Erika Flores-Loyola

Background: Epitope immunodominance describes the phenomenon whereby some antigenic epitopes preferentially elicit immune responses, whereas other epitopes remain subdominant or immunologically silent. Epitope immunodominance hierarchies are the result of coordinated molecular, structural, and cellular mechanisms. These hierarchies emerge from selective immune recognition processes that balance effective immunity and self-tolerance mechanisms. Objective: The aim of this study is to describe the molecular, structural, and cellular parameters that mediate epitope immunodominance in antigens. In addition, it details how central and peripheral tolerance mechanisms influence epitope selection and immunodominance hierarchies in T- and B-cell responses. Conclusion: Epitope immunodominance arises from molecular and structural characteristics, including the nature of the antigen, the level of protein structure, host genetic factors, and immune regulatory mechanisms. Epitope immunodominance hierarchies depend on multiple factors, including the structural accessibility of epitopes, the epitope density, the distinctive binding affinities of antigen-derived peptides to MHC molecules, the availability of T cells able to recognize peptide-MHC complexes, the molecular stability of conformational epitopes recognized by BCRs, and the efficiency of antigen processing by antigen-presenting cells. Collectively, these factors focus immune recognition, determining whether specific epitopes dominate the immune response or remain immunologically silent.

Soil–Forage–Livestock systems (SFL-systems) integration is fundamental for sustainable land management in arid lands, where conventional crop production is often unfeasible. Aridisols dominate dryland agroecosystems and their edaphic constraints, together with climatic limitations, constitute a major bottleneck for fertility and productivity in key arid regions worldwide. This narrative review provides a taxonomic and edaphic framework to guide sustainable SFL-systems and integrates current approaches and technological applications for forage production in arid environments, focusing on an edaphic-digital scheme that combines organic and inorganic soil amendments with AI-based decision support to improve Aridisols productivity and resilience. Searches of the literature (ScienceDirect, EBSCOhost, Clarivate Web of Science; English, 2021–2025) screened 309 records and selected 169 references; seminal older works were consulted for context. Representative quantitative outcomes from the reviewed literature include SOC increases of ~15–30% after multi-year organic inputs; forage biomass gains of ~10–25% following amendments that correct sodicity; and water-productivity improvements up to ~30% with hydrogels or biochar. AI tools can improve soil diagnostics and amendment selection (diagnostic accuracy improvements of ~15–30% in recent studies) and generate predictive models of amendment–response that facilitate optimization of application rates and water use. The novel contribution of this review is the explicit linkage of SFL-systems and amendment-based soil restoration with AI-driven diagnostics and decision support, providing actionable metrics and research priorities to translate digital diagnostics into measurable forage gains in arid and semi-arid regions. Overall, the evidence suggests that targeted soil restoration, reinforced by AI-based support systems, is a feasible strategy to increase forage availability and ecosystem service provision in drylands.

Bacterial cellulose (BC) is a high-value biopolymer with remarkable physicochemical properties and diverse applications in biotechnology and advanced materials. In this study, a BC-producing strain was isolated from Ficus carica and identified as Gluconacetobacter entanii through partial 16S rRNA gene sequencing, showing 99% identity. The strain was cultivated in Hestrin–Schramm medium under static conditions, promoting biofilm formation at the air-liquid interface. BC production increased progressively in both wet and dry weight during cultivation, reaching maximum values between days 11 and 13, with a dry weight of up to 7.7 g L⁻¹ and a maximum yield of 38.5%. The produced BC exhibited a high water retention capacity (>95%), indicative of a highly porous and hydrated nanostructure. Statistical analysis revealed that pH and temperature significantly influenced BC yield, with optimal conditions at pH 6.0 and 30 °C. Fourier-transform infrared (FT-IR) spectroscopy confirmed the presence of functional groups typical of pure bacterial cellulose, with no evidence of contaminants. Overall, the results demonstrate that G. entanii isolated from F. carica is an efficient and sustainable source of bacterial cellulose with potential applications in biotechnology and functional materials.

The application of zinc oxide nanoparticles prepared by green synthesis (GS-ZnONPs) has demonstrated essential benefits in boosting the clean and sustainable production of agricultural crops worldwide. In this part of the study we evaluate the effect of GS-ZnONPs foliar spraying on the yield, nutraceutical quality, capsaicin concentration, and antioxidant metabolism of chili fruit (Capsicum annuum L., CHISER-522 variety) grown under greenhouse conditions. GS-ZnONPs treatments were applied at concentrations of 10, 20, 30, 40, and 50 ppm every 15 days post-transplant, with the control group treated only with distilled water. The results indicated that treatments with 40 and 50 ppm of GS-ZnONPs significantly improved fruit yield, length, and fruit amount. At the same time, the concentrations of 30 and 40 ppm significantly increased the levels of vitamin C, bioactive compounds, and antioxidant capacity, indicating a better nutraceutical quality of the fruit. In addition, an increase in the catalase activity and the content of macro and micro-minerals in the fruit treated with GS-ZnONPs was observed. Our results suggest that the foliar application of GS-ZnONPs acts as a nanobioestimulant, offering an excellent biotechnological tool for developing agroecological strategies to increase the nutraceutical and antioxidant quality of chili pepper fruit.

Ante la creciente demanda de aditivos por la industria, se busca cubrir necesidadesimportantes de la población, por lo cual se buscan nuevas técnicas y fuentes en laproducción de aditivos que sean eficientes y amigables con el medio ambiente, donde losmicroorganismos oleaginosos como Mortierella alpina, promete ser una alternativa eficientede producción y de bajo costo. M. apina es un hongo basal que tiene la capacidad deproducir altas cantidades de ácidos grasos poliinsaturados (PUFAs) tales como ARA, EPA,DHA entre los más importantes, los cuales son utilizados en la prevención de enfermedadescrónicas no transmisibles, estos PUFAs, pueden ser sintetizados hasta el 50 % en base asu peso seco, M. alpina también genera biosurfactantes, compuestos que ayudan adisminuir la tensión superficial, fungiendo como emulsificantes los cuales poseenpropiedades de interés como son las actividades: antivirales, antiproliferativa,anticancerígenas, inmunomoduladoras con capacidades terapéuticas combatiendotrastornos inmunológica. Por lo tanto M. alpina es un microorganismo excelente paragenerar aditivos que se pueden emplear en diversas áreas tales como: alimenticias,farmacológicas, cosmetológicas, etc.

Agroindustrial residues are generated during several manufacturing procedures, representing an environmental concern, nonetheless, also is an ideal material for microbial support, and biotechnological molecule production. Four fungi: Trichoderma asperellum (TA), Trichoderma harzianum (TH), Aspergillus niger GH1 (A.GH1), and Aspergillus niger PSH (PSH), were investigated in terms of growth rate, co-culture compatibility, and antagonistic assays against Fusarium spp and Colletotrichum spp., for co-culture design. The viability of peanut shells (PS), orange (OP), and melon peels (MP), for Solid State Fermentation was analyzed by proximate, physicochemical characterization, and growth kinetics. SSF extracts were kinetically obtained and their polyphenolic content and in vitro activity against Colletotrichum spp were tested. TA-TH and TH-A.GH1 co-cultures enhance the biocontrol character of single strains through higher growth speeds (0.85-1.57 mm/h) and phytopathogen inhibition for volatile (39.5-67.9%) and nonvolatile (66.3-76.7%) compounds. MP and PS promote higher growth speeds. The 36 h PS TH-TA extract had higher antifungal effects (88.8%). MP and TH-TA co-culture promote the higher polyphenolic content of 1.32 ± 0.02 mg GAE/g at 72 h. SSF rise polyphenol content 85.9% in PS, and 11.1% in MP. The fungal co-culture improves the antifungal activities through multiple biocontrol tools. Agro-wastes represent a green solution for BCA propagation.

This research aimed to evaluate the effectiveness of the biosynthesized spherical zinc oxide nanoparticles (BZnONPs) applications on morphological and physiological indices of serrano pepper plants cv. ‘Chiser-522’. The treatments applied by foliar spray every 15 days from 20 days after transplantation consisted of 10, 20, 30, 40, and 50 ppm of BZnONPs and control (distilled water). A completely randomized design was used with six treatments and fifteen replicas per treatment. Morphological and physiological characteristics such as crop growth rate (CGR), net assimilation rate (NAR), leaf area index (LAI), photosynthetic pigments, and phytochemical compounds were evaluated. The results indicated that the plants treated with 30 and 40 ppm of BZnONPs had higher height, thicker stems, longer roots, and higher CGR, NAR, and LAI than control. Their amounts of photosynthetic pigments and antioxidant compounds were also increased compared to those of the other treatments. Therefore, we conclude that BZnONPs are promising technology that significantly influences chili pepper cultivation's physiological and morphological development at low-level exposures.

The medicinal plants of the desert can be a potential source of natural bioactive compounds with applications in health and food preservation. This work aimed to investigate the phenolic content and antioxidant potential of twenty-three plants from the arid zone of Viesca, Mexico. The antioxidant potential was determined by three methods (ABTS, FRAP, and DPPH). Two extraction methods and three different concentration levels (1:10 mg/mL, 1:25 mg/mL, and 1:50 mg/mL) were evaluated. According to the results, Turnera diffusa (Damiana), Gutierrezia sarothrae (Hierba de San Nicolas), and Leucophyllum frutescens (Cenizo) present the largest content of phenolic compounds and high antioxidant activity. The highest values of antioxidant activity were achieved using a solid/liquid ratio of 1:50 g/mL for T. diffusa and G. sarothrae and 1:25 mg/mL for L. frutescens. The maceration method was the most suitable for extracting antioxidant compounds from T. diffusa and L. frutescens, while ultrasound-assisted extraction was more efficient for G. sarothrae. The HPLC-MS analysis showed the presence of important phenolic compounds. This study shows for the first time that three plants that naturally grow in Viesca have great potential as a source of natural antioxidant compounds.

Zinc oxide nanoparticles have gained attention in the last decades due to their versatile applications; in agriculture, they have been used for their multiple benefits. In this study, the effects of zinc oxide nanoparticles, obtained via chemical and biological synthesis and of 70–80 nm in size, on the germination and seedling growth of Capsicum annuum and Solanum lycopersicum seed were determined. The physiological parameters, photosynthetic pigments, the content of total phenols, total flavonoids, as well as the antioxidant capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH), and the enzymatic activity of catalase, peroxidase, and polyphenol oxidase were evaluated. The results indicated that treatment with zinc oxide nanoparticles obtained via green synthesis improved seed germination rate, while chemically synthesized nanoparticles at higher concentrations decreased germination percentage. In general, the parameters of enzymatic and nonenzymatic antioxidants in treated plants showed significant differences with respect to the control. However, the treatments with the bionanoparticles resulted in more beneficial parameters. Zinc oxide nanoparticles obtained via green synthesis are more effective in generating bioactive compounds and activating the enzyme defense system due to being more biocompatible.