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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- Effect of SOx from simulated flue gas on growth and gene expression of S-compounds in the microalgae Desmodesmus abundans(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-11-11) Hernández Barrientos, Bryan Zeth; Pacheco Moscoa, Adriana; emimmayorquin; Mora Godinez, Shirley María; School of Engineering and Sciences; Campus MonterreyDesmodesmus abundans high CO2 acclimated strain (HCA) is a microalga adapted for 13 years to high CO2 atmospheres. Previous studies have shown overexpression of genes associated with purines and folate biosynthesis under model flue gas (250 000 ppm CO2, 700 ppm NO, and 100 ppm SO2). Therefore, it is hypothesized that a high S concentration in the growth medium generates biomass with desirable concentrations of S-containing compounds reflected in the overexpression of key genes involved in the biosynthesis of purines and folate, and other associated pathways such as cysteine, methionine, and S metabolism. D. abundans was cultured with different S concentrations in Erlenmeyer flasks to ¾ log phase (4 d) under 25% v/v CO2/air (continuous flow at 0.05 vvm), 300 mL BG11 medium, 25 ± 2 °C, 100 rpm, and 85 µmol PAR-photons m-2 s-1 of continuous light). Three experimental conditions in triplicate, and duplicated biologically, were tested: i) low S (BG11-3/4S, 7 mg L-1 SO42-), ii) high S (BG11-S+SOx, 100 ppm SO2 continuous supply), and iii) control (BG11, 29.2 mg L-1 SO42-). Gene expression analysis of pathways of interest was done using RNA-Seq. Analysis of differential expression of genes (DEGs) compared S treatments to the control (|Log2FC > 1| padj < 0.05). DEGs were obtained using CDS information of D. abundans HCA and filtered genes were mapped against KEGG pathways. Also, free amino acids were analyzed using a Waters ACQUITY UPLC® System with a fluorescence detector. Neither culture was inhibited by the growth condition (no lag phase) and exponential growth was similar among cultures; however, final biomass production was highest in the control (0.8 ± 0.1 g L-1 d.w.), followed by the high S and low S conditions (0.6 ± 0.06 and 0.51 ± 0.06 g L-1 d.w. respectively). Therefore, the presence of SOx slightly reduced by 19% final biomass production. A similar trend was observed for total protein content with a greater reduction of 38% under high S (56.2 ± 1.6%, 34.6 ± 0.41%, and 26.5 ± 3.7% d.w. for the control, high S, and limited S, respectively). DEGs showed that S-limitation resulted in up-regulation of sulfate assimilation- related genes but did not correlate to a greater quantity of S-containing amino acids and only the serine O-acetyltransferase (SAT) gene was upregulated in the cysteine and methionine pathways under this condition. Although upregulation in the folate biosynthesis pathway could be observed in both conditions, these genes were not related to the interconversion of folate derivatives. Given that gene expression of reactions of interest was not clearly observed through transcriptomic analysis, neither synthesis of S-containing amino acids, implementation of direct approaches based on sequence homology of specific genes and quantification of other S related compounds as folate should be pursue.
- Characterization of arbuscular mycorrhizal fungi and endophytic bacteria in mycorrhizal and non-mycorrhizal mutant maize by a metagenomics approach(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-12-15) Guerrero Peña, Naomi Jocelyn; PACHECO MOSCOA, ADRIANA; 274621; Pacheco Moscoa, Adriana; emipsanchez; Gradilla Hernández, Misael Sebastián; Díaz de la Garza, Rocío Isabel; Escuela de Ingeniería y Ciencias; Campus Monterrey; Senés Guerrero, CarolinaArbuscular mycorrhizal fungi (AMF) establish mutualistic symbiosis with almost 80% of all plants. AMF are widely used in agriculture because they offer a substitute to chemical biofertilizers as they can boost plant growth under non-ideal conditions. Maize is the most important commercial and cultural crop in Mexico. The common symbiosis pathway (CSP) is a well conserved molecular signaling pathway in all plants that can achieve mycorrhizal and rhizobia symbiosis, which starts with specific receptors that recognize each microorganism. Here, maize-associated AMF species and endophytic bacteria composition from two variants of maize, a mycorrhizal wild type and a non-mycorrhizal mutant type, were assessed by using high-throughput MiSeq-Illumina sequencing. Mutant maize did not possess the HUN gen, a CASTOR homologous gene, that is involved in the CSP by starting upstream Ca2+ oscillations and activating molecular signaling cascade. Composite root samples of wild type (n=9) and mutant maize (n=10) were used for microbial characterization. Mycorrhization was observed in all samples. A total of 22 AMF species were found with abundance >1%, and only 7 species were shared by both types of maize. Differences among AMF composition were observed, where mutant plants showed absence of the AMF generalist species Rhizophagus. Shannon and Chao1 diversity indexes were higher in mutant plants than wild type maize. Regarding endophytic bacteria, 137 and 135 amplicon sequence variants (AVS) were found in wild type and mutant maize, where 105 were shared by both treatments. Streptomyces and Bulkholderia were the most predominant among all samples. Streptomyces abundance suggest that this genus may play a main role in bacterial and AMF composition, as it is known for improving AMF germination and symbiosis due to its chitinase production. As mutation of HUN gene was not sufficient to block complete symbiosis between AMF and the plant, further characterization of downstream genes of the CSP in maize and field experimentation are required.
- 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.
- Formulation and testing of biofertilizers obtained from native soil microbiota associated with strategic crops from arid zones of northern Mexico(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-06-15) Guardiola Marquez, Carlos Esteban; GUARDIOLA MARQUEZ, CARLOS ESTEBAN; 875808; Pacheco Moscoa, Adriana; tolmquevedo, emipsanchez; Treviño Alvarado, Victor; Escuela de Ingeniería y Ciencias; Senés Guerrero, CarolinaAgriculture is a major contributor to environmental and soil degradation. Currently, crop areas are expanding to arid zones generating the challenge to maintain or increase plant production under drought conditions in a sustainable manner. The correct formulation and use of biofertilizers is a sustainable strategy to overcome this problem. Microorganisms play a fundamental role in improving nutrient uptake efficiency and increasing plant stress-tolerance. Therefore, the objective of this study was to characterize and isolate native plant growth-promoting (PGP) microorganisms associated to six economically relevant crops in arid zones of northern Mexico, for the formulation and testing of crop-specific biofertilizers. Isolates were screened for different PGP attributes (N-fixation, P and K solubilization, and indole acetic acid (IAA) production) and candidates with the best performance were selected for MALDI-TOF mass spectrometry identification. Moreover, to understand the overall microbial community composition, MiSeq Illumina sequencing was used for bacteria and arbuscular mycorrhizal fungi (AMF) identification (Chapter 1). From the isolates, several Penicillium and Pseudomonas species were identified and described as potential candidates for arid zone biofertilizer formulation. Formulation and testing of self-made and commercial biofertilizers were conducted under seedbeds, to assess early plant response, and greenhouse and field conditions, to analyze plant yield (Chapter 2). Molasses was found to be a cheap culture media supplement for bacteria and vermicompost leachate, combined with PGP bacteria and AMF, achieved higher plant growth yields under 35% chemical fertilizer reduction. Early plant response to different microbial consortia was evaluated in maize where fungal consortia had greater effects on root development, while bacteria showed better results in shoot growth. Finally, a commercial biofertilizer based on the model AMF species Rhizophagus irregularis was tested on jalapeño pepper under 35% drought stress; a significant increase in fruit production was observed when plants were inoculated with the highest spore dose (1500 spores). In conclusion, the strategies applied in this study were useful to isolate and characterize soil microorganisms with PGP attributes from arid zones. Tests of commercial and self-made biofertilizers revealed that they can be implemented to reduce chemical fertilizer and water usage. These findings represent a starting point for the formulation of crop-specific biofertilizers and implementation of sustainable agricultural practices.
- Differential Transcriptome and Lipidome Analysis of the Microalga Desmodesmus abundans Under a Continuous Flow of Model Cement Flue Gas in a Photobioreactor(Instituto Tecnológico y de Estudios Superiores de Monterrey) Mora Godínez, Shirley María; Pacheco Moscoa, Adriana; Senés Guerrero, CarolinaMicroalgae represent a potential strategy for flue gas mitigation as they capture CO2 at high rates. Flue gases can also supply certain nutrients and, as a result, it can be valorized through biomass conversion into value-added compounds. The objective of this study was to characterize growth and analyze transcriptome, lipidome and cellular structure and composition of Desmodesmus abundans under continuous flow of cement model flue gas (MFG) in a 1 L photobioreactor using two strains adapted for nine years to atmospheres of 50% CO2 and air, referred to as HCA (high CO2 acclimated) and LCA (low CO2 acclimated), respectively. Controls with the LCA strain were also evaluated in air, CO2 and CO2+cement kiln dust (CKD). Higher initial growth rates were observed with strain HCA; however, at the end of the run (5 days) similar biomass productivity was reached by the two strains (0.30-0.34 g d.w. L-1 d-1). As expected, the CO2 control presented the highest growth rate (1.7-fold higher than under MFG), and when CKD was incorporated a slightly decreased (14 %) in growth was observed. Transcriptome analysis by RNA-seq, performed at day 4, resulted in a de novo assembly of 70 458 contigs with a N50 of 1 677 bp. Strain comparison under MFG resulted in 16 435 up-regulated and 4 219 down-regulated genes for strain HCA. Most of these genes were related with nucleotide, amino acid and carbon metabolisms; specifically, C3 and C4 cycle, glycolysis and gluconeogenesis, and TCA cycle, where almost all the contigs were up-regulated. In accordance, cell component GO terms up-regulated were in cell wall, chloroplast and photosystems. Likewise, starch and TAG metabolism were up-regulated. Cell structure analysis by SEM and TEM showed that most cells of both strains under MFG were unicellular contrary to typical Desmodesmus morphology; under air, some cells still preserved a grouping morphology. Strains cell size under MFG was similar (17-37 μm2), while under air cells were significant smaller (7-13 μm2). Both strains under MFG possessed high content of starch granules, a disorganized chloroplast and several lipid bodies, while a thicker cell wall was only observed in strain HCA. Biomass composition at the end of the run (day 5) showed no differences in proximate analysis between strains under MFG. A 1.8 to 2-fold higher protein content in strain LCA was found in complete medium (BG-11) than under MFG (BG-11-N-S). Under MFG, LCA presented the highest starch content (47.2 ± 22.3 % d.w) followed by HCA (23.1 ± 4.5 % d.w). On the contrary, HCA showed a higher content of pigments compared to LCA but the highest values were found in the control with only CO2. Lipidome analysis resulted in 663 detected features. Under MFG no many differences were found between strains by day 5; however, clear differences were observed at day 4 when both strains were in exponential growth. Particularly, 12 glycerolipids (GL) and 18 glycerophospholipids (GP) increased, and 27 GL and 3 GP decreased in HCA compared LCA. Still, most differences were found when strain LCA under MFG was compared with CO2+CKD (incomplete vs complete culture medium) that showed changes in GL (42 increased and 27 decreased) and GP (58 increased and 42 decreased), possibly attributed to low N in MFG. The results presented in this study show significant differences between strains HCA and LCA under MFG. However, most differences were observed at the transcriptome level (day 4), while biomass production was comparable at the end of the experimental period (day 5). Morphological changes appeared to be induced by the high CO2 condition at the moment of growth, with no significant differences between acclimated strains, except for a thicker cell wall in the HCA strain. Overall, both strains presented a high content of starch that represents a high value compound under MFG. Further studies could contemplate continuous cultures under MFG with longer experimental periods (>5 days) to validate differences between strains. Also, explore differences between strains at the genome level such as synonymous mutation rates by sequencing and studies of epigenetic changes. Additionally, metabolome and proteome analysis to better understand differences under the different control conditions.
