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Background: Alzheimer’s disease is a neurodegenerative disease that has no cure. The drugs used to treat Alzheimer’s disease are based on the inhibition of the enzyme acetylcholinesterase (AChE). In this sense, marine fungal metabolites represent an alternative source for the discovery of drugs based on AChE inhibition (IAChE). The present research carried out a bioprospecting study of marine fungi with acetylcholinesterase inhibition potential. Results: A total of 17 marine fungi were isolated from three stony corals from the Veracruz Reef System. The fungal genera identified were Geotrichum, Curvularia, Penicillium, Aspergillus, and Daldinia. The IAChE was evaluated from the broth and biomass extracts of each fungal strain. As a result, Daldinia eschscholtzii was one of the three fungi with the greatest IAChE effect (32.7%). Subsequently, a bio-directed chromatographic purification of the methanolic extract of the biomass of D. eschscholtzii was carried out. The FRL8.1 fraction was the most active with an IAChE of 41.0%, a value close to Galantamine positive control (44.0%). Furthermore, compound analysis was carried out by GC-MS. Finally, it was determined that the metabolites responsible for the inhibitory effect are probably 4,7-dihydroxycoumarin and 5-nitro-2-naphthalenamine, which was demonstrated by their interactions with the AChE enzyme receptor through molecular docking studies. Conclusions: Coral-associated marine fungi produce secondary metabolites that inhibit acetylcholinesterase. This is the first report of D. eschscholtzii isolated from the stony coral Siderastrea siderea. Finally, we consider that more studies are needed to demonstrate the IAChE potential of marine fungi associated with corals or other marine organisms.How to cite: Olivo-Flores KG, Couttolenc A, Suárez-Medellín J, et al. Acetylcholinesterase inhibition exerted by the extract of Daldinia eschscholtzii, a marine fungus associated with the coral Siderastrea siderea: GC–MS analysis and molecular docking of identified compounds. Electron J Biotechnol 2024;72. https://doi.org/10.1016/j.ejbt.2024.08.001.

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.

Background: Marine fungi are considered as a promising source of pharmacologically important extracts and compounds owing to the new chemical structures that they can synthesize due to the environmental conditions of their habitat. The aim of this work is to evaluate the free radical scavenging capacity of methanolic extracts from marine fungi and their relationship to their total phenolic content. For this, the radical tests ABTS, DPPH, and Galvinoxyl were used, comparing these results with the antioxidant Trolox as reference. The total phenol content was quantified using the Folin-Ciocalteu method. All data were analyzed by ANOVA followed by Tukey's post hoc tests (p

In our search for quorum-sensing (QS) disrupting molecules, 75 fungal isolates were recovered from reef organisms (endophytes), saline lakes and mangrove rhizosphere. Their QS inhibitory activity was evaluated in Chromobacterium violaceum CVO26. Four strains of endophytic fungi stood out for their potent activity at concentrations from 500 to 50 μg mL−1. The molecular characterization, based on the internal transcribed spacer (ITS) region sequences (ITS1, 5.8S and ITS2) between the rRNA of 18S and 28S, identified these strains as belonging to four genera: Sarocladium (LAEE06), Fusarium (LAEE13), Epicoccum (LAEE14), and Khuskia (LAEE21). Interestingly, three came from coral species and two of them came from the same organism, the coral Diploria strigosa. Metabolic profiles obtained by Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS) suggest that a combination of fungal secondary metabolites and fatty acids could be the responsible for the observed activities. The LC-HRMS analysis also revealed the presence of potentially new secondary metabolites. This is, to the best of our knowledge, the first report of QS inhibition by marine endophytic fungi.