Dissertations / Theses on the topic 'Biodeterioration'

The standard agar plate technique was found to be a good method for screening the presence of leachable antimicrobial additives in rubber compounds. However, this technique restricts the growth of microorganisms to the perimeter of the samples and is less satisfactory as a long term test. In a liquid medium, there should not be any problem for the microorganisms to gain access to the inorganic and organic nutrients as well as oxygen. Many experimental trials were carried out in liquid media under dynamic and static conditions with Streptomyces lipmanii NCIMB 9841 as test organism. This led to the development of the modified batch processes. The modified tests allowed experiments to be performed over a long period of time without concern of accumulation of toxins from the leachable antimicrobial additives in the rubber samples and the metabolites from the utilisation of carbon sources by the microorganisms. The test procedure developed proved to be very reproducible and repeatable. The use of neutral chemically defined media with no added carbon source, the absence of strong oxidation catalysts coupled with the use of proper control samples defined the least vigorous conditions for biodeterioration of rubber compounds. On the other hand, the degradation of the rubber compounds under field and semi-field tests is likely to be a combined effect of biodeterioration, hydrolytic degradation, leaching and oxidation of samples. Five strains of fungi and four strains of actinomycetes were tested against five carbon black-filled seal compounds. The types of rubbers used were based on natural, styrene/butadiene, peroxide-cured EPDM, sulphur-cured EPDM and acrylonitrile /butadiene rubbers. Among all the species tested, Nocardia was found to be the most aggressive group of microorganisms in affecting the rubber samples. The strains NCIMB 12811 and 12814 had activity towards vulcanised gum NR samples, whilst Nocardia asteriodes NCIMB 12082 was very capable of utilizing rubber additives. It was found that besides the physical dimensions, types and formulations of rubber compounds; test conditions such as temperature, agitation speed, pH; amount of rubber sample used per unit volume of test medium, and renewal or non-renewal of test media also played an important role in affecting the activities of microorganisms towards rubber compounds.

A survey was undertaken to determine the relative incidence of fungal biodeteriogens in contaminated in—service samples of synthetic and oil emulsion metal working fluids, and a list of isolates is submitted. A technique for assessing the concentration of surface—active components of both synthetic and oil emulsion metal working fluids is described. Results obtained using this technique provided evidence of surfactant depletion in oil emulsion fluids as a result of growth of a mixed fungal inoculum, but this effect was not recorded when these isolates were grown in synthetic fluids. Synthetic metal working fluds of known composition were formulated and the ability of selected fungal isolates to utilise both these fluids and the individual components thereof as sole sources of carbon and nitrogen was assessed. The metal working fluid components triethanolamine and diethanolamine borate were found to be readily available nutrient sources for growth of the isolates, the extent of growth being limited by the availability of carbon rather than nitrogen. Varying the initial pH of the medium was found to have no significant effect upon the extent of growth recorded at initial pH values of 7.0, 8.0 and 9.0. The use of respirometric techniques provided evidence to suggest that some of the enzymes involved in the fungal degradation of synthetic metal working fluid components might be inducible. The effect of fungal growth upon the composition of the complete synthetic metal working fluids was determined using the techniques of nuclear magnetic resonance spectroscopy and gas—liquid chromatography linked mass spectrometry. Results obtained using these techniques also provided evidence of the depletion of the triethanolamine and diethanolamine borate components of the complete fluids as a result of fungal growth.

Limestone built heritage is at risk from the effects of biofilms, a microbial community encapsulated in a matrix of sugars, protein and extracellular DNA. Although biofilm research has been carried out in Mediterranean regions, few studies cover temperate Northern Europe climates, or the UK. This study concentrates on bacterial colonisation of Lincoln limestone, a highly vulnerable building material, and identifies the species, their role in biodeterioration and the efficacy of biocides against them. As part of this study the core species which comprise the bacterial component of the limestone microbiome have been characterised for the first time; this has allowed the identification of non-core species which are significantly associated with damaged and undamaged surfaces. Four mechanisms of biodeterioration have been identified, one previously unidentified, and isolated species have been characterised as to whether they are biodeteriorative and the mechanisms of biodeterioration that they employ. Two species, Curtobacterium flaccumfaciens and Solibacillus silvestris, have been characterised as producing biofilm matrix which actively causes biomechanical damage to the oolitic limestone structure as opposed to the passive enhancement of physical weathering which has been previously associated with biofilm matrix. Species capable of biodeterioration have also been shown to be present on both damaged and undamaged surfaces, something which has not been previously investigated. Environmental sampling, species identification and characterisation of species for biodeterioration have all combined to identify markers of biodeterioration, ie both physical markers and biomarkers. Specifically, a surface pH of 5.5 or lower and the presence of B. licheniformis is indicative of biodeterioration with a proportionally higher level of M. luteus when comparing damaged and undamaged stone. Finally this study brings the literature on conservation methods up to date by testing biocides which are in current usage, as many biocides in the literature are discontinued. This study is also the first in the field to show their efficacy against biofilm encapsulated bacteria and their propensity for chemically disrupting the biofilm matrix.

Biodeterioration is the least understood decay mechanisms of outdoor stone monuments. Microbial colonisation is largely determined by the properties of the stone and environmental conditions. The literature on microorganisms on outdoor stone monuments and their decay mechanisms was reviewed. For the assessment and quantification of microbial deterioration, methods that can be carried out by cultural heritage conservators with limited microbiological skills were selected and adjusted for the application on outdoor stone monuments. To this end, the total biomass was quantified by a protein assay (Folin-Lowry method), its phototrophic contribution through chlorophyll a absorbance and the amount of extracellular substances (EPS) were assessed by carbohydrate quantification (phenol method). Microbial activity was measured through two different enzyme assays: fluorescein diacetate cleavage and dehydrogenase activity (INT reduction). In order to develop a long-term monitoring strategy, these parameters were tested in the morning (8 am) and in the afternoon (4 pm) on biofilms from a sunny and a shady sampling site on a limestone wall in the south of Mexico. The experiments were performed in the dry season and the rainy season. Changes in biofilm composition and activity during the day were very small, while seasonal changes were more pronounced. The largest differences could be seen in samples from the different sampling sites (sun and shade), where the microbial population had established over years of distinct environmental conditions. Variations in biofilm composition and activity exceeding such natural variation may indicate the necessity for an antimicrobial treatment. The choice of an antimicrobial agent is difficult and the ideal treatment does not exist. Of the various chemical antimicrobial agents tested (Mergal K14, Parmetol DF12, Troysan S97, Preventol R50 hydrogen peroxide and ethanol) on microbial biofilms on stone, ethanol (70%) was the most effective, as revealed by ATP measurements. A flexible, non-invasive in vivo system, employing the bioluminescent bacterium Vibrio fischeri, was developed to assess sub-lethal effects of antimicrobial treatments and to test combined treatments for synergy. Various biocides and ultrasound (267 kHz, 20 kHz), alone and in combination, were tested for their effect on V. fischeri (Mergal K14, Parmetol DF12, Troysan S97, Preventol R50 hydrogen peroxide and ethanol) and a microbial biofilm on stone (Troysan S97, Preventol R50 and ethanol). The tests did not reveal synergistic effects however, a systematic, comprehensive study on chemical and/or physical methods might reveal an innovative approach towards a more environmentally friendly microbial eradication method for outdoor stone monuments. Long-term monitoring of the composition and activity of a microbial biofilm may provide data to determine if an antimicrobial treatment is necessary. If an antimicrobial intervention cannot be avoided, low-toxic substances, such as ethanol, should be considered first. For the evaluation of the success of an antimicrobial treatment, ATP measurement has proven to be a reliable and simple method that does not require specialised skills.

Fusarium solani, a mould normally associated with the biodeterioration of harvested crops and plants was identified as the species responsible for contamination and biodeterioration of an aqueous antacid formulation. The spoiled preparation was rendered vulnerable to opportunist pathogens during consumption and became implicated during several cases of infantile gastrointestinal infections. The Fusarium solani strain isolated was thought to be resistant to the antacid preservative system and capable of producing toxic metabolites during growth within the suspension. Experiments in submerged culture not only demonstrated the mould's resistance to the preservative Bronopol but highlighted its utilisation of the nitro group within that compound. Investigations failed to establish any links between this strain of Fusarium and the production of trichothecenes, however that it may become toxigenic under certain environmental conditions could not be ruled out. The action of the antacid suspension as a sporulation medium was assessed by examining the carbon/nitrogen ratio within the formulation and the effect individual ingredients had on the sporulation stimulus, this included monitoring the type of spores generated. The effects of pH on the induction of sporulation were also examined in shake flask culture. Members of the genus Fusarium can thus be directly involved in the biodeterioration (spoilage) of aqueous pharmaceutical suspensions. Their origin can be traced to damp conditions in the manufacturing environments of such products and are, therefore, not isolated to one specific manufacturing facility. Examination of other antacid suspensions has also indicated that this type of contamination, while not common, is certainly not rare. The reformulation of such products to preclude contamination by Fusarium solani would seem to be a necessary aspect of their future pharmaceutical development.

Animal hides are the basic raw material of the leather industry and they undergo rapid putrefaction unless "cured". This study investigated the role and interactive effects of three selected bacteria, Pseudomonas aeruginosa. Clostridium histoly ticum and Clostridium sporogenes in in-situ cattle hide degradation using a model system set up for the purpose. The system consisted of 3cm diameter hide pieces contained in sealed jars and sterilised by ethylene oxide to remove resident microbes and inactivate autolytic tissue enzymes. The inocula were prepared either as individual cultures or as combinations of two inocula or all three inocula. Degradative changes during storage at 30°C were measured for up to 8 days using ten different parameters. Initial trials confirmed that the selected inocula were readily isolated from raw hides and could outcompete resident populations to produce putrefactive decomposition. Growth rates and enzyme profiles of the organisms and the effects of nutrients and reductants on their relative denaturative effects were used to standardise the system. Trials on the effects of ethylene oxide indicated the suitability of the method for hide and collagen sterilisation. The findings of in-situ trials with the selected inocula confirmed previous studies of protein putrefaction in that a bacterial succession was evident involving aerobic proteolytic bacteria, micro-aerophilic proteolytic bacteria and strictly anaerobic amino acid degrading bacteria. However, this study showed that the micro-aerophilic collagenase producing C. histolyticum degraded hides at a far greater rate when inoculated on its own than when in the presence of either or both of the other two inocula. It also demonstrated a bacterial antagonism between the two clostridia in which C. sporogenes prevented degradative changes occurring for up to 4-6 days possibly due to cysteine production by C. sporogenes. These findings have implications for hide preservation since maintenance of aerobic conditions and suppression of spore outgrowth could be used to delay growth of collagenase producing clostridia. The use of C. sporogenes as a biocontrol agent is also postulated. The model system was also used to examine salted hides during storage and these studies indicated that Halobacteriaceae do not produce collagenase but that inadequately salted hides could possibly be subject to degradation by delsulfovibrios.

Different techniques were studied to evaluate the presence of different microorganisms that played important roles in decay processes of historic stones. In that scope, limestones and sandstones from Nemrut Mount Monument, and marbles and andesites from Temple of Augustus were studied. For measurement of enzymatic activity, fluorescein diacetate (FDA) hydrolysis method previously applied to assess soil microbial activity was carried out. Total microflora method based on countings of colony number was conducted for determination of the level of bacterial and fungal activity of stones. ATP bioluminescence method, developed for the field of hygiene monitoring, was carried out in order to detect global metabolic activity degree in historic stones. Most probable number (MPN) method was carried out to detect the number of microbial cells, namely nitrifying and sulphur oxidising bacteria which could take part in the decay processes. Moreover, fungi identification was done for determining occurance of detrimental species. Presence of lichenic and algal zones existed on stones of Nemrut Mount Monument and the presence of black discolorations on stones of Temple of Augustus was common. Results have shown that the bacterial and fungal activity was low, however considerable quantity of FDA hydrolyses has shown the importance of algal population in the stones of two studied historical sites. This study has proved that FDA hydrolyses, total microflora and MPN method were efficient for the evaluation of biodeterioration in historic stones.

Metal shaping processes are clear examples of engineering applications where a hard material is worn by a softer one - i.e. the tool and workpiece respectively. The soft impressor technique, introduced by Brookes and Green (1973), has proved valuable in measuring the relevant mechanical properties of tool materials - e.g. the measurement of the flow stress of diamond single crystals at temperatures up to 1500°C (Brookes, 1992). In this work, the technique has been extended further in order to form a basis for the comparison and evaluation of ultra-hard materials. Three main aspects of the performance of these tool materials have been covered: the effect of temperature on flow stress; cumulative deformation under point loading conditions; wear due to repeated traversals (fatigue). In the first part, the technique has been extended to determine the flow stress of polycrystalline diamond and cubic boron nitride as a function of temperature and a mathematical model has been proposed to estimate the flow stress in isotropic polycrystalline materials. This model was first analysed by Love (1928) and was used as the basis on which to identify the threshold pressure above which dislocation movement is initiated in diamond single crystals (Brookes et al (1990)). The applicability of this model for polycrystals was verified by correlating the yield strength of polycrystalline copper, measured in tension, with the determination of minimum contact mean pressure to plastically deform the same material. According to the model, the first evidence of plastic deformation should be observed at the contact periphery and this has been verified in this work. Consequently, using this approach, the effect of temperature on the flow stress of polycrystalline diamond (Syndax) and polycrystalline cubic boron nitride (Amborite) has been established and it is shown that there are three distinct regimes. In regime I, the deformation is brittle and fracture occurs above a given mean pressure; in regime II dislocations are mobile and the flow stress decreases sharply as the temperature rises; and in regime III the flow stress is independent of the temperature. In the earlier work, the brittle-ductile transition temperature (BOT) has been identified as that temperature where regime I ends and II begins. Above the BDT, time dependent plastic flow has been observed, in all of these materials, leading to a measurable increase in the size of the impression. However, this particular type of cumulative deformation, described as impression creep, is shown to be different to conventional creep as measured under uniaxial stress conditions. Finally, the room temperature friction and deformation of various polycrystalline diamond based specimens, Le. aggregates with a binder phase of cobalt (Syndite) or silicon carbide (Syndax), a polycrystalline coating produced by a chemical vapour deposition processes (CVDite) and cubic boron nitride (Amborite) were studied when softer metallic and ceramic sliders were used. As a result of increasing the number of traversals, significant wear of the CVDite diamond coating by softer metallic sliders (aluminium and mild steel) was observed. This could be attributed to the high level of residual stresses in the diamond layer which is thought to be due to the difference in the thermal expansion coefficients of the coatings and their substrates. Burton et al (1995) reported a strain of 0.3% on the surface of the diamond coating and hence the tensile stress on the upper side of the coating will be equivalent to about 3.0 GPa. This value is comparable to the theoretical cleavage strength of diamond. It is suggested an additional tensile stress, due to the sliding friction, could have caused cleavage of individual diamond crystals. The resultant wear debris then becoming embedded in the metallic slider. These embedded diamond particles in the tip of the slider could be responsible for the increased friction and wear.

Dans le contexte actuel d’accroissement de la population mondiale, il est nécessaire de construire d’avantage d’infrastructures pour répondre à la pression industrielle grandissante. Ces constructions se font principalement sur la mer comme les ports, les îles artificielles ou encore les logements touristiques. Le béton est le matériau majoritairement utilisé en raison de son faible coût de production mais aussi de sa résistance à l’eau de mer. Comme tout matériau immergé en milieu marin, le béton est colonisé par les organismes vivants, devenant ainsi support de leur développement. Cependant, l’eau de mer est un milieu particulièrement agressif vis-à-vis des matériaux cimentaires ; des dégradations physiques, chimiques et biologiques sont observées dans le temps. Les deux premiers types de dégradation sont particulièrement bien documentés par la communauté scientifique. En revanche, les dégradations biologiques sont peu étudiées. L’objectif de cette thèse est donc de tout d’abord mettre en place un dispositif expérimental en laboratoire, permettant la colonisation d’un matériau cimentaire par des microorganismes. Des outils pertinents pour caractériser le biofilm sur le matériau ont été choisis après une étude bibliographique, dans le but de mieux comprendre la cinétique de colonisation. Des analyses chimiques du matériau ainsi que de l’eau de mer artificielle ont été effectuées à échéances régulières pour évaluer les actions du biofilm sur le matériau cimentaire. Différents matériaux ont été formulés pour étudier l’impact de la formulation sur la colonisation
In the current context of increased world population, it is necessary to built more infrastructures to meet the increasing industrial pressure. These constructions are erected on the sea as harbors, artificial islands or tourist accommodation. Concrete is mainly used because of its low-cost and durability in the marine environment. Like any material immersed in seawater, concrete is colonized by living organisms, becoming an habitat for their development. However, seawater is a very aggressive environment towards cementitious materials; physical, chemical and biological degradations are observed with time. Nowadays, physical and chemical degradations are well understood and reported in the literature but there is a lack of knowledge concerning biological effects. The aim of this thesis is first develop an experimental device in laboratory, allowing the colonization of cementitious material by microorganisms. Relevant tools to characterize the biofilm on the material were chosen to better understand colonisation’s kinetic. Chemical analysis of material and seawater were made to evaluate the actions of the biofilm on cementitious material. Different materials were produced to study the impact of the formulation on the colonization

During firing, the deformation of ceramic articles under their own weight may be problematic particularly in the sanitary ware industry where articles are large. A model has been developed that predicts the viscoelastic deformation of a range of vitreous china testpieces during the firing process. The model constitutes a novel application of the transmission line modelling technique to viscoelastic deformation. The applicability of the model to the sanitary ware industry is addressed.

This thesis describes the novel test techniques that were developed to measure the parameters associated with the plastic shrinkage, and subsequent possible plastic shrinkage cracking, of high strength concrete. The parameters measured during the first 24 hours after placing were the stress- strain relationship, negative pore pressure and free shrinkage strain development. The plastic behaviour of eight high strength concrete mixes was quantified and these mixes were then tested to assess their propensity towards plastic shrinkage cracking, using restrained ring tests. A review of the parameters associated with plastic shrinkage cracking was carried out. The general view was that as the particle size in a cement matrix gets smaller, then the negative pore pressures developed are greater and hence shrinkage increases. This meant that the presence of secondary cementing materials, of very small diameter, such as microsilica, in high strength concretes would explain their apparent susceptibility to plastic shrinkage cracking. Eight high strength concrete mixes were tested in exposed and sealed conditions. It was found that when tested in sealed conditions none of the parameters measured presented itself as the sole driving force behind plastic shrinkage or plastic shrinkage cracking. Also, when cured in sealed conditions, none of the mixes tested in the restrained ring test apparatus cracked. When tested in exposed conditions, the presence of wind had little effect on the stress-strain relationship of the mixes tested. However the presence of wind seemed to cause negative pore pressures to develop earlier than in the sealed samples and increased free shrinkage by 3 to 40 times depending on the mix. The samples that exhibited the highest free shrinkage strains, in exposed conditions, were the mixes that cracked when tested in the restrained shrinkage rings. The mixes that cracked all contained microsilica and these mixes did not crack when the same mixes were tested without microsilica. Polypropylene fibres were found to reduce the cracked area of the samples that cracked. The supplementary cementing materials used in this study were ground granulated blast furnace slag, metakaolin, microsilica and pulverised fuel ash.

Green building standards recommend use of a variety of new thermal insulation products. However, durability of wooden framing used in conjunction with new insulation materials has not been thoroughly examined, specifically in reference to interstitial condensation. This research used a single-sided hot-box design to measure moisture content of wood framing during a 60-day period. The resulting moisture content of the wood framing was compared as tested with spray-applied cellulose and polyurethane versus fiberglass batt insulation. The average moisture content of framing insulated with cellulose and polyurethane was greater than framing insulated with fiberglass. Based on the results from this research, the use of spray-applied cellulose and polyurethane insulation materials may increase the risk of structural durability. Green building standards, such as LEED for Homes or the National Green Building Standard, emphasize creating energy efficient structures to limit negative impact on the environment. Green building practices employed to increase energy efficiency of the building enclosure may overlook possible adverse effects that these practices may have on structural durability. Because spray-applied cellulose and polyurethane insulation increase moisture content of wooden framework within building enclosures, it can be deduced that energy efficient insulation may increase risk of moisture-related biodeterioration of the building enclosure. After review of points awarded for insulation materials within LEED for Homes and the National Green Building Standard, results from this study imply that the National Green Building Standard does not emphasize durability of wooden structures in their guidelines at the present time.
Master of Science

Egg (the whole, the yolk or the white) is a natural product used since ancient times as tempera painting medium mainly in Europe and the Mediterranean Basin countries. In addition, egg is a complex multicomponent microstructured system susceptible of being influenced by the pigments that compose the paints, as well as a source of nutrient susceptible of biodeterioration. Modifying effect of artists' pigments on the binding medium as well as, the microbial biodeterioration are responsible for changes in the structure and composition of the binding medium and, consequently, on the physico-chemical properties of the paint. For this purpose, analytical techniques such as Fourier transform infrared spectroscopy - attenuated total reflection (FTIR-ATR) was used for the chemical characterization, Field emission scanning microscopy (FESEM) and Atomic force microscopy - nanoindentation (AFM-nanoindentation) were run for morphological and mechanical characterization of the deterioration processes resulted from the pigment-binder interactions involved in tempera painting. On the other hand, the current research report the application of the voltammetry of microparticles (VMP), complemented with FTIR-ATR, FESEM and AFM-nanoindentation techniques to monitor the deterioration of a series of tempera reconstructed model paint specimens under the action of different biological agents. This methodology would be of application for identifying the type of biological agent causing deterioration of painting, which is an important problem affecting cultural heritage. The analysis of biodeterioration processes is complicated by the fact that the action of microorganisms can affect both pigment and binding media. The deterioration of pictorial specimens by Acremonium chrysogenum, Aspergillus niger, Mucor rouxii, Penicillium chrysogenum and Trichoderma pseudokoningii fungi and Arthrobacter oxydans, Bacillus amyloliquefaciens and Streptomyces cellulofans bacteria was tested using sample-modified graphite electrodes immersed into aqueous electrolytes. Finally, the study carried out by means of FTIR-ATR, FESEM and AFM-nanoindentation confirms that egg proteins attached to the pigment grains changes their secondary structures. The results obtained also confirm that proteins and phospholipids are prevalently established linkages with the solid particles of pigment whereas triglycerides should be integrated in the complex binding network responsible for the cohesion of the paint film. Interactions between egg components with solid pigment particles are described and correlated with micromorphology and mechanical properties determined at micro- and nano-scale on the reconstructed model paint specimens. As a result of the crossing of VMP data with the results obtained by means of FTIR, FESEM and AFM-nanoindentation, the voltammetric signals obtained were associated to the electrochemical reduction of pigments and different complexes associated to the binding media. These results were particularly relevant in the study of biodeterioration, to allowing the electrochemical monitoring of biological attack.
El huevo (entero, yema o clara) es un producto natural utilizado desde la antigüedad como medio aglutinante en la pintura al temple, principalmente en Europa y los países de la cuenca mediterránea. Además, el huevo es un complejo sistema multicomponente microestructurado susceptible de ser alterado por los pigmentos que componen las pinturas, así como fuente de nutrientes susceptible de biodeterioro. El efecto de los pigmentos sobre el medio aglutinante, así como el biodeterioro microbiano son responsables de cambios en la estructura y composición del medio aglutinante y, por consiguiente, en las propiedades fisicoquímicas de la pintura. Es por esto que, se utilizaron técnicas analíticas como la Espectroscopía Infrarroja por Transformada de Fourier en modo Reflexión Total Atenuada (FTIR-ATR), para la caracterización química de los procesos de deterioro resultantes de las interacciones pigmento-aglutinante en la pintura al temple. Así mismo, se utilizó Microscopía Electrónica de Emisión de Barrido (FESEM) para el estudio morfológico de las muestras, y para el estudio de las propiedades mecánicas Microscopía de Fuerza Atómica en modo Nanoindentación (AFM-nanoindentación). Por otro lado, la presente investigación propone el uso de la Voltamperometría de Micropartículas (VMP), en conjunto con otras técnicas de análisis como FTIR-ATR, FESEM y AFM-nanoindentación para el estudio del biodeterioro producido por hongos y bacterias sobre una serie muestras pictóricas sometidas. El estudio de las alteraciones causadas por el biodeterioro es complicado por el hecho de que la acción de los microorganismos puede afectar tanto al pigmento como al medio aglutinante. Para esto, se prepararon una serie de muestras de pinturas al temple y emulsión que fueron inoculadas con los hongos Acremonium chrysogenum, Aspergillus niger, Mucor rouxii, Penicillium chrysogenum, y Trichoderma pseudokoningii, y las bacterias Arthrobacter oxydans, Bacillus amyloliquefaciens y Streptomyces cellulofans. El estudio voltamperometrico se realizó utilizando electrodos de grafito modificados con las muestras inmersos en un electrolito acuoso. Las conclusiones obtenidas de manera general, apuntan a que las proteínas presentes en el huevo cambian su estructura secundaria al adherirse a los granos de pigmento. La información química, morfológica y mecánica obtenida por las diferentes técnicas de análisis instrumental es consistente. Finalmente, como resultado del cruce de los datos VMP con los resultados obtenidos mediante FTIR, FESEM y AFM-nanoindentación, las señales voltamperometricas obtenidas se asociaron a la reducción electroquímica de los pigmentos y a los complejos formados con el medio aglutinante. Estos resultados fueron particularmente relevantes en el estudio del biodeterioro de las películas pictóricas inoculadas, para permitir la monitorización electroquímica del ataque microbiológico.
L'ou (sencer, rovell o clara) és un producte natural utilitzat des de l'antiguitat com a mitjà aglutinant en la pintura al tremp, principalment a Europa i els països de la conca mediterrània. A més, l'ou és un complex sistema multicomponent MICROESTRUCTURAT susceptible de ser alterat pels pigments que componen les pintures, així com a font de nutrients susceptible de biodeterioració. L'efecte dels pigments sobre el medi aglutinant, així com el BIODETERIORI microbià són responsables de canvis en l'estructura i composició del medi aglutinant i, per tant, en les propietats fisicoquímiques de la pintura. És per això que, es van utilitzar tècniques analítiques com l'Espectroscòpia Infraroja per Transformada de Fourier en mode Reflexió Total Atenuada (FTIR-ATR), per a la caracterització química dels processos de deteriorament resultants de les interaccions pigment-aglutinant en la pintura al tremp. Així mateix, es va utilitzar Microscòpia Electrònica d'emissió de Rastreig (FESEM) per a l'estudi morfològic de les mostres, i per a l'estudi de les propietats mecàniques Microscòpia de Força Atòmica en mode Nanoindentació (AFM-nanoindentació). D'altra banda, la present investigació proposa l'ús de la Voltamperometría de Micropartícules (VMP), en conjunt amb altres tècniques d'anàlisi, com FTIR-ATR, FESEM i AFM-nanoindentació per a l'estudi de l'biodeterioració produït per fongs i bacteris sobre una sèrie de mostres pictòriques sotmeses. L'estudi de les alteracions causades pel biodeteriori és complicat pel fet que l'acció dels microorganismes pot afectar tant el pigment com al medi aglutinant. Per això, es van preparar una sèrie de mostres de pintures al tremp i emulsió que van ser inoculades amb els fongs Acremonium chrysogenum, Aspergillus niger, Mucor rouxii, Penicillium chrysogenum, i Trichoderma pseudokoningii i els bacteris Arthrobacter oxydans, Bacillus amyloliquefaciens i Streptomyces cellulofans. L'estudi voltamperomètric es va realitzar utilitzant electrodes de grafit modificats amb les mostres immersos en un electròlit aquós. Les conclusions obtingudes de manera general, apunten que les proteïnes presents en l'ou canvien la seva estructura secundària al adherir-se als grans de pigment. La informació química, morfològica i mecànica obtinguda per les diferents tècniques d'anàlisi instrumental és consistent. Finalment, com a resultat de l'encreuament de les dades VMP amb els resultats obtinguts mitjançant FTIR, FESEM i AFM-nanoindentació, els senyals voltamperomètrics obtinguts es van associar a la reducció electroquímica dels pigments i als complexos formats amb el medi aglutinant. Aquests resultats van ser particularment rellevants en l'estudi del biodeteriori de les pel·lícules pictòriques inoculades, per tal de permetre la monitorització electroquímica de l'atac microbiològic.
Ortiz Miranda, A. (2017). Development of analytical methods for the characterization of tempera paintings at micro- and nano-scale and their deterioration and biodeterioration processes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90571
TESIS

The aim of this work is the fungal contamination assessment on mortar painted with waterborne paint with and without biocide, this material is widely used in building. The identification of the commonest fungal species in this region and during one year and the biofilm gradual development was analysed and environment temperature, superficial temperature and humidity were also evaluated. Beyond the environment experiment, paper painted with 7 waterbonr paint were setting in controlled environment. The results showed that the main contaminants were Cladosporium sp. e Penicillium sp., that were settled on paint during all seasons. The others contaminants were: Alternaria sp., Aspergillus nigrum e A. aureum, Curvularia sp., Phoma sp. e Epicoccum nigrum and two fungal mycelia. In the environmental experiment, the best performance was paint 7, halb-brightness paint, commercially called first line. The controlled experiment showed that it needs a better development for its application, because it had a diverse results in relation to the field assay.
Este trabalho tem por objetivo o estudo da contaminação fúngica, tendo como substrato argamassa pintada com película seca de tinta latéx com e sem biocida, material amplamente utilizado no revertimento das paredes de residências e estabelecimentos comerciais. Procurouse identificar as espécies fúngicas mais comuns encontradas na região, como também a evolução do biofilme, e a incidência da microbiota fúngica em diversas épocas do ano. Foram identificadas as espécies de maior incidência na região em relação aos doze meses do ano, levando-se em consideração as temperaturas tanto ambientais como de superfície do substrato e a umidade relativa do ar. Além do experimento ambiental, foi empregado o ensaio acelerado utilizando-se papel pintado com os diversos tipos de tinta. Os resultados demonstraram que os principais contaminantes são Cladosporium sp. e Penicillium sp., estando esses fungos presentes nas quatro estações do ano. Os demais contaminantes, mas em menor proporção, são os fungos: Alternaria sp., Aspergillus nigrum e A. aureum, bem como os fungos Curvularia sp., Phoma sp. e Epicoccum nigrum, além de outros dois fungos que não apresentaram esporulação. No ensaio ambiental a tinta com melhor desempenho foi a tinta 7, semi-brilho, denominada comercialmente de primeira linha. O resultado do experimento acelerado demonstrou a necessidade de um melhor desenvolvimento do mesmo para sua aplicação, devido aos resultados diversos em relação ao ensaio de campo.

The aim of this work has been to use the soft impressor technique to investigate the plastic deformation of single crystal diamond and in particular to determine the effect that single substitutional nitrogen has on plasticity. Traditionally hardness tests in the form of Vickers or Knoop rigid indenters have been used to investigate the mechanical properties of materials which cannot be fabricated into tensile or three point bend test specimens. The high stress concentrations created by these types of test introduce a large degree of brittle failure in ultra-hard, covalently bonded materials. The soft impressor technique, on the other hand, allows large pressures to be applied without large stress concentrations. The result is that plastic deformation can be more readily induced into super hard materials such as diamond. This work has shown that not only can diamond be readily plastically deformed but that traces of nitrogen impurities within the lattice have a significant effect on the conditions necessary to produce dislocations. For this work, several different soft impressors were used to produce a range of pressures in the temperature range 800° to 1400°C. A selection of synthetic (HPHT) diamonds with various nitrogen concentrations were impressed and compared with impressions placed in natural type IIa specimens containing no nitrogen but heavily dislocated. Numerous analytical techniques were used to determine the level of deformation produced and gain a better understanding of the effect of nitrogen related defects. The first two chapters of this thesis review, first plasticity and then diamond, with reference to those properties/characteristics relevant to this topic. The third chapter discusses the principle of the soft impressor technique and the methodologies used. In the fourth chapter, models by which single crystal diamond plastically deforms are introduced, together with results that have extended the brittle-ductile transition schematic produced by Brookes, EJ. (1992). Results on the effect of dwell time and the phenomenon of impression creep are also presented. The fifth chapter identifies the predominant defects associated with substitutional nitrogen in HPHT diamond and presents profiles of impressions for diamonds with different 'grown-in' defect levels. The results are discussed and conclusions are made, in conjunction with suggestions for further work in chapter 6.

Dissertação apresentada para a obtenção do grau de Doutor em Conservação e Restauro pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia
The conservation of historic buildings and monuments from cultural heritage is a major issue in modern societies, both from an economical and cultural point of view. The wide distribution of stone monuments and lithic works of art, and their cultural, artistic and religious importance emphasise the general need to safeguard this praiseworthy cultural heritage. This PhD thesis arises from the growing national and international interest on the biodeterioration of stone cultural heritage as one of the most complex areas of stone conservation and restoration. This study aimed to evaluate the primary bioreceptivity of limestones widely used as building materials in European countries from the Mediterranean Basin. In the first instance, a review of the literature was achieved in order to compare and be acquainted with the most abundant cyanobacteria and green algae detected on stone monuments. Gloeocapsa, Phormidium and Chroococcus, among cyanobacteria, and Chlorella, Stichococcus and Chlorococcum, among chlorophyta, were the most widespread genera identified on outdoor stone monuments. Limestone and marble were the lithotypes presenting the greatest diversity of phototrophic microorganisms. In the second step, five green biofilms were collected from Orologio Tower in Martano (Italy), Santa Clara-a-Velha Monastery (Coimbra) and Ajuda National Palace(Lisbon), both in Portugal, and Seville and Granada Cathedrals from Spain. The biofilm samples were subsequently characterised by molecular biology techniques and cultivated under laboratory conditions. DNA-based molecular analysis of 16S rRNA gene fragments revealed that the biofilms from Orologio Tower and Santa Clara-a-Velha Monastery were dominated by the microalga Chlorella, whereas the cyanobacterium Chroococcidiopsis was the dominating genus from Ajuda National Palace. The biofilms from Seville and Granada Cathedrals (Spain) were both dominated by the cyanobacterium Pleurocapsa. DGGE analysis of the cultivated biofilms revealed a remarkable stability of the microbial components from the Coimbra biofilm. This multiple-species phototrophic culture was further used as inoculum for stone bioreceptivity experiments. Laboratory-based stone colonisations relied on the inoculation of five limestone types with the selected biofilm culture, incubation within a growth chamber and monitoring of photosynthetic biomass through different analytical approaches. Subsequently, the primary bioreceptivity of Ançã (CA) and Lioz (CL) limestones, San Cristobal (SC) and Escúzar (PF) stones and Lecce stone (PL) was determined, evaluating the relationship between stone intrinsic properties and photosynthetic growth. The results were statistically analysed by means of principal component analysis (PCA) and analysis of variance (ANOVA)in an attempt to determine their bioreceptivity to phototrophic microorganisms and to evaluate the direct relationships between stone bioreceptivity and petrophysical properties.

La contamination fongique est un problème majeur de conservation des œuvres d’art et des monuments historiques. Les travaux de thèse ont pour objet d’étudier la biodiversité microbienne associée à la biodégradation du bois dans les bâtiments historiques dans un contexte de développement de traitements alternatifs aux traitements actuels. Différents monuments historiques seront inclus dans l’étude avec notamment le pavillon de la Muette dans la forêt de Saint Germain en Laye. La biodiversité microbienne sera appréhendée par des approches classiques de culture et par des approches de biologie moléculaire. La sensibilité à des agents antifongiques de référence, à des biocides couramment utilisés en traitement de bâtiments et à des molécules naturelles (huiles essentielles, tanins, etc.), de souches de champignons isolées de monuments contaminés sera étudiée. L’action antimicrobienne sera appréhendée par quantification d’inhibition de croissance et par imagerie afin de décrire les effets morphologiques. De la même manière que les traitements antifongiques, l’application de stratégies de biocontrôle du développement de champignons lignivores sera évaluée in vitro avec différents microorganismes décrits comme ayant ce type d’activité (souches de Bacillus, de Trichoderma). Les différents traitements seront évalués en laboratoire selon les tests de référence. Des associations de différents traitements seront testées afin de rechercher des effets synergiques ou additifs. L’objectif global est d’apporter de nouvelles connaissances sur les champignons lignivores et leur biodiversité et d’ouvrir la voie vers le développement de traitements du bois innovants applicables à la préservation du patrimoine
Fungal contamination is a major problem for art and historical monuments conservation. The thesis work aims to study microbial diversity associated with biodegradation of wood in historic buildings in a context of development of alternative treatments to current treatments. Various historical monuments will be included in the study including the Pavilion de la Muette in the forest of Saint Germain en Laye. Microbial biodiversity will be apprehended by conventional culture approaches and by molecular biology approaches. The sensitivity to antifungal agents of reference, biocide commonly used in treatment of buildings and natural molecules (essential oils, tannins, etc.) will be studied on the fungal strains isolated from contaminated monuments. The antimicrobial action will be apprehended by growth inhibition and quantification imaging to describe the morphological effects. Application of biocontrol strategies for the development of wood-destroying fungi will be evaluated in vitro with different microorganisms described as having this type of activity (Bacillus strains of Trichoderma). The treatments will be evaluated according to laboratory reference testing. Different associations of treatments will be performed to find synergistic or additive effects. The overall goal is to bring new data on wood-destroying fungi and their biodiversity and to pave the way towards the development of innovative timber treatment applicable to heritage preservation

Abstract In recent years, operators in the restoration sector are adding to their historical-artistic competences also scientific knowledge in order to find solutions more and more effective and respectful toward the cultural heritage, the operator and the environment. Among the different scientific branches, biotechnologies allow for an innovative and precise approach to the complexity of the problems that the restorer has to face in his own daily work. Biotechnology research in the field of cultural heritage develops in two directions: on the one hand focuses on the development of accurate diagnostic techniques, useful for the correct identification and characterization of alterations and biodeteriogens; on the other hand focuses on the development of innovative restoration methods, based on the employment of new products. The employment of biotechnologies in restoration of cultural heritage is the main topic of the present PhD doctoral thesis, which deals with both of the aforementioned sides. In Chapter 1 a review on the employment of biotechnologies in the field of cultural heritage is presented, considering both diagnostic techniques for characterization of biodeteriogens, and the use of microorganisms and enzymes for restoration. The first part of the thesis focuses on a microbial product, based on sulfate-reducing bacteria (SRB) belonging to D. vulgaris species, applied for the removal of sulfate crusts from artwork surfaces. In studies carried out in the last decades, this product has turned out to be very promising and favorable, compared to traditional restoration techniques, thanks to its capability of combining effectiveness to selectivity and safety for the restorer and the environment. Such a technology, original, innovative and sustainable, has been successfully experimented on important artworks. In Chapter 2 a review on the current knowledge of Desulfovibrio genus is presented, in particular concerning its physiology, biochemistry and biotechnological applications. Nevertheless, the D. vulgaris-based product presented four limitations: i) low production yields and inability of long-term conservation of D. vulgaris biomass; ii) lack of an appropriate method for monitoring of abundance and activity of the biomass; iii) time-consuming application technique; iv) application limited to stone surfaces. The overcoming of the above mentioned limitations has been the aim of the first part of the present work. A research work, structured in different phases, has been conducted for the optimization of the production process and the development of a method for the long-term conservation of the bacterial biomass (Chapter 3). Initially the laboratory protocol has been set up on small volumes at liter scale, in order to define the growth curve of the bacterium and evaluate its metabolic response to different substrates and growth conditions. subsequently the fermentative process has been transferred from the flask to 5 lt fermentor, optimizing the control of pH and H2S concentration. H2S is the main metabolic product in the fermentative process of SRB, its accumulation is toxic for bacteria, leading to unfavorable growth conditions. These improvements allowed a significant increase in biomass production, from a concentration of 1*108 cell/ml in 120h of fermentation in flask, to the concentration of 3*109 cell/ml in 72h of fermentation in bioreactor. For the long-term conservation of D. vulgaris biomass, freeze-drying has been carried out, testing the effectiveness of different cryoprotective agents. Among them, the best in terms of cell viability post-rehydration resulted to be lactose, which ensured the stability of the product for a minimum of 6 months. Chapter 4 deals with the development of new molecular approaches for monitoring of D. vulgaris biomass concentration and viability since traditionally employed methods, such as Most Probable Number (MPN) and microscope counting, resulted unsuitable. The research focused on the set up of a method applicable not only to liquid cultures, but also to cells embedded in the delivery system used for the applications of D. vulgaris cells on the surfaces during the biorestoration treatment. Among all the tested methods, the most effective and suitable resulted to be the spectrophotometric measurement of the fluorescence specifically emitted by the prosthetic group of bisulfite reductase, a key enzyme in dissimilatory sulfate reduction. The results showed that fluorescence emission is proportional to viable cells present in liquid culture as well as when embedded in the delivery system. Real-time PCR quantification of the SRB-specific dsr gene allowed to significantly quantify D. vulgaris cells in liquid culture, but when applied on cells embedded in the delivery system the detection limit (107 cell/ml) was too high to make this method efficient. The development of new methodologies for the application of D.vulgaris-based product, aimed at the reduction of time and number of required applications for the removal of sulfations, has been conducted on the funeral monument realized in memory of ‘Neera’, the poetess Anna Zuccari, located in the Cimitero Monumentale in Milan (Chapter 5). Besides biological treatment, two other methods have been tested: chemical treatment, based on the non-ionic detergent Tween 20 and a combined treatment, consisting in a chemical pre-treatment followed by the biological treatment. The combined method resulted to be effective in the removal of the black crust, without altering the underlying stone, obtaining a 70% reduction in cleaning time. Moreover, the combined method preserved all the advantages of the biocleaning approach: selectivity toward the alteration and respectfulness toward the original material. For the purpose of extending this biocleaning approach to substrates other than stone artworks, such as mural paintings, an experimentation has been carried out on two scenes belonging to the pictorial cycle decorating ‘Queen Teodolinda Chapel’ in Monza Cathedral (Chapter 6). The applicability test on surfaces characterised by fragility, such as pigmented surfaces, is of primary importance for the further development of this technology. The obtained results can be regarded very promising, in terms of sulfations removal and respectfulness towards such a delicate surface. However, this study has to be considered merely preliminary and incomplete, and further research must be conducted in order to verify the compatibility of the treatment with different kinds of materials, such as pigments. The last part of this thesis focuses on diagnostic methodologies for the identification and characterisation of biodeteriogens from two artworks. In the past, microorganisms responsible for deterioration of cultural assets were identified through conventional methods based on the cultivation of potential biodeteriogen microorganisms and their identification and phenotypic characterisation. Here molecular biology technologies independent from bacteria cultivation were employed, which complete and expand the information provided by the cultivation-dependent approach. These methodologies have been employed for the analysis of an acrylic monochrome painting on canvas realised by the artist E. Castellani (Chapter 7) and of a paper print realized in the 17th century, conserved in the Monastery of “S. Maria al Carrobiolo” in Monza (Chapter 8). The acrylic monochrome painting on canvas presented alterations characterised by yellow-earth/red point areas of different extensions, spread on the whole posterior surface. Molecular analyses on the total microbial community have been carried out through Denaturing Gradient Gel Electrophoresis (DGGE) method. Among the identified bacteria, the most abundant were Bacillus subtilis, Bacillus licheniformis and Deinococcus gobiensis; whereas among fungi, Leptosphaerulina and Penicillium genera. Culture-dependent techniques confirmed the dominance of bacteria belonging to Bacillus genus, whilst no fungal species has been isolated. However, presence of fungi was confirmed by microscope analysis, which allowed the visualization of fungal hyphae and spores in all the samples. Considering morphology and dimensions, these structures visualized by microscope were ascribable to mycelia and spores of fungi belonging to Penicillium genus, confirmed also by comparison with literature images. Afterwards the characterization of microbial community, the activity of four different biocides on the potential biodeteriogens was evaluated. Biotin N, Biotin R, New Des 50 and Amuchina (in single and mixed) were tested toward the single microbial isolates and the whole microbial community. According to the antibiogram test, the combination of Biotin R 4% in ethyl acetate + Biotin N 4% in white spirit resulted to be the most effective in terms of inhibiting activity, both on single strains and on the whole bacterial community. The paper print realized in the 17th century, conserved in the Monastery of “S. Maria al Carrobiolo” in Monza, presented whitenings and small dark spots, on the obverse and on the reverse side, respectively. In this case, a microbial investigation was executed through culture-dependent techniques for the isolation of bacteria and fungi, in order to characterize the possible deteriogens and determine their phylogenetic affiliation. The results demonstrated a negligible presence of bacteria. The most frequently cultured strains belonged to the Staphylococcus genus, which is associated to human skin, and to the Sphingomonas genus, which is an environmental bacterium, which have never been associated to biodeteriogen activity. As concerns fungi, the results showed a dominant presence of Neurospora pannonica, both on the obverse and on the reverse side of the print. In summary, the research emphasized the importance of biotechnologies in the field of cultural heritage. The optimization of D. vulgaris-based product, described in the first part of the work, has been successful, therefore this result underlines the importance of research for the improvements of biotechnological methodologies employed in restoration. The overall results suggest that further research is required for additional enhancement of this sulfates removal methodology and for the development of novel approaches, more and more effective and convenient, to be used in the field of cultural heritage.

La bio-détérioration des documents culturels compte parmi les types de détériorations les plus complexes que sont amenés à subir ces objets; et ce, parce qu’elle implique des organismes vivants ainsi que la conjonction de nombreux facteurs. Il existe différentes formes de biodétérioration; les taches de substrat (support?) engendrées par des champignons pigmentés en sont un exemple. Une multitude d’actions se développent aux “interfaces” entre le substrat (support?) et les champignons, depuis le premier contact avec les spores, en passant par la prolifération fongique, jusqu’aux interactions avec l’environnement. L’analyse multi-échelle et multisensorielle de l’interface entre les moisissures pigmentées noires et le support papier est le sujet de ces thèses. Deux types de pigmentations fongiques noires ont fait l’objet d’une analyse; la première apparaissait spontanément sur les œuvres d’art , la deuxième résultait d’une pigmentation déclenchée en biosimulation, sur des papiers connus, dans un environnement maitrisé. Les caractéristiques des papiers telles que le relief et la structure de la surface, la morphologie des champignons, les processus de dépôt de la biomasse pigmentée, ainsi que la prolifération fongique, ont fait l’objet de multiples examens, tant en termes d’instruments que de méthodes :microscopie à lumière transmise, microscopie électronique à balayage (MEB) dans une chambre à pression variable, microscopie confocale à balayage laser, profilomètre confocal à lumière blanche, microtomographie aux rayons L’objectif ultime étant de développer une stratégie de préservation des objets du patrimoine culturel bio-détériorés, le choix des instruments et des méthodes d’analyse était dicté par un souci pratique qui limitait l’échantilllonage des éléments analysés. Ce travail constitue une première tentative afin de mieux comprendre les forces en présence au niveau des “interfaces”, dans le cas des taches sur le papier dues aux champignons
Biodeterioration of cultural materials is one of the most complex types of deteriorations that cultural materials are subjected to mainly, because it involves living organisms and synergy of many factors. There are different forms of biodeterioration, stains of substrate caused by pigmented fungi is one of them. Multitude of events occurs at interfaces between substrate and fungi, from the moment of spores’ first contact with surfaces, next fugal growth and their responses to the environment. Multiscale and multisensory analysis of interfaces between black pigmented fungi and paper substrate was the subject of these theses. Two types of black fungal pigmentations were analyzed; one that occurred on the original artworks the other one was induced in biosymulation on known papers in controlled environment. Paper characteristics, such as surface topography and structure, morphology of fungi and patterns of their pigmented bio-mass deposition as well as fungal growth were examined with an array of analytical instruments and methods: transmitted light microscopy, scanning electron microscopy in variable pressure, confocal laser scanning microscopy, white light confocal profilometer and X-ray microtomography. The ultimate goal was to develop a preservation strategy for biodeteriorated cultural heritage material; therefore the choice of the analytical methods and instruments was dictated by real-life protocols that limit sampling of cultural materials. This works is the first attempt towards a better understanding of interfacial forces in fungal stains on paper

Um problema na indústria coureira é a deterioração de peles e couros devido ao desenvolvimento de microrganismos no processamento do couro. As peles e os couros contêm nutrientes adequados para o crescimento de microrganismos, como carboidratos, gorduras e proteínas, além das condições ambientais, alta umidade, temperatura de armazenagem e pH favoráveis. Alguns gêneros de bactérias e fungos sintetizam importantes substâncias deste substrato, causando modificações prejudiciais na superfície do couro e nas propriedades físico-mecânicas, deixando manchas pigmentadas de difícil remoção, afetando a qualidade do produto final e causando perda de valor comercial. Desta forma, surge a necessidade de desenvolver estratégias de controle dos microrganismos de modo a reduzir ou eliminar este problema. Para tanto, recorre-se comumente à utilização de microbicidas. No passado, a ação esperada dos agentes antimicrobianos era principalmente de fornecer uma proteção eficaz, mas em anos mais recentes, a preocupação com a sua toxicidade e com potenciais riscos ecológicos tornou-se também importante. Nos dias atuais uma grande preocupação mundial é o cuidado com a preservação do meio ambiente. Devido a isto, várias pesquisas estão voltadas para o desenvolvimento de novas tecnologias limpas e renováveis como também a otimização de processos. Tendo em vista a melhoria de processos no que diz respeito ao uso de microbicidas adicionados em peles e couros, para prevenir a contaminação dos mesmos por microrganismos, esta dissertação centrou-se na avaliação do desempenho de microbicidas comerciais convencionalmente utilizados na indústria do couro sendo eles 2-(tiocianometiltio) benzotiazole (TCMTB), isotiazolina, dispersão oleosa de 2-n-octil-4-isotiazolin-3-ona + carbendazim (OIT+BMC/óleo), dispersão aquosa de 2-n-octil-4-isotiazolin-3-ona + carbendazim (OIT+BMC/água), 2-n-octil-4-isotiazolin-3-ona (OIT) e para-cloro-meta-cresol (PCMC) contra as espécies de bactérias Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa e Streptomyces sp. e as espécies de fungos Aspergillus niger, Aspergillus flavus, Penicillium herguei e Penicillium chrysogenum. Os microbicidas foram aplicados nas etapas de remolho, píquel, curtimento de couro com cromo e curtimento/engraxe com tanino vegetal. Os efeitos antimicrobianos dos microbicidas foram avaliados através de ensaios microbiológicos acelerados de plaqueamento e de acondicionamento em câmara tropical e testes de biodeterioração no solo, seguidos de análises visual, Microscopia eletrônica de varredura e ensaio de tração. Também foi testada a sorção e wash-out dos microbicidas em couros wet-blue. Outro teste feito nos próprios microbicidas foi o de concentração inibitória mínima (MIC). Os resultados demonstraram baixa capacidade antibacteriana e antifúngica dos microbicidas selecionados quando aplicados no processo de remolho contra o ataque das bactérias Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Streptomyces sp. e no processo de engraxe para o couro curtido com tanino vegetal contra o ataque dos fungos Aspergillus niger, Aspergillus flavus. Dois dos microbicidas estudados, TCMTB e OIT+BMC/água aplicados no couro wet-blue, revelaram elevada capacidade antifúngica contra os quatro diferentes fungos testados. Dos microbicidas submetidos ao teste de absortividade e wash-out, o microbicida à base de TCMTB apresentou alta e rápida absortividade pelo couro wet-blue, além de possuir resistência à lavagem.
A problem in the leather industry is the deterioration of leather skins due to the development of microorganisms, in the processing of leather. The skin and leather containing nutrients suitable for the growth of microorganisms such as carbohydrates, fats and proteins , as well as environmental conditions, high humidity, storage temperature and pH favorable. Some genera of bacteria and fungi synthesize important ingredients of this substrate, causing harmful changes in the surface of the leather and the physical and mechanical properties, leaving pigmented spots are difficult to remove, affecting the quality of the final product and loss of commercial value. Thus, there arises the need to develop strategies for control of microorganisms in order to reduce or eliminate this problem, therefore, appeal commonly the use of microbicides. In the past, the expected action of antimicrobial agents was mainly to provide effective protection, but in more recent years, concerns about the toxicity and potential ecological risks has also become important. Nowadays a major global concern is the careful preservation of the environment, due to this many researches are focused on the development of new clean and renewable technologies as well as process optimization. In view of the improvement of processes in respect to the use of microbicides added to hides and skins to prevent contamination thereof by microorganisms , this work has focused on the evaluation of the performance of commercial microbicides conventionally used in the leather industry, 2-metiltiocianato benzothiazole (TCMTB) isothiazoline, oily dispersion of 2-n-octil-4-isotiazolin-3-ona + carbendazim (OIT+BMC/oil), water dispersion of 2-n-octil-4-isotiazolin-3-ona + carbendazim (OIT+BMC/water), 2-n-octil-4-isotiazolin-3-ona (OIT) and para-chloro-meta-cresol (PCMC), against the bacterial species Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosas and Streptomyces sp. e species of fungi Aspergillus niger, Aspergillus flavus, and Penicillium herguei Penicillium chrysogenum, compared with the control. Microbicides were applied in steps of soaking, pickling, chrome tanning and grease/tanning with vegetable tannin. The antimicrobial effects of microbicides made for these applications were evaluated by accelerated plating microbiological testing and tropical chamber rain and biodegradation tests on the ground, followed by analysis (visual , SEM and tensile test) . Also was tested the absorptivity and wash-out of microbicides in wet-blue leather. Another test done on their own microbicides was the minimal inhibitory concentration (MIC). The results showed low capacity antibacterial and antifungal activities of selected microbicides when applied in the process of soaking the attack of the bacteria Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Streptomyces. sp. e in the process of grease for leather vegetable tannin against fungal attack Aspergillus niger, Aspergillus flavus. Two of microbicides studied TCMTB and OIT + BMC/water applied in wet-blue leather, high capacity antifungal against revealed four different fungi tested. For microbicides tested for absorbency and wash-out the microbicide based TCMTB showed high and rapid absorbency by wet-blue leather also has resistance to washing.

For over 50 years, synthetic petrochemical-based plastics have been produced in ever growing volumes globally and since their first commercial introduction; they have been continually developed with regards to quality, colour, durability, and resistance. With some exceptions, such as polyurethanes, most plastics are very stable and are not readily degraded when they enter the ground as waste, taking decades to biodegrade and therefore are major pollutants of terrestrial and marine ecosystems. During the last thirty years, extensive research has been conducted to develop biodegradable plastics as more environmentally benign alternatives to traditional plastic polymers. Polyvinyl alcohol (PVA) is a water-soluble polymer which has recently attracted interest for the manufacture of biodegradable plastic materials. PVA is widely used as a paper coating, in adhesives and films, as a finishing agent in the textile industries and in forming oxygen impermeable films. Consequently, waste-water can contain a considerable amount of PVA and can contaminate the wider environment where the rate of biodegradation is slow. Despite its growing use, relatively little is known about its degradation and in particular the role of fungi in this process. In this study, a number of fungal strains capable of degrading PVA from uncontaminated soil from eight different sites were isolated by enrichment in mineral salts medium containing PVA as a sole carbon source and subsequently identified by sequencing the ITS and 5.8S rDNA region. The most frequently isolated fungal strains were identified as Galactomyces geotrichum, Trichosporon laibachii, Fimetariella rabenhorsti and Fusarium oxysporum. G. geotrichum was shown to grow and utilise PVA as the sole carbon source with a mean doubling time of ca. 6-7 h and was similar on PVA with molecular weight ranges of 13-23 KDa, 30-50 KDa and 85-124 KDa. When solid PVA films were buried in compost, Galactomyces geotrichum was also found to be the principal colonizing fungus at 25°C, whereas at 45°C and 55°C, the principle species recovered was the thermophile Talaromyces emersonii. ESEM revealed that the surface of the PVA films were heavily covered with fungal mycelia and DGGE analysis of the surface mycelium confirmed that the fungi recovered from the surface of the PVA film constituted the majority of the colonising fungi. When PVA was added to soil at 25°C, and in compost at 25°C and 45°C, terminal restriction fragment length polymorphism (T-RFLP) revealed that the fungal community rapidly changed over two weeks with the appearance of novel species, presumably due to selection for degraders, but returned to a population that was similar to the starting population within six weeks, indicating that PVA contamination causes a temporary shift in the fungal community.

This investigation examines the structure-property relationships of high modulus fibres. Five fibre classes were chosen for examination. These are p-aromatic copolyamide (Armos and SVM) and poly-p-aramids (Terlon and Kevlar) obtained from rigid chain polymers; poly-m-aramids (Phenylon and Nomex) obtained from semi rigid chain polymers, and aliphatic polyamide (Capron and Nylon) and Polyethylene obtained from flexible chain polymers. The thermo-mechanical properties studied include tensile properties, thermal shrinkage, creep-recovery, stress-relaxation and residual deformation over a range of temperatures. Results show that mechanical properties are highly related to chain rigidity, orientation and crystallinity of the fibres. The presence of aromatic rings in polymer chains increase the polymer rigidity. The higher the intermolecular attractive force and chain rigidity, the greater the resistance to heat. Study of the creep-recovery properties of polyamide fibres shows that irrecoverable residual deformation for the rigid chain polymers is accumulated within a very short initial period of time (15 seconds) when the load is applied. However for semi-rigid or flexible chain polymer fibres, the residual deformation is accumulated during the whole creep process. The characteristics of tensile stress-strain properties and the accumulation of residual deformation are found to be temperature dependent, especially in the case of Armos and SVM. The mechanical properties of polyamide fibres are also influenced by moisture which is associated with intermolecular interaction. Supplementary studies using FTIR, SEM and DSC were also undertaken. FTIR was used for preliminary investigation into the intermolecular hydrogen bonding and associated moisture in fibres. The results support the explanation of the thermomechanical properties of polyamide fibres. SEM results show the fibre rupture mechanism related to the fibre structures.

Biodeterioration has an important role in weathering of historical materials. Natural stone materials become vulnerable to physical and chemical changes in outdoor conditions, favouring the biological growth. In this study, biodeterioration on calcareous stones and its control by biomineralisation were studied on limestones from Nemrut Mount Monument and marbles from Pessinous Archaeological Site. For qualitative and quantitative detection of biological activity fluorescein diacetate (FDA) method that was developed for soil microbial activity was applied to stones of historic monuments. Qualitative FDA analysis was used on cross sections of the samples in order to observe the depth of penetration and effects of biomineralisation using a light microscope with fluorescent light source. Quantitative FDA analysis was done by spectrophotometric determination of fluorescence formed by FDA treatment. X-Ray Diffraction (XRD) analyses were used in determining mineralogical structure of patinas and stone base. Light microscopy was used to investigate changes in morphological structure of historic stone in cross and thin sections of the samples. The control of biodeterioration on stone surfaces was studied by biomineralisation treatments using Bacillus cereus. The results of biomineralisation were evaluated by XRD, light microscopy, SEM-EDX and FDA analyses. The results of this study showed that the biodeterioration was an important decay factor in stone materials. It started from the surface and penetrated through the microstructure of the stone up to about four cm depth. Biodeterioration also contributed to the growth of microcracks. Results of biomineralisation using B.cereus to form a protective coating on limestone and marble were also discussed.

La digestion anaérobie est une succession d’étapes de dégradation de la matière organique, par l’intermédiaire de microorganismes, opérée industriellement dans des digesteurs en béton. Des métabolites microbiens (acides gras volatils (AGV), NH4+, CO2) produits au cours du processus de digestion attaquent la matrice cimentaire du béton. Afin d’assurer un développement pérenne de la filière de méthanisation, il est donc nécessaire de comprendre d’abord tous ces phénomènes d’altération pour ensuite proposer des solutions durables pour les matériaux de construction des digesteurs. Les objectifs de la thèse visaient à identifier et quantifier les agents agressifs pour le béton présents dans les milieux de la méthanisation, puis à comprendre leurs rôles dans les mécanismes d’altération des matrices cimentaires. Enfin, l’action de ces milieux a pu être comparée sur un panel de matériaux cimentaires réalisées à partir de différents liants : ciment Portland ordinaire, ciment de haut-fourneau, ciment d’aluminate de calcium et liant alcali activé. Dans des digesteurs de laboratoire, les concentrations maximales des agents chimiques agressifs mesurées pendant la digestion anaérobie d’un biodéchet modèle étaient de 3000 mg.L-1 d’AGV, de 800 mg.L-1 de NH4+, et de 140 mg.L-1 de CO2 dissous. La prolifération de microorganismes capables de métaboliser ces composés chimiques agressifs a été observée à la surface des matériaux cimentaires exposés dans le biodéchet au cours de sa digestion. La zone dégradée des matériaux cimentaires exposés est partiellement décalcifiée, vraisemblablement du fait de l’action des AGV et de l’ammonium NH4+, et carbonatée en raison de la présence de CO2 dissous. Des essais in situ, c’est à dire en conditions réelles, réalisées sur une plateforme expérimentale de méthanisation, ont permis de confirmer les phénomènes d’altération observés en laboratoire. En termes de durabilité, le ciment alumineux présente la meilleure résistance face aux attaques biochimiques lorsqu’on le compare au ciment ordinaire ou aux ciments composés de laitier de haut-fourneau au sein de systèmes de méthanisation en laboratoire ou in situ
Anaerobic digestion consists in the degradation of organic matter by the successive actions of microorganisms, industrially operated in digesters made of concrete. Microbial metabolites (volatile fatty acids (VFA), NH4+, CO2) produced during this process attack the cementitious matrix of the concrete. To ensure the development of this new industrial field, it appears essential to understand first the alteration phenomena, then to propose durable solutions for digesters’ construction materials. The thesis’ objectives were first to identify and to quantify the aggressive agents for concrete in anaerobic digestion media, then to understand their impacts on the cementitious materials’ alteration mechanisms. Finally, the impacts of those media were compared on different cement pastes made of : ordinary Portland cement, blast furnace slag cement, calcium aluminate cement or alkali activated materials. During laboratory tests, the maximal concentration in aggressive agents measured during the digestion of a synthetic biowaste were 3 000 mg.L-1 of VFA, 800 mg.L-1 of NH4+, and 140 mg.L-1 of dissolved CO2. The colonization of the microorganisms able to produce the aggressive agents has been observed on the cementitious materials’ surfaces exposed to the biowaste during digestion. The external degraded layers of the exposed cementitious materials are partially decalcified, most likely regarding to the action of the VFA and the NH4+. Carbonation has also been detected caused by the dissolved CO2. In situ experiments, in real conditions, achieved in an experimental anaerobic digestion platform, confirmed the alteration phenomena distinguished in the laboratory tests. In terms of durability, calcium aluminate cement present the best performances against the biochemical attacks compared to ordinary cement or blast furnace slag cement in laboratory or in situ anaerobic digestion systems

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Agents climatic, biological and human action are the main responsible for deterioration of historic buildings, thus the growing concern with the preservation and maintenance of these buildings. This study was conducted at the Central Library Manuel Marques de Souza - Conde de Porto Alegre, located at the Federal University of Santa Maria and its main objective is to identify fungal contamination at the site, which has been a cause of biodeterioration incident in the building. For this work were discussed theoretical frameworks relevant to the subject, photographic surveys, as well as the use of a methodology aimed at collecting fungi, serving as a subsidy for the identification and characterization of microorganisms that are biodeteriorando the building. This was followed by a graphical representation of the pathologies of the building, through maps Damage. After the identification and evaluation of biological agents that cause biodeteriorações that are hitting the building, the data were tabulated to assess the fungal contamination of the Central Library UFSM, which can cause deterioration and also cause disease in users and occupants of that environment.
Agentes climáticos, biológicos e a ação do homem são os principais responsáveis pela degradação das edificações históricas, com isso a crescente preocupação com a conservação e manutenção desses prédios. Este trabalho foi realizado na Biblioteca Central Manuel Marques de Souza Conde de Porto Alegre, localizada na Universidade Federal de Santa Maria e tem como objetivo principal identificar a contaminação fúngica no local, que vem sendo uma das causas da biodeterioração incidente na edificação. Para a realização deste trabalho, foram abordados referenciais teóricos pertinentes ao assunto, levantamentos fotográficos, como também a utilização de uma metodologia voltada à coleta de fungos, servindo de subsídio para a identificação e caracterização de microrganismos que estejam biodeteriorando a edificação. Posteriormente, foi realizada a representação gráfica das patologias do prédio através de Mapas de Danos. Após a identificação e a avaliação dos agentes biológicos causadores das biodeteriorações, que estão atingindo a edificação, os dados foram tabulados a fim de avaliar a contaminação fúngica da Biblioteca Central da UFSM, que podem causar deterioração como também causar doenças nos usuários e ocupantes desse ambiente.

Le comportement de l'alpha-amylase d'aspergillus oryzae a ete etudie dans des conditions de microenvironnement se rapprochant de celles des milieux industriels: en milieu concentre et en presence de limitations diffusionnelles. L'activite globale de l'enzyme n'est pas inhibee par des concentrations en amidon de 400 g/l et en maltotetraose de 500 g/l. Les reactions de transglycosylation voient leur importance augmenter avec la concentration en substrat. Par contre, la presence d'agents depresseurs de l'activite de l'eau (polyols) en concentration elevee n'a pas d'influence sur la quantite de produits de transglycosylation formes, mais elle favorise la formation de produits de faible degre de polymerisation. Ces memes polyols ont un effet protecteur contre la denaturation thermique de l'enzyme, dont la demi-vie a 60#oc peut etre multipliee par un facteur 2000 en presence de sorbitol a la concentration 4 m. Les polyols sont des inhibiteurs competitifs de l'alpha-amylase et leur effet stabilisant peut etre correle a leur affinite pour le site actif, sauf pour le sorbitol. L'effet tres important de ce dernier compose, tant sur la specificite que sur la stabilite de l'enzyme, est attribue a des interactions directes entre le polyol et l'enzyme, mises en evidence en spectroscopie uv et raman. L'introduction de limitations diffusionnelles, par immobilisation de l'alpha-amylase, modifie la specificite de l'enzyme, qui produit alors davantage de produits de faible degre de polymerisation. Cette modification est d'autant plus marquee que le sont le defaut de substrat et l'accumulation de produits dans le microenvironnement de l'enzyme, provoques par les resistances au transfert

Dans le cadre de la mise en uvre potentielle de levures du genre schizosaccharomyces pour realiser la fermentation malo-alcoolique dans les produits derives du raisin, le comportement cinetique et metabolique de cultures a fortes concentrations en cellule de s. Pombe obtenues en reacteur a recyclage par procede membranaire a ete etudie. L'influence de divers facteurs d'environnement sur la croissance de la levure et son aptitude a degrader l'acide malique a ete caracterisee et quantifiee en cultures discontinues. Les cinetiques observees sont le resultat de l'intervention de limitations nutritionnelles qui s'ajoutent aux effets inhibiteurs du malate et de l'ethanol. La culture en reacteur a recyclage des cellules permet d'atteindre des concentrations en biomasse et des productivites elevees. En recyclage total de la biomasse, les variables operatoires de conduite des cultures determinent leur comportement cinetique et le type metabolique des cellules. La conduite des cultures en recyclage partiel des cellules a rendu possible la determination des potentialites physiologiques de la souche (vitesse specifique d'utilisation des substrats), la caracterisation de la flexibilite de son comportement metabolique (metabolismes oxydatif ou oxydo-reductif), l'identification des stchiometries de reaction (rendements de croissance et de production) et enfin la quantification de grandeurs caracteristiques de l'energetique cellulaire (rendement y#a#t#p, et efficience de la phosphorylation oxydative p/o)

Questo studio polifasico ha permesso di descrivere i biofilm fototrofi che si sviluppano sui dipinti murali presenti negli ipogei maltesi. L’architettura dei biofilm è stata caratterizzata tramite microscopia confocale (CLSM) ed elettronica a scansione (SEM) e la distribuzione, diversità e ruolo ecologico di cianobatteri e microalghe nei biofilm studiata dal punto di vista citomorfologico e genetico. La comprensione dei processi di biodeterioramento e biomineralizzazione è stata resa possibile grazie all’applicazione di tecniche quali la microsonda a raggi X (ESEM-EDS), la fluorescenza X (μXRF) e la diffrazione a raggi X (μXRD). La componente fototrofa predominante, associata sempre a una componente batterica chemoorganotrofa, è risultata essere costituita da microalghe appartenenti ai morfotipi di Chlorella e Trentepohlia e da cianobatteri appartenenti agli ordini Oscillatoriales, Nostocales e Stigonematales. I risultati del presente studio sono stati confrontati con quelli ottenuti da studi di biofilm fototrofi sviluppatisi in grotte e catacombe sempre situate in area mediterranea. Si è così riscontrata una generale somiglianza in termini di biodiversità e distribuzione, fattori che indicano che queste comunità sono specifiche di questi ambienti. I processi fotosintetici, controllando indirettamente l’azione microbica sul substrato, promuovono il biodeterioramento delle superfici di interesse archeologico. La gran parte dei ceppi cianobatterici isolati appartengono a taxa che non sono attualmente ancora ben definiti dal punto di vista tassonomico e filogenetico.
This polyphasic study provided for a description of the microbiocoenosis of the wall paintings in Maltese hypogea. Biofilm architecture was characterised by CLSM and ESEM. The cyanobacterial and microalgal diversity in phototrophic biofilms was described in terms of cytomorphology, distribution, molecular biology and environmental role. An understanding of biodeterioration and biomineralisation processes was achieved through the application of ESEM-EDS, μXRF and μXRD. The subaerial biofilms were made up of taxonomically complex, metabolically interactive, self-sustaining microbial communities. The main phototrophic organisms consisted of Oscillatorialean, Nostocalean and Stigonematalean cyanobacteria and Chlorococcalean microalgae, associated with chemoorganotrophic bacteria. An effort was made to integrate the results of the present study with those obtained from other studies of phototrophic biofilms growing in other Mediterranean catacombs and caves. The same general trends in biodiversity and distribution were found, a fact which clearly indicates that these communities are habitat-specific. Autotrophic production indirectly controlled microbially mediated processes and thus, the resulting biodeterioration of the archaeological surface. Most isolated cyanobacterial strains belong to presently undefined taxa, the status of which should be clarified in the near future.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O desenvolvimento econômico e a necessidade de proporcionar melhor qualidade de vida a toda a população, constituem alguns aspectos responsáveis para que a produção de residuos sólidos seja cada dia maior, aumentando a necessidade da busca de soluções ambientais corretas, para sua destinação. A compostagem consiste em importante ferramenta para o tratamento da fração orgânica dos resíduos sólidos, através do uso de tecnologias que processam os resíduos originados da agricultura, agroindústria, silvicultura, dos domicílios e, ainda, do loda da estação de tratamento de esgoto, adequando-os para serem incorporados ao solo e contribuindo para redução de adubos químicos. No Brasil, o emprego do processo de compostagem, é ainda bastante restrito, pelo alto grau de empirismo utilizado no controle e avaliação do processo e por falta de conhecimento técnico. Este estudo aborda o problema do tratamento de resíduos sólidos orgânicos provenientes das estações de tratamento de esgoto, através de pesquisa experimental de co-compostagem com outros resíduos orgânicos. No processo desenvolvido, denominado de método respirométrico, utilizou-se metodologia na qual os parâmetros de degradação biológica dos resíduos são quantificados na fase gososa. Os parâmetros avaliados, nesse trabalho, na fase gasosa de processos de co-compostagem do lodo de esgoto, possibilitaram a determinação do consumo de O2 e a geração de CO2 e da demanda bioquímica de oxigênio (DBO). Ao obter valores em substância totalmente homogênia, seu emprego apresentou como vantagens maior representatividade, precisão e confiabilidade, representando uma evolução quando comparados aos métodos tradicionais, permitindo o acompanhamento on line e contínuo. Os resultados foram muito superiores, quando...
Economic development and the need to provide better quality of life for the entire population, are responsible for some aspects of the production of solid waste each day is greater, increasing the need to search for environmental solutions right to your destination. Composing is an important tool for the treatment of the organic fraction of solid waste throgh the use of technologies that process the waste generated from agriculture, agribusiness, forestry, households, and also sludge from sewage treatment plant, adapting them to be incorporated into the solid and contribuing to reduction of chemical fertilizers. In Brazil the use of traditional composting process is still very limited, the high degree of empirism used in the control and evaluation of the process and lack of technical knowledge. This study addressed the problem of the treatment of organic solid waste from the sewage treatment plants, through experimental research of co-composting with other organic waste. In the process developed, called respirometric method was used methodology in which the parameters of biological degradation of waste are quantified in the gas phase. The parameters evaluated in this study, in the gas phase of the co-composting of sewage sludge, allowed the determination of O2 consumption and CO2 generation and biochemical oxygen demand (BOD). By obtaining values in totally homogeneous substance, its use had advantages as greater representation, accuracy and reliability, representing an evolution when compared to traditional methods, enabling monitoring on line and continuous. The results were far superior when compared to the traditional method, obtaining data lines 1440/day, while in the conventional process, these data are sun up to a daily measurement of temperature, which makes the respirometric method an... (Complete abstract click electronic access below)

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itt Performance - Instituto Tecnológico em Desempenho da Construção Civil
A durabilidade de estruturas de concreto é assunto de interesse no contexto de sustentabilidade, pois a sustentabilidade das obras concluídas pode ser verificada por meio da análise da durabilidade dos seus materiais constituintes. A previsão de vida útil de um material poderá ser verificada estudando os seus mecanismos de degradação. Dentre os fatores de degradação do concreto, encontra-se a biodeterioração. Contudo, o ataque microbiológico ainda é um assunto pouco estudado na área de construção civil. A proposta deste trabalho foi verificar a biorreceptividade de concretos com diferentes relações água/cimento e diferentes acabamentos de superfícies ao desenvolvimento de algas a partir do desenvolvimento de um método de análise da biorreceptividade do concreto específico para este trabalho. O método consistiu em ensaio acelerado de biodeterioração em câmaras de ensaio com temperatura e iluminação controladas, alto teor de umidade e inoculação de alga coletada in loco. A análise permitiu verificar um decréscimo da mancha biológica nos corpos de prova de todas as variáveis. A diferença da velocidade do decréscimo da mancha biológica nas diferentes variáveis evidenciou a biorreceptividade dos materiais. Foi possível identificar uma tendência em que quanto maior a relação água/cimento, maior a biorreceptividade e quanto menor a rugosidade, menor a biorreceptividade. Assim, estes parâmetros poderão auxiliar na obtenção de concretos mais duráveis frente ao crescimento de algas.
The durability of concrete structures is subject of interest in the context of sustainability, since the sustainability of the edifications can be verified by analyzing the durability of their constituent materials. Among the factors degradating the concrete there is the biodeterioration. Nevertheless the microbiological attack is still a subject little studied in the construction area. The purpose of this was verify the bioreceptivity of concrete with different water / cement ratio and different surface finishing facing the development of algae from the development of a method of analysis of the concrete bioreceptivity specific to this work. The method consisted of accelerated test of biodeterioration in test chambers with temperature and lighting controlled, high humidity and inoculation of Heterochlorellas luteoviridis, algae collected in loco and identified in the laboratory. The analysis has shown a decrease of biological stains in the specimens of all variables. The difference of decrease rate of biological stain on different variables showed the materials bioreceptivity. It was possible the verification that the higher the water / cement ratio, the greater the biorreceptividade and in the same way the lower the roughness, the lower the biorreceptividade. Thus, these parameters could help in getting more durable concrete facing the growth of algae.

La fermentation de l'acetate par une bacterie methanogene thermophile acetoclaste, methanosarcina sp. Msta-1, est etudiee. L'etude de l'influence des parametres physico-chimiques sur la cinetique et la stchiometrie de la fermentation de l'acetate montre que la souche presente un optimum de croissance #m#a#x=vitesse specifique maximale de croissance (#m#a#x=0,050-0,055 h##1) a 55#oc, dans une zone de ph de 6,5-7,5 unites et pour une concentration initiale en acetate comprise entre 50 et 100 mm. Contrairement au rendement de methane, les rendements cellulaires sont dependants des conditions physico-chimiques. La consommation energetique de maintenance apparait etre a l'origine de ce decouplage entre la croissance et la methanogenese. Contrairement a d'autres bacteries methanogenes. Methanosarcina sp. Msta-1 ne peut assimiler l'azote moleculaire. Une etude comparee entre la fermentation de l'acetate et celle du methanol au niveau cinetique et au niveau des teneurs intracellulaires en nucleotides adenyliques indique que la charge energetique de la cellule est independante des activites specifiques et du caractere energetique du substrat

Les procedes classiques de traitement aerobie des eaux usees domestiques transforment la matiere organique en co2 et biomasse. S'ils utilisent le recyclage des cellules pour augmenter les cinetiques de degradation, ils sont limites par la clarification de l'effluent traite et le probleme de traitement de boues. Un procede nouveau, associant un fermenteur et un module de filtration, par procede membranaire a ete mis en uvre. Il permet de travailler a forte charge volumique, mais a faible charge massique par minimisation des boues d'un facteur 3 a 5. Cette minimisation de la production des boues resulte de l'amplification et de la maitrise des phenomenes de lyse cellulaire et de la croissance cryptique. Les cinetiques biologiques sont quantifiees grace a la caracterisation, en terme d'activite, des differentes populations dans la culture, et confrontees au concept general de maintenance. Un modele global est construit qui considere deux types de biomasse, l'une active l'autre morte, differentiees par leur activite respiratoire. Les predictions du modele sont en accord avec les resultats experimentaux. Le modele peut etre facilement transposable a la gestion du fonctionnement d'un procede d'epuration type boues activees et reste generalisable a d'autres reactions biologiques mettant en jeu des microorganismes en limitation de substrat

L'évolution physico-chimique et microbiologique de foins humides conditionnés en balles rondes a été suivie durant le stockage; la dynamique des populations microbiennes, conduisant au remplacement de la flore du champ par une flore de stockage à dominantes thermophile et xérophile n'est pas apparue corrélée avec le pic initial de température. L'étude du déterminisme des phénomènes d'échauffement a été poursuivie à l'échelle du laboratoire à partir de mesures d'intensité respiratoire de végétaux coupés et d'expériences sur la conservation de foins stérilisés et contaminés; les rôles respectifs de la respiration du végétal dans la thermogenèse initiale et des microorganismes dans la perspective de l'échauffement et la disparition d'une partie de la matière organique ont été établis. L'expérimentation de conservateurs liquides et solides n'a pas donné de résultats satisfaisants en raison de l'imparfaite homogénéité du traitement réalisé au champ (cas de l'acide propionique), aggravée pour les spécialités commerciales et le chlorure de sodium par l'insuffisance des doses recommandées et une action inhibitrice limitée. L'ammoniac introduit par fumigation à l'intérieur de meules bâchées permet d'améliorer nettement la conservation mais implique des précautions particulières lors de la distribution des foins traités aux animaux.

La production de colorants alimentaires par une souche selectionnee de monascus sp. 07 en culture immergee est mise au point et optimisee. Le produit obtenu, de couleur globale rouge, est constitue de plusieurs composes pigmentes. Il est comparable a celui obtenu par fermentation par le procede anka. L'etude de la morphogenese du champignon et de son cycle de developpement fait apparaitre une secretion du colorant sur un nodule rouge forme simultanement a la croissance du mycelium, essentiellement lorsque celui-ci est court, foisonnant et tres ramifie. Par cycle de fermentation de 48 heures, 15 grammes de colorants sont obtenus par littre. Par modification des conditions operatoires (ph regule, et procede en 2 etapes) le metabolisme peut etre oriente vers la production d'un autre produit a dominante jaune. L'extrapolation du procede est discutee ainsi que l'eventuelle production de monacoline (medicament) qui est envisage

Production d'ethanol en culture continue dans un reacteur couplant fermentation et decantation. La biomasse s'accumule jusqu'a 60 g/l et une productivite de 18 g/l. H peut etre obtenue. Le taux de charge critique en substrat est de 40 g/l. H. Les cellules libres ne sont que tres peu actives, au contraire des levures du floc

La these comprend une etude bibliographique sur la biodegradation des lignines par les microorganismes, ainsi que les resultats experimentaux obtenus avec des bacteries: isolement des bacteries ligninolytiques; etude de la biodegradation des lignines de paille de ble et de bois de peuplier; analyse cytochimique de la delignification du bois de peuplier; etude de la degradation bacterienne en milieu anaerobie; etude des voies metaboliques de degradation d'un compose modele de type dimere par pseudomonas cepacia. Tous les resultats presentes ont ete publies precedemment sous forme d'articles

L'utilisation des enzymes dans le domaine medical est de plus en plus frequente, aussi bien d'un point de vue analytique que therapeutique. Deux exemples ont ete etudies: la mise au point d'un kit de dosage de l'acide urique present dans l'urine et l'immobilisation de la trypsine en vue de la detersion des plaies necrosees. Dans le premier cas, l'utilisation du systeme uricaseperoxydase- 4-aminoantipyrine/acide 3,5-dichloro 2-hydroxy benzene sulfonique provoque l'apparition d'une coloration rose qui s'intensifie lorsque la concentration en acide urique augmente. Teste sur 182 urines, le kit donne de bons resultats dans plus de 95 % des cas. En ce qui concerne l'utilisation therapeutique de la trypsine, l'immobilisation de la protease sur un support fourni par la societe pierre fabre medicament a ete optimisee en ayant recours aux plans d'experiences. L'activite de la trypsine immobilisee dans les conditions optimales determinees est de 1 600 u/g support, avec un rendement de 26 %. Le produit mis au point est teste "in vivo" sur des animaux.

La biphenyle dioxygenase (bdo) catalyse la dihydroxylation du biphenyle et des polychlorobiphenyles (pcb) chez la bacterie pseudomonas sp. B4, pour former un cis-dihydrodiol. C'est une enzyme a trois composantes : une dioxygenase (isp), une ferredoxine (fer) et une reductase (red). Le locus bpha codant la bdo b4 a ete clone, sequence et surexprime chez e. Coli. Les composantes isp, fer et red ont ete isolees, et caracterisees au niveau biochimique et spectroscopique. Isp et fer possedent chacune un centre 2fe-2s de type rieske. Nous avons isole la composante red de comamonas testosteroni b-356, plus facile a obtenir que celle de b4, l'avons combinee aux composantes isp et fer de b4 afin de reconstituer un complexe catalytique actif in vitro. La cinetique d'oxydation du nadh par le complexe bdo a ete determinee in vitro par spectroscopie de fluorescence, l'oxydation concomitante du biphenyle et des pcb ayant ete suivie par chromatographies hplc et cpg/sm. Une bonne correlation a ete observee entre l'oxydation du nadh, la degradation du biphenyle ou du 4,4-chlorobiphenyle et l'apparition du dihydrodiol. Dans le cas des composes doublement substitues en ortho, qui ne sont pas oxydes par l'enzyme, on observe une oxydation du nadh non couplee a celle du substrat aromatique. La region situee en amont du locus bpha a ete clonee, sequencee et fusionnee au gene rapporteur gfp (green fluorescent protein) dans le but d'elaborer un biocapteur bacterien a pcb. Cette region possede 2 cadres de lecture de fonction inconnue (orf), dont l'un est homologue a un orf present dans l'operon de deux souches de pseudomonas degradant le naphtalene. Introduites chez la souche b4, les constructions n'ont induit aucun signal de fluorescence significatif en presence de biphenyle. Cependant, la souche b4 peut etre utilisee directement pour detecter le biphenyle dans une gamme de 10 a 100 ppm, par mesure de la fluorescence endogene de la bacterie.

Le rhamnogalacturonane ii ou rg-ii est un polysaccharide pectique complexe qui joue un role essentiel dans la regulation de la cohesion et de la taille des pores au sein de la paroi primaire. Sa resistance aux activites enzymatiques mises en uvre dans le domaine de la transformation des fruits et des legumes a ete mise en evidence et l'abondance de cette molecule dans les jus de fruits et les vins a ete demontree. La purification de rg-ii a ete realisee a partir du vin rouge ; ce qui a permis des avancees importantes tant dans le domaine de sa caracterisation structurale que pour l'evaluation de l'influence de sa presence dans les produits finis. Une souche de penicillium daleae a ete isolee a partir d'un echantillon de sol forestier pour sa capacite a degrader le rg-ii. Apres avoir fixe les conditions de culture de ce champignon filamenteux, les enzymes de degradation du rg-ii ont ete fractionnees. Une fraction proteique substantiellement pure degradant le rg-ii a ete obtenue et la proteine majoritaire, possedant une masse molaire apparente de 110 kda a ete sequencee. Cette enzyme, de sequence inconnue dans les bases de donnees, et possedant des caracteristiques de glycohydrolases, a ete clonee chez aspergillus niger. L'utilisation de la fraction proteique purifiee a egalement permis la production de fragment de rg-ii, dont la caracterisation structurale, par analyse rmn 1d et 2d, nous a permis de preciser l'organisation generale de cette molecule complexe.

Over centuries, different lithotypes – either calcitic such as limestones and marbles, and/or silicious such as sandstones and granites have been used in historical monuments, whose deterioration/degradation differs as per the hardness, porosity and chemical composition of each stone. However, over the last decades living microorganisms have been associated with structural and aesthetical damages to building stone in historical monuments. The current research focuses on the investigation of degradation/deterioration in architectural marble monuments, with the aim to contribute to a better understanding the role of microbial agents on the biodegradation/biodeterioration of monuments built in marble. A multidisciplinary approach was employed to perform material characterisation and alteration products detection involving in situ and laboratory analysis in order to arrive at a comprehensive assessment of biocolonisation. Studying the microbial proliferation gave a wider perspective on recognising the role of microorganisms and their ability to degrade cultural heritage materials, which in turn helps understand and chalk out a mitigation process for future. The micro-analytical techniques distinguished and identified the alterations processes like patina formation, pigmentation and biofilms formation. The biocontamination was characterised by SEM-EDS, culture-dependent methods (CDM) and Next Generation Sequencing (NGS). CDM and NGS confirm the presence of several strains of bacteria, filamentous fungi and yeasts that appears to contribute to the presence of calcium oxalates, carotenoids and biofilms formation. Thus, it is imperative to study and comprehend the causes for marble degradation/deterioration, and recognise the source for the alteration of these materials, in order to define effective strategies to prevent marble decay and safeguard our cultural heritage; RESUMO: Biocolonização de pedra calcária: O caso de estudo do Convento das Maltesas em Estremoz Ao longo dos séculos, diferentes litotipos - calcíticos, como calcários e mármores, e / ou siliciosos como arenitos e granitos - têm sido utilizados em monumentos históricos, cuja degradação/deterioração difere de acordo com a dureza, porosidade e composição química de cada pedra. Nas últimas décadas, a presença de microrganismos tem sido associada a danos estruturais e estéticos de pedra utilizada em monumentos históricos. O presente trabalho tem como objetivo o estudo da degradação/deterioração de mármore aplicado em património arquitetónico, com o objetivo de contribuir para uma melhor compreensão do papel dos agentes microbianos na biodegradação/biodeterioração deste material, em contexto histórico. Foi utilizada uma abordagem multidisciplinar na caracterização de materiais e na deteção de produtos de alteração, envolvendo análises in situ e em laboratório, no sentido de obter uma avaliação abrangente da biocolonização. O estudo da proliferação microbiana permite uma perspetiva mais ampla no reconhecimento do papel dos microrganismos e da sua capacidade para degradar os materiais do património cultural, o que, por sua vez pode vir a ser útil na definição de estratégias de mitigação, para o futuro. As técnicas microanalíticas permitiram distinguir e identificar alguns processos de alteração, como formação de pátinas, pigmentação e formação de biofilmes. A biocontaminação foi caracterizada por SEM-EDS, através de métodos dependentes de cultura (CDM) e por Sequenciação de Nova Geração (NGS). CDM e NGS confirmam a presença de várias espécies de bactérias, fungos filamentosos e leveduras que parecem contribuir para a presença de oxalatos de cálcio, formação de carotenóides e de biofilmes. Assim , é imperativo estudar e compreender as causas da degradação/deterioração do mármore, e reconhecer os agentes responsáveis pela alteração destes materiais, de forma a que possam ser definidas estratégias eficientes para prevenção do seu declínio, contribuindo para a salvaguarda dos nossos bens patrimoniais.

Resumo: O desenvolvimento econômico e a necessidade de proporcionar melhor qualidade de vida a toda a população, constituem alguns aspectos responsáveis para que a produção de residuos sólidos seja cada dia maior, aumentando a necessidade da busca de soluções ambientais corretas, para sua destinação. A compostagem consiste em importante ferramenta para o tratamento da fração orgânica dos resíduos sólidos, através do uso de tecnologias que processam os resíduos originados da agricultura, agroindústria, silvicultura, dos domicílios e, ainda, do loda da estação de tratamento de esgoto, adequando-os para serem incorporados ao solo e contribuindo para redução de adubos químicos. No Brasil, o emprego do processo de compostagem, é ainda bastante restrito, pelo alto grau de empirismo utilizado no controle e avaliação do processo e por falta de conhecimento técnico. Este estudo aborda o problema do tratamento de resíduos sólidos orgânicos provenientes das estações de tratamento de esgoto, através de pesquisa experimental de co-compostagem com outros resíduos orgânicos. No processo desenvolvido, denominado de método respirométrico, utilizou-se metodologia na qual os parâmetros de degradação biológica dos resíduos são quantificados na fase gososa. Os parâmetros avaliados, nesse trabalho, na fase gasosa de processos de co-compostagem do lodo de esgoto, possibilitaram a determinação do consumo de O2 e a geração de CO2 e da demanda bioquímica de oxigênio (DBO). Ao obter valores em substância totalmente homogênia, seu emprego apresentou como vantagens maior representatividade, precisão e confiabilidade, representando uma evolução quando comparados aos métodos tradicionais, permitindo o acompanhamento "on line" e contínuo. Os resultados foram muito superiores, quando... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Economic development and the need to provide better quality of life for the entire population, are responsible for some aspects of the production of solid waste each day is greater, increasing the need to search for environmental solutions right to your destination. Composing is an important tool for the treatment of the organic fraction of solid waste throgh the use of technologies that process the waste generated from agriculture, agribusiness, forestry, households, and also sludge from sewage treatment plant, adapting them to be incorporated into the solid and contribuing to reduction of chemical fertilizers. In Brazil the use of traditional composting process is still very limited, the high degree of empirism used in the control and evaluation of the process and lack of technical knowledge. This study addressed the problem of the treatment of organic solid waste from the sewage treatment plants, through experimental research of co-composting with other organic waste. In the process developed, called respirometric method was used methodology in which the parameters of biological degradation of waste are quantified in the gas phase. The parameters evaluated in this study, in the gas phase of the co-composting of sewage sludge, allowed the determination of O2 consumption and CO2 generation and biochemical oxygen demand (BOD). By obtaining values in totally homogeneous substance, its use had advantages as greater representation, accuracy and reliability, representing an evolution when compared to traditional methods, enabling monitoring "on line" and continuous. The results were far superior when compared to the traditional method, obtaining data lines 1440/day, while in the conventional process, these data are sun up to a daily measurement of temperature, which makes the respirometric method an... (Complete abstract click electronic access below)
Orientador: Rosane Aparecida Battistelle
Coorientador: Jorge Akutsu
Banca: Erich Kellner
Banca: Adilson Renofio
Mestre

Ce memoire contribue a l'etude de l'optimisation d'une fermentation alcoolique continue en reacteur cascade. Dans un premier temps, des etudes cinetiques mettent en evidence certaines limitations nutritionnelles et plus particulierement en biotine et en mesoinositol. L'importance de ces deux facteurs nutritionnels sur le controle de la dynamique fermentaire est demontree. Nous proposons un modele cinetique ne faisant intervenir que l'inhibition par l'ethanol pour la description du procede. Les performances du reacteur, en terme de productivite, sont discutees. Afin de pallier le manque d'instrumentation directe, nous estimons en ligne par la methode du filtrage de kalman la concentration en ethanol dans les differents etages de la cascade. Enfin, l'application en ligne d'algorithmes de commande, bases sur l'utilisation des techniques adaptatives, est realisee pour assurer le controle de la concentration de substrat

Rendements eleves en ethanol dans des reacteurs en cascade. Construction d'un modele cinetique pour rendre compte des inhibitions de la fermentation (inhibition par ethanol, principalement, plus inhibition liee a la biomasse). Action sur taux de dilution, repartition de l'apport de milieu, pour ameliorer les performances. Mise au point de capteurs pour mesure en ligne des concentrations en sucre et de la biomasse. Estimation possible de la concentration en ethanol par filtrage kalman. Un algorithme de regulation adaptative est teste en simulation, afin de minimiser la concentration de substrat dans l'effluent.

A l'issue de trois cents protocoles cliniques, il apparaît que la thérapie génique est susceptible d'être utilisée pour traiter une large variété de pathologies. Néanmoins, excepté quelques cas individuels, il n'existe aucune preuve tangible qu'un protocole de thérapie génique ait réussi à traiter une maladie humaine. Trois raisons principales sont évoquées : le très grand nombre de cellules à cibler, la connaissance insuffisante de la physiologie cellulaire humaine et des moyens de transfection encore limités. Les inconvénients des méthodes virales et des vecteurs synthétiques justifient le développement de nouvelles techniques de transfert de gènes in vivo. Nous avons appliqué le principe de l'électroporation in vitro au transfert de gènes in vivo. Cette méthode consiste à appliquer un courant électrique permettant à l'ADN de passer la membrane cellulaire. Nous montrons que l'électrotransfert est une technique de transfection efficace pour le tissu cérébral et musculaire. Dans le cerveau, la transfection de cellules bordant les espaces ventriculaires et des astrocytes a été obtenue à long terme. L’électrotransfert a également permis une expression du transgène maximale et stable sur plusieurs mois dans les fibres du muscle tibialis anterior de souris. Nos efforts ont également porté sur l'électrotransfert in vivo de tumeurs gliales. En conclusion, l'électrotransfert in vivo est une nouvelle méthode efficace de transfert de gènes dans le tissu cérébral, tumoral et musculaire. Cette technique est une méthode alternative aux méthodes virales et aux vecteurs synthétiques.