Cell-free protein synthesis is an emerging technology that has many applications. The open nature of this system makes it a compelling technology that can be manipulated to answer many needs that are unavailable in other systems. This dissertation reports on engineering this technology for: 1) sense codon emancipation for incorporation of multiple unnatural amino acids; 2) expressing a hard-to-express anticancer biotherapeutic and introducing a just-add-water system; 3) a biosensing ligand that interacts with nuclear hormone receptors. Emancipating sense codons toward a minimized genetic code is of significant interest to science and engineering. A promising approach to sense codon emancipation is the targeted in vitro removal of native tRNA. Here we introduce a new in-vitro or "cell-free" approach to emancipate sense codons via efficient and affordable degradation of endogenous tRNA using RNase-coated superparamagnetic beads. The presented method removes greater than 99% of tRNA in cell lysates, while preserving cell-free protein synthesis activity. The resulting tRNA-depleted lysate is compatible with in vitro-transcribed synthetic tRNA for the production of peptides and proteins. Biotherapeutics have many promising applications, such as anti-cancer treatments, immune suppression, and vaccines. However, due to their biological nature, some biotherapeutics can be challenging to rapidly express and screen for activity through traditional recombinant methods. In this work, we demonstrate the use of cell-free systems for the expression and direct screening of the difficult-to-express cytotoxic protein onconase. Using cell-free systems, onconase can be rapidly expressed in soluble, active form. Furthermore, the open nature of the reaction environment allows for direct and immediate downstream characterization without the need of purification. Also, we report the ability of a "just-add-water" lyophilized cell-fee system to produce onconase. Here we introduce a Rapid Adaptable Portable In-vitro Detection biosensor platform (RAPID) for detecting ligands that interact with nuclear hormone receptors (NHRs). The biosensor is based on an engineered, allosterically-activated fusion protein, which contains the ligand binding domain from a target NHR. The presented RAPID biosensor platform is significantly faster and less labor intensive than commonly available technologies, making it a promising tool for detecting environmental EDC contamination and screening potential NHR-targeted pharmaceuticals.

Philosophiae Doctor - PhD (Chemistry) / There is growing concern on endocrine disrupting compounds (EDCs). The presence of drugs in water supplies was first realized in Germany in the early 1990s when environmental scientists discovered clofibric acid. Clofibric acid has the ability to lower cholesterol in ground water below a water treatment plant. Endocrine disrupting compounds can be defined as those chemicals with the ability to alter daily functioning of the endocrine system in living organisms. There are numerous molecules that are regarded or referred to as EDCs such as but not limited to organochlorinated pesticides, industrial chemicals, plastics and plasticizers, fuels, estrogens and many other chemicals that are found in the environment or are in widespread use. 17?- estradiol is the principal estrogen found in mammals during reproductive years. Estriol is produced in large quantities during pregnancy. 17?-estradiol is the strongest, estriol the weakest. Estriol is water soluble, estrone and estradiol are not. Although estrogen is produced in women they are also at risk of over exposure to estrogen. Pesticides are extensively used today in agricultural settings to prevent and control pests. Various pesticides, including banned organochlorines (OCs) and modern non-persistent pesticides, have shown the ability to disrupt thyroid activity, disturbing the homeostasis of the thyroid system. Because these EDCs have adverse effects on health of both human and wildlife, it is imperative to develop viable costeffective analytical methods for the detection of these EDCs in complicated samples and at very low concentrations. Very high selectivity towards particular compounds is a very important property for the suitability of a detection method. This is because these compounds mostly coexist in complex matrices which makes the detection of a specific compound very challenging. It is paramount to develop highly sensitive and selective methods for the detection of these estrogens and phosphoric acid-based pesticides at trace levels. / 2021-08-31

Devido à escassez de recursos hídricos, efluentes de plantas de tratamento de águas residuárias têm sido reutilizadas ou recicladas em todo o mundo. Em algumas regiões áridas e em particular em regiões semi-áridas, o reuso de água tem sido reconhecido como um valioso recurso. Entretanto, dependendo da natureza do uso, surgem preocupações sobre potenciais riscos associados à presença de patógenos e contaminantes e a saúde humana. Uma grande variedade de contaminantes orgânicos pode estar presente nos esgotos domésticos e ser recirculado pelo ambiente. Alguns desses compostos apresentam o potencial de desregular as funções normais do sistema endócrino dos organismos e assim, causar efeitos adversos sobre a saúde humana. Entre esses compostos, incluem-se os hormônios estrógenos naturais e sintéticos. Nesse trabalho, desenvolvido na Estação Experimental de Tratamento de Águas Residuárias Urbanas do IPH/UFRGS, localizada nas dependências da ETE São João – Navegantes / DMAE / Porto Alegre / RS, foi investigada a ocorrência de hormônios naturais e sintéticos em grãos de milho cultivados por processo de irrigação por sulcos com efluentes domésticos tratados. O método analítico utilizado para quantificação dos hormônios de interesse foi a cromatografia líquida de alto desempenho (HPLC). Os resultados obtidos confirmam a presença de hormônios naturais e sintéticos no esgoto bruto e nos efluentes tratados, mas em concentrações extremamente baixas e não indicam processo de transferência ou acúmulo desses contaminantes para os grãos de milho. / Due to the scarcity of fresh water resources, effluents from wastewater treatment plants have increasingly been reclaimed and reused around the world. In some arid and semiarid regions, in particular, reclaimed water has been recognized as a valuable resource for non-potable use such as irrigating crops. However, depending on the nature of application, there is concern about potential risks associated with pathogens and organic contaminants to the environment and human health. A wide range of organic contaminants may be present in wastewater and the environment receiving it. These include natural and synthetic estrogens have the potential to disrupt the normal function (s) of endocrine systems in organisms and thus causing health effects on wildlife and humans. In the present work, developed at “Estação Experimental de Tratamento de Águas Residuárias Urbanas do IPH/UFRGS”, located on the ETE São João – Navegantes /DMAE / Porto Alegre /RS, was investigated the occurrence of natural and synthetic hormones in corn’s grain (Zea mays) cultivated by furrow irrigation of treated domestic effluents. The analytic method used for the hormones quantification was the High Performance Liquid Chromatography (HPLC). The results confirm the presence of natural and synthetic hormones on the untreated and treated effluents, although with a very low concentration and not indicated accumulation of this one to the corn’s grain.

Devido à escassez de recursos hídricos, efluentes de plantas de tratamento de águas residuárias têm sido reutilizadas ou recicladas em todo o mundo. Em algumas regiões áridas e em particular em regiões semi-áridas, o reuso de água tem sido reconhecido como um valioso recurso. Entretanto, dependendo da natureza do uso, surgem preocupações sobre potenciais riscos associados à presença de patógenos e contaminantes e a saúde humana. Uma grande variedade de contaminantes orgânicos pode estar presente nos esgotos domésticos e ser recirculado pelo ambiente. Alguns desses compostos apresentam o potencial de desregular as funções normais do sistema endócrino dos organismos e assim, causar efeitos adversos sobre a saúde humana. Entre esses compostos, incluem-se os hormônios estrógenos naturais e sintéticos. Nesse trabalho, desenvolvido na Estação Experimental de Tratamento de Águas Residuárias Urbanas do IPH/UFRGS, localizada nas dependências da ETE São João – Navegantes / DMAE / Porto Alegre / RS, foi investigada a ocorrência de hormônios naturais e sintéticos em grãos de milho cultivados por processo de irrigação por sulcos com efluentes domésticos tratados. O método analítico utilizado para quantificação dos hormônios de interesse foi a cromatografia líquida de alto desempenho (HPLC). Os resultados obtidos confirmam a presença de hormônios naturais e sintéticos no esgoto bruto e nos efluentes tratados, mas em concentrações extremamente baixas e não indicam processo de transferência ou acúmulo desses contaminantes para os grãos de milho. / Due to the scarcity of fresh water resources, effluents from wastewater treatment plants have increasingly been reclaimed and reused around the world. In some arid and semiarid regions, in particular, reclaimed water has been recognized as a valuable resource for non-potable use such as irrigating crops. However, depending on the nature of application, there is concern about potential risks associated with pathogens and organic contaminants to the environment and human health. A wide range of organic contaminants may be present in wastewater and the environment receiving it. These include natural and synthetic estrogens have the potential to disrupt the normal function (s) of endocrine systems in organisms and thus causing health effects on wildlife and humans. In the present work, developed at “Estação Experimental de Tratamento de Águas Residuárias Urbanas do IPH/UFRGS”, located on the ETE São João – Navegantes /DMAE / Porto Alegre /RS, was investigated the occurrence of natural and synthetic hormones in corn’s grain (Zea mays) cultivated by furrow irrigation of treated domestic effluents. The analytic method used for the hormones quantification was the High Performance Liquid Chromatography (HPLC). The results confirm the presence of natural and synthetic hormones on the untreated and treated effluents, although with a very low concentration and not indicated accumulation of this one to the corn’s grain.

Devido à escassez de recursos hídricos, efluentes de plantas de tratamento de águas residuárias têm sido reutilizadas ou recicladas em todo o mundo. Em algumas regiões áridas e em particular em regiões semi-áridas, o reuso de água tem sido reconhecido como um valioso recurso. Entretanto, dependendo da natureza do uso, surgem preocupações sobre potenciais riscos associados à presença de patógenos e contaminantes e a saúde humana. Uma grande variedade de contaminantes orgânicos pode estar presente nos esgotos domésticos e ser recirculado pelo ambiente. Alguns desses compostos apresentam o potencial de desregular as funções normais do sistema endócrino dos organismos e assim, causar efeitos adversos sobre a saúde humana. Entre esses compostos, incluem-se os hormônios estrógenos naturais e sintéticos. Nesse trabalho, desenvolvido na Estação Experimental de Tratamento de Águas Residuárias Urbanas do IPH/UFRGS, localizada nas dependências da ETE São João – Navegantes / DMAE / Porto Alegre / RS, foi investigada a ocorrência de hormônios naturais e sintéticos em grãos de milho cultivados por processo de irrigação por sulcos com efluentes domésticos tratados. O método analítico utilizado para quantificação dos hormônios de interesse foi a cromatografia líquida de alto desempenho (HPLC). Os resultados obtidos confirmam a presença de hormônios naturais e sintéticos no esgoto bruto e nos efluentes tratados, mas em concentrações extremamente baixas e não indicam processo de transferência ou acúmulo desses contaminantes para os grãos de milho. / Due to the scarcity of fresh water resources, effluents from wastewater treatment plants have increasingly been reclaimed and reused around the world. In some arid and semiarid regions, in particular, reclaimed water has been recognized as a valuable resource for non-potable use such as irrigating crops. However, depending on the nature of application, there is concern about potential risks associated with pathogens and organic contaminants to the environment and human health. A wide range of organic contaminants may be present in wastewater and the environment receiving it. These include natural and synthetic estrogens have the potential to disrupt the normal function (s) of endocrine systems in organisms and thus causing health effects on wildlife and humans. In the present work, developed at “Estação Experimental de Tratamento de Águas Residuárias Urbanas do IPH/UFRGS”, located on the ETE São João – Navegantes /DMAE / Porto Alegre /RS, was investigated the occurrence of natural and synthetic hormones in corn’s grain (Zea mays) cultivated by furrow irrigation of treated domestic effluents. The analytic method used for the hormones quantification was the High Performance Liquid Chromatography (HPLC). The results confirm the presence of natural and synthetic hormones on the untreated and treated effluents, although with a very low concentration and not indicated accumulation of this one to the corn’s grain.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / No Brasil, estudos de avaliaÃÃo de micropoluentes emergentes em matrizes ambientais como esgotos sanitÃrios e hospitalares, e corpos de Ãgua, ainda sÃo bastante incipientes, assim como a remoÃÃo desses compostos em EstaÃÃes de Tratamento de Esgotos (ETEs) de baixo custo como lagoas de estabilizaÃÃo, assim como em sistemas de lodos ativados e sistemas anaerÃbio-aerÃbio compactos. O presente trabalho teve como objetivo geral investigar a presenÃa de micropoluentes em matrizes ambientais como esgotos sanitÃrios e hospitalares, e Ãgua superficial, avaliar a remoÃÃo destes compostos em ETEs de baixo custo e aplicar o processo de oxidaÃÃo avanÃada (POA) UV/H2O2 como opÃÃo de pÃs-tratamento. Os principais micropoluentes emergentes estudados foram: 2,4,6-triclorofenol, pentaclorofenol, cafeÃna (CAF), dipirona (DIP), diclofenaco de sÃdio (DCF), bis (2-etil-hexil) ftalato (DEHP), estrona (E1), 17β-estradiol (E2), β-estradiol 17-acetato (EA2), 17α-etinilestradiol (EE2) e colesterol (COL). As amostras foram coletadas em ETEs localizadas em Fortaleza e em sua regiÃo metropolitana. Os corpos receptores investigados foram o Rio Maranguapinho e o Riacho Paupina. Para a prÃ-concentraÃÃo dos micropoluentes utilizou-se extraÃÃo em fase sÃlida (SPE) com cartuchos C-18 e extraÃÃo lÃquido-lÃquido (ELL). A SPE foi a tÃcnica mais eficiente na concentraÃÃo da maioria dos micropoluentes emergentes, e a ELL se mostrou a melhor tÃcnica para compostos organoclorados. Foram realizados estudos de otimizaÃÃo das condiÃÃes de detecÃÃo dos compostos pelo uso de tÃcnicas de cromatografia gasosa acoplada à espectrometria de massas (GC/MS). Foram identificados compostos farmacÃuticos e desreguladores endÃcrinos em todas as amostras de esgotos com as seguintes faixas de concentraÃÃes efluentes: CAF (3,0-15,8 μg/L), DIP (0,3 μg/L), DCF (1,9 μg/L), DEHP (0,01-8,5μg/L), E1 (0,04-1,7 μg/L), E2 (0,03-4,0 μg/L), EA2 (0,14-9,3 μg/L), EE2 (1,0 μg/L) e COL (0,01-6,2 μg/L). Nos dois corpos receptores estudados (Rio Maranguapinho e Riacho Paupina) foram identificados desreguladores endÃcrinos. Os tratamentos realizados pelas ETEs nÃo foram suficientes para remoÃÃo total de todos os micropoluentes estudados, no entanto, a eficiÃncia para a maioria dos compostos foi acima de 50%. Em se tratando da avaliaÃÃo em sistemas de lagoas de estabilizaÃÃo, o estudo revelou boas eficiÃncias de remoÃÃo em sistemas constituÃdos de lagoa anaerÃbia seguida de facultativa e de maturaÃÃo, sendo os menores valores de remoÃÃo alcanÃados quando uma Ãnica lagoa facultativa primÃria estava presente. A avaliaÃÃo do uso do POA por meio do planejamento fatorial multivariado revelou que as melhores condiÃÃes para remoÃÃo de micropoluentes emergentes foram pH Ãcido (pH 3), concentraÃÃo de perÃxido de hidrogÃnio acima de 400 mg/L e tempos de detenÃÃo hidrÃulica no reator acima de 50min. / In Brazil, studies evaluating emerging micropollutants in environmental matrices such as sewage and hospital wastewater, as well as surface waters, are still quite incipient as well as the removal of these compounds in low cost Wastewater Treatment Plants (WWTPs) such as stabilization ponds, as well as in activated sludge systems or anaerobic/aerobic compact systems. This work aimed to investigate the presence of micropollutants in environmental matrices such as sewage and hospital wastewaters, and in surface waters. Additionally, this study evaluated the removal of these compounds in low-cost WWTPs and studied the advanced oxidation process (AOP) â UV/H2O2 â as a post-treatment option. The main emerging micropollutants studied were: 2,4,6-trichlorophenol, pentachlorophenol, caffeine (CAF), dipyrone (DIP), sodium diclofenac (DCF), bis (2-ethylhexyl) phthalate (DEHP), estrone (E1), 17β-estradiol (E2), estradiol acetate (EA2), 17α-ethinyl estradiol (EE2) and cholesterol (CHO). The samples were collected from WWTPs located in Fortaleza and its metropolitan region. The receiving surface waters investigated were: Maranguapinho River and Paupina Creek. For the pre-concentration studies of micropollutants, solid phase extraction (SPE) with C-18 cartridges was used, as well as the liquid-liquid extraction (LLE) method. The SPE technique was the most efficient method in concentrating the majority of emerging micropollutants, and the LLE proved to be the best technique for organochlorine compounds. Optimization studies were performed to detect the ideal conditions to determine the compounds by using gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) techniques. In all wastewater samples pharmaceuticals and endocrine disrupting compounds were identified, and the range of effluent concentrations were: CAF (3.0-15.8 μg/L), DIP (0.3 μg/L), DCF (1.9 μg/L), DEHP (0.01-8.5μg/L), E1 (0.04-1.7 μg/L), E2 (0.03-4.0 μg/L), EA2 (0.14-9.3 μg/L), EE2 (1.0 μg/L) and CHO (0.01-6.2 μg/L). Endocrine disrupting compounds were identified in the Maranguapinho River and Paupina Creek. The wastewater treatment in the WWTPs was not enough for the complete removal of all micropollutants studied; however, the efficiency level for most of compounds was above 50%. Regarding the evaluation in stabilization ponds systems, the study revealed good removal of micropollutants in systems composed of anaerobic pond followed by facultative and maturation ponds, in which the lowest efficiency levels were verified when a single facultative pond was present. The evaluation of the AOP as a post-treatment option by multivariate factorial design showed that the optimal conditions for the removal of emerging micropollutants were acidic pH (pH 3), hydrogen peroxide concentration above 400 mg/L and hydraulic retention times in the reactor above 50 minutes.

Desreguladores endócrinos são compostos que podem alterar o sistema endócrino dos indivíduos, bem como sua fertilidade e por em risco a saúde dos mesmos. Muitas questões relacionadas a esses compostos ainda não foram elucidadas, apesar de serem muito estudados recentemente. Diversas pesquisas têm sido feitas investigando-se o emprego de processos oxidativos avançados na degradação dos desreguladores endócrinos em águas naturais e residuárias. O presente trabalho teve como objetivo estudar a remoção do hormônio 17\'beta\'-estradiol em soluções aquosas por oxidação química. A pesquisa foi dividida em duas etapas, sendo que a primeira etapa consistiu na investigação do uso de brometo de prata/dióxido de titânio (\'AG\'BR\'/\'TI\'O IND.2\') como catalisador no processo de fotocatálise com luz visível. Para isso, foram avaliadas a influência da concentração de \'AG\'BR\'/\'TI\'O IND.2\' (0,020; 0,025; 0,050; 0,070 e 0,100 g/L) e a intensidade de luz visível incidente (6,6 x \'10 POT.5\' e 1,3 x \'10 POT.6\' Ix) na eficiência de degradação do 17\'beta\'-estradiol. Na segunda etapa avaliou-se o emprego de ozônio na degradação de 17\'beta\'-estradiol em soluções aquosas, variando-se as dosagens de ozônio (1,7; 3,3, 5,0 e 7,5 mg \'0 IND.3\'/L) aplicadas e o pH (3; 5; 7; 9 e 11) das amostras. Na primeira etapa, os resultados demonstram que E2 foi bastante sensível aos processos oxidativos empregados. A fotocatálise foi eficiente para oxidar 17\'beta\'-estradiol, demandando tempo de exposição pequeno, em torno de 4 minutos para obtenção de remoção da ordem de 98%, quando aplicada concentração de \'AG\'BR\'/\'TI\'O IND.2\' de 0,100 g/L e a intensidade de luz visível incidente de 1,3 x \'10 POT.6\' Ix. Na segunda etapa, observou-se que o aumento do pH promoveu maior rapidez na degradação do E2 e o aumento da massa de ozônio aplicada promoveu maior eficiência de degradação do 17\'beta\'-estradiol. / Endocrine disrupting chemicals are compounds that can alter the endocrine system of individuals and their fertility and threaten their health. Many issues related to these compounds have not been elucidated, although much studied recently. Many researchers have investigated the use of advanced oxidative processes in the degradation of endocrine disrupting compounds in water and wastewater. This work is a study of the removal of 17\'beta\'-estradiol in aqueous solutions by chemical oxidation. This work was divided into two stages. In the first one, the use of bromide of silver/titanium dioxide (\'AG\'BR\'/\'TI\'O IND.2\') was investigated as catalyst in the photocatalysis activity under visible light irradiation. It was evaluated the influence of the concentration of \'AG\'BR\'/\'TI\'O IND.2\' (0.020; 0.025; 0.050; 0.070 and 0.100 g/L) and the incident light intensity (6.6 x \'10 POT.5\' and 1.3 x \'10 POT.6\' Ix) in the efficiency of degradation of 17\'beta\'-estradiol. In the second step, it was evaluated the use of ozone in the degradation of 17\'beta\'-estradiol in aqueous solutions, ranging up the masses of applied ozone (1.7; 3.3; 5.0 and 7.5 mg \'0 IND.3\'/L) and the pH (3, 5, 7, 9 and 11) of the samples. In the first stage, the results show that E2 was very sensitive to oxidative processes applyed. The photocatalysis was efficient to oxidize the 17\'beta\'-estradiol, requiring short exposure time, around 4 minutes, to obtain the removal of 98% (0.100 g/L of \'AG\'BR\'/\'TI\'O IND.2\' and incident visible light intensity of 1.3 x \'10 POT.6\'. In the second step, it was observed that the raise in pH promoted faster degradation of E2 and the increase of the mass of applied ozone promoted high efficiency of degradation of 17\'beta\'-estradiol.

No description available.

This study was carried out to evaluate the performance of Soil Aquifer Treatment (SAT) under different loading regimes, using wastewater of much higher strength than usually encountered in SAT systems, and also to investigate the removal of the endocrine disruptors triclocarban (TCC), estrone (E1), 17¿-estradiol (E2) and 17¿- ethinylestradiol (EE2). SAT was simulated in the laboratory using a series of soil columns under saturated and unsaturated conditions. Investigation of the removal of Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Dissolved Organic Carbon (DOC), nitrogen and phosphate in a 2 meter long saturated soil column under a combination of constant hydraulic loading rates (HLRs) and variable COD concentrations as well as variable HLR under constant COD showed that at fixed HLR, a decrease in the influent concentrations of DOC, BOD, total nitrogen and phosphate improved their removal efficiencies. It was found that COD mass loading applied as low COD wastewater infiltrated over short residence times would provide better effluent quality than the same mass applied as a COD with higher concentration at long residence times. On the other hand relatively high concentrations coupled with long residence time gave better removal efficiency for organic nitrogen. Phosphate removal though poor under all experimental conditions, was better at low HLRs. In 1 meter saturated and unsaturated soil columns, E2 was the most easily removed estrogen, while EE2 was the least removed. Reducing the thickness of the unsaturated zone had a negative impact on removal efficiencies of the estrogens whereas increased DOC improved the removal in the saturated columns. Better removal efficiencies were also obtained at lower HLRs and in the presence of silt and clay. Sorption and biodegradation were found to be responsible for TCC removal in a 300 mm long saturated soil column, the latter mechanism however being unsustainable. TCC removal efficiency was dependent on the applied concentration and decreased over time and increased with column depth. Within the duration of the experimental run, TCC negatively impacted on treatment performance, possibly due to its antibacterial property, as evidenced by a reduction in COD removals in the column. COD in the 2 meter column under saturated conditions was modelled successfully with the advection dispersion equation with coupled Monod kinetics. Empirical models were also developed for the removal of TCC and EE2 under saturated and unsaturated conditions respectively. The empirical models predicted the TCC and EE2 removal profiles well. There is however the need for validation of the models developed / Netherlands Organisation for International Cooperation in Higher Education (Nuffic) / The Appendix files for this thesis are unavailable online via Bradford Scholars.

<p> Per- and polyfluoroalkyl substances (PFAS) are a class of persistent environmental contaminants that have become ubiquitous, resulting in widespread exposure among humans and wildlife. Amphibians are regularly exposed in the field, making them susceptible to sublethal effects of PFAS exposure. In amphibians exposed to PFAS, deleterious effects have been observed, including reduction in body condition measured using the scaled mass index (SMI) and degraded hepatic condition, among others. PFAS may dysregulate lipid metabolism by altering signaling cascades regulated by peroxisome proliferator activated receptors (PPAR), but whether changes in energy stores can explain changes in amphibian SMI and/or hepatic condition remain underexplored. Since lipids are a critical energy reserve for anurans, understanding whether lipid metabolism is being perturbed is critical. The central objective of this thesis was to investigate the effect of PFAS on lipid homeostasis in <em>Xenopus laevis </em>tadpoles within the context of a PPAR mechanism of action (MOA), considering apical, molecular, and lipidomic endpoints. I conducted three studies: (a) a study to characterize SMI and the relative expression of the hepatic xPPARα/β/γ during metamorphosis, (b) a pharmaceutical exposure to assess the <em>in vivo</em> effects of xPPARα/β/γ agonism on hepatic gene expression for select downstream targets (<em>apoa5, fabp1, acox1,​ pck1</em>), and (c) a chronic PFAS exposure to investigate the effects of environmentally relevant concentrations (PFOS, PFHxS, PFOA, PFHxA at 0.5 ppb; binary mixture of PFOS:PFHxS at 1 ppb) on lipid homeostasis through apical endpoints (mass, snout vent length, SMI, hepatic condition), relative hepatic gene expression, and Multiple Reaction Monitoring (MRM) profiling of the hepatic lipidome for changes in relative class abundance. In study (a), I identified SMI and hepatic expression of <em>xPPARα/β/γ</em> is dynamic during late metamorphosis, indicating the potential for heightened susceptibility. However, in study (b), pharmaceutical agonists had no effect on <em>X. laevis</em> at high doses. For study (c), I did not observe effects on a majority of apical endpoints, including SMI, but detected a significant sex-specific reduction in hepatic condition for male<em> X. laevis</em> tadpoles exposed to single-chemical perfluorosulfonic acid (PFSA) treatments. For gene expression, I observed a transient downregulation for apolipoprotein-V (<em>apoa5</em>) at Nieuwkoop and Faber (NF) stage 62 for <em>X. laevis</em> tadpoles exposed to single-chemical perfluorocarboxylic acid (PFCA) treatments. Lipid profiling detected transient dysregulation of predominantly membrane lipids in-response to short-chain PFAS treatments at NF 58. Overall, our findings indicate PFAS may exert toxicity during anuran metamorphosis through multiple mechanisms of action (MOA) with sex-specific and developmental-stage specific outcomes.</p>