Nelda Xanath Martínez-Galero

Spontaneous fermentations contribute to the identity of ancestral mezcal, although duration and yield may vary. This study selected an indigenous yeast and evaluated it as a starter candidate. Four native isolates (Torulaspora delbrueckii A1GM and A6GM, Kluyveromyces marxianus A2GM, and Saccharomyces cerevisiae A5GM) and a spontaneous control were compared in Agave cupreata microfermentations. Selection considered distillate alcohol content and preliminary ethanol-tolerance assays. A5GM was subsequently evaluated in three production batches containing A. angustifolia + A. karwinskii, A. angustifolia, or A. cupreata + A. angustifolia, with three independent vats per treatment. Fermentation profiles, distillate composition, yield, and sensory acceptance were assessed. A5GM produced the highest microfermentation distillate alcohol content (43.91 ± 0.89% Alc. Vol.) and grew at 16% ethanol (v/v). In the first two production batches, inoculated vats showed higher volumes standardized to 45% Alc. Vol. and lower calculated agave requirements than the controls; these were batch-specific observations under the operating conditions studied. Sensory evaluation used pooled vat-derived distillate composites, and the A5GM composites received the highest mean hedonic scores. Because strain-level establishment and persistence of A5GM were not confirmed, the observed outcomes cannot be attributed exclusively to this strain. Sensory interpretation is limited by fixed presentation order. Further independent batches, standardized management, and strain-level monitoring are needed to assess reproducibility.

Spontaneous fermentation is central to ancestral mezcal production, yet the bacterial and fungal communities associated with Agave cupreata must remain insufficiently characterized. This exploratory study described community composition and predicted functional profiles at three stages of a traditional fermentation defined by sugar depletion: 10 °Brix (0 h), 5 °Brix (72 h), and 2 °Brix (144 h). Ambient temperature ranged from 21.7 to 23.7 °C, must temperature from 28.5 to 29.9 °C, pH from 4.6 to 5.2, and relative humidity from 51.3% to 58.7%. At each stage, material collected from two wooden vats and three vertical positions was pooled into one composite sample. Bacterial 16S rRNA gene and fungal ITS1 amplicons were sequenced and analyzed using QIIME 2. At 10 °Brix, five dominant bacterial genera accounted for more than 93% of relative abundance. Lactic and acetic acid bacteria represented more than 91% at 5 °Brix, while Pediococcus, Lactiplantibacillus, and Loigolactobacillus were prominent at 2 °Brix. Seven fungal genera represented more than 98% of the initial profile, whereas Saccharomyces, Debaryomyces, and Maudiozyma accounted for more than 98% at 2 °Brix. PICRUSt2 predicted pathways related to carbohydrate degradation and fermentation, whereas FUNGuild assignments were predominantly saprotrophic at the later stages. Because one pooled sample was analyzed per stage, these patterns are descriptive and require validation in replicated fermentations. Despite these limitations, this study provides baseline information on the microbial communities associated with ancestral A. cupreata fermentation and identifies taxa and predicted functions that merit future isolation and experimental validation.

The cultivation of Soledad pepper (Capsicum annuum L.) is essential in Oaxaca and Veracruz, but it faces issues with pests and diseases, which affect yield and cause economic losses. To mitigate these impacts, farmers have started using biostimulants such as chitosan and plant growth promoting bacteria instead of agrochemicals due to their environmental and health benefits. This study evaluated the effect of Bacillus subtilis and chitosan, both individually and combined, on the growth, yield, and fruit quality of Soledad pepper under greenhouse conditions. Four treatments were applied at different stages of the crop cycle: Q (Chitosan), BS (Bacillus subtilis), Q + BS (Chitosan + Bacillus subtilis), and T (Control). The results showed that the combination of chitosan and Bacillus subtilis significantly improved plant growth, especially in height and stem diameter. The chitosan treatment produced the highest number of fruits and plant weight, while the combination of chitosan and Bacillus subtilis enhanced fruit quality, increasing characteristics such as size, weight, pericarp thickness, and physicochemical parameters, notably in brix degrees, citric acid percentage, and pH, outperforming the individual treatments and the control.

Benzoxazoles are recognized as significant building blocks in organic synthesis and materials science. This work observed the formation of benzoxazole from o-aminophenol and o-hydroxybenzaldehyde using online ¹H NMR (continuous flow cell, 80 MHz). The identification of changes in the functional group was complemented by ATR-FTIR analysis. Additionally, the kinetic roles of phenylboronic acid and cyanide in the one-pot condensation-cyclization reaction are examined. Real-time monitoring has revealed three observable events: the rapid condensation of the aldehyde and o-aminophenol to produce the imine; the formation of the boron complex in the presence of phenylboronic acid; and the cyanide-assisted cyclization that converts the intermediate into benzoxazole. The findings clarify the transformations that control throughput and provide valuable insights for optimizing reagent loadings under environmentally friendly conditions.

Mechanosynthesis in solid state represents an efficient method for synthesizing precursor molecules required for the development of organic light-emitting diode devices. In this study, nine benzoxazoles were synthesized using a high-energy planetary ball mill. A 2^k factorial experimental design was employed, focusing on reactor-operating conditions. The mechanosynthesis process was confirmed by nuclear magnetic resonance and infrared spectrometry analyses, while ultraviolet spectroscopy indicated the formation of luminescent products. Reactions were typically completed within 1 to 3 h, affording yields ranging from 19% to 98%.

The devil fish (Hypostomus plecostomus) is a highly invasive exotic species due to its remarkable adaptability and the significant ecological damage it causes in aquatic ecosystems. This research aimed to extract, characterize, and evaluate the chemical purification of chitosan from fish tegumental shields, comparing it with chitosan obtained from shrimp exoskeletons. The biopolymer was purified through acid-alkaline hydrolysis (0.6 M HCl/25°C/1h and 0.4 M NaOH/28°C/3h), deacetylation (40% NaOH/110°C/5.5h), and depigmentation (38% NaClO/28°C/0.15h). Desmineralization, deproteinization, color chart, insoluble content, degree of acetylation, molecular weight, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were evaluated. Chitosans from shrimp exoskeletons and devil fish tegumental shields obtained deproteinization percentages of 98.91 and 97.67%, desmineralization of 98.19 and 97.95%, deacetylation percentages of 82.031 and 83.346%, and molecular weights (MW) of 112.934 and 206.507 kDa respectively. FT-IR results identified an absorption band corresponding to C=O stretching in both samples, indicating the presence of carboxylic anion (-COO). Thermograms showed lower degradation temperatures (308°C) for commercial chitosan compared to that from devil fish (324°C). Devil fish tegumental shields offer chitosan similar to commercial sources, with significant economic potential and a 25% yield, potentially controlling invasive populations and restoring ecosystems.

In 2050, the planet will need more food because the world population will be close to 10 billion people. Since 2015, agriculture has opened the door to the incorporation of technologies such as autonomous robots and artificial intelligence. Intelligent systems allow automatic learning through data obtained through sensors, drones and internet of things. These systems use algorithms to predict the behavior of variables such as soil quality, humidity, diseases or sales price behavior. In this way, agriculture can function as the first link in an integrated, efficient, intelligent production chain, with permanent interconnectivity and timely decisions thanks to machine information processing through artificial intelligence.

Pseudomonas aeruginosa is a bacterium capable of living in diverse environments, producing biosurfactants, fixing nitrogen, tolerating heavy metals, and is capable of transferring resistance genes to Pb, Cd and As by means of plasmids. These characteristics make it an excellent proposal for bioremediation studies in sites contaminated with metals. The objective of this study was to search for bacterial strains associated with the rhizosphere of T. latifolia with biotechnological potential. For this purpose, strains were isolated from the rhizosphere of the aquatic plant and only those capable of producing biosurfactants by foam production in PPGAS broth, droplet collapse, IE24h were selected. MIC to Pb, Cd and As was determined, nitrogen fixation was detected on NFb agar, plasmid extraction was performed by Kieser's method, and PCR detection of arsA, cadA and pbrA genes. Only four strains PAR1, PAB12, J2 and J3 able to produce biosurfactants and fix nitrogen were isolated. They did not present plasmids and only amplified Pb and Cd resistance genes (cadA and pbrA). These strains are proposed for further study and use in wetland bioremediation processes in sites contaminated with heavy metals.

The cultivation of Soledad pepper (Capsicum annuum L.) is essential in Oaxaca and Veracruz, but it faces issues with pests and diseases, which affect yield and cause economic losses. To mitigate these impacts, farmers have started using biostimulants such as chitosan and plant growth-promoting bacteria instead of agrochemicals due to their environmental and health benefits. This study evaluated the effect of Bacillus subtilis and chitosan, both individually and combined, on the growth, yield, and fruit quality of Soledad pepper under greenhouse conditions. Four treatments were applied at different stages of the crop cycle: Q (Chitosan), BS (Bacillus subtilis), Q+BS (Chitosan + Bacillus subtilis), and T (Control). The results showed that the combination of chitosan and Bacillus subtilis significantly improved plant growth, especially in height and stem diameter. The chitosan treatment produced the highest number of fruits and plant weight, while the combination of chitosan and Bacillus subtilis enhanced fruit quality, increasing characteristics such as size, weight, pericarp thickness, and physicochemical parameters, notably in brix degrees, citric acid percentage, and pH, outperforming the individual treatments and the control.

Passak is a deciduous tree native to Mexico, Florida, parts of South America, and the Greater Antilles. It has been used in soil restoration and silvopastoral systems, and its seeds have been used to extract oil for biodiesel production and livestock feed. In states like Oaxaca, Passak is grown for ornamental purposes, causing its seeds to fall and rot without being utilized. One part that remains entirely unused is the shell covering the seed which is why, this research developed an adsorbent material from these shells by subjecting them to a pretreatment and subsequent preparation using phosphoric acid at a 60% (w/w) concentration, followed by calcination of the material. The adsorbent was then tested in batch experiments with a 200 mg/L solution of CMT (a model molecule commonly used in adsorbent testing), achieving a removal efficiency exceeding 99%.