Background: culture collections are responsible of the search of alternative methods to preserve fungal species that sensitive to specific techniques due to its characteristics such as the vacuolar size and conidia, susceptibility to desiccation or low temperatures, spore production and slow growth. Objective: to recover 18 isolates of Hirsutella citriformis and two of Hirsutella thompsonii preserved in mineral oil (MO), to assess their viability and suggest this method as alternative for its conservation, in laboratories that do not have the resources for preserve at -70 and -196 °C. Methods: isolates were preserved in MO and recovered in Sabouraud Dextrose Agar (SDA) with 1% yeast extract (SDAY) after six years of preservation, and their viability, morphology and purity were assessed. Results and conclusions: 19 strains of Hirsutella spp. were viable (95%), except for CHE-CNRCB 333. The CHE-CNRCB 345 strain showed differences in its growth, with respect to the initial characteristics observed for H. citriformis. In SDAY H. citriformis produced the characteristic synemas of the species. MO can be used as a preservation alternative for Hirsutella spp. allowing their preservation, compared to sterile water and lyophilization where their viability is reduced.

Background: Pleurotus agaves is a mushroom that grows wild on the agave plant and is consumed by rural populations in some regions of Mexico. Objective: To compare biological efficiencies (BEs) and basidiome sizes between the wild strain of P. agaves (IE-771) and a commercial strain of Pleurotus pulmonarius (IE-115). Method: The strains were cultivated in agave leaves mixed with barley straw (M) and barley straw alone (S), used as a control substrate. The fiber (lignin, cellulose, hemicellulose) content of the substrates during the crop cycles was analyzed. Results and conclusions: The BEs were 42.1 % (S) and 64.6 % (M) for IE-771 and 37.3 % (S) and 71.3 (M) for IE-115, with statistical differences found between the substrates, but not between the strains. Crop cycles were longer in the P. agaves strain. IE-771 presented pileus sizes Ø from ≤ 4.9 to 19.9 cm on substrate S and from ≤ 4.9 to ≥ 20 cm on substrate M, whereas IE-115 presented sizes from ≤ 4.9 to 14.9 cm in both substrates. A greater decrease in polysaccharide compounds in the substrates was associated with the incubation stage. Due to its acceptable morphological characteristics, P. agaves strain could be suitable for commercial cultivation.

Antecedentes: El síndrome de nariz blanca causado por Pseudogymnoascus destructans ha disminuido drásticamente las poblaciones de murciélagos en Canadá y Estados Unidos de América; no se ha detectado en México. Objetivo: Caracterizar la micobiota en los murciélagos que comparten la distribución con las especies susceptibles de ser parasitados por P. destructans. Métodos: Se realizaron muestreos de murciélagos en San Luis Potosí y Jalisco. Se tomaron muestras de rostro y alas, que se sembraron en agar rosa Bengala cloranfenicol. Se purificaron en papa dextrosa agar e identificaron a nivel de género, cuando fue posible a especie con base en la morfología y micromorfología. Los murciélagos se identificaron hasta especie. Resultados y conclusiones: Los resultados mostraron una alta diversidad fúngica identificándose 32 géneros, donde Acremonium, Aspergillus, Cladosporium, Penicillium y Scopulariopsis, se observaron en las 17 especies de murciélagos. Se documentó la presencia de Pseudogymnoascus pannorum, pero no de P. destructans.

Background: Talaromyces is a genus of Eurotiales divided into eight sections. The species are adapted to habitats such as soil, processed foods, immunocompromised patients, and plants. Objective: Identify three Talaromyces isolating from pseudostems of Musa sp. AAB ‘Manzano’. Methods: The morphology of Talaromyces colonies in recommended media was analyzed, ascospores were observed under scanning electron microscopy, and a phylogeny of the concatenated ITS-RPB1-RPB2 was performed. Results and conclusion: The three strains are clustered in the same clade within the section Talaromyces, being T. rubicundus the most related species. The isolates morphology, color, and growth rate are distinguishable from T. rubicundus and other related species. No conidia formation was detected under any conditions, but cleistothecia are widely produced on an oatmeal-agar medium, which harbors asci with ascospores with spiny ornamentation. We propose these strains are representative of Talaromyces oaxaquensis sp. nov.

Antecedentes: la vainilla (Vanilla planifolia) es fuente de la vainillina. Fusarium oxysporum f. sp. vanillae (Fov) es el principal problema sanitario del cultivo. Objetivo: se evaluó el efecto de un gradiente térmico en el desarrollo in vitro de cepas de F. oxysporum patógenas y no patógenas de V. planifolia. Métodos: se seleccionaron dos cepas de F. oxysporum de patogenicidad alta, dos moderadas y dos no patogénicas de V. planifolia. Se evaluó el efecto de un gradiente entre 23 y 32 °C en la producción de micelio y esporas de las cepas en caldo papa dextrosa, durante 15 días. Los datos se procesaron mediante ANOVA, pruebas de Tukey y Kruskal Wallis. Resultados y conclusiones: se encontró diferencia significativa en la producción de biomasa de cinco cepas de Fov, excepto para JAGH3 cepa altamente patogénica, la cual creció abundantemente en todas las temperaturas evaluadas. En general, el mayor peso micelial se obtuvo a 28 y 30 °C, el menor a 25 y 32 °C. La producción de esporas de las seis cepas se incrementó significativamente a 23 y 32 °C. Se concluye que Fov se desarrolla de forma óptima a 28 y 30 ºC, con mayor esporulación a 23 y 32 ºC.

Background: Cordyceps s.l. is a paraphyletic group of Ascomycete fungi that parasitize mainly arthropods. In Mexico, these fungi have been little studied and the current state of their diversity is unknown.Objective: To describe the history of the records of Cordyceps s.l. from Mexico, and to generate a checklist of the species, detailing their hosts and geographical distribution.Methods: A literature review was conducted addressing on Cordyceps s.l. cited from Mexico from 1864 to 2022. Geographical distribution maps of Clavicipitaceae, Cordycipitaceae, and Ophiocordycipitaceae were created in the QGIS 3.18.1 Software.Results and conclusions: The first record of Cordyceps in Mexico dates back to 1864. To date, 35 species of Cordyceps s.l. have been recorded, equivalent to 3.5% of the diversity of the genus recorded worldwide. The geographical distribution of these species is determined by their hosts and consequently by the vegetation. The species with the greatest geographical distribution were: Beauveria bassiana and Cordyceps militaris of Cordycipitaceae; Metarhizium anisopliae of Clavicipitaceae; and Tolypocladium capitatum and T. ophioglossoides of Ophiocordycipitaceae. Beauveria bassiana and Metarhizium anisopliae are the most studied species due to their pathogenicity to different crop pests.

Background: Colletotrichum gloeosporioides causes anthracnose in various agricultural crops. Objective: To evaluate the antifungal activity of Ricinus communis and Cyperus rotundus against WSFT and Tainung strains of C. gloeosporioides, comparing them with commercial products containing Bacillus subtilis (Serenade®) and Streptomyces spp. (Blite Free®). Methods: Inhibition percentages were determined through a dose-response bioassay with Serenade® and Blite Free® and the ethanolic extracts of R. communis and C. rotundus on the strains of C. gloeosporioides isolated from Carica papaya. Results and conclusions: R. communis induced higher mycelial inhibition (62.7 %) in the Tainung strain compared to Serenade® (54.2 %) and Blite Free® (0 %). The EC50 values obtained in the WSFT strain were similar between R. communis (0.80 %) and Serenade® (0.79 %). The antifungal activity of the plant extracts proved comparable to that of commercial products, suggesting their potential for controlling C. gloeosporioides.

Antecedentes: En México, se conocen 12 especies de Xylaria sobre frutos y semillas, X. liquidambaris crece sobre frutos de Liquidambar styraciflua. Hasta ahora, su hábito de crecimiento (endófito, saprobio o parásito) no ha sido caracterizado. Objetivo: Determinar el hábito de crecimiento de X. liquidambaris, con el fin de ampliar la información sobre su ecología, hábitat y cultivo, para construir una discusión sobre su conservación. Métodos: En época de secas se recolectaron frutos de L. styraciflua, en el ANP La Martinica, Banderilla, Veracruz. Los frutos se clasificaron en categorías según su estado de maduración. Porciones de los frutos, fueron procesadas para recuperar los hongos endófitos, en medios sólidos y líquidos, con y sin extractos de frutos de liquidámbar triturados. Resultados y discusión: Se corroboró el hábito endófito de X. liquidambaris, la única especie recuperada en el proceso experimental. El micelio de los frutos requirió 60 días para formar estromas y el micelio cultivado en medios sólidos y líquidos 90 días. Estos resultados aportan elementos para construir una discusión que contribuya a evaluar de mejor manera su ecología y estado de conservación. La vía de infección de los frutos necesita ser estudiada a detalle.

Background: Tree nuts and dried fruits are very profitable products, highly vulnerable to contamination and subsequent deterioration by molds such as Penicillium spp., Aspergillus spp. and Rhizopus spp. In Mexico, microbial contamination of nuts and dried fruits, particularly of the product sold for bulk consumption, which also has a lax regulation. Objectives: To study the fungal contamination status of peanuts, pecans, pumpkin seeds and walnuts from different regions of the country. Methods: The moisture content and water activity of 111 samples of peanuts (36), pecans (30), walnuts (12) and pumpkin seeds (33) were measured. Additionally, the different species of molds present in the samples were isolated and identified. Results and conclusions: Only some samples, mainly pumpkin seed, were found with mold and yeast contents above what is allowed by Mexican regulations. However, many samples were contaminated with toxigenic mold species, such as Aspergillus flavus, Penicillium spp. and Fusarium spp., as well as other deteriorating molds. Although contamination levels do not seem to be cause for alarm, the sale of nuts in bulk should be monitored and regulated, as there is a potential risk to the consumer if storage conditions are not adequate.

Background: Coffee residues, including spent coffee grounds (SCG), are an important source of bioactive components like phenolic compounds which are characterized to exert bioactivity. Objective: Evaluate the antioxidant effect of the aqueous extract obtained from SCG, under submerged-state fermentation using Pleurotus ostreatus. Methods: Submerged-state fermentation using Pleurotus ostreatus was used to release phenolic compounds from SCG (0, 5 and 10 %). After fermentation, the qualitative and quantitative phytochemical content was monitored (carbohydrates, polyphenols, flavonoids, and cafeoylquinic acid), as well as the antioxidant properties (antiradical activity and reducing power). In addition, lipid oxidation levels of pork meat homogenates incorporated with SCG extract during storage were evaluated. Results and conclusions: The results showed an increase in phytochemical content and antioxidant properties in the aqueous extract from SCG fermented with P. ostreatus, in dependence of the used substrate concentration. Also, a reduction in lipid oxidation values was showed in pork meat homogenates treated with the fermented SCG extract. Fungal fermentation process of coffee residues using Pleurotus spp., could be a promissory strategy to obtain natural additives.