Procyanidins are bioactive molecules with industrial and pharmaceutical relevance, they are present in recalcitrant agro-industrial wastes that are difficult to degrade. In this study, we evaluated the potential consumption of procyanidins from Aspergillus niger and Trichoderma harzianum strains in submerged fermentations. For this purpose, a culture medium containing salts, glucose, and procyanidins was formulated, where procyanidins were added to the medium after the near-total consumption of glucose. The submerged cultures were carried out in amber flasks at 30 °C and 120 rpm. The addition of procyanidins to the culture medium increased the formation of micellar biomass for all the strains used. The use of glucose affected the growth of A. niger GH1 and A. niger HS1, however, in these assays, a total consumption of procyanidins was obtained. These results show that the consumption of procyanidins by fungal strains in submerged fermentations was influenced by the pH, the use of glucose as the first source of carbon, and the delayed addition of procyanidins to the medium. The study showed that A. niger and T. harzianum strains can be used as a natural strategy for the consumption or removal of procyanidins present in recalcitrant residues of risk to the environment and human health.

The goals of the present study were to characterize the phages isolated by magnetic nanocomplex, to determine the effect of natural polyphenols on phage activity against E. coli and the stability of free and encapsulated bacteriophages under UV irradiation, and their efficacy against E. coli on romaine lettuce (Lactuca sativa L. var. longifolia) as a fresh food model. The morphology of the two magnetically isolated phages were characterized using the transmission electron microscope (TEM). All isolated phages were classified in a morphological family of tailed phages of the order Caudovirales, Myoviridae family. The PCR results showed that the stx1 and cI genes were not on any phage. Assays were carried out to determine the effect of four polyphenolic natural extracts on phages under UV radiation. The highest activity and stability of phages expressed in phage titer (PFU/ml) were observed in the presence of polyphenols from tarbush leaves (Flourensia cernua DC). Coliphages were encapsulated in alginate/chitosan and alginate/PVA carriers with and without polyphenols from tarbush leaves. Encapsulation led to a higher phage stability under UV radiation. All encapsulated formulations and free coliphages were applied on the surfaces of romaine lettuce containing E. coli cells. An effective reduction of 2 log of E. coli titers from lettuce was observed. Encapsulated phage formulations with and without polyphenols from tarbush leaves could be considered for future application in fresh food preservation.

The development of green technologies and bioprocesses such as solid-state fermentation (SSF) is important for the processing of macroalgae biomass and to reduce the negative effect of Sargassum spp. on marine ecosystems, as well as the production of compounds with high added value such as fungal proteins. In the present study, Sargassum spp. biomass was subjected to hydrothermal pretreatments at different operating temperatures (150, 170, and 190 °C) and pressures (3.75, 6.91, and 11.54 bar) for 50 min, obtaining a glucan-rich substrate (17.99, 23.86, and 25.38 g/100 g d.w., respectively). The results indicate that Sargassum pretreated at a pretreatment temperature of 170 °C was suitable for fungal growth. SSF was performed in packed-bed bioreactors, obtaining the highest protein content at 96 h (6.6%) and the lowest content at 72 h (4.6%). In contrast, it was observed that the production of fungal proteins is related to the concentration of sugars. Furthermore, fermentation results in a reduction in antinutritional elements, such as heavy metals (As, Cd, Pb, Hg, and Sn), and there is a decrease in ash content during fermentation kinetics. Finally, this work shows that Aspergillus oryzae can assimilate nutrients found in the pretreated Sargassum spp. to produce fungal proteins as a strategy for the food industry.

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El objetivo del artículo es analizar cómo se construyen formas de entender y vivir las violencias sociales en los espacios escolares a través de la identificación de espacios intersticiales en una escuela secundaria ubicada en Uruapan, Michoacán, México. Se realizaron entrevistas, grupos focales y mapeos participativos con la intención de recabar información cualitativa sobre los usos y percepciones del espacio escolar. A través de interacciones cotidianas dentro y fuera de los espacios educativos institucionalizados, los jóvenes van construyendo relaciones y percepciones sobre el espacio que les genera pedagogías sobre la violencia, aprendizajes sobre las zonas de riesgo, de vulnerabilidad, de impunidad, de indefensión, entre otras. Estas interacciones surgen dentro de escenarios de alta conflictividad como son las zonas urbanas marginales de Michoacán, estado que en años recientes ha ocupado altos índices de violencia armada derivada de la presencia del narcotráfico y las políticas para combatirlo. A través de esta información se detectaron espacios en los que confluyen lazos o redes que muestran la intersección e interacción entre la violencia institucional y la cotidiana dentro de las escuelas conformando así pedagogías de la violencia entre la comunidad escolar.

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Leishmaniasis is a neglected vector-borne disease; there are different manifestations of the diseases and species involved, and cutaneous leishmaniasis caused by Leishmania (L.) mexicana is the most prevalent in Mexico. Currently, the drugs available for the treatment of leishmaniasis are toxic, expensive, and often ineffective; therefore, it is imperative to carry out research and development of new therapeutic alternatives, with natural products being an attractive option. In particular, oregano is a plant with worldwide distribution; in Mexico, two species: Lippia berlandieri Schauer and Poliomintha longiflora Gray are endemic. Both essential oils (EO’s) have been reported to have antimicrobial activity attributed to their main components, thymol and carvacrol. In this research, the leishmanicidal effect and mechanism of cell death induced by L. berlandieri EO, P. longiflora EO, thymol, and carvacrol in L. mexicana promastigotes were determined in vitro. Additionally, the cytotoxic activity in mammalian cells was evaluated. L. berlandieri EO presented higher leishmanicidal activity (IC50 = 41.78 µg/mL) than P. longiflora EO (IC50 = 77.90 µg/mL). Thymol and carvacrol were the major components of both Mexican oregano EO’s. Thymol presented higher leishmanial inhibitory activity (IC50 = 22.39 µg/mL), above that of carvacrol (IC50 = 61.52 µg/mL). All the EO’s and compounds evaluated presented lower cytotoxic activity than the reference drug; thymol was the compound with the best selectivity index (SI). In all cases, apoptosis was identified as the main mechanism of death induced in the parasites. The leishmanicidal capacity of the Mexican oregano EO is an accessible and affordable alternative that can be further explored.

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