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The soil bacterium Rhodococcus has a wide array of secondary metabolic pathways such as production of pigments, siderophores, and antibiotics that makes it an organism of interest for the production of novel natural products. Analysis of the genome sequence of Rhodococcus indicates the presence of 24 non-ribosomal peptide synthases and 7 polyketide synthases possibly involved in production of secondary metabolites. The use of a solid agar extraction method to screen soil isolates of Rhodococcus for compounds with inhibitory activity against other bacteria resulted in the discovery of a promising candidate molecule. The Rhodococcus strain KCHXC3, isolated from eastern Tennessee soil, produces a substance that inhibits the growth of several Gram-negative bacteria such as Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumonia and Gram-positive bacteria such as Micrococcus luteus and, Staphylococcus aureus. After bulk extraction of this compound with ethyl acetate from agar plates, the material was partially purified through different chromatography processes.

Trichomonas vaginalis is a sexually-transmitted parasite that is the causative agent in the disease trichomoniasis. Resistance to the only FDA-approved medication to this disease, metronidazole, has been on the increase giving rise to the need for finding targets for new inhibitors to exploit. New inhibitors can target enzymes such as 4-coumarate:CoA ligase and S-adenosylhomocysteine hydrolase. Another potential target is a cathepsin D-like protease found in T. vaginalis . This aspartic protease in humans is responsible for degrading proteins in the lysosome, and degrading hemoglobin in P. falciparum as the homologue plasmepsin. Searching the gene database, only one cathepsin-D like protease was discovered throughout the organism's genome. Utilizing RT-PCR, this gene is found to be expressed in two different strains of the organism. Transfection of an epitope-tagged version of this cathepsin D-like protease into T. vaginalis was accomplished, and subsequent immunofluorescence of this tagged version shows it to be localized in intracellular compartments, which can be colocalized using the SNARE and VAMP proteins found in T. vaginalis .

La tesis engloba un estudio sobre preferencias económicas, en concreto, preferencias individuales bajo Riesgo, Riesgo Compuesto y Ambigüedad. Este trabajo muestra la evidencia de un experimento de laboratorio en el que los individuos se enfrentan a una incertidumbre creciente (Riesgo/Riesgo compuesto/Ambigüedad) en tres dimensiones diferentes: probabilidades, pagos y tiempo. Se obtiene el Equivalente Cierto del Valor Presente (PVCE) de 36 loterías con tres fechas de pago diferentes para cada sujeto, y se atribuyen a las condiciones de tratamiento las diferencias entre esos PVCE. Utilizando pruebas no paramétricas y regresiones de efectos aleatorios, la evidencia muestra una notable heterogeneidad en el comportamiento de los individuos según la dimensión afectada por la incertidumbre. En concreto, si bien confirmamos la amplia evidencia sobre la aversión a la Ambigüedad en las probabilidades, encontramos que este efecto prácticamente desaparece cuando las dimensiones de incertidumbre son los pagos y, aún más, el tiempo. Para el caso del Riesgo Compuesto, los resultados encontrados van en la misma línea. Además, se encuentra heterogeneidad en cuanto al comportamiento bajo Riesgo. / Esta tesis ha sido elaborada gracias a la financiación de la Generalitat Valenciana (SEJI/2019/005 y Research Project Group 3/086).

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This collection of studies focuses on a PCO system for the oxidation of a model compound, ethanol, using an adsorption-enhanced silica-Ti02 composite (STC) as the photocatalyst; studies are aimed at addressing the optimization of various parameters including light source, humidity, temperature, and possible poisoning events for use as part of a system for gaseous trace-contaminant control system in closed-environment habitats. The first goal focused on distinguishing the effect of photon flux (i.e., photons per unit time reaching a surface) from that ofphoton energy (i.e., wavelength) of a photon source on the PCO of ethanol. Experiments were conducted in a bench-scale annular reactor packed with STC pellets and irradiated with either a UV -A fluorescent black light blue lamp O·max=365 nm) at its maximum light intensity or a UV -C germicidal lamp O.·max=254 nm) at three levels of light intensity. The STC-catalyzed oxidation of ethanol was found to follow zero-order kinetics with respect to C02 production, regardless of the photon source. Increased photon flux led to increased EtOH removal, mineralization, and oxidation rate accompanied by lower intermediate concentration in the effluent. The oxidation rate was higher in the reactor irradiated by UV -C than by UV-A (38.4 vs. 31.9 nM s-1 ) at the same photon flux, with similar trends for mineralization (53.9 vs. 43.4%) and reaction quantum efficiency (i.e., photonic efficiency, 63.3 vs. 50.1 nmol C02 ~mol photons-1 ). UV-C irradiation also led to decreased intermediate concentration in the effluent compared to UV -A irradiation. These results demonstrated that STC-catalyzed oxidation is enhanced by both increased photon flux and photon energy. The effect of temperature and relative humidity on the STC-catalyzed degradation of ethanol was also determined using the UV-A light source at its maximum intensity. Increasing ii temperature from 25°C to 65°C caused a significant decrease in ethanol adsorption (47.1% loss in adsorption capacity); minimal changes in EtOH removal; and ·a dramatic increase in mineralization (37.3 vs. 74.8%), PCO rate (25.8 vs. 53.2 nM s-1 ), and reaction quantum efficiency (42.7 vs. 82.5 nmol C02 J..Lmol phontons-1 ); intermediate acetaldehyde (ACD) evolution in the effluent was also decreased. By elevating the reactor temperature to 45°C, a -32% increase in reaction quantum efficiency was obtained over the use ofUV-C irradiation at room temperature; this also allowed for increased energy usage efficiency by utilizing both the light and heat energy of the UV-A light source. Higher relative humidity (RH) also caused a significant decrease (16.8 vs. 6.0 mg EtOH g STCs-1 ) in ethanol adsorption and dark adsorption 95% breakthrough times (48.5 vs.16.8 hours). Trends developed for ethanol adsorption correlated well with studies using methanol as the target VOC on a molar basis. At higher RH, ethanol removal and ACD evolution were increased while mineralization, PCO rate, and reaction quantum efficiency were decreased. These studies allowed for the development of empirical formulas to approximate EtOH removal, PCO rate, mineralization, and ACD evolution based on the parameters (light intensity, temperature, and RH) assessed. Poisoning events included long-term exposure to low-VOC laboratory air and episodic spikes of either Freon 218 or hexamethylcyclotrisiloxane. To date, all poisoning studies have shown minimal (0-6%) decreases in PCO rates, mineralization, and minimal increases in ACD evolution, with little change in EtOH removal. These results, while studies are still ongoing, show great promise of this technology for use as part of a trace contaminant control system for niche applications such as air processing onboard the ISS or other new spacecrafts.

The food industry is increasingly concerned with operational sustainability and food waste reduction. In the United States, the tomato industry was worth $1 billion in 2020, and tomatoes are currently ranked second as the most consumed vegetable after potatoes. Tomato processors have striven to valorize pomace by-products, which contain seeds with valuable compounds such as 45% fiber, 30% oil, and 26% protein. The U.S. peach industry, which was worth $599 million in 2017, is also looking for alternative ways to utilize their seeds, made up of 52% oil. Both tomato and peach seeds are rich in bioactive compounds such as carotenoids and polyphenols, respectively. Meanwhile, global edible oil production is forecasted to reach 632 million tons in 2022, and there is increasing interest to produce specialty oils. Organic solvent extractions are commonly used to extract oils from various commodities in the food industry, but this method comes with some environmental concerns, such as toxicity and flammability. Enzyme-assisted aqueous extractions (EAEP) have been proposed as a green alternative to solvent extractions of oilseeds. However, research on the economic feasibility of this process has been limited. There is a need for a better understanding of the potential of EAEP and performing such analysis on peach and tomato seeds would be valuable based on the importance of these commodities in California and in the U.S. in general. To determine whether applying such a process to tomato and peach seeds would be valuable, data on oil yields from EAEP, quality of the extracted oils, and economics associated with EAEP is needed. The U.S. snack food industry was worth approximately $42 billion as of 2019, and this market continues to grow as an increasing number of people eat snacks as meal replacements. There is also growing consumer demand for natural and functional foods, which offer health benefits beyond basic nutritional value, such as reducing risk of disease. Therefore, this consumer landscape provides excellent opportunities for by-products from vegetable and fruit processing to be transformed into functional ingredients. With these key ideas in mind, the objectives of this research were 1) to determine the impact of various extraction factors on oil yields from EAEP of tomato and peach seeds; 2) to evaluate the effect of aqueous extractions on oil quality; 3) study whether these processing steps are economically feasible for industrial commercialization and 4) identify another potential use for tomato pomace as a functional ingredient in snack food application. Tomato and peach seeds were each isolated and ground into a flour, then analyzed for fiber, fat, protein, moisture, and ash content. The effects of pH (set to 3, 9, and sequential adjustment of 3 followed by 9), time (2–8 h), and addition of cellulase, protease, and 1:1 enzymatic cocktail at a concentration of 4% were evaluated during aqueous extractions of tomato oils. Peach oil extractions were evaluated for the same parameters except for time which was fixed at 2 h. The impact of the pH of aqueous extractions on the oxidative stability and nutritional composition of tomato and peach oils were also determined. Techno-economic analyses were conducted using Superpro software to estimate operational costs and profits from this process. To assess the value of tomato by-product as a functional ingredient, pomace flour was added to crisp snacks at usage levels of 0 and 7% (w/w flour basis). Crisp snacks were stored at ambient room temperature and frozen temperatures (-23 °C) for ten weeks. Proximate analyses on the crisp snacks were conducted. Sensory evaluation was performed over time using hedonic scoring surveys. For tomato seeds, the highest oil yield (41%) was obtained during 2 h extractions at pH 9, which were 68% higher than from 2 h extractions performed at pH 3. Enzyme addition was only beneficial during 8 h extractions of tomato seeds using 4% cellulase at pH 3, which led to 53% higher oil yield compared to the control performed in the same conditions without enzymes. Increasing incubation time from 2 to 8 h improved oil yields by 63% for cellulase extractions at pH 3 and 69% for protease extractions at pH 9. Peach oil yield of the controls at pH 9 (53%) and the yield obtained with protease extractions at pH 9 (45%) were approximately eight times higher than all extractions set to pH 3. Once extracted, some properties of the tomato and peach oils were determined. The pH of the aqueous extractions did not have a significant effect on quality parameters on both tomato and peach oils, except for polyphenol content, DPPH production, peroxide and TBARS values. Overall, both tomato and peach oils had peroxide and free fatty acid values comparable to other specialty oils, such as sunflower and sesame oils. From a techno-economic point of view, tomato oil production at flow rate of 1,752,000 kg pomace/yr garnered $13 million in profit (equivalent to $7.42/kg pomace) after a payback time of 1.6 years, which was more profitable than the industry’s current pomace disposal practice. Peach oil processing became profitable once the production scale reached 65,700,000 kg pits/yr, which led to $15.5 million in profit ($0.24/kg pits). Overall, production of tomato oil was more profitable than peach oil. When tomato pomace was added into crisp snacks at 7% concentration, fiber increased by 35.2% compared to the control. Moisture content and water activity for the control and pomace crisp snacks remained constant during room temperature and frozen storage for ten weeks. However, the addition of tomato pomace led to a bitter aftertaste of the crisp snacks and reduced overall liking scores by panelists compared to scores for the control crisp snacks. Overall, this research took multiple, innovative approaches to valorize tomato and peach seeds, while also studying the economic, environmental, and industrial implications of such approaches. It highlighted alternative, sustainable strategies of how tomato and peach by-products could be repurposed to reduce waste and make value-added food products.

The field of analytical chemistry is very important to today's society as more and more regulations and legislations emerge regarding trace elements in food, consumer products, medicines, and the environment. Like many areas of science, the current goals of trace elemental measurements and speciation are to increase knowledge on the subject and to improve upon current techniques by enhancing the figures of merit, such as accuracy and reproducibility, meanwhile balancing with the cost and time of analysis. The topics covered in this work were investigated primarily through the use of inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). The phenomenon of compound-dependent responses in plasma spectrometry is discussed, seeking possible causes of it and offering some advice on how to prevent it. A new method was developed for the speciation of selenium in dietary supplements using anion-exchange chromatography ICP-MS. A novel method for the determination of total mercury at trace concentrations in rice was developed for use with conventional ICP-MS. Inductively coupled plasma mass spectrometry was also used for fingerprinting the rare earth elements in Maya archaeological pottery for provenance studies.