Guillermo Mendoza

Basidiomycota is a cosmopolitan fungal phylum recognized for its nutritional properties and as a natural source of bioactive compounds. Within this group, the family Marasmiaceae Roze ex Kühner remains comparatively understudied. In this study, we performed a metabolic characterization and bioactivity screening of four marasmioid fungal strains using untargeted metabolomic and bioinformatic tools to analyze the metabolic profiles of broth extracts from strains Montiel04, FGR1289, FGR1276, and CC45, detecting 296, 447, 167, and 99 spectrometric features (m/z_RT), respectively. The extracts exhibited notable antibacterial activity, particularly against Clavibacter michiganensis and Erwinia persicina, with strain FGR1289 demonstrating the highest efficacy. Furthermore, extracts from strains FGR1289 and FGR1276 exhibited significant antioxidant capacity against ABTS⁺, DPPH, and galvinoxyl radicals. Pathway enrichment analysis identified putative metabolic pathways involved in organic acid biosynthesis, amino acid metabolism, and butyrate, which may contribute to the observed bioactivities. These findings highlight the marasmioid group as a promising reservoir of bioactive metabolites and support further research on their potential pharmaceutical and agricultural applications. Graphical Abstract Untargered UHPLC-MS/MS metabolomics combined with bioactivity assays enables the identification of bioactive metabolites in fungal crude extracts.

Las enzimas lacasas obtenidas de hongos ligninocelulósicos tienen potencial en diversos procesos industriales y biotecnológicos. La cepa Ganoderma sp. GV81, perteneciente al grupo de hongos de pudrición blanca, es productor de lacasas, sin embargo, su rendimiento requiere ser optimizado para producciones a mayor escala. Este estudio tuvo como objetivo evaluar la actividad lacasa de la cepa GV81en cultivo sólido y líquido, determinando cualitativamente la actividad enzimática y cuantificando su producción, estableciendo las condiciones de cultivo óptimas de pH, sustrato e inductor. Se realizaron ensayos cualitativos en medio ABTS, calculando el Índice de Potencia (ip). La producción enzimática se cuantificó a través de ensayos espectrofotométricos en fermentación líquida. La optimización se llevó a cabo mediante un diseño experimental Box-Behnken, evaluando pH (3, 5, 7), sustrato (glucosa, paja de trigo y cereal) y concentraciones de Cu+2 (0.5, 1, 1.5 mM). Se detectó actividad lacasa cualitativamente con un ip máximo de 0.60. En fermentación líquida, la actividad máxima se alcanzó a los 12 días (161.60 U/L). El análisis estadístico identificó al sustrato como el factor más significativo. La combinación óptima para el sustrato cereal fue pH 7 y 0.5 mM de Cu+2, incrementando la producción enzimática en un 71 % respecto a la combinación estándar. La cepa GV81 demostró un alto potencial para la producción de lacasa. La optimización estadística permitió identificar condiciones de cultivo específicas que mejoran significativamente el rendimiento enzimático, sentando las bases para su posible aplicación biotecnológica.

Background. Fungi of the genus Ganoderma cause white rot of wood in forest trees and trees of economic importance due to the variety of lignocellulolytic enzymes they produce, which may be widely applied for environmental, food production, and biotechnological purposes, among others. Methodology. Fourteen strains of the genus Ganoderma isolated from the central region of Veracruz were studied. Qualitative assays were conducted in Petri dishes to determine the production of cellulase, laccase, and peroxidase enzymes in media with CMC, ABTS, and Azure B, respectively. Activity indexes were calculated according to the formation of discoloration and oxidation halos. Five strains with significant activity were selected, which were used for the quantitative determination of cellulase, laccase, lignin peroxidase, and manganese peroxidase activities using crude extracts obtained from liquid cultures in flasks with minimal medium by spectrophotometric assays with CMC, ABTS, Azure B, and manganese sulfate as reaction substrates. Results. The qualitative assays showed cellulase and laccase activity but not peroxidase activity in the studied strains. The quantitative assays showed cellulase, laccase, and lignin peroxidase activity but not manganese peroxidase activity, where laccase activity was the most relevant. The strains G. weberianum GV26 and Ganoderma sp. GV11 showed the highest laccase production on the 16th day of culture at 27±1 °C, with 102.8 and 106.2 U/L, respectively. Implications. The strains with significant enzymatic activities are candidates for further studies of optimization, purification, and bioremediation of recalcitrant xenobiotic compounds. Conclusion. The strains Ganoderma GV11 and GV26 are a potential source of lignocellulolytic enzymes that could be applied in biotechnological processes.

The prolonged use of synthetic pesticides in agriculture has resulted in the emergence of resistant organisms, high residual levels, and negative impacts on beneficial organisms and human health. These issues highlight the need to explore alternative control strategies based on natural products from ecosystems such as mangroves. In this study, the antimicrobial activity of endophytic fungal extracts from the mangrove Avicennia germinans was evaluated against phytopathogens. Antibacterial activity was assessed by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), while antifungal activity was evaluated based on the percentage of inhibition of mycelial growth (PIMG), spore germination rate (SGR), and reductions in disease incidence (DI%) and severity (DS%) in tomato fruits. The toxicity of an extract (LC ₅₀ ) was determined using Artemia salina . Thirty‐one endophytic fungi were isolated from the mangrove, eight of which showed bioactive properties. Extracts of Fusarium pernambucanum and F. arcuatisporum showed activity against Gram‐positive and Gram‐negative bacteria, while F. keratoplasticum exhibited significant antifungal effects. F . pernambucanum showed very strong inhibitory (7.8 μg/mL) and bactericidal (31.2 μg/mL) effects against Clavibacter michiganensis , as well as moderate inhibitory (250 μg/mL) and bactericidal activity (1000 μg/mL) against Pseudomonas syringae . F. arcuatisporum extract exhibited good inhibitory (125 μg/mL) and bactericidal (1000 μg/mL) activity against Rhizobium radiobacter . At 1 mg/mL, F. keratoplasticum extract showed very high inhibition (85.37%) against Colletotrichum asianum and high inhibition (62.77%) against Acremonium strictum . It also reduced the SGR, DI%, and DS% of C. asianum by 70%, 50%, and 68.75%, respectively, at 1 mg/mL and completely suppressed its DI% and DS% (100%) at 2.5 mg/mL. None of the bioactive extracts exhibited toxic effects on A. salina . These findings highlight the potential of endophytic fungal extracts from A. germinans as promising sources of bioactive compounds for phytopathogen control.

Chikungunya virus (CHIKV) induces an acute infection known as chikungunya fever; however, the persistence of CHIKV infections has been reported. This report investigated the persistence of CHIKV over six months in the cervix of two infected women. The infectious CHIKV was isolated from three samples. Our findings demonstrated the persistence of CHIKV in the cervix, highlighting the importance of evaluating other tissue types.

Many phytopathogenic and human pathogenic microorganisms have increased their resistance to conventional antibiotics and fungicides, which is why the most recent research has focused on exploring new strategies for their management and control. One of these strategies is the search for new natural compounds present in wild edible macrofungi, which in early research have shown evidence of having bioactive properties and high nutritional value, profitability, and biodegradability, among other benefits. The present study is aimed at determining the antibacterial and antifungal activity and acute toxicity of crude extracts obtained from fruit bodies of the wild mushrooms Cantharellus veraecrucis , Cantharellus violaceovinosus , and Turbinellus floccosus . The results revealed that the three fungal species have antibacterial activity, where the most notable species was Turbinellus floccosus , with an MIC = 1000  μ g/mL against Enterococcus faecalis , while C . violaceovinosus and C . veraecrucis showed an MIC = 62.5  μ g/mL, MBC = 250  μ g/mL, and MIC = 250  μ g/mL against Clavibacter michiganensis , respectively. Additionally, Turbinellus floccosus inhibited the phytopathogenic fungus Acremonium strictum , with a PIMG % = 62.20, and also exhibited a PIMG % = 58.73 ( p ≤ 0.05) against Colletotrichum asianum . Regarding toxicity, the three fungal extracts showed moderate toxicity within an LC ₅₀ range of 100–500 μ g/mL against Artemia salina . This study provides a first approximation to the potential pharmaceutical and/or agricultural use of extracts of these wild edible mushrooms. The results obtained open the possibility of testing these extracts in plant models ( in vivo ), contributing to the development of future biodegradable pesticides of natural origin.

El glifosato es un herbicida de amplio espectro que ha sido aplicado en los campos agrícolas de más de 200 países desde hace 40 años. Debido a recientes investigaciones que demostraron su relación como cancerígeno, se ha abierto un debate a nivel mundial sobre su uso y prohibición. México se ha sumado al movimiento de prohibir su uso en el decreto emitido en diciembre de 2020. El efecto del glifosato residual debido a la aplicación constante del mismo tiene afectaciones en diferentes compartimentos ambientales, entre ellos el suelo. Por lo tanto, el objetivo fue identificar las prácticas agrícolas y manejo de arvenses que se emplean en el ejido de Bella Esperanza, Coatepec, Veracruz, como parte de la caracterización del sitio de muestreo para el proyecto de investigación en torno a la biorremediación del glifosato con microorganismos endógenos. Mediante un acercamiento de campo, se realizaron encuestas a los productores de la zona, donde los resultados mostraron que el 54% emplea el glifosato como principal control de malezas. Asimismo, no emplean ningún equipo de protección y consideran al glifosato como un producto inocuo para el medio ambiente. Del mismo modo, el resultado de este estudio observó que el ejido de Bella Esperanza es un área de muestreo adecuada para el estudio de microorganismos con posibles aplicaciones en biorremediación.

Background. Mangrove ecosystems in oil-producing areas in the south of Veracruz, Mexico are permanently threatened by oil spill contamination. In this context, Rhizophora mangle and the microbiota associated with its rhizosphere have adapted over time to processes of bioremediation and natural attenuation of petroleum hydrocarbons. Objective. To evaluate the hydrocarbonoclastic potential of filamentous fungi isolated from the rhizosphere of R. mangle present in a hydrocarbon-contaminated site in Veracruz. Methodology. A rhizosphere sample was characterized physicochemically and total petroleum hydrocarbons were quantified. Fungal strains with hydrocarbonoclastic capacity were isolated in Noble agar medium, salts, and paper impregnated with Maya crude oil. The strains were identified by cell morphology and rDNA ITS region sequencing, and the sequences were used to construct a phylogenetic tree using the maximum likelihood method. A liquid culture was developed in a mineral medium added with petroleum for 30 days and the saturated, polar, and aromatic fractions were quantified to determine the percentage of biodegradation. Results. Six strains of hydrocarbonoclastic fungi were isolated and identified in R. mangle rhizosphere contaminated with 109 916.5 mg kg-1 of TPHs. Of these strains, Aspergillus niger and A. flavus showed the highest hydrocarbon biodegradation with 30.5 and 26.1%, respectively. The highest biodegradation of the saturated fraction was observed with A. niger, A. flavus, and A. egyptiacus; Fusarium oxysporum and A. niger preferred the polar fraction, while A. niger and A. flavus assimilated more of the aromatic fraction. Implications. These hydrocarbonoclastic strains may be potentially used in restoration strategies for hydrocarbon-contaminated mangroves. Conclusion. The microorganisms associated with contaminated mangroves are part of the natural attenuation of the studied site and may be useful for the treatment of sites affected by petroleum spills. Antecedentes. Los ecosistemas de manglar presentes en zonas petroleras del sur de Veracruz, México, se encuentran permanentemente amenazados por la contaminación por derrames de hidrocarburos. En este sentido, Rhizophora mangle y su microbiota asociada a la rizosfera se han adaptado a través del tiempo a procesos de biorremediación y atenuación natural de hidrocarburos del petróleo. Objetivo. Evaluar el potencial hidrocarbonoclasta de hongos filamentosos aislados de la rizosfera de R. mangle presentes en un sitio contaminado con hidrocarburos de Veracruz. Metodología: Se caracterizó fisicoquímicamente una muestra compuesta de rizosfera y se cuantificaron los hidrocarburos totales del petróleo. Se aislaron cepas fúngicas con capacidad hidrocarbonoclasta en medio agar noble, sales y con papel impregnado de petróleo crudo Maya. Las cepas fueron identificadas por morfología celular y por secuenciación de la región ITS del ADNr, se realizó un árbol filogenético con las secuencias por el método de máxima verosimilitud. Se realizó cultivo líquido en medio mineral adicionado con petróleo durante 30 días, se cuantificaron la fracción saturada, polar y de aromáticos determinando los porcentajes de biodegradación. Resultados: Se aislaron e identificaron seis cepas de hongos hidrocarbonoclastas a partir de rizosfera de R. mangle contaminado con 109 916.5 mg kg-1 de HTP, de las cuales Aspergillus niger y A. flavus fueron los que presentaron una mayor biodegradación de hidrocarburos con un 30.5 y 26.1%, respectivamente. La mayor biodegradación de la fracción saturada fue con A. niger, A. flavus y A. egyptiacus; Fusarium oxysporum y A. niger prefirieron mejor la fracción polar; mientras que A. niger y A. flavus asimilaron más la fracción de aromáticos. Implicaciones Estas cepas hidrocarbonoclastas pueden tener un potencial para utilizarse en estrategias de restauración de manglares contaminados con hidrocarburos. Conclusión Los microorganismos asociados al manglar contaminado forman parte de la atenuación natural del sitio estudiado y podrían ser útiles en el tratamiento de sitios impactados por derrames de petróleo.

En la educación universitaria, las actividades que requieren un trabajo en equipo son comunes. Por lo que el éxito o fracaso en esta etapa está influenciado en muchos casos en la capacidad del estudiante en poder desenvolverse en trabajos de equipo de forma eficiente. Desde la perspectiva del profesorado, conocer la actitud de sus estudiantes hacia el trabajo en equipo, puede ser útil. Durante la revisión bibliográfica no se encontraron instrumentos para medir la actitud hacia el trabajo en equipo. Por tal motivo, el objetivo principal de este trabajo es presentar la escala de Actitud hacia el Trabajo en Equipo (ATE) validada en el contexto universitario. La escala fue aplicada en una muestra de 223 estudiantes universitarios de Santa Cruz de la Sierra, Bolivia. Los resultados muestran 22 ítems que se distribuyen en cuatro factores: 1) disposición a trabajar en equipo, 2) participación en el equipo, 3) desinterés; y 4) comunicación intragrupo. El coeficiente alfa de Cronbach de la escala es de 0.86 con lo que se demuestra la fiabilidad de la escala ATE. Asimismo, la escala se encuentra con validez de contenido apoyada por tres expertos y con validez de constructo. Finalmente se discuten los posibles usos de esta herramienta.

In this bioprospecting study the biological activities of extracts of the in vitro culture of Ganoderma Mexican strains were evaluated. The extracts were tested by the Sulforhodamine B staining method for antiproliferative activity and the plate microdilution method for antibacterial activity. Extracts that proved bioactive in these two activities, the antioxidant activity (Galvinoxyl, ABTS, and DPPH) and total phenolic contents (Folin-Ciocalteu) were additionally determined, as well as acute toxicity (Artemia franciscana). In the antiproliferative activity Ganoderma curtisii strain (GH-16-015) obtained a remarkable value of GI₅₀ ≤ 50 µg/mL against tumor lines: A549, HBL-100, HeLa, and T-47D. G. curtisii strains (GH-16-012 and GH-16-015) showed MIC values = 500 µg/mL against Staphylococcus aureus. G. curtisii strain (GH-16-012) almost reduced by 50% the radical Galvinoxyl. Finally, G. curtisii strain (GH-16-023) presented the lowest level of toxicity with a LC₅₀ of 490.881 µg/mL against A. franciscana. These results support the potential medicinal effects of Mexican strains of G. curtisii.