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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- Microalgae-based livestock wastewater treatment and resource recovery: a circular bioeconomy approach(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-12-07) López Sánchez, Anaid; Carrillo Nieves, Danay; emijzarate; Orozco Nunnelly, Danielle A.; Senés Guerrero, Carolina; Aguilar Juárez, Óscar; Escuela de Ingeniería y Ciencias; Campus Monterrey; Gradilla Hernández, Misael SebastiánThe livestock industry is a sector of great relevance worldwide. This sector accounts for 1.4% of the world's Gross Domestic Product (GDP) and is a source of livelihood for more than 1.3 billion people. Furthermore, thirty-nine percent of the worldwide protein demand is covered by this sector. However, this activity is one of the top polluting industries, accounting for 14% of the greenhouse gasses (GHG) originated from anthropogenic sources. Additionally, the livestock sector is the largest land user on earth, using 70% of the total agricultural land and 30% of Earth’s land surface. One-third of the global cereal production is destinated for animal feed, of which some nutrients are retained by the animals and the rest is released to the environment without previous treatment, resulting in soil degradation, water and air pollution and, consequently, serious human health impacts. Circular bioeconomy (CBE) has emerged as a potential driver towards the sustainability of livestock production systems. One of the main objectives of the CBE model within the livestock industry is the minimization of the usage of raw material resources through the recycling, reuse, and revalorization of waste and wastewater. Microalgae-based wastewater treatment (MbWT) is a potential solution aligned with the CBE principles, in which the nutrients contained in the livestock wastewater (LW) are recovered and transformed into high value-added products with a wide range of industrial applications. The overall performance of MbWT (i.e., nutrient removal efficiencies and biomass production) is highly dependent on a wide range of factors, such as the microalgal strain and the composition of the wastewater. However, most of the existing studies that implemented MbWT have focused on a single LW type. Therefore, the main objective of this thesis is to treat a mixed effluent composed of the most common ADLW (from cattle, swine, and poultry), to understand the effects of the mixture of all three types of LW on cell growth and pollutant removal efficiencies of microalgal cultures (Chlorella vulgaris, Haematoccocus pluvialis and Chlamydomonas spp.). Through an evaluation of the mixture design, the optimal fraction of these different types of effluents (ADCW, ADSW, and ADPW) was analyzed to obtain maximum microalgal biomass productivity and 7 pollutant removal rates (COD, TN and TP). Furthermore, these microalgae were tested in all possible combinations of mono-, bi-, and tri-cultures. The first chapter of the present thesis consists of a thorough review of the literature to address the most significant factors affecting nutrient removal and biomass productivity in MbWT, including: (i) microbiological aspects, such as the microalgal strain used for MbWT and the interactions between microbial populations; (ii) physical parameters, such as temperature, light intensity and photoperiods; and (iii) chemical parameters, such as the C/N ratio, pH and the presence of inhibitory compounds. Additionally, different strategies to enhance nutrient removal and biomass productivity, such as acclimation, UV mutagenesis, multiple microalgae culture stages (including monocultures and multicultures) are discussed. The second chapter of this thesis presents the first study of MbWT using anaerobically digested swine, poultry and cattle wastewater (ADSW, ADPW and ADCW) mixtures. A centroid mixture design was used to determine the optimal mixture to promote higher cell concentrations and pollutant removal efficiencies of the microalgae Chlorella vulgaris, Haematococcus pluvialis and Chlamydomonas spp. cultured as mono-, bi-, and tri-cultures. Additionally, A redundancy analysis was performed to analyze the correlation between microalgal cultures and the removal efficiencies of the digestate pollutants. The results herein show that C. vulgaris as a monoculture in a digestate mixture of 0.125:0.4375:0.4375 (ADSW:ADPW:ADCW) resulted in cell growth of 3.61×107 ± 2.81x106 cell mL-1, a total nitrogen removal of 85%±2%, a total phosphorus removal of 66%±3% and a chemical oxygen demand removal of 44%±7%. The specific composition of the effluents plays a key role in microalgal performance due to their respective nitrogen and phosphorus content. Furthermore, this study suggests that a mixture of the three most common digestates generated by livestock farms offers a promising alternative for the treatment and revalorization of LW, by taking advantage of the unique composition that each digestate possesses. Further studies are warranted to gain a deeper understanding of the interspecific microalgal interactions occurring in mixed cultures that may enhance or hinder the performance of MbWT.
- Characterization of the chromium reduction activity of an endemic bacterium from the Atoyac river with potential use in water bioremediation(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-06-15) Puón Meraz, Ramón Iván; CARDENAS CHAVEZ, DIANA LINDA; 46659; Cárdenas Chávez, Diana Linda; puelquio; Luna, Itza Eloisa; Gutiérrez Uribe, Janet Alejandra; Rocha Pizaña, Maria del Refugio; Escuela de Ingeniería y Ciencias; Campus MonterreyWater pollution has become a major issue all over the world. One of the most devastating examples in Mexico is the Atoyac River, a victim mainly of the textile and automotive industries that produce contaminants such as phenolic compounds or heavy metals. Most of the contaminants in water bodies turn these ecosystems practically lifeless. However, unicellular organisms seem to be the only beings that thrive in polluted rivers. Bacteria are receiving more attention as model systems for bioremediation applications, given their availability and wide diversification in extreme ecosystems. This, in combination with the relative simplicity of the techniques for receiving genetic modifications, makes them ideal candidates as a source of biomolecules that might be used in the development of biosensors for monitoring the presence of pollutants in situ. Here, I propose a thesis whose main objective is to identify the possible mechanism, mainly the mediated by enzymes, of the hexavalent chromium reduction by an endemic bacterium (named Cr2.23a) isolated from the Atoyac River. In the characterization of this bacterial strain, it showed an optimal chromium reduction growing at pH of 8 and a temperature of 42°C. This reduction was localized on intracellular extracts, that would increase its efficiency by adding external electron donors such as glucose, lactose, sodium acetate, and NADPH. An API biochemical test identified this Cr 2.23a strain as two possible species: Klebsiella oxytoca and Raoultella planticola. To confirm these identification results, the 16s region of this strain was cloned and isolated. The molecular isolates were sent for sequencing to the Instituto Potosino de Investigación Científica y Tecnológica. These results will allow for the development of new strategies for water bioremediation and possibly a microbial biosensor for the detection of polluted bodies of water by heavy metals.
- Microbial inoculation of Tagetes erecta in a phytoremediation system to enhance arsenic and cadmium removal from polluted soils(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-06-01) Sánchez Jiménez, Arantza; FIERROS ROMERO, GRISEL; 330919; Fierros Romero, Grisel; tolmquevedo, emipsanchez; Valiente Banuet, Juan Ignacio; Medrano Roldán, Hiram; Kothe, Erika; School of Engineering and Sciences; Campus Monterrey; Chávez Avilés, Mauricio NahuamIn the presented research, a phytoremediation system was established by the inoculation of heavy metal resistant microorganisms isolated from the Mexican volcanic area of Los Azufres, Michoacán into the Mexican ornamental flower Tagetes erecta; with the final purpose of enhancing their individual bioremediation capacities when combined for their application in ex situ bioremediation of soils polluted with arsenic and cadmium. The methodology consisted of three main steps: the microbial isolation and characterization, the in vitro system establishment between the isolated microbes and the selected plant species to evaluate their interaction, and the creation of microcosms to evaluate their potential for ex situ bioremediation use. The results suggest that our isolated microbes, determined as LA1 & LA2, are heavy metal resistant, with a respective MIC of 1800 ppm of As and 250 ppm of As and Cd each; and that LA2 favors the development of Tagetes erecta in a medium supplemented with these heavy metals and enhances the plant's tolerance. This signifies an intriguing option to use as a phytoremediation system for ex situ bioremediation of soils polluted with arsenic and cadmium.