Mustard seed–associated endophytes suppress Sclerotinia sclerotiorum causing Sclerotinia rot in mustard crop / Los endófitos asociados a la semilla de mostaza suprimen Sclerotinia sclerotiorum causando la pudrición de Sclerotinia en el cultivo de mostaza

Mustard-rapeseed cultivation is affected by Sclerotinia sclerotiorum resulting in loss of oil yield and degradation of crop quality. This study adopted an environment friendly biocontrol approach of screening mustard endophytes against the pathogen. Two bacterial isolates, Bacillus safensis (TS46 bac4) and Bacillus australimaris (SM2) showed potential biocontrol activity under both in vitro and in vivo conditions. Dual culture assay reported 90% inhibition of fungal growth. The bacterial cell free supernatant of isolate SM2 showed 52.89% inhibition and the other isolate TS46 bac4 showed 57.97% inhibition. The crude (10 mg/ml) and purified (10 mg/ml) metabolite extract of SM2 showed 100% and 97% inhibition respectively. Both crude (10 mg/ml) and purified (7.5 mg/ml) metabolite extract of TS46 bac4 exhibited 99% inhibition of the pathogen. Antifungal lipopeptides: surfactin, iturin and fengycin were identified in bacterial metabolite extract of the isolates. Both strains promoted healthy germination and prevented the formation of any disease symptoms in seedling. The selected Bacillus strains applied by spray method showed better results against fungal infection on mustard leaf and stem. Microscopic studies revealed degradation of fungal mycelial growth by both isolates. These findings support the employment of the bacterial strains as potential biocontrol agents to reduce the effects of S. sclerotiorum in mustard-rapeseed.(AU)

Bat white-nose syndrome: a devastating epizootic in North America / El síndrome de la nariz blanca en murciélagos: una devastadora epizootia en Norteamérica

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Effect of the taxonomic group of fungi and type of substrate on the antioxidant activity of a solid-state fermentation system

The enzymatic and non-enzymatic antioxidant activities of a solid-state fermentation system (SSFS) employing six basidiomycete and four ascomycete fungi on orange peel have been evaluated. Class comparisons revealed highly significant effect of fungal group on the antioxidant activity. Peroxidase activity appeared only in the basidiomycete fungi (particularly Pleurotus columbinus, Ganoderma resinaceum, and Pleurotus floridanus) whereas catalase activity appeared in the two fungal groups in favor of the ascomycetes (particularly Paecilomyces variotii and Aspergillus fumigatus). Maximal peroxidase and minimal catalase activities were found at moderate phenolic content, with extreme phenolic levels leading to low peroxidase activity but high catalase activity. Production of the non-enzymatic antioxidants (phenolics, flavonoids, reducing power, and DPPH scavenging) was in favor of the ascomycetes, which showed great native ability to synthesize flavonoids and also to release flavonoids from orange peel. The basidiomycete fungi, which have limited native ability to produce phenolics, had high ability to consume orange peel phenolics. By contrast, the ascomycete fungi exhibited great native ability for production of phenolics and low ability to consume exogenous phenolics

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Role of the antioxidant defense system during the production of lignocellulolytic enzymes by fungi

Fungi are used for the production of several compounds and the efficiency of biotechnological processes is directly related to the metabolic activity of these microorganisms. The reactions catalyzed by lignocellulolytic enzymes are oxidative and generate reactive oxygen species (ROS). Excess of ROS can cause serious damages to cells, including cell death. Thus, the objective of this work was to evaluate the lignocellulolytic enzymes produced by Pleurotus sajor-caju CCB020, Phanerochaete chrysosporium ATCC 28326, Trichoderma reesei RUT-C30, and Aspergillus niger IZ-9 grown in sugarcane bagasse and two yeast extract (YE) concentrations and characterize the antioxidant defense system of fungal cells by the activities of superoxide dismutase (SOD) and catalase (CAT). Pleurotus sajor-caju exhibited the highest activities of laccase and peroxidase in sugarcane bagasse with 2.6 g of YE and an increased activity of manganese peroxidase in sugarcane bagasse with 1.3 g of YE was observed. However, P. chrysosporium showed the highest activities of exoglucanase and endoglucanase in sugarcane bagasse with 1.3 g of YE. Lipid peroxidation and variations in SOD and CAT activities were observed during the production of lignocellulolytic enzymes and depending on the YE concentrations. The antioxidant defense system was induced in response to the oxidative stress caused by imbalances between the production and the detoxification of ROS

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Gene profiling and expression of major allergen Alt a 1 in Alternaria alternata and related members of the Pleosporaceae family / Perfil de expresión génica del alérgeno Alt a 1 mayoritario en Alternaria alternata y otros taxones próximos de la familia Pleosporaceae

Background: Members of the Pleosporaceae family are known as important sources of airborne allergens which are responsible for asthma and allergic diseases. Aims: The purpose of this study was to investigate the gene profiling and expression pattern of Alt a 1 in Alternaria alternata and other members of the Pleosporaceae family including Stemphylium botryosum, Ulocladium chartarum, Curvularia lunata, Cladosporium cladosporioides, and Epicoccum nigrum. Methods: Alternaria alternata and related genera were cultured on Czapek-Dox broth medium at 25°C for 21 days. The presence of Alt a 1 was assessed in fungal culture filtrates by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and then confirmed by immunoblot analysis. Real-time PCR was carried out for quantitation of the Alt a 1 gene encoding corresponding protein at the transcriptional level using cDNA prepared from fungal RNA. Results: SDS-PAGE showed protein bands ranging from 14 to 100 kDa. A 14kDa band corresponding to Alt a 1 was present in A. alternata, S. botryosum and U. chartarum. The gene expression of Alt a 1 was reported in A. alternata and some other related genera. The Ct mean value recorded for A. alternata strains ranged from 24.70 to 27.84 while it was in the range 23.62-32.09 for other related taxa. No apparent transcription or expression was revealed in C. cladosporioides. Conclusions: The presence and efficient expression of Alt a 1 gene in A. alternata and other related taxa indicate that Alt a 1 protein is a major component of the secretory machinery of Pleosporaceae family members, and it may play a crucial role in its allergenicity

Antecedentes: Los miembros de la familia Pleosporaceae son una fuente importante de alérgenos aéreos causantes de asma y enfermedades alérgicas. Objetivos El objetivo de este trabajo fue estudiar el perfil de expresión génica de la proteína Alt a 1 en Alternaria alternata y otros miembros de la familia Pleosporaceae, entre las cuales pueden citarse Stemphylium botryosum, Ulocladium chartarum, Curvularia lunata, Cladosporium cladosporioides y Epicoccum nigrum. Métodos: Alternaria alternata y otros géneros relacionados se cultivaron en caldo Czapek-Dox a 25°C durante 21 días. La existencia de Alt a 1 en los filtrados de los cultivos se evaluó mediante electroforesis en gel de poliacrilamida con dodecilsulfato sódico (SDS-PAGE) para después confirmarla mediante inmunotransferencia. Se realizó RCP en tiempo real para la cuantificación de la transcripción del gen responsable (Alt a 1) utilizando ADNc a partir del ARN del hongo. Resultados: Mediante SDS-PAGE se visualizaron bandas de proteínas de 14 a 100 kDa. La banda de 14 kDa, correspondiente a Alt a 1, estaba presente en A. alternata, S. botryosum y U. chartarum. Se detectó expresión génica de Alt a 1 en A. alternata y otros géneros relacionados. El valor medio de Ct registrado en los aislamientos de A. alternata varió entre 24,70 y 27,84; en otros taxones cercanos, el intervalo estuvo entre 23,62 y 32,09. No se detectó transcripción o expresión en C. cladosporioides. Conclusiones: La presencia del gen Alt a 1 y su expresión en A. alternata y otros taxones próximos indica que la proteína Alt a 1 es uno de los componentes principales del mecanismo secretorio de los miembros de la familia Pleosporaceae y puede desempeñar un papel fundamental en su capacidad alergénica

Cutaneous infection by Phaeoacremonium parasiticum / Infección cutánea por Phaeoacremonium parasiticum

Background: Phaeoacremonium parasiticum is considered a rare infectious agent that is part of a heterogeneous group of fungi causing phaeohyphomycosis. This organism is capable of producing subcutaneous infections, eumycetomas, osteomyelitis, arthritis, myositis and also disseminated diseases, such as fungemia and endocarditis. Case report: We describe a case of cutaneous infection by P. parasiticum in a kidney transplant patient. The identification of this microorganism was performed by microbiological and histopathological studies and confirmed with the sequence of the gene encoding β-tubulin and a real time panfungal PCR targeting 18S ribosomal RNA gene. The microorganism was correctly identified by phenotypic and molecular methods. The patient was treated with oral antifungal therapy and a debulking surgery and evolved without any complication. Conclusions: The diagnosis of this infection is difficult and usually affects kidney transplant patients, but the reasons of this association are still unknown

Antecedentes: Phaeoacremonium parasiticum es considerado un agente infeccioso poco común que forma parte de un grupo heterogéneo de hongos causantes de feohifomicosis. Este microorganismo es capaz de producir infección cutánea, eumicetoma, osteomielitis, artritis, miositis e incluso enfermedad diseminada como fungemia y endocarditis. Caso clínico: Se describe un caso de infección cutánea por P. parasiticum en un paciente trasplantado renal. Para la identificación del microorganismo se realizaron pruebas microbiológicas e histopatológicas, y se confirmó la identificación con la secuenciación del gen de la β-tubulina y una PCR a tiempo real para la detección del gen 18S rRNA. El microorganismo fue identificado correctamente por métodos fenotípicos y moleculares. El paciente recibió tratamiento con antifúngicos orales y citorreducción quirúrgica, y evolucionó sin ninguna complicación. Conclusiones: El diagnóstico de esta infección es difícil y se presenta habitualmente en pacientes trasplantados renales. Sin embargo, la asociación de esta infección con este tipo de pacientes no ha sido aún explicada

Degradative properties of two newly isolated strains of the ascomycetes Fusarium oxysporum and Lecanicillium aphanocladii

Two ascomycete strains were isolated from creosote-contaminated railway sleeper wood. By using a polyphasic approach combining morpho-physiological observations of colonies with molecular tools, the strains were identified as Fusarium oxysporum Schltdl. (IBPPM 543, MUT 4558; GenBank accession no. MG593980) and Lecanicillium aphanocladii Zare & W. Gams (IBPPM 542, MUT 242; GenBank accession no. MG593981). Both strains degraded hazardous pollutants, including polycyclic aromatic hydrocarbons, anthraquinone-type dyes, and oil. Oil was better degraded by F. oxysporum, but the aromatic compounds were better degraded by L. aphanocladii. With both strains, the degradation products of anthracene, phenanthrene, and fluorene were 9,10-anthraquinone, 9,10-phenanthrenequinone, and 9-fluorenone, respectively. During pollutant degradation, F. oxysporum and L. aphanocladii produced an emulsifying compound(s). Both fungi produced extracellular Mn-peroxidases, enzymes possibly involved in the fungal degradation of the pollutants. This is the first report on the ability of L. aphanocladii to degrade four-ring PAHs, anthraquinone-type dyes, and oil, with the simultaneous production of an extracellular Mn-peroxidase

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Endophytic fungi associated with roots of date palm (Phoenix dactylifera) in coastal dunes / Hongos endófitos asociados con raíces de palmera datilera (Phoenix dactylifera) en dunas costeras

Background. Symbiotic interactions with fungal endophytes are argued to be responsible for the tolerance of plants to some stresses and for their adaptation to natural conditions. Aims. In this study we aimed to examine the endophytic fungal diversity associated with roots of date palms growing in coastal dune systems, and to screen this collection of endophytes for potential use as biocontrol agents, for antagonistic activity and mycoparasitism, and as producers of antifungal compounds with potential efficacy against root diseases of date palm. Methods. Roots of nine individual date palms growing in three coastal locations in the South-East of Spain (Guardamar, El Carabassí, and San Juan) were selected to isolate endophytic fungi. Isolates were identified on the basis of morphological and/or molecular characters. Results. Five hundred and fifty two endophytic fungi were isolated and assigned to thirty morphological taxa or molecular operational taxonomic units. Most isolates belonged to Ascomycota, and the dominant order was Hypocreales. Fusarium and Clonostachys were the most frequently isolated genera and were present at all sampling sites. Comparisons of the endophytic diversity with previous studies, and their importance in the management of the date palm crops are discussed. Conclusions. This is the first study on the diversity of endophytic fungi associated with roots of date palm. The isolates obtained might constitute a source of biological control agents and biofertilizers for use in crops of this plant (AU)

Antecedentes. Se ha propuesto que la simbiosis con hongos endófitos puede ser responsable de la tolerancia de las plantas a algunas situaciones de estrés ambiental y de su adaptación a las condiciones naturales. Objetivos. Este estudio tiene como objetivo analizar la diversidad de hongos endófitos asociados con las raíces de palmeras datileras que crecen en sistemas de dunas costeras. La finalidad es la evaluación de un grupo de cepas fúngicas para su uso como agentes de control biológico por su actividad antagónica o micoparasitaria, o como productores de compuestos antifúngicos con potencial aplicación frente a enfermedades radiculares de la palmera datilera. Métodos. Se muestrearon raíces de 9 palmeras que crecían en 3 localidades costeras en el Sudeste de España (Guardamar, El Carabassí y San Juan), y se aislaron sus hongos endófitos asociados. Las cepas se identificaron mediante el estudio de caracteres morfológicos y/o moleculares. Resultados. Se aislaron 552 hongos endófitos, que se clasificaron en 30 taxones morfológicos o unidades taxonómicas operativas moleculares. La mayoría de las cepas pertenecen a la división Ascomycota; el orden dominante fue Hypocreales. Los géneros aislados con más frecuencia fueron Fusarium y Clonostachys, que estuvieron presentes en todos los sitios de muestreo. Nuestros resultados de diversidad hongos endófitos se comparan con los de otros estudios previos, y se discute su importancia para el tratamiento de cultivos de palmera datilera. Conclusiones. Este es el primer estudio sobre la diversidad fúngica endofíticamente asociada con raíces de palmera datilera. Las cepas obtenidas son una fuente potencial de agentes de control biológico o biofertilizantes para la aplicación en cultivos de esta planta (AU)

Papel de las subunidades alfa de proteínas G en los procesos morfogénicos de hongos filamentosos de la división Ascomycota / Role of G-protein alpha sub-units in the morphogenic processes of filamentous Ascomycota fungi

La división Ascomycota comprende alrededor del 75% de las especies fúngicas descritas e incluye especies de enorme importancia médica, fitosanitaria, agrícola y biotecnológica. La capacidad para propagarse, explorar y colonizar nuevos sustratos es una característica de vital importancia para este grupo de organismos. En ese sentido, procesos como la germinación conidial, la extensión de las hifas y la esporulación constituyen el eje central del desarrollo en la mayoría de los hongos filamentosos. Estos procesos requieren de una maquinaria morfogénica especializada, coordinada y regulada por mecanismos que aún están siendo dilucidados. En los últimos años se ha avanzado sustancialmente en la comprensión del papel que desempeña la ruta de señalización mediada por proteínasG heterotriméricas en los procesos biológicos básicos de diversos hongos filamentosos. Por lo anterior, esta revisión se enfoca en el papel que desempeñan las subunidades alfa de dichas proteínas en los procesos morfogénicos de los hongos filamentosos de la división Ascomycota (AU)

The phylum Ascomycota comprises about 75% of all the fungal species described, and includes species of medical, phytosanitary, agricultural, and biotechnological importance. The ability to spread, explore, and colonise new substrates is a feature of critical importance for this group of organisms. In this regard, basic processes such as conidial germination, the extension of hyphae and sporulation, make up the backbone of development in most filamentous fungi. These processes require specialised morphogenic machinery, coordinated and regulated by mechanisms that are still being elucidated. In recent years, substantial progress has been made in understanding the role of the signalling pathway mediated by heterotrimericG proteins in basic biological processes of many filamentous fungi. This review focuses on the role of the alpha subunits of heterotrimericG proteins in the morphogenic processes of filamentous Ascomycota (AU)

Assessment of compatibility between the nematophagous fungi Arthrobotrys robusta and Duddingtonia flagrans under laboratory conditions / Valoración de la compatibilidad entre los hongos nematófagos Arthrobotrys robusta y Duddingtonia flagrans en condiciones de laboratorio

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Taxonomía y biología de los hongos causantes de infección en humanos / Taxonomy and biology of fungi causing human infection

En los últimos años la taxonomía de los hongos causantes de infecciones en el hombre ha cambiado sustancialmente especialmente debido al rápido desarrollo de las técnicas de secuenciación de ADN que han permitido avanzar en el conocimiento de las relaciones filogenéticas entre estos microorganismos. El número de especies fúngicas potencialmente patógenas ha sufrido un espectacular aumento, siendo muchas de ellas especies crípticas que forman parte de complejos de especies que han sustituido a lo que antes eran consideradas como simples morfoespecies. Ello ha ocurrido en diferentes géneros de mucorales y especialmente de ascomicetes tales como Aspergillus, Fusarium, Sporothrix y Scedosporium, entre otros. Es frecuente que dichas especies difieran en virulencia y en su respuesta a los antifúngicos por lo que su correcta identificación es de especial importancia para el adecuado tratamiento del paciente. En esta revisión se resumen algunos de los cambios más significativos en la taxonomía de los hongos patógenos que se han producido en los últimos años

The advent of molecular techniques, mainly DNA sequencing, has led to important changes in the taxonomy of pathogenic fungi and a better understanding of the phylogenetic relationships among them. The number of fungal species potentially pathogenic for humans has increased dramatically. Most of them are cryptic species belonging to complex species that have replaced traditional single morphospecies. This has occurred in several genera of mucorales and particularly in different ascomycetous genera, such as Aspergillus, Fusarium, Sporothrix and Scedosporium, among others. The correct identification of these species is crucial for a better management of patients, since on many occasions those species show different virulence and different antifungal responses. This review summarises some of the most striking recent taxonomic changes produced in pathogenic fungi (AU)

Aislamiento y evaluación de la actividad enzimática de hongos descomponedores de madera (Quindío, Colombia) / Isolation of wood-decaying fungi and evaluation of their enzymatic activity (Quindío, Colombia)

Se realizó la colecta de hongos (rdas.) en troncos caídos con diferentes estados de descomposición en un bosque subandino (la reserva natural La Montaña del Ocaso) y se evaluó su actividad ligninolítica. Se cultivaron en Agar extracto de malta y se realizaron pruebas semicuantitativas de actividad lacasa utilizando como inductor enzimático el ácido 2,2’azino-bis-[3-etilbenzotiazolin-6-sulfónico] y el 2,6-diclorofenolindofenol para la celobiosa deshidrogenasa (CDH). Se seleccionaron los hongos con mayor actividad enzimática de troncos con diferente grado de descomposición: Cookeina sulcipes (de estado 1), un hongo de la familia Corticiaceae (de estado 2), Xylaria polymorpha (de estado 3) y Earliella sp. (de estado 4). La fermentación se realizó a 28°C durante 11 días, a 150r.p.m., con mediciones diarias para biomasa, glucosa, actividad lacasa, actividad CDH y proteínas. Los hongos de los troncos con estados de descomposición 1 a 3 presentaron mayor actividad lacasa, a medida que aumentaba el estado de descomposición. Hubo un aumento en la actividad CDH a medida que se incrementó el estado de descomposición de los troncos. Hubo una relación positiva entre la producción de las 2 enzimas. Earliella sp. fue el hongo con mayor producción de biomasa (1.140,19g/l), actividad lacasa (157Ul−1) y CDH (43,50Ul−1). Este trabajo es el primer reporte de actividad lacasa y CDH en C. sulcipes y Earliella sp. Además, sienta las bases para la utilización de estos hongos nativos en aplicaciones biotecnológicas y se adentra en el conocimiento de su función dentro del proceso de descomposición de la madera en bosques(AU)

White rotfungi(AscomycotaandBasidiomycota)werecollectedonfallentrunkswithdifferentdecaystages, inasubandeanforest(LaMontan˜a delOcasonaturereserve),anditwasevaluatedtheirligninoliticactivity.Theywereculturedonmaltextractagar.Thenitwasperformedsemiquantitativetestsforlaccaseand cellobiosedehydrogenase(CDH)activityusingABTSandDCPIPasenzymaticinducers.Basedontheresults ofthesetests,thefungiwithhigheractivitiesfromtrunkswithdifferentdecaystageswereselected:Cookeina sulcipes (for stage1),afungusfromthefamilyCorticiaceae(forstage2), Xylariapolymorpha (forstage 3)and Earliella sp. (forstage4).Afermentationwasperformedat28 1C, during11days,inarotatoryshaker at150rpm.Biomass,glucose,proteinsandenzymeactivitiesmeasurementswereperformeddaily.The fungithatwereinthetrunkswithdecaystatesfrom1to3,showedhigherlaccaseactivityasthestateof decayincreased.AhigherDCHactivitywasalsoassociatedwithahigher.Also,therewasapositiverelationship betweenbothenzymes’activities.Erliellawasthefunguswhichpresentedthehighestbiomass production(1140,19g/l),laccaseactivity(157UL 1) andCDHactivity(43,50UL 1). Thisworkisthefirst reportoflaccaseandCDHactivityfor Cookeina sulcipes and Earliella sp. Moreover,itgivesbasisforthe useofthesenativefungiinbiotechnologicalapplicationsandtheacknowledgmentoftheirfunctioninthe wooddecayprocessinnativeforest

Influence of nutrients on enhancing laccase production by Botryosphaeria rhodina MAMB-05

The physiological requirements needed to enhance the production of laccases by the ascomycete Botryosphaeria rhodina MAMB-05 in submerged cultivation were examined under non-induced and induced (veratryl alcohol, VA) conditions. Under non-induced conditions (-VA), the initial pH, C:N ratio, and inorganic N source did not influence laccase production, in contrast to Tween 80, soybean oil, and copper, which significantly increased laccase production, and proline and urea, which suppressed laccase formation. In addition, Tween 60 could serve as the sole carbon source for the production of these enzymes. Under VA-induced conditions of fungal growth, factors such as inoculum type, time-point of addition of inducer, initial pH, C:N ratio, and type of N source, influenced the production of laccases; however, unlike the non-induced conditions, proline and urea did not act as suppressors. Each of these physiological conditions exerted different effects on biomass production. The nutritional conditions examined for B. rhodina MAMB-05 are discussed in relation to their influence on fungal growth and laccase production (AU)

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Pandora's mycological box: molecular sequences vs. morphology in understanding fungal relationships and biodiversity

Fundamental reappraisals of diverse traditional ideas in mycology have become necessary as a result of molecular insights. These different insights are discussed in relation to: the positions of microsporidia, slime moulds and oomycetes; the basal position of lichen fungi in the evolution of ascomycetes forming fruit bodies; remodelling of orders and families; changed generic concepts; the issue of whether permitting a dual nomenclature for the different states of pleomorphic fungi should be continued; and the recognition of additional cryptic species within a "species". The molecular data has necessitated a reassessment of the systematic importance of many types of characters. Also, the techniques open exciting horizons and undreamed of abilities through being able to identify non-sporing fungi in ecological samples and plant material, and revealing unexpected levels of diversity in hitherto little-explored habitats. Major advances in understanding how fungi operate through total genomic approaches can be anticipated as more are completely sequenced. The Pandora's box of molecular surprises is to be seen as one of blessings and not one of miseries and evils(AU)

Marine fungi from Mira river salt marsh in Portugal

The occurrence of fungi in the Mira salt marsh, Portugal was investigated for 12 months. Baits of Spartina maritima stems were exposed to permanent or temporary submersion at the upper and lower limits of the intertidal zone. The baits were observed for fruit bodies and spores directly and after incubation in moist chambers. Twenty six marine species were identified (17 Ascomycota, two Basidiomycota and seven mitosporic fungi). Twenty four are new records for Portugal. Nia globospora Barata and Basílio was published as a new species. Species were characterized with respect to frequency of occurrence, colonization capability and substrate succession. The diversity and similarity indexes of the fungi under different conditions were determined(AU)

Ambrosia fungi in the insect-fungi symbiosis in relation to cork oak decline

Ambrosia fungi live associated with beetles (Scolytidae and Platypodidae) in host trees and act as a food source for the insects. The symbiotic relation is important to the colonizing strategies of host trees by beetles. Ambrosia fungi are dimorphic: they grow as ambrosial form and as mycelium. The fungi are highly specialized, adapted to a specific beetle and to the biotope where they both live. In addition other fungi have been found such as tree pathogenic fungi that may play a role in insects host colonization success. Saprophytic fungi are also present in insects galleries. These may decompose cellulose and/or be antagonistic to other less beneficial fungi. This paper summarizes the importance of ambrosia fungi and the interaction with insects and hosts. The possibility of the transport of pathogenic fungi by Platypus cylindrus to cork oak thus contributing for its decline is discussed(AU)

New and simple plate test for screening relative transfructosylation activity of fungi

Several microorganisms are reported to have transfructosylation activity due to fructosyltransferase and/or fructofuranosidase activities. However, the search for other fungi with higher transfructosylation activity remains a challenge. So, a presumptive and indirect colorimetric plate assay for the evaluation of transfructosylation activity in fungi was developed which involved the simultaneous determination in the same plate of glucose and fructose released from sucrose. The method entailed the (a) glucose oxidase-peroxidase coupled reaction using phenol and 4-aminoantipyrine for determination of glucose; and (b) fructose dehydrogenase oxidation in the presence of a tetrazolium salt for determination of fructose. The presence of enzymes with transfructosylation activity was identified by the formation of pink (presence of glucose) and blue (presence of fructose) halos around the fungal colony. In conclusion, the results showed that the method is suitable for screening a large number of fungi due to its simplicity, reproducibility and rapidity and also gives a relative quantitative idea of the transfructosylation activity of different fungi species(AU)

¿Es activa la amfotericina B frente a hongos dermatófitos y Scopulariopsis brevicaulis? / Is amphotericin B active against dermatophytes and Scopulariopsis brevicaulis?

Se ha evaluado la actividad antifúngica de la amfotericina B, en comparación con la de griseofulvina, ketoconazol, clotrimazol y terbinafina, frente a 193 aislamientos de hongos dermatófitos y Scopulariopsis brevicaulis por medio de un método de difusión en agar (NeoSensitabs®) que permite la categorización de los aislamientos en sensible, intermedios y resistentes a los antifúngicos. Con este método comercializado y siguiendo un protocolo estándar adaptado a las condiciones de crecimiento de los hongos dermatófitos y el moho oportunista S. brevicaulis (tamaño de inóculo, temperatura y tiempo de incubación), se han obtenido tasas de sensibilidad in vitro del 72 por ciento, el 94,3 por ciento, el 81,9 por ciento, el 72 por ciento y el 86 por ciento para amfotericina B, terbinafina, griseofulvina, ketoconazol y clotrimazol, respectivamente. Del mismo modo, las tasas de resistencia obtenidas han sido del 12,4 por ciento, el 3,6 por ciento, el 18,1 por ciento, el 10,4 por ciento y el 4,1 por ciento para los mismos antifúngicos. La amfotericina B no mostró actividad frente a S. brevicaulis, y frente a hongos dermatófitos la actividad se sitúa en un rango comparable al obtenido con ketoconazol, siendo ambas inferiores a las de clotrimazol y terbinafina. (AU)

Fungus propagules in plastids: the mycosome hypothesis / Propágulos fúngicos en plástidos: la hipótesis micosómica

A stress-induced «mycosome» phase of Aureobasidium pullulans consisting of minute reproductive propagules that may revert directly to walled yeast cells is described. Mycosomes detected by light- and electron-microscopy reproduce within senescent plant plastids, and display three developmental pathways: wall-less cells (protoplasts), yeast cells, or membrane-bounded spherules that harbor plastids. Widespread in plant and algal cells, mycosomes are produced by both ascomycete and basidiomycete fungi (AU)

En este artículo se describe una fase «micosómica» inducida por estrés en Aureobasidium pullulans, consistente en minúsculos propágulos reproductivos que pueden revertir directamente a células de levadura con pared. Los micosomas, detectados por microscopía óptica y electrónica, se reproducen en el interior de plástidos senescentes en plantas, y muestran tres tipos de desarrollo diferentes: células sin pared (protoplastos), células de levadura, y esférulas rodeadas por membrana que contienen plástidos. Muy extendidos en células de plantas o algas, los micosomas son producidos por hongos ascomicetes o basidiomicetes (AU)