In Situ Thermal Treatment (ISTT) is a candidate remediation technology for dense non-aqueous phase liquids (DNAPLs). However, the relationships between gas production, gas flow, and contaminant mass removal during ISTT are not fully understood. A laboratory study was conducted to assess the degree of mass removal, as well as the gas generation rate and the composition of the gas phase as a function of different heating times and initial DNAPL saturations. The temperature of the contaminated soil was measured continuously using a thermocouple to identify periods of heating, co-boiling and boiling. Samples were collected from the aqueous and DNAPL phase of the condensate, as well as from the source soil, at different heating times, and analyzed by gas chromatography/mass spectrometry. In addition to laboratory experiments, a mathematical model was developed to predict the co-boiling temperature and transient composition of the gas phase during heating of a uniform source. Predictions for single-component sources matched the experiments well, with a co-boiling plateau at 88°C ± 1°C for experiments with tetrachloroethene (PCE) and water. A comparison of predicted and observed boiling behaviour showed a discrepancy at the end of the co-boiling period, with earlier temperature increases occurring in the experiments. The results of this study suggest that temperature observations related to the co-boiling period during ISTT applications may not provide a clear indication of complete NAPL mass removal, and that multi-compartment modeling associated with various NAPL saturation zones is required to consider mass-transfer limitations within the heated zone. Predictions for multi-component DNAPL, containing 1,2-Dichloroethane (1,2-DCA), PCE and Chlorobenzene, showed no co-boiling plateau. CB is the least volatile component and dominates in the vapour phase at the end of the co-boiling process, and it can be used as an indicator of the end of the co-boiling stage. Two field NAPL mixtures were simulated using the screening-level analytical model to demonstrate its potential application on ISTT. The two mixtures with similar composition but different mass fractions result in distinct co-boiling temperature and mass transfer behaviour. The non-volatile component in the NAPL mixture results in larger amounts of water consumption and longer ISTT operation time. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-09-30 09:26:00.857

Inkjet printing (jetting) technology, due to its high speed of operation and accuracy, is utilised in Additive Manufacturing (AM) of three dimensional parts. Commercially available AM processes that use jetting technology include three dimensional printing (3DP by Z-Corporation), Polyjet (by Objet), Multi Jet Modelling (MJM by 3D Systems) and three dimensional printing by Solidscape. Apart from 3D Printing by Z-corporation, all the other jetting based processes require a support material to successfully build a part. The support material provides a base to facilitate the removal of the part from the build platform and it helps manufacturing of cavities, holes and overhanging features. These support materials present challenges in terms of their removability and reusability. This research is therefore, aimed towards finding a support material composition that can be used with jetting based AM processes. The support material should be easily removable either by melting or by dissolution and also, if possible, it should be reusable. AM processes often process materials with poor mechanical properties and therefore, the parts produced by these processes have limited functionality. In an attempt to obtain complex shaped, functional parts made of nylon (i.e. Polyamide 6), a new jetting based AM process is under research at Loughborough University. The process uses two different mixtures of caprolactam (i.e. the monomer used to produce polyamide). These mixtures are to be jetted using inkjet heads and subsequently polymerised into polyamide 6. Therefore, another aim of this research was to consider the support material s suitability for jetting of caprolactam. Two different polymers were researched which included Pluronic F-127 and methylcellulose (MC). Both these polymers are known for gel formation upon heating in aqueous solutions. Due to the inhibition of polymerisation of polyamide 6 by the presence of water, non-aqueous solvents such as ethylene glycol, propylene glycol and butylene glycol were studied. Since both F-127 and MC in the glycols mentioned above had not been studied before, all the compositions prepared and investigated in this report were novel. F-127 did not show gel formation in propylene and butylene glycol but formed a gel in ethylene glycol at a concentration of 25% (w/w) F-127. MC, on the other hand, showed gel formation upon cooling in all the three glycols at concentrations as low as 5% for ethylene glycol and 1% for both propylene and butylene glycol. These compositions were characterized using experimental techniques such as Fourier Transform Infrared (FTIR) spectroscopy, hot stage microscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). A mechanism of gelation for both F-127 and MC in glycols is presented based on the results of these characterisation techniques. Viscosity and surface tension measurements along with the texture analysis of selected compositions were also performed to evaluate their suitability for jetting. All these compositions, due to their water solubility and/or low melting temperatures (i.e. near 500C) present the advantage of ease of removal. Removal by melting at low temperatures can also provide reusability of these support materials and thus advantages such as reduction in build cost and environmental effect can be achieved.

Fractured rock formations represent a valuable source of groundwater and can be highly susceptible to contamination by dense, non-aqueous phase liquids (DNAPLs). The goal of this research is to evaluate the effectiveness of three accepted remediation technologies for addressing DNAPL contamination in fractured rock environments. The technologies under investigation in this study are chemical oxidation, bioremediation, and surfactant flushing. Numerical simulations were employed to examine the performance of each of these technologies at the field scale. The numerical model DNAPL3D-RX, a finite difference multiphase flow-dissolution-aqueous transport code that incorporates RT3D for multiple species reactions, was modified to simulate fractured rock environments. A gridding routine was developed to allow the model to accurately capture DNAPL migration in fractures and aqueous phase diffusion gradients in the matrix while retaining overall model efficiency. Reaction kinetics code subroutines were developed for each technology so as to ensure the key processes were accounted for in the simulations. The three remedial approaches were systematically evaluated via simulations in two-dimensional domains characterized by heterogeneous orthogonal fracture networks parameterized to be representative of sandstone, granite, and shale. Each simulation included a DNAPL release at the water table, redistribution to pools and residual, followed by 20 years of ‘ageing’ under ambient gradient conditions. Suites of simulations for each technology examined a variety of operational issues including the influence of DNAPL type and remedial fluid injection protocol. Performance metrics included changes in mass flux exiting, mass destruction in the matrix versus the fractures, and percentage of injected remedial fluid interacting with the target contaminant. The effectiveness of the three remediation technologies covered a wide range; the mass of contaminants destroyed were found to range from 15% to 99.5% of the initial mass present. Effectiveness of each technology was found to depend on a variety of critical factors particular to each approach. For example, in-situ chemical oxidation was found to be limited by the organic material present in the matrix of the rocks, while the efficiency of enhanced bioremediation was found to be related to factors such as the location of indigenous bacteria present in the domain and rate of bioremediation. In the chemical oxidation study, the efficiency of oxidant consumption was observed to be poor across the suite of scenarios, with greater than 90% of the injected permanganate consumed by natural oxidant demand. This study further revealed that the same factors that contributed to forward diffusion of contaminants prior to treatment are critical to this remediation method as they can determine the extent of contaminant destruction during the injection period. Bioremediation in fractured rock was demonstrated to produce relatively good results under robust first-order decay rates and active microorganisms throughout the fractures and matrix. It was demonstrated that under ideal conditions, of the total initial mass present, up to 3/4 could be reduced to ethene, indicating bioremediation may be a promising treatment approach due to the effective penetration of electron donor into the matrix during the treatment period and the ongoing treatment that occurs after injection ceases. However, when indigenous bacteria was assumed to exist only within the fractured walls of sandstone, it was found that under the same conditions, the rate of dechlorination was 200 times less than the Base Case. Since the majority of the mass resided in the matrix, lack of bioremediation in the matrix significantly reduced the effectiveness of treatment. Surfactant treatment with Tween-80 was proven to be a relatively effective technique in enhanced solubilisation of DNAPL from the fractures within the domain. However, by comparing the aqueous and sorbed mass at the start and end of the Treatment stage, it is revealed that surfactant treatment is not efficient in removing these masses that reside within the matrix. Furthermore, DNAPLs identified in dead end vertical fractures were found to remain in the domain by the end of the simulations across all scenarios studied; indicating that the injected surfactant experiences difficulty in accessing DNAPLs entrapped in dead end fractures. Altogether, the results underscore the challenge of restoring fractured rock aquifers due to the field scale limitations on sufficient contact between remedial fluids and in situ contaminants in all but the most ideal circumstances.

Ce travail s’intéresse au renforcement mécanique de films lubrifiants auto-assemblés en milieu aqueux par réticulation. Deux stratégies ont été suivies. La première consiste à réticuler physiquement un film de tensioactifs cationiques par coadsorption d’un copolymère associatif anionique. La deuxième est de réticuler chimiquement un film de copolymères triblocs par la création de liaisons covalentes entre les différentes macromolécules. Nous étudions l’auto-assemblage des films par microbalance à cristal de quartz et microscopie à force atomique (AFM). Nous discutons ensuite les effets de la réticulation sur la morphologie des films (caractérisée par AFM), et sur leurs propriétés mécaniques mesurées avec l’appareil à mesure de force SFA-nanotribomètre. Cette étude a montré que dans les deux cas, la réticulation modifie les propriétés des films lubrifiants et permet une augmentation de la cohésion des films adsorbés. / In this work, we study the effect of cross-linking on boundary lubricant films in aqueous media. Two strategies have been followed. First, we investigate a physical network on a cationic surfactant bilayer by coadsorption of an anionic copolymer. Secondly a tribloc copolymer film was chemically cross-linked by creating some chemical bounds between macromolecules. We study film self-assembling by Quartz Crystal Microbalance and Atomic Force Microscopy. We discuss then on the effect of cross-linking on the morphology of the film and its mechanical properties by combining AFM and Surface Force Apparatus SFA-nanotribometer. We have shown that in both cases, lubricant films properties are modified and the cohesion of the adsorbed films is increased by cross-linking.

Catalysis plays an important part in our society. Numerous transition metal catalysts have been developed which can convert many different substrates in a wide range of reactions. Catalysis also plays an important role in nature and therefore special catalysts, enzymes, have evolved over time. Enzymes are tremendously efficient giving high yields and selectivities both regio and chemical but have a limited substrate and reaction scope. It was speculated that by combining the two, an ideal catalyst can be obtained. We planned to achieve this by introducing a transition metal, the catalytic centre, into the chiral environment of a double helical oligonucleotide. The transition metals were introduced by coordinating them to a ligand which was located in the chiral environment of a double helix. The ligand was either covalently bound (Chapter 2) or non-covalently bound (Chapter 3) to the oligonucleotide (Figure 1). Figure 1: A) covalent introduction of a transition metal into a nucleotide B) non-covalent introduction of a transition metal into a nucleotide For the covalent approach a phosphine ligand was chosen. A nucleoside was modified with an alkyne to which a phosphine moiety could be coupled via the copper catalysed 1,3-dipolar cycloaddition. The modified nucleoside was incorporated into an oligonucleotide before attempting to attach the phosphine moiety. The monomer was used as a ligand in allylic substitution and hydroformylation. In the non-covalent approach polyamide minor groove binders were functionalised with an amine linker. Phosphine moieties were connected via amide bond formation. Although the coupling worked effortlessly the phosphines oxidised during purification therefore dienes were also investigated.

Soils represent an important terrestrial carbon (C) sink, storing up to three times the amount of atmospheric C, however climate and land use changes may transform soils into C sources. River corridor (RC) soils and associated C are at risk to become mobilized by erosion such as bank failure and scour events. Once soil-derived organic C is transferred into the stream, microbial processes and photodegradation of the dissolved, labile (or bioavailable) fractions can lead to the production of CO2, which can evade and increase atmospheric CO2 levels. Because predicted increases in heavy precipitation will likely increase this type of riverine erosion, it is important to better understand the potential for the release of bioavailable C from RCs. One objective of this thesis was therefore to identify and characterize representative samples of soils from a typical Vermont RC for common land covers and simulate the production of dissolved organic matter (DOM) during riverine soil erosion. Field sites representative of typical agricultural and forested land uses were selected based on the analysis of 106 existing samples and resampled multiple times over the summer of 2015. Production of DOM from riverine erosion was simulated using aqueous soil extracts (ASE), where soil and water were shaken at fixed ratios followed by the separation of the extract. To study the characteristics of these extracts (which serve as analogue of stream water after erosion), water extractable C (WEOC) concentrations, water extractable nitrogen, fluorescence properties of DOM, and bioavailability were determined. Results indicated a common, dominantly terrestrial source material for all land covers, but C concentrations and fluorescence properties differed. High but variable amounts of soil organic C and WEOC were observed in agricultural riparian and agricultural stream bank samples, and lower concentrations in agricultural field, forest, forest riparian, and forest stream banks. WEOC bioavailability was high in all agricultural land covers and low in forested land covers. Because this study is the first in which ASE are used as analogues for stream water after riverine erosion, a second objective was to test laboratory methods used in this study for their effect on WEOC, fluorescence properties, and bioavailability. Specifically, the effects of soil drying, soil storage, and the effects of the extraction solution were tested. For this, ASE were prepared from soils that were field moist, dried, and after two years of storage. In addition, dried soils were extracted using different solutions including a salt solution, river water, and double deionized (DDI) water. Results indicated WEOC concentration and microbial humic-like fluorescence from extracts of dried soils were higher than those in extracts of field moist soils, while WEOC concentration and microbial humic-like fluorescence was highest in extracts of soils stored long term. In addition, the bioavailability of WEOC was higher in dried soils than field moist soils. The extraction solutions of DDI water and river water produced DOM with similar fluorescence properties, while the salt solution extracted a different, less humified pool of C. Overall, the ASE methods used in this study are effective in simulating stream bank erosion and subsequent C release into stream water, however the effects of drying the soils need to be considered when assessing DOM.

Para o estudo usou-se uma coluna de vidro, com 2,75 m de altura e 3,7 cm de diâmetro interno, contendo 29 pratos perfurados (diâmetro dos furos, 0,3 cm e área livre de 35 %), com espaçamento de 9,35 cm. O solvente percorria a coluna no sentido ascendente e a fase contínua, no contrário. A pulsação era fornecida ao sistema líquido por uma biela ligada excentricamente a uma polia, de um lado, e a uma junta de expansão, do outro. A frequência variou de 0 a 2,8 s-1 e a amplitude, de 0,6 a 2,3 cm. Uma primeira série de ensaios foi feita com o sistema binário acetato de n-butila-água, pois, para ele, há dados disponíveis para comparação. Dos resultados obtidos, concluiu-se ser conveniente o desempenho do equipamento. Em seguida, usou-se (a) o sistema metil isobutil cetona-água para levantar curvas de inundação e retenção da fase dispersa para várias condições de operação e (b) o sistema metil isobutil cetona-fenol-água para obter dados de transporte de massa, ou seja, altura equivalente a um estágio de equilíbrio e eficiência da remoção do fenol. Os resultados foram comparados, quando possível, com outros da literatura e com correlações existentes; em alguns casos, obtiveram-se correlações próprias. Os resultados alcançados são reprodutíveis e, para propriedades físicas e geométricas semelhantes, comportam-se de modo compatível com os da literatura. O processo é razoavelmente eficiente na remoção do fenol. / The extraction of phenol from aqueous solutions using a pulsed perforated-plate column was studied. The glass column, 2.75 m high and 3.7 cm internal diameter contains 29 perforated plates (0.3 cm holes and 35% of free area). The solvent flows upwards and the continuous phase, downwards. The pulsation was obtained by the expansion and compression of an expansion joint. Frequency varied from 0 to 2.8 s-1 and amplitude, from 0.6 to 2.3 cm. The initial tests were undertaken with the binary system n-butyl acetate-water because, for this system, there are data for comparison. It was shown that the equipment leads to convenient results. Then, the system methylisobutylketone-water was used to obtain flooding curves and dispersed phase hold-up and the system MIBK-phenol-water to study height equivalent to a theoretical stage and the phenol separation efficiency. The results were compared, whenever possible, with data from the literature and with existing correlations; specific correlations were obtained in certain cases. Results are reproducible and, for similar geometries and physical properties they are compatible with those of literature. The equipment is rather efficient in removing the phenol from the solution.

O peixe dourado é extensivamente utilizado em pesquisas sobre visão devido a diversos fatores: é um animal pecilotermo, o que possibilita manter sua retina ex-vivo viável para manipulação experimental por mais tempo; apresenta uma organização retiniana semelhante à de mamíferos; possui neurônios grandes, facilitando estudos eletrofisiológicos e morfológicos e, diferentemente de mamíferos, é dotado de neurogênese constante de alguns tipos celulares retinianos. A produção, composição e escoamento dos meios oculares nesta espécie, fundamentais para a formação de imagens sobre a retina, são, entretanto, pouco conhecidos. A variedade padrão desta espécie apresenta desenvolvimento ocular normal, enquanto a variedade demekin é extremamente míope por possuir crescimento ocular exagerado (buftalmia), condição característica de alguns tipos de glaucoma em mamíferos. O presente trabalho investigou aspectos morfofisiológicos do sistema de produção e drenagem do humor aquoso e a composição do humor vítreo nestas duas variedades de peixe dourado, com o objetivo de melhor compreender as causas subjacentes ao crescimento ocular do demekin. Para estudar a drenagem do humor aquoso, foram realizadas injeções de corante na câmara anterior de animais das duas variedades, com processamento histológico posterior em intervalos de tempo pré-determinados (5, 15, 30, 60, 120 minutos e 1, 2, 3 4 e 7 dias, n <= 3 olhos de cada variedade por grupo experimental). Não foram observadas diferenças na drenagem de humor aquoso entre as duas variedades. Em ambas, o humor aquoso é drenado principalmente pela malha trabecular contida na porção ventral do ângulo de drenagem, entre a íris e o ligamento anular. Duas vias secundárias de drenagem foram encontradas nas duas variedades de peixe dourado estudadas: (i) a via irídica e (ii) a drenagem através de vasos epirretinianos. Estas vias são aparentemente mais lentas do que a via trabecular, uma vez que foi encontrado corante nessas regiões até quatro dias após as injeções de corante na câmara anterior. Foi realizado também estudo ultraestrutural da retina e epitélio ciliar em ambas as variedades através de microscopia eletrônica de transmissão. O epitélio pigmentado da retina do demekin apresentou grânulos de melanina mais escassos, e observamos certa desorganização da camada de fotorreceptores, bem como redução da sua densidade. Através de aparato invasivo construído por Joselevitch e Smith (1997), foi mensurada a pressão intraocular (PIO) de 14 olhos de cada variedade. O demekin apresentou valores de PIO ligeiramente aumentados em relação ao animal padrão (3,6 ± 0,9 mmH2O para o demekin e 1,9 ± 0,6 mmH2O para o peixe dourado padrão). A composição proteica do corpo vítreo foi estudada através de eletroforese em gel de poliacrilamida utilizando um pool de humor vítreo de 4 animais da variedade padrão e 2 da variedade demekin. As proteínas de baixa massa molecular (entre 15 a 25 kDa) estavam expressas em ambas - embora com maior expressão na variedade padrão - e outras, de maior massa molecular, expressas apenas no humor vítreo do demekin (50-75 kDa e 150 kDa). Os resultados obtidos sugerem, portanto, que há diferenças importantes na ultraestrutura retiniana, na composição proteica do humor vítreo e na pressão intraocular do demekin. Para melhor compreensão do crescimento ocular desta variedade faz-se necessária a realização de um estudo proteômico, identificando quais são as proteínas do humor vítreo evidenciadas através da eletroforese, bem como estudos morfológicos em animais de diferentes tamanhos visando a quantificação dos danos retinianos decorrentes do seu crescimento ocular / The goldfish is extensively used in vision research due to several factors: it is a poikilothermic animal, which allows ex-vivo experiments using its retina for longer periods of time; its retinal organization is very similar to that of mammals; it has large neurons, which facilitates electrophysiological and morphological studies and, unlike mammals, it is endowed with constant neurogenesis of some retinal cell types. However, the production, composition and outflow of ocular media in this species, which are fundamental for image formation onto the retina, are poorly understood. The standard goldfish has normal eye development, while the Black Moor goldfish is extremely myopic due to excessive eye growth (buphthalmos), a condition that is present in certain types of mammalian glaucoma. The present study investigated morphophysiological aspects of the aqueous humor production and drainage system and vitreous humor composition in these two varieties of goldfish to better understand the causes underlying the eye growth of the Black Moor. To study the drainage of the aqueous humor, anterior chamber dye injections and histological processing were performed in animals of both varieties after predetermined time intervals (5, 15, 30, 60, 120 minutes and 1, 2, 3, 4, and 7 days, n <= 3 eyes of each variety for each experimental group). No differences were observed in the drainage of aqueous humor between the two varieties. In both, the aqueous humor is drained mainly by the trabecular meshwork contained in the ventral portion of the drainage angle, between the iris and the annular ligament. Two secondary drainage routes were found in the two goldfish varieties studied: (i) the iridic route and (ii) drainage through epiretinal vessels. These pathways are apparently slower than the trabecular route, since the dye was found in these regions 4 days after the injections. An ultrastructural study of the retina and ciliary epithelium was also carried out in both varieties through transmission electron microscopy. The retinal pigment epithelium of the Black Moor presented more scarce melanin granules and we observed some disorganization of the photoreceptor layer, as well as a reduction in its density. Through an invasive device constructed by Joselevitch and Smith (1997), the intraocular pressure (IOP) of 14 eyes of each variety was measured. The Black Moor presented slightly increased IOP values compared to the standard animal (3.6 ± 0.9 mmH2O for demekin and 1.9 ± 0.6 mmH2O for the standard goldfish). The protein composition of the vitreous body was studied by polyacrylamide gel electrophoresis using a vitreous humor pool of 4 animals of the standard variety and 2 of the Black Moor variety. Low molecular weight proteins (15 to 25 kDa) were expressed in both - although with greater expression in the standard variety - and others of higher molecular mass, expressed only in the vitreous humor of the Black Moor (50-75 kDa and 150 kDa). These results suggest, therefore, that there are important differences in the retinal ultrastructure, the protein composition of the vitreous humor and the intraocular pressure of the Black Moor. To better understand the ocular growth in this variety, it is necessary to carry out a proteomic study, identifying which are the vitreous humor proteins evidenced through electrophoresis, as well as morphological studies in animals of different sizes aiming the quantification of the retinal damages caused by its ocular growth

Bromelina é um nome coletivo para enzimas proteolíticas encontradas no talo, fruto e folhas do abacaxi (Ananas comosus Merr). A bromelina possui propriedades anti-inflamatórias, de debridamento, entre outras. Para a produção da bromelina deve-se, preferencialmente, usar resíduos do abacaxi, visto que os produtos do fruto têm aplicação comercial. Este trabalho teve como objetivo a extração de bromelina a partir de cascas de abacaxi através de sistema de duas fases aquosas (SDFA), e sua aplicação em hidrogel polimérico. Foram realizados estudos de estabilidade da bromelina comercial, em que se observou maior estabilidade em pH 5,0 com menor perda da atividade relativa em todas as temperaturas estudadas (20, 30, 40 e 50°C). O estudo da extração da bromelina em SDFA formado por polietileno glicol (PEG) e ácido poliacrílico (PAA) (com auxílio da análise de variância de parâmetros como rendimento, fator de purificação e coeficiente de partição) proporcionou rendimento de 335% e fator de purificação de 25,8. Os hidrogéis poliméricos à base de PEG estudados apresentaram-se flexíveis, com pouca elasticidade e taxa de absorção superior a 1000%. Hidrogel carreado de bromelina pelo método de turgescência proporcionou a maior liberação da enzima, assim como a maior atividade (80% da bromelina liberada em 24 h e 278 ± 89 U/mL). / Bromelain is a collective name for the proteolytic enzymes found in the stem, fruit and leaves of pineapple (Ananas comosus Merr.). Bromelain possesses anti-inflammatory properties, debridement, among others. For bromelain production one should preferably use the waste materials, whereas pineapple fruit products have commercial application. This study aimed to extract bromelain from pineapple peels using aqueous two-phase system (ATPS), and its application in polymeric hydrogels. Stability studies of commercial bromelain were performed, which found greater stability at pH 5.0 with minor loss of relative activity at all temperatures studied. The study of bromelain extraction in ATPS composed by polyethylene glycol (PEG) and poly acrylic acid (PAA) (with assistance of variance analysis of parameters such as yield, purification factor and partition coefficient) showed yield 335% and purification factor of 25.8. The PEG-based hydrogels studied presented flexibility, low elasticity and swelling ratio higher than 1000%. Hydrogel containing bromelain, loading by embedding (solvent sorption) method, yielded the highest enzyme release, as well as the highest activity (80% bromelain released over 24 h and 278 ± 89 U / mL).

Neste trabalho foram estudadas duas abordagens para a obtenção de novos metabólitos secundários a partir de fungos. Na primeira, o ácido hidroxâmico suberoilanilida (SAHA) e cinco análogos foram sintetizados. Sua atividade como modificadores epigenéticos foi avaliada em oito linhagens fúngicas do ambiente marinho. Os fungos Penicillium sp. e Acremonium sp. apresentaram modificações no seu perfil metabolómico quando foram crescidos em pequena escala em presença do derivado 4F-SAHA, enquanto Microphaeropsis sp. apresentou modificação em presença do 3AM-SAHA. O fungo P. decaturense foi crescido em maior escala e os compostos de interesse foram isolados. Na segunda abordagem, uma nova estratégia de extração utilizando mistura de resinas XAD 2-4-7 permitiu a extração e posterior isolamento de seis novos alcaloides peptídicos (72-77) e dois peptídeos (78-79) a partir da fração aquosa do meio de cultivo do fungo antártico Penicillium solitum IS1-A. Utilizando a mesma metodologia, o metabolismo secundário do fungo antártico Thelebolus globosus E2 foi estudado. A partir de seu extrato metanólico do meio liquido PDB foram isoladas a ciclopenina (86) e o ciclopenol (87) e foram detectados os alcaloides viridicatina (88) e viridicatol (89). O fungo Thelebolus globosus mostrou-se produtor de estatinas, sendo isoladas como composto majoritário a mevastatina (90). / In this work two approaches to obtain new secondary metabolites from fungi were studied. Suberoylanilide hydroxamic acid (SAHA) and five analogues were synthesized and assessed as epigenetic modifiers in eight marine-derived fungi. The fungus Penicillium sp. and Acremonium sp. presented changes in their metabolomic profile when they were grown on a small scale in presence of 4F-SAHA derivative and Microphaeropsis sp. presented a modification in the presence of the 3 AM-SAHA. In the second approach a new extraction strategy using XAD 2-4-7 resin mixture allowed the extraction and subsequent isolation of six new peptide alkaloids (72-77) and two peptides (78-79) from the aqueous fraction of the culture medium of the Antarctic fungus Penicillium solitum IS1-A. Using the same methodology, the secondary metabolism of the Antarctic fungus Thelebolus globosus E2 was studied. From the methanolic extract of the PDB liquid medium cyclopenine (86) and cyclopenol (87) were isolated and the viridicatine (88) and viridicatol (89) alkaloids were detected. The fungus Thelebolus globosus was shown to be a producer of statins, mainly of mevastatin (90).