Search

Antarctica is a continent that presents extreme conditions for life. Numerous buildings that served as housing for expeditioners and scientists are considered historical heritage, including Casa Moneta Museum, located at the Orcadas Base on Laurie Island, South Orkney Islands (Antarctic Peninsula). It is built entirely of wood, and currently shows visible signs of deterioration. In this work, we studied the mycobiota present in the deteriorated wood of the museum to characterize the fungal diversity present. Macro-, micro-morphological and phylogenetic studies were carried out to identify the fungi isolated. Temperature tests were also performed to study the growth of different strains. Almost 20% of the fungi isolated belonged to Cadophora. Other frequently obtained genera were Tulasnella (16%), Cerinosterus (12%), Coniochaeta (7%), Geomyces (7%), Acremonium (7%) and Penicillium (7%). Temperature tests indicated all strains isolated are psychrotolerant. Five species have been reported for the first time for Antarctica. Deterioration of historic wooden structures and artifacts in extreme environments is currently causing great concern, and in this study the identification of the fungi present in Casa Moneta’s wood and the characterization of their metabolism could be a guide to the development of preservation strategies for this historical building.

The mycelia of wood-decay fungi can persist at a latent endophytic phase in living plant tissues and switch their trophic state under certain environmental conditions. Wood-decay models that take into account these organisms would improve predictability importance in urban environments. In this study, we evaluated the relationship between endophytic and pathogenic strains of Inonotus and Daldinia from urban London plane trees. In vitro wood-decay tests, oxidase reactions and phylogenetic analyses (ITS region, beta-tubulin and nLSU genes) were used to differentiate endophytic and wood-decay strains. All strains significantly reduced the weight of London Plane wood in vitro and had positive oxidase reactions. Endophytic and pathogenic strains of both genera were phylogenetically indistinguishable as evidenced by high sequence similarities, suggesting that endophytic strains can switch their trophic state and can cause wood decay. The capacity of endophytic fungi to switch from a quiescent to a degradative trophic state should be incorporated into predictive models of tree longevity. These revised models could help to predict the impact of wood decay in urban landscapes.

Nanoparticles are widely studied due to their possible uses in biological and technological systems. Four psychrotolerant strains of Tulasnella albida isolated from Antarctica were tested and compared in their ability to synthesize silver nanoparticles. The four strains were capable of synthesizing silver nanoparticles with the addition of AgNO3 (final concentration of 0.5 mM), showing similar results under the same conditions: 28°C, 200 rpm, pH 9. Additionally, we registered the synthesis of nanoparticles at 6°C using biomass generated at the same temperature. For the characterization of synthesized nanoparticles, TEM and SEM microscopy analyses were performed. The images obtained showed the existence of spherically shaped silver nanoparticles with a log-normal size distribution centered at 2 nm diameter for 28°C. The largest ones showed a capping shell around them, appearing associated with the formation of small silver nanoparticles. Theoretical calculations of optical absorption based on core-shell Ag-Ag2O nanoparticles were used to characterize the experimental absorption spectra of silver nanoparticles colloids. This work contributes to expanding the studies and possible technological applications of psychrotolerant organisms in the industry, particularly in the green synthesis of nanoparticles at suboptimal conditions.

Studies involving biological control of wood decay fungi and pests in forest areas are scarce. The basidiomycete Granulobasidium vellereum (Ellis & Cragin) Jülich has been isolated as wood endophyte from London Plane trees (Platanus acerifolia (Ait.) Willd). This basidiomycete produces a variety of sesquiterpenes with antifungal activity. In this study we evaluated the potential activity of G. vellereum against wood decay fungi and fungi associated with the ambrosia beetle Megaplatypus mutatus Chapuis, an important forest pest in Populus sp. A combination of in vitro assays was made, in cultures and on wood blocks. Granulobasidium vellereum’s Volatile Organic Compounds (FVOCs) were characterized and their potential role in biocontrol was assessed. Granulobasidium vellereum did not cause a significant loss of weight on P. acerifolia and Populus wood and inhibited the growth of the target fungi, mainly when inoculated first. Up to nineteen volatile compounds were determined in G. vellereum strains. The growth of all target fungi was inhibited by FVOCs and in some cases the morphology of the fungi was altered. These results indicate that G. vellereum can be used as a Biological Control Agent (BCA) of xylophagous fungi and fungi related to forest pests. Further investigations should focus on developing application strategies for M. mutatus management. Fil: Robles, Carolina Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Ceriani Nakamurakare, Esteban Daniel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Micología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Slodowicz, Mariel Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación de Plagas e Insecticidas; Argentina Fil: Gonzalez Audino, Paola Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación de Plagas e Insecticidas; Argentina Fil: Carmaran, Cecilia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina

Considering that rhizospheric microorganisms play a critical role in providing the plant nutrients for growth and in the adaptation of plants to ecosystems, the aim of the present study was to evaluate the association between foliar endophytes and their effect on soil and rhizospheric fungi using Jatropha curcas, a promising crop for high-quality biofuel, as a model plant. We conducted a factorial experiment. Endophytes and selected rhizospheric fungi were isolated and identified, and the colonization of mycorrhizal fungi was recorded. While the most interesting result was the significant increase in mycorrhizal colonization when J. curcas was associated with endophytes, it was also evident that this association is able to modulate some soil chemical parameters. This study suggests that the association between J. curcas and endophytes has an impact on specific root symbiotic fungi that usually plays relevant roles in nutrient availability for plants, and it would provide tools to enhance plant growth and oil yields. Fil: D'jonsiles, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Carmaran, Cecilia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Robles, Carolina Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Ceriani Nakamurakare, Esteban Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina

New records of Xylariales (Ascomycota) in Argentina. Camillea scriblita, and Nemania immersidiscus are reported for the first time for Argentinean mycobiota. Descriptions and photographs of both species, and of the recently reported Phylacia turbinata are included. In addition, a map showing the distribution based on their records in the Neotropics is presented.

Conocer las características de cepas fúngicas locales aumenta nuestra capacidad de poder hacer uso de sus propiedades e implementar, en consecuencia, nuevas y mejores formas de aprovechamiento de los recursos biológicos nativos. Con el fin de contribuir al conocimiento de estos organismos, en este trabajo se presentan descripciones detalladas y estudios de cultivo de 5 especies previamente reportadas como basidiomicetes endofíticos: Coprinopsis cinerea, Granulobasidium vellereum, Inonotus rickii, Phanerochaete chrysosporium y Trichosporon sporotrichoides, aisladas como endofitos de madera de plátanos de sombra (Platanus acerifolia) en la Ciudad de Buenos Aires, Argentina. Coprinopsis cinerea es descripta por primera vez en cultivo y se señalan las diferencias que presentan los cultivos de G. vellereum e I. rickii con reportes previos. Los caracteres de cultivo de P. chrysosporium y T. sporotrichoides no presentaron diferencias apreciables con descripciones previas. The knowledge of local fungal strains' features increases our ability to make use of their properties and to implement, in consequence, new and better ways of using the native biological resources. To contribute to the knowledge of these organisms, in this work we present descriptions and cultural studies of 5 species previously reported as endophytic basidiomycetes: Coprinopsis cinerea, Granulobasidium vellereum, Inonotus rickii, Phanerochaete chrysosporium and Trichosporon sporotrichoides, isolated from wood of London plane trees (Platanus acerifolia) in Buenos Aires City, Argentina. Coprinopsis cinerea is described in culture for the first time and differences in cultures of G. vellereum and I. rickii with previous reports are listed. Culture characters of P. chrysosporium and T. sporotrichoides did not show appreciable differences with previous descriptions. Fil: Robles, Carolina Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Lopez, Silvia Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina Fil: Carmaran, Cecilia Cristina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina