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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- Fabrication and characterization of microalgae extract loaded chitosan/alginate-based nanoparticles with ultraviolet protection features(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-12-06) Santiesteban Romero, Berenice; Iqbal, Hafiz Muhammad Nasir; puemcuervo, emipsanchez; Martínez Ruiz, Manuel; Coronado Apodaca, Karina Guadalupe; Gámez Méndez, Ana María; School of Engineering and Sciences; Campus Monterrey; Sosa Hernández, Juan EduardoMicroalgae are constantly exposed to ultraviolet rays because they are usually found in areas with high sunlight exposure. Several studies have addressed the harmful impact of increased ultraviolet radiation on various microalgae. However, some microalgae have a great ability to overcome or counteract different stresses such as intense solar ultraviolet radiation, this has been happening over the years and with the evolution of microalgae, some examples of defense and/or tolerance mechanisms are DNA repair, synthesis of antioxidants, and enzymatic/non-enzymatic compounds, such as mycosporine-like amino acids and scytonemin to counteract the harmful effects of ultraviolet radiation. This characteristic has not only been investigated to learn more about microalgae, but also for applications such as product creation, since they grow rapidly and are considered the most promising and sustainable sources of biomass. Due to their performance under optimal conditions, they have been widely studied for different bioproducts. Which is why microalgae extracts, by showing resistance to both types of rays, show great potential as sunscreens and this gives a very strong advantage to future bioproducts. This study deals with the application of microalgae extracts for the creation of polymeric nanoparticles based on chitosan and alginate. The synthesis of nanoparticles with a size of 500 nm and a polydispersity index of 0.1 was successfully achieved, indicating the uniformity of these nanoparticles. Different characterization techniques were used for the analysis of these nanoparticles, including UV-Visible spectrophotometry (UV-Vis), Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). All these techniques allow us to see different aspects of the nanoparticles confirming their structure, uniformity, and composition for further effective utilization.
- 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.
- Culture of Euglena gracilis in photoautotrophy for paramylon production: effect of pH and media composition(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-11-15) Martín Roldán, María; ; Pacheco Moscoa, Adriana; puemcuervo/tolmquevedo; Senés Guerrero, Carolina; School of Engineering and Sciences; Campus Monterrey; Valledor González, LuisMicroalgae have been widely studied in biotechnology for their application in various areas such as bioremediation, production of biofuels, or use in nutrition. More specifically, certain species are recognized to produce compounds of high commercial value. Euglena is a group of microalgae characterized by the generation of the reserve polysaccharide paramylon, with promising prospects for its application in pharmacology, nutrition, to produce bioplastics, or biodiesel. Paramylon is accumulated mainly in the presence of organic carbon in the culture medium; however, this represents a challenge when establishing a large-scale culture due to the risk of biological contamination. In this study, an extensive study of the literature was carried out with respect to the autotrophic culture of Euglena gracilis destined to paramylon production. As a result, we evaluated the effect of culture pH, vitamin supplementation, and nitrogen source in the culture medium in order to reach the maximum biomass productivity. A pH of 7.5 and ammonium as nitrogen source were optimum for the autotrophic culture of E. gracilis, while an improvement in productivity was not observed with vitamin supplementation. Finally, it was possible to scale up the photoautotrophic culture of E. gracilis to a 1-L airlift photobioreactor. In conclusion, there is still much optimization work to achieve the biomass and paramylon productivity reported for the heterotrophic cultures of E. gracilis, but the results of this study reveal its viability.