Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Modeling growth kinetics and community interactions in microalgal monocultures and co-cultures for bioremediation of anaerobically digested swine wastewater(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-07-21) Palafox Sola, María Fernanda; Gradilla Hernández, Misael Sebastían; dnbsrp; Yebra-Montes, Carlos; Escuela de Ingeniería y Ciencias; Campus Guadalajara; González López, Martín EstebanThe pork production industry generates high annual volumes of swine wastewater that increase proportionally to the global demand for pork meat. Incorrect handling and discharge of swine wastewater causes the eutrophication of water bodies as well as soil and air pollution. Microalgal-based wastewater treatment has been proposed as a cost-effective alternative to traditional treatment methods. It also possess several environmental benefits and offers the opportunity to harvest valuable biomass, thus making wastewater treatment a biocircular economy process. Additionally, microalgae can be used in either primary or secondary wastewater treatments, as they allow for the simultaneous removal of nutrients (TN - total nitrogen and TP - total phosphorus) and organic matter. Most of the existing research is based on laboratory cultures under highly controlled conditions and with previous modification of the substrate, either by applying dilution or sterilization. However, these practices make full-scale implementation complex and cost-elevated. Three microalgal strains, Chlorella vulgaris, Scenedesmus acutus and Arthrospira maxima, were monocultured and co-cultured in raw (undiluted, non-sterelized) anaerobically digested swine wastewater. An overall performance index showed that all of the treatments that included C. vulgaris were the most efficient in terms of biomass production, along with COD and nutrient removal. The co-culture of C. vulgaris and S. acutus achieved the highest OPI of 0.68, displaying 9 biomass folds, a production of 2.97 ± 0.36 gL-1, as well as 89%, 56% and 67% removal efficiencies for COD, TN and TP, respectively. Additionally, three mathematical models were used to calculate relevant growth kinetic parameters, including the specific growth rate, lag-phase duration, interspecific interaction, affinity constant and biomass productivity. C. vulgaris monoculture kinetics were adjusted using a double Gompertz model, showing a maximum growth rate (µ2) of 0.89 days-1 and a lag phase (λ2) of 9.69 days. The Lotka-Volterra model was used to assess interactions between both strains in the co-culture, showing a commensalistic relationship between C. vulgaris and S. acutus, as denoted by the interspecific paramaters βcs = 1.99 ± 0.92 and βsc = -0.007 ± 0.008. Finally, the growth kinetics as a function of the three substrates (COD, TN and TP) were adjusted to the monod model, and the resulting parameters were used in a dynamics simulation of the inside of a continuously stirred reactor tank. A SOWT (strenghts, opportunities, weaknesses and threats) analysis was developed to assess the feasibility of MbWT implementation at industrial level. MbWT is an efficient solution for the treatment of SWW, however, further research in pilot or full-scale systems is still required to move towards full-scale industry implementation. Therefore, the results of the present work presented herein should be applied to eventually make MbWT a viable circular bioeconomy solution to SWW management in Mexico and other developing countries around the world.
- Characterization of the effect of UV-A light and agitation on the exopolysaccharide production of Chlorella vulgaris and Porphyridium cruentum(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-05) Garza Rodríguez, Zaida Berenice; GARZA RODRIGUEZ, ZAIDA BERENICE; 838147; Benavides Lozano, Jorge Alejandro; emipsanchez; Jacobo Velázquez, Daniel Alberto; Santacruz López, Yolanda Arlette; School of Engineering and Sciences; Campus Monterrey; Hernández Pérez, JesúsMicroalgae species are photosynthetic microorganisms that are a sustainable source of bioproducts due to their ability to reduce anthropogenic carbon dioxide in the atmosphere. The number of studies focused on their biologically active molecules, such as lipids, proteins, polysaccharides, and pigments, has been increasing in the last years due to their promising application as valuable products. In this context, the exopolysaccharides (EPS) from microalgal sources stand out as high-value molecules for their potential applications in the nutraceutical and pharmaceutical industries. However, studies aimed to find strategies and optimal conditions to promote the biosynthesis of EPS are still required to make these molecules economically feasible. The effect of ultraviolet light A (UV-A) is studied on biomass and EPS productivity of the red microalgae Porphyridium cruentum and the green microalgae Chlorella vulgaris testing three levels: L0, L1 and L2. Likewise, the effect of the agitation factor on cell growth and EPS productivity are analyzed for the two microalgae species testing two levels: A0 and A1. After recovering the EPS using centrifugation and diafiltration, their potential antioxidant activity was tested using the 2,2-Diphenyl-1-prykylhydrazyl (DPPH) radical scavenging assay. The UV-A light (315-400 nm), along with photosynthetic active radiation (PAR) increased EPS productivity in both C. vulgaris and P. cruentum to 1.21-fold and 2.43-fold, respectively, compared to light control conditions (PAR at 35.6 µmol m⁻² s⁻ ¹). The highest P. cruentum EPS productivity was 8.67 mg/g DW biomass at the highest tested UV-A level and lowest agitation(L2A0), and the highest biomass concentration was 8.57 g/L at the highest agitation (A1) due to a possible improvement in nutrient distribution. For C. vulgaris, the highest productivity was 1380 mg/g DW biomass at intermediate UV-A light level (L1). The highest biomass concentration of C. vulgaris was 0.34 g/L at the highest UV-A level (L2), treatment that conversely displayed the lowest EPS productivity (73.08 mg/g DW biomass). The study of antioxidant activity revealed that EPS show DPPH radical scavenging activity. The mean highest radical scavenging effect (%) of P. cruentum and C. vulgaris EPS was 56.48 ± 4.46 and 46.31 ± 3.2 at 4 mg/mL and 2 mg/mL, respectively. This work contributes to the characterization of abiotic factors that could potentially influence the production of high-value EPS molecules that display bioactivity of interest for health applications.
- Evaluación del uso de microalgas para la biofijación de CO2 de centrales de ciclo combinado(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-05) Mercado Alemán, Andrea; Parra Saldívar, Roberto; mtyzramirez; Sosa Hernández, Juan Eduardo; Coronado Apodaca, Karina Guadalupe; Salazar Silva, Jesús Fidencio; Escuela de Ingeniería y Ciencias; Campus Monterrey; Martínez Ruiz, ManuelEn México, el reducir las emisiones de las Centrales de Ciclo Combinado (CCC) es un tema de vital importancia en cuestiones de cambio climático, ya que estas centrales son las principales en satisfacer la demanda eléctrica del país, por lo que constituyen un factor clave para reducir las emisiones del sector energético. Sin embargo, debido a la composición y características que presentan los gases de combustión de estas centrales, los actuales sistemas de captura de carbono no son compatibles para mitigar sus emisiones, por lo que nuevas formas para capturar dióxido de carbono deben ser investigadas. El uso de microalgas para la biofijación de CO2 de los gases de combustión de Centrales de Ciclo Combinado se presenta como una alternativa viable, ya que estos microorganismos cuentan con cualidades capaces de afrontar los problemas asociados a las emisiones de estas centrales, y tienen la capacidad de biofijar cantidades considerables de CO2 mediante su proceso de fotosíntesis. Por lo anterior, el objetivo de este trabajo es determinar si efectivamente el uso de microalgas representa una opción factible para reducir las emisiones del sector eléctrico mexicano, por lo que esta tesis primero presenta una investigación sobre los estudios más recientes respecto al uso de microalgas para la captura de dióxido de carbono. Posteriormente, se realizó un análisis con los datos encontrados en la literatura para de esta manera, estimar el potencial de recuperación de CO2 que se podría obtener en las centrales en cuestión. Por último, y para corroborar el posible potencial de recuperación de CO2, se realizó un trabajo experimental, en el cual que se cultivó Chlorella vulgaris bajo condiciones ambientales y diferentes parámetros de cultivo utilizando una mezcla de gases de simulación de CCC como su fuente de carbono.
- Applications of artificial neural networks for experimental design optimization of Chlorella vulgaris microalgae growth(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022) Díaz Hernández, María Monserrat; CHAIREZ ORIA, JORGE ISAAC; 42787; dnbsrp; Parra Saldívar, Roberto; Escuela de Ingeniería y Ciencias; Campus Ciudad de México; Alfaro Ponce, MarielThis thesis proposes developing an optimization experimental model to optimize nutrient consumption and microalgae growth from the Novozymes company’s sidestream. The optimization model was created using the Box-Behnken experimental design for three factors. These three criteria were considered to raise the Chlorella v. biomass, and three different levels for each factor were chosen and implemented. The first factor chosen was CO2 since microalgae are important in producing energy for growth and proteins, lipids, and nucleoid acid. The second component chosen was agitation, which allows for the exchange of gases in the medium and the uniform consumption of nutrients from the medium. The day/night cycle was used to generate mixotrophic cultivation, which encouraged the culture to utilize the carbon in the sidestream while maintaining the green pigments of Chlorella vulgaris due to the presence of light. Following the experimentation phase, the best levels for each factor were 0.5% CO2, 70 RPM of agitation, and 8:16 hrs of day/night cycle. These amounts were used in a photobioreactor to cultivate and observe nutrient consumption behavior for eight days. Following these days, the COD level was reduced by 47.34%, the total nitrogen decrement was 48.70 %, the total phosphorus decrement was 96.42 %, and the dry biomass increased by 300 %. Simultaneously, a suitable neural network was designed to optimize the optimal levels for the same three parameters; this model was trained, validated, and evaluated using the experimental results. The ideal amounts for each factor were 0.5% CO2, 77 RPM of agitation, and 8:16 hours of day/night cycle. These levels were used in a photobioreactor to cultivate and observe nutrient consumption behavior for eight days. Following these days, the COD level declined by 40.80%, the total nitrogen decrement was 44.63%, the total phosphorus decrement was 98.65%, and the dry biomass increased by 400%. Both models are based on the work’s greatest contribution of reducing sidestream nutrients and promoting the increase in microalgae biomass in a shorter time than traditional methods that range from 12 to 14 days, as well as being a solution for treating wastewater from the enzyme manufacturing process.