Identification of Insect-Deterrent Metabolites from Acremonium masseei strain CICY026, a Saprophytic Fungus from a Sinkhole in Yucatán.

Micromycetes from unexplored sources represent an opportunity to discover novel natural products to control insect pests. With this aim, a strain of Acremonium masseei CICY026 isolated from a tropical sinkhole was identified, cultured on fermented rice, and its ethyl acetate extract (EAE) was evaluated against three serious phytophagous insects (Bemisia tabaci, Myzus persicae, and Rhopalosiphum padi). DNA from A. masseei CICY026 was used to confirm its identity. EAE caused settling inhibition (SI) of M. persicae and R. padi (67.5% and 75.3%, respectively). Bioassay-guided fractionation of the active EAE led to the isolation of a novel metabolite, named hexahydroacremonintriol (1), and of acremonin A glucoside (2). The structures of 1 and 2 were determined using IR, one- and two-dimensional NMR, HRMS, and confirmed by theoretical data. The aphid M. persicae was noticeably sensitive to 1 and 2 (SI: 55.6% and 67.2%, respectively), whereas R. padi was only slightly affected by 1 (SI: 59%). This new knowledge about mycobiota from these special sinkhole ecosystems will inform the development of new biorational pesticides.

Enhancing laccase production by white-rot fungus Funalia floccosa LPSC 232 in co-culture with Penicillium commune GHAIE86.

To obtain enzymatic preparations with higher laccase activity levels from Funalia floccosa LPSC 232, available for use in several applications, co-cultures with six filamentous microfungi were tested. A laccase non-producing soil fungus, identified as Penicillium commune GHAIE86, showed an outstanding ability to increase laccase activity (3-fold as compared to that for monoculture) when inoculated in 6-day-old F. floccosa cultures. Maximum laccase production with the F. floccosa and P. commune co-culture reached 60 U/mL, or twice that induced by chemical treatments alone. Our study demonstrated that co-culture with soil fungi might be a promising method for improving laccase production in F. floccosa. Although the enhancement of laccase activity was a function of P. commune inoculation time, two laccase isoenzymes produced by F. floccosa remained unchanged when strains were co-cultured. These data are compatible with the potential of F. floccosa in agricultural applications in soil, whose enzyme machinery could be activated by soil fungi such as P. commune.

Insect deterrent and nematicidal screening of microfungi from Mexico and anti-aphid compounds from Gliomastix masseei.

Fungal metabolites are promising alternatives for the development of biorational pesticides. In this sense, microfungi from tropical regions are valuable sources of natural compounds for pest management. With the aim of broadening the search for new eco-friendly products to manage plant pests, this study was carried out to evaluate the biological activity of 23 tropical fungal extracts on three species of phytophagous insects and a plant parasitic nematode. In addition, the active principles of the most effective extract were identified. The insect deterrent activity of fungal extracts was evaluated on the settling of aphids Myzus persicae and Rhopalosiphum padi, and on the feeding of lepidoptera larva Spodoptera littoralis; the nematostatic activity was evaluated on the mobility of Meloidogyne javanica. Active metabolites from Gliomastix masseei were identified by GC-MS techniques and by comparison with commercial standards. Results showed seven extracts with strong effect on the settling of M. persicae and R. padi (settling inhibition >80%). The calculated median of effective concentration (EC50) values ranged from 8 to 38µg/cm2 for the extracts of Clonostachys rosea and G. masseei, respectively. Bioassay-guided separation of the ethyl acetate extract of G. masseei revealed the presence of fatty acids and their derivatives, where methyl 9-octadecenoate was the most active compound with EC50 values of 16µg and 35µg/cm2 for M. persicae and R. padi, respectively. Extracts of C. rosea and G. masseei could be a promising option in the control of pest aphids in agriculture.

Insect deterrent and nematicidal screening of microfungi from Mexico and anti-aphid compounds from Gliomastix masseei / Evaluación de la actividad disuasiva de insectos y nematotóxica de microhongos de México y compuestos anti-áfidos de Gliomastix masseei

Fungal metabolites are promising alternatives for the development of biorational pesticides. In this sense, microfungi from tropical regions are valuable sources of natural compounds for pest management. With the aim of broadening the search for new eco-friendly products to manage plant pests, this study was carried out to evaluate the biological activity of 23 tropical fungal extracts on three species of phytophagous insects and a plant parasitic nematode. In addition, the active principles of the most effective extract were identified. The insect deterrent activity of fungal extracts was evaluated on the settling of aphids Myzus persicae and Rhopalosiphum padi, and on the feeding of lepidoptera larva Spodoptera littoralis; the nematostatic activity was evaluated on the mobility of Meloidogyne javanica. Active metabolites from Gliomastix masseei were identified by GC-MS techniques and by comparison with commercial standards. Results showed seven extracts with strong effect on the settling of M. persicae and R. padi (settling inhibition >80%). The calculated median of effective concentration (EC50) values ranged from 8 to 38 µg/cm² for the extracts of Clonostachys rosea and G. masseei, respectively. Bioassay-guided separation of the ethyl acetate extract of G. masseei revealed the presence of fatty acids and their derivatives, where methyl 9-octadecenoate was the most active compound with EC50 values of 16 µg and 35 µg/cm² for M. persicae and R. padi, respectively. Extracts of C. rosea and G. masseei could be a promising option in the control of pest aphids in agriculture.

Los metabolitos fúngicos son agentes prometedores para el desarrollo de plaguicidas biorracionales. En este sentido, los hongos microscópicos de zonas tropicales representan una valiosa fuente de compuestos naturales para el manejo de plagas. Con la finalidad de ampliar la investigación en productos amigables con el medio ambiente, en este estudio se evaluó la actividad biológica de 23 extractos de hongos sobre 3 especies de insectos fitófagos y un nematodo fitoparásito; además se identificaron los componentes del extracto más activo. El efecto disuasivo de los extractos fúngicos se evaluó en el asentamiento de Myzus persicae y Rhopalosiphum padi, así como en la alimentación de Spodoptera littoralis; la actividad nematostática se evaluó sobre la movilidad de Meloidogyne javanica. Los metabolitos activos de Gliomastix masseei se identificaron por cromatografía de gases-espectrometría de masas y por comparación con muestras comerciales. Los resultados mostraron 7 extractos con fuerte efecto en la inhibición del asentamiento (> 80%) de M. persicae y R. padi. Los valores de la concentración efectiva media (CE50) estuvieron en el rango de 8 a 38 µg/cm² para los extractos de Clonostachys rosea y G. masseei, respectivamente. El extracto de acetato de etilo de G. masseei se fraccionó por un proceso biodirigido y reveló la presencia de ácidos grasos y sus derivados, donde el 9-octadecenoato de metilo fue el más activo, con una CE50 de 16 µg/cm² para M. persicae y 35 µg/cm² para R. padi. Los extractos fúngicos de C. rosea y G. masseei pueden ser una alternativa promisoria en el control de áfidos que son plaga en la agricultura.

Antimycobacterial and antileishmanial effects of microfungi isolated from tropical regions in México.

A total of 82 fungal extracts were selected and screened against Mycobacterium tuberculosis and promastigotes of Leishmania mexicana strains. Results showed inhibitory activity in 29 % of the fungal strains against at least one of the targets tested. The most significant antituberculosis (antiTB) effects were presented by Cylindrocarpon sp. XH9B, Fusarium sp. TA54, Fusarium XH1Ga, Gliocladium penicillioides TH04 and TH21, Gliocladium sp. TH16, Kutilakesa sp. MR46, and Verticillium sp. TH28 strains (minimal inhibition concentration (MIC) = 1.56-25 µg/ml). Mortality of L. mexicana promastigotes was displayed by only four strains, Fusarium sp. TA50, Fusarium sp. TA54, Verticillium sp. TH28, and the unidentified 2TA2 strain (IC(50) = 14.23-100 µg/ml and IC(100) = 50-100 µg/ml). Seven of these most active strains were defatted and their corresponding fractions evaluated again. The results showed the best antiTB activity in Gliocladium sp. TH16 (MIC = 1.56 µg/ml) and the highest leishmanicidal potential in Fusarium sp. TA54 (IC(50) = 6.36 µg/ml). These results show that fungi living in the tropical regions of México have the ability to produce bioactive metabolites that could be used in the near future as natural products to control neglected tropical diseases.

The hyphomycete genus Piricauda, with the description of a new species.

The genus Piricauda comprises eight species characterized by monotretic conidiogenous cells and micronematous arched conidiophores: P. cochinensis, P. cubensis, P. longispora, P. mexicana, P. paraguayensis, P. pseudarthriae, P. taiwanensis, and P. vulcanensis sp. nov. P. caribensis is transferred to Acrodictys. Species usually colonize dead petioles and rachides of palms in tropical and subtropical areas, but can also be found on branches and leaves of different trees. The species are illustrated and briefly described, and a key to them is provided.