the Q channel, the areas covered by algae and the areas of clean mortar

  16. Pathologies and analytical study of mosaic materials from Carmona and Italica

    Directory of Open Access Journals (Sweden)

    Palomar, T.

    2011-12-01

    Full Text Available This work reports on the characterization of Roman mosaic samples from Carmona and Italica (Spain. A physico-chemical study of both glass tesserae and mortar fragments to determine their composition, to evaluate their state of conservation and to study their production technology was carried out. Samples were characterized by means of a binocular microscope, SEM-EDS, visible spectrophotometry, XRD and petrographic analysis. The tesserae were made from soda lime silicate glass, even though one of them showed high contents of lead and copper oxides. The samples from Carmona showed deterioration pathologies associated to the humidity affecting the mosaic during burial, while those from Italica presented traces of biodeterioration. The data also indicated that the glass used in the tesserae had a lower technical quality than that used in tableware pieces of similar chronology.

    Este trabajo presenta los resultados del estudio realizado en muestras de mosaicos romanos procedentes de Carmona e Itálica (Sevilla. El objetivo principal del estudio consistió en la caracterización químico-física de teselas de vidrio y fragmentos de mortero para determinar su composición, evaluar su estado de conservación y estudiar su tecnología de producción. Las muestras se caracterizaron mediante lupa binocular, MEB-EDS, espectrofotometría visible, DRX y análisis petrográfico. Los resultados indicaron que las teselas se realizaron con vidrio de silicato sódico cálcico, aunque una de ellas mostró elevados contenidos de óxidos de plomo y de cobre. Las muestras procedentes de Carmona presentaron patologías de deterioro asociadas a la humedad retenida por el mosaico durante su enterramiento, mientras que las muestras de Itálica presentaron huellas de biodeterioro. Asimismo, los resultados indicaron que en las teselas se utilizó un vidrio de inferior calidad técnica que el empleado en piezas de vajilla de cronología semejante.

  17. The Sense-City equipment project: insight into the prototyping and validation of environmental micro- and nanosensors for a sustainable urbanization

    Science.gov (United States)

    Lebental, Bérengère; Angelescu, Dan; Bourouina, Tarik; Bourquin, Frédéric; Cojocaru, Costel-Sorin; Derkx, François; Dumoulin, Jean; Ha, Thi-Lan; Robine, Enric; Van Damme, Henri

    2013-04-01

    -City will provide an environment of intermediate complexity for the testing of environmental sensors, a realistic urban test space in climatic conditions, both far more complex than clean rooms and far more controllable than actual cities. References: [1] Joblin Y et al., International Biodeterioration & Biodegradation 2010, 64, 210-217 [2] Lee C S et al., Nanotechnology 2012, accepted [3] Nachef K et al., IEEE/ASME Journal of Microelectromechanical Systems 2102, 21

  18. Sulphate-reducing bacteria associated with biocorrosion: a review

    Directory of Open Access Journals (Sweden)

    Tania C. de Araujo-Jorge

    1992-09-01

    Full Text Available Biocorrosion means any process of corrosion in wich microorganisms are somehow involved. As far as the petroleum industry is concerned, the anaerobic type is the more important, with Sulphate-Reducing Bacteria (SRB accouting for half of the described processes. SRB are obligate anaerobs that use sulphur, sulphate or other oxidized sulphur compounds as oxidizing agents when decomposing organic material. A typical product of SRB metabolism, hydrogen sulphide -H2S-, is extremely toxic. In the present work we review the literature on mechanisms underlying biocorrosive process in wich SRB are involved and summarize some of the ultrastructural and eletrochemical work developed using SRB obtained from water injection flow in wells located on PETROBRAS offshore marine plataforms, sampled directly in the field over metallic probes, or cultured under laboratory conditions. Biofilms develop when SRB adhere to inert surfaces. A high diversity of morphological types is found inside these biofilms. Their extracellular matrix is highly hydrated and mainly anionic, as shown by its avid reaction with cationic compounds like ruthenium red. We have noted that variations in iron contet lead to interesting changes in the ultrastructure of the bacterial cell coat and also in the rate of corrosion induced in metallic test cupons. Since routine methods to prevent and treat SRB contamination and biodeterioration involve the use of biocides that are toxic and always have some environmental impact, an accurate diagnosis of biocorrosion is always required prior to a treatment decision. We developed a method that detects and semi-quantifies the presence of living or dead SRB by using free silver potentials as an indicator of corrosive action by SRB-associated sulphides. We found a correlation between sulphide levels (determined either by spectrophotometry, or using a silver electrode -E(Ag- that measured changes in free potentials induced by the presence of exogeneously

  19. Fungal Spores Viability on the International Space Station

    Science.gov (United States)

    Gomoiu, I.; Chatzitheodoridis, E.; Vadrucci, S.; Walther, I.; Cojoc, R.

    2016-04-01

    In this study we investigated the security of a spaceflight experiment from two points of view: spreading of dried fungal spores placed on the different wafers and their viability during short and long term missions on the International Space Station (ISS). Microscopic characteristics of spores from dried spores samples were investigated, as well as the morphology of the colonies obtained from spores that survived during mission. The selected fungal species were: Aspergillus niger, Cladosporium herbarum, Ulocladium chartarum, and Basipetospora halophila. They have been chosen mainly based on their involvement in the biodeterioration of different substrate in the ISS as well as their presence as possible contaminants of the ISS. From biological point of view, three of the selected species are black fungi, with high melanin content and therefore highly resistant to space radiation. The visual inspection and analysis of the images taken before and after the short and the long term experiments have shown that all biocontainers were returned to Earth without damages. Microscope images of the lids of the culture plates revealed that the spores of all species were actually not detached from the surface of the wafers and did not contaminate the lids. From the adhesion point of view all types of wafers can be used in space experiments, with a special comment on the viability in the particular case of iron wafers when used for spores that belong to B. halophila (halophilic strain). This is encouraging in performing experiments with fungi without risking contamination. The spore viability was lower in the experiment for long time to ISS conditions than that of the short experiment. From the observations, it is suggested that the environment of the enclosed biocontainer, as well as the species'specific behaviour have an important effect, reducing the viability in time. Even the spores were not detached from the surface of the wafers, it was observed that spores used in the

  20. RICHNESS, CELLULOLYTIC ACTIVITY, AND FUNGICIDE SUSCEPTIBILITY OF FUNGI FROM A BIRD BIOLOGICAL COLLECTION

    Directory of Open Access Journals (Sweden)

    Henry Arenas-Castro

    2015-11-01

    Full Text Available ABSTRACTBiological collections in natural history museums serve important purposes to the scientific community and the general public, however, their value and utility might be diminished by biodeterioration. We studied a biological collection that represents more than sixty years of avifauna sampling of Colombia, the country with the highest bird diversity. An initial inspection of the collection showed that the general appearance of some specimens was compromised by mold-like growth on their surfaces. We aimed at (i identifying the taxonomic affiliation of these fungi, (ii evaluating their cellulolytic activity, and (iii probing chemical agents that could be utilized to control their growth. The most common fungi genera were Aspergillus, Penicillium, Chaetomium, and Trichophyton, most of which can degrade cellulose. Zinc chloride and salicylic acid showed to be effective fungicides. Based on this, we propose some actions to control the fungi-pest in this biological collection of birds.RESUMENLas colecciones biológicas en los museos de historia natural juegan un papel importante tanto para la comunidad científica como para el público en general. Sin embargo, su valor y utilidad pueden verse afectados por la biodeterioración de sus ejemplares. Se estudio una colección biológica de aves que representa más de sesenta años de esfuerzo de muestreo de la avifauna del país más rico en aves. Una inspección inicial mostró que la apariencia general de algunos de los especímenes de la colección se encontraba afectada por hongos. Los objetivos de este estudio fueron (i identificar la afiliación taxonómica de los hongos, (ii determinar la actividad celulolítica y (iii probar agentes químicos que puedan ser utilizados para controlar su desarrollo. Los géneros de hongos más comunes fueron Aspergillus, Penicillium, Chaetomium y Trichophyton, de los cuales la mayoría presentan la capacidad de degradar celulosa. Adicionalmente, el cloruro de

  1. Bioreceptivity of dolostones to fungal colonization

    Directory of Open Access Journals (Sweden)

    Ascaso, C.

    2008-06-01

    Full Text Available In many historic monuments in which signs of biodeterioration have been frequently reported, dolostones were used as dimension stone for their construction. In an effort to assess the influence of the texture of dolostones on their potential bioreceptivity, we characterized microbial colonization strategies in dolostone samples of predictably different textural features by scanning electron microscopy in back scattered electron mode (SEM-BSE, low temperature scanning electron microscopy (LTSEM, transmission light microscopy (TLM and mercury intrusion porosimetry (MIP. Fungi were the predominant microorganisms in the dolostones examined and their colonization showed three well defined stages with the final consequence of complete rock disaggregation. The results of this study indicate that porosity differences (mainly the extent and type were particularly relevant for determining the presence and extent of each colonization stage. As a determinant of bioreceptivity, the porosity of dolostones will also condition the decay processes associated with this colonization. These findings highlight the fact that the intrinsic properties of dolostones, such as texture, need to be considered when selecting this type of stone for future construction projects.La dolomía ha sido empleada como piedra de fábrica en la construcción de muchos monumentos históricos en los que se han detectado fenómenos de biodeterioro en numerosas ocasiones. En este trabajo se evalúa cómo influye la textura de las dolomías en las estrategias adoptadas por los microorganismos para colonizar estos materiales pétreos. Para ello se han caracterizado muestras de dolomías con diferentes texturas mediante microscopía electrónica de barrido en modo de electrones retrodispersados (SEM-BSE, microscopía electrónica de barrido a bajas temperaturas (LTSEM, microscopía de luz transmitida (TLM y porosimetría por intrusión de mercurio (MIP. De estas observaciones se deduce que

  2. Microbial deterioration and degradation of Polymeric materials

    Directory of Open Access Journals (Sweden)

    Krishna Mohan

    2010-12-01

    -bidi-theme-font:minor-bidi;}  Polymeric materials due to its structural versatility are widely used in aerospace applications, aviation and space industries. As they are potential source of carbon and energy for heterotrophic microorganisms including bacteria and fungi in several ways its biodegradation affect these industries. The information on degradability can provide fundamental information facilitating design and life-time analysis of materials. Literature survey shows that polymers which are susceptible to biofilm formation includes paints, adhesives, plastics, rubbers, sealants, FRPCMs, lubricating materials, fuels etc. Even though the understanding of polymer degradation has been advanced in recent years the subject is still inadequately addressed because of the lack of information available. The review focuses on polymer biodeterioration and biodegradation and its mechanisms, the types of microorganisms involved, the reactions of enzymes of importance in the biodegradation of polymers, consequences, of biodegradation, the factors involved in biodegradation of polymers and its prevention and the tests used to evaluate it.

  3. Analysis of Algae Growing on the Surface of the North City Wall of Liangzhu Site%良渚北城墙考古土遗址表面藻类的分析研究

    Institute of Scientific and Technical Information of China (English)

    武发思; 汪万福; 贺东鹏; 徐瑞红; 苏伯民

    2014-01-01

    This paper seeks to better clarify the major algal groups that have caused biofouling to earthen sites preserved in humid environments and to provide evidence for studying biodeterioration while establishing ap-propriate countermeasures for later periods. Modern molecular biology research methods were applied for: the extraction of total DNA of the samples, amplification of the targeted fragments, construction of the clone library, determination of sequences, and analysis of phylogeny. Lab results show that three phylums and five genuses of algae might cause biofouling to the earthen sites. Among them, the Nostoc group which belongs to the phylum Cyanophyta is most dominant, the groups of Nitzschia and Phaeodactylum that belong to the phylum Bacillario-phyta are less dominant, and the Microcoleus of the phylum Cyanophyta and other unidentified genus of the phy-lum Chlorophyta are the least dominant. In addition, most sequences retrieved from some samples are similar to Leptobryum, which belongs to the Bryopsida class of the Bryophyta phylum. The differences in community com-ponents between photosynthetic algae and mosses are greatly influenced by the spatial positions of sampling sites and by the water contents of the soil. To reduce the lighting intensity and water penetration in the environment of the earthen sites might be the most efficient way to control the photosynthetic organism erosion.%为了探明造成潮湿环境土遗址生物污损的主要藻类类群,给后期生物退化机理的研究和防治体系的构建提供可靠依据,本研究采用现代分子生物学技术,对杭州良渚北城墙考古土遗址表面的藻类进行了检测和分析。结果表明,引起土遗址生物污损的病害藻类共3门5属,主要为蓝藻门念珠藻属类群,硅藻门菱形藻属与褐指藻属类群次之,蓝藻门壳藻属与绿藻门的未鉴定属最少。另外,苔藓植物门藓纲与薄囊藓属相近的类群在部分样品中占

  4. A critique of Phanerozoic climatic models involving changes in the CO 2 content of the atmosphere

    Science.gov (United States)

    Boucot, A. J.; Gray, Jane

    2001-12-01

    impart reliability to the model constructs. Most modelers focus almost exclusively on one or a few variables as proxy to measure atmospheric CO 2, nor consider the many other variables involved, nor agree on what these variables are or how to measure them. In this paper, it is the reliability of the present data bases used in these atmospheric models that we wish to consider. We focus most attention on the Berner models, such as GEOCARB I, II and BLAG, because of the basic role they attribute to tracheophytes in regulating atmospheric CO 2 and our own interest in pre-tracheophytic land plants and the atmospheric composition of the pre-tracheophytic Paleozoic. We survey the presence of symbiotic mycorrhizae and question the assumption that all tracheophytes are obligately associated with them. Although pre-tracheophytic embryophytes, cyanobacteria, and possibly other organisms preceded tracheophytes on land by millions of years, Berner's models do not consider a significant role for them in affecting pre-Devonian climate/temperature and atmospheric composition. In effect, Berner assumes that pre-tracheophytic life inhabited a world governed largely by abiotic physical and chemical reactions. We consider uncertainties raised by minimizing possible roles for pre-tracheophytic oxygenic and heterotrophic microorganisms analogous to those speculated to be unique to tracheophytes both with regard to an active role in biodeterioration of rock and soil mineral substrates and in the sequestration of organic carbon. Additionally, Berner does not consider marine productivity, which might have been high in the Precambrian and Early Paleozoic and possibly consequent organic carbon sequestration, even in the possible absence of terrestrial organisms, or even in the absence of a significant preserved biomass of terrestrial and marine organisms. The important roles played by cyanobacteria, for example, are briefly reviewed by Giller and Malmqvist in lakes and rivers as regards both

  5. Búsqueda y selección de una proteasa fúngica con potencial aplicación en la restauración de documentos históricos en el Archivo de Bogotá

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Cruz Ramírez

    2012-08-01

    historical valuable documents were performed and was selected for this work, from the filamentous fungi collection of the Bogota Archive. 32 morphotypes of 74 evaluated show hydrolytic activities over differential solid media. From them, 8 morphotypes obtained directly from documental samples and representative of the genera Penicillium and Stachybotrys were selected and their isoenzyme profile were tested. Also 2 previous morphotypes with promisorius proteolytic activities and representative of the genera Chaetomium and Eladia were analysed. Extracelullar proteases production was induced in differential liquid media on three fermentation steps and analitycal isoelectrofocusing were performed over pH 3.0-10.0 ranges. Only the morphotypes 8D (Chaetomium sp., and 21D (Eladia sp., showed an alkaline isoform with pIs 8.5 and 8.8, respectly, suceptible of selection for its purification and characterization through efficient and economical way. The others morphotypes only showed acid isoforms with pIs in the range of 4.0 and 5.0. Key words: biodeterioration; filamentous fungi; protease; hydrolytic halo; isoelectric point

  6. 交联型改性剂提高速生杨木材的应用品质及机理分析%Cross-linking modifier improves applied quality of fast-growing poplar

    Institute of Scientific and Technical Information of China (English)

    郎倩; 毕增; 郑雪; 苗新伟; 蒲俊文

    2013-01-01

    Wood is one of the oldest renewable resources used by human activity because of its many excellent material properties, such as good mechanical strength, aesthetic appearance, and easy processing. The main components of wood are cellulose, hemicelluloses, and lignin, accompanied by minor contributions of low molecular weight compounds and mineral salts. The major drawback of wood, intrinsically connected with the structure of its three main macromolecular components, is that it is easily affected by environmental factors, such as light, water, temperature, and biological organisms. Wood modification is a generic term describing the application of chemical, physical, and biological methods to improve its’properties. The aim is to improve the performance of the wood, including improvements in dimensional stability against moisture and bio-deterioration, mechanical property, and weathering resistance. In the case of chemical modification, this involves treatment with various chemical polymers to reduce the content of hydroxyl groups. To enhance the applied quality, the functional wood modifier was used to modify the fast-growing poplar. The stress relaxation and the profile density of fast-growing poplar were analyzed. Moreover, the fast-growing poplar was characterized by the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Scanning Electron Microscope with Energy Dispersive X-Ray Analysis (SEM-EDXA). The results demonstrated that the plasticity of wood enhanced for stress relaxation dropped with increasing amounts of modifier. The XRD analysis showed that the crystalline properties of wood obviously increased, but the ordered structure of the crystalline region on the remaining cellulose was not disrupted after modification. FTIR data confirmed the cross-link reaction between wood fiber and modifier. The XPS analysis results indicated that the content of carbon elements decreased while of oxygen

  7. Preservation of a Bamboo Culm in Relation to its Structure%竹材结构的防腐

    Institute of Scientific and Technical Information of China (English)

    Prof. Dr. Walter Liese

    2005-01-01

    由于在露天环境中遭遇生物腐蚀,竹秆的持久性差,所以需要采取化学手段增强其耐力.但是它的解剖构造使化学物质难以像木材那样容易进入竹材.竹秆的外部由其表皮保护防水,不像木材那样有径向渗透的途径.而其内部腔隙也有保护性纤维.化学物质的主要渗透途径位于竹秆根部微管束的后生木质部.这些渗透途径分布于横剖面,很不均匀,且少,只占总面积的8~10%,而且在通过竹节时改变方向.由于在采伐时砍伤竹秆,通向导管的细胞腔被堵塞,渗透途径也受影响.周围的薄壁细胞是竹秆组织的主要部分,它们通过微小的纹孔互相连接,只能通过弥散进入.它们所含的淀粉是昆虫和某些真菌的食品.对纤维的保护也有赖于弥散.用化学物质进行保护,对于新鲜的含水量高的竹秆效果最好.就像简单的根部处理,或技术性较强的细胞液改善.新鲜竹秆的薄壁组织和纤维也能通过垂直弥散的方法得到保护.如进行滴渍和浸渍工作,最好在竹材含水分时劈开,因为薄壁组织容易接受弥散.技术措施如竹秆的水分储存和熏蒸的过程,与竹秆的自然结构,尤其是薄壁组织有关.%The low durability of a bamboo culm towards biodeterioration in an exposed environment requires mostly a protection with chemical solutions for long time use. Its anato mical structure, however, makes an efficient treatment difficult as bamboo provides more resistance to penetration than wood. At its outside the culm is protected by an epidermis as a water-tight seal. No pathways for radial penetration exist, like the ray cells in wood. Also on its inner side towards the lacuna a special tissue acts protective. Main avenues for penetration are the metaxylem vessels of the vascular bundles at the ends of the culm. They are unevenly distributed over the cross-section with only about 8~10% of the total area. Their strongly axial orientation is