Primers from the isoepoxydon dehydrogenase gene of the patulin biosynthetic pathway to indicate critical control points for patulin contamination of apples

The mycotoxin patulin is subjected to European Union statutory limits, and has action levels imposed in the United States of America in fruit products. Samples from soil and an orchard were analysed by primers of the isoepoxydon dehydrogenase gene of the patulin biosynthetic pathway as an HACCP procedure in an initial assessment. A non-orchard soil appeared to inhibit the reaction. However, the reaction was positive from orchard soils. Negative results from orchard samples appeared to be because of target DNA being absent. Bramley samples contained the gene frequently. The method may be useful in the determination of critical control points.Fundação para a Ciência e a Tecnologia (FCT); UK Food Standards Agency; CABI Bioscience

Cordyceps : a traditional chinese medicine and another fungal therapeutic biofactory?

Traditional Chinese medicines (TCM) are growing in popularity. However, are they effective? Cordyceps is not studied as systematically for bioactivity as another TCM, Ganoderma. Cordyceps is fascinating per se, especially because of the pathogenic lifestyle on Lepidopteron insects. The combination of the fungus and dead insect has been used as a TCM for centuries. However, the natural fungus has been harvested to the extent that it is an endangered species. The effectiveness has been attributed to the Chinese philosophical concept of Yin and Yang and can this be compatible with scientific philosophy? A vast literature exists, some of which is scientific, although others are popular myth, and even hype. Cordyceps sinensis is the most explored species followed by Cordyceps militaris. However, taxonomic concepts were confused until a recent revision, with undefined material being used that cannot be verified. Holomorphism is relevant and contamination might account for some of the activity. The role of the insect has been ignored. Some of the analytical methodologies are poor. Data on the ‘‘old” compound cordycepin are still being published: ergosterol and related compounds are reported despite being universal to fungi. There is too much work on crude extracts rather than pure compounds with water and methanol solvents being overrepresented in this respect (although methanol is an effective solvent). Excessive speculation exists as to the curative properties. However, there are some excellent pharmacological data and relating to apoptosis. For example, some preparations are active against cancers or diabetes which should be fully investigated. Polysaccharides and secondary metabolites are of particular interest. The use of genuine anamorphic forms in bioreactors is encouraged.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/ 34879/2007

Ganoderma : a therapeutic fungal biofactory

Ganoderma is a basidiomycete white rot fungus which has been used for medicinal purposes for centuries particularly in China, Japan and Korea. A great deal of work has been carried out on Ganoderma lucidum. The common names for preparations include Lingzhi, Munnertake, Sachitake, Reishi and Youngzhi. This review collates the publications detailing activities and compounds by representative species whilst considering the most valid claims of effectiveness. The biological activities reported of preparations from Ganoderma are remarkable and given most emphasis herein as distinct from structure/activity information. The metabolites consist of mainly polysaccharides and terpenoids. Many are activities against the major diseases of our time and so the present review is of great importance. The list of effects is huge ranging from anti-cancer to relieving blockages of the bladder. However, the reports have not all been tested scientifically with the convincing evidence is reserved for assays of pure compounds. It is a prime example of an ancient remedy being of great relevance to the modern era. There does appear to be an assumption that the therapeutic effects attributed to the fungus have been proven. The next step is to produce some effective medicines which may be hampered by problems of mass production.Fundação para a Ciência e a Tecnologia (FCT

Aflatoxins contamination in chilli samples from Pakistan

The aim of this study was to prioritise disease and pest constraints in chilli by highlighting aflatoxin concentrations to assist local farmers in control. All samples contained aflatoxin B1 and high levels were obtained from all ground samples. A direct relationship was observed between aflatoxin B1 and aflatoxin B2 concentrations. There was no relation between aflatoxin and Aspergillus flavus detection. Chilli production in Pakistan may be heavily constrained by aflatoxin contamination. Simply removing A. flavus may be insufficient for control. Aflatoxins from chilli may be a threat to the health of populations and a constraint on development in Pakistan.Fundação para a Ciência e a Tecnologia (FCT)National Resources Institut

Ganoderma disease of oil palm : a white rot perspective necessary for integrated control

White rot fungi such as Ganoderma, are extraordinary organisms capable exclusively of degrading lignin to carbon dioxide and water: celluloses are then available as nutrients for the fungus. Oil palm (OP) is a highly significant crop in many countries and is prone to a rot caused by the fungus. It is necessary to consider this mode of attack as a white rot involving lignin biodegradation, for integrated control. The existing literature does not report this area and appears to be concerned particularly with the mode of spread and molecular biology of Ganoderma. The white rot perception opens up new fields such as (a) especially breeding/selecting for resistant cultivars of OP with high lignin content, (b) ensuring that the conditions for lignin decomposition are reduced, and (c) simply sealing damaged OP specifically to stop decay. It is likely that spread is by spores rather than roots. The knowledge gained can be employed in the rapid degradation of OP waste on the plantation floor by inoculating suitable fungi, and/or treating the waste more appropriately (e.g. chipping and spreading over the floor rather than windrowing). In conclusion, the control of Ganoderma on OP would benefit from further consideration of the process as one of white rot.Fundação para a Ciência e a Tecnologia (FCT

Some fungicides and growth inhibitor/biocontrol-enhancer 2-deoxy-D-glucose increase patulin from penicillium expansum strains in vitro

This study assessed the effect of disease control agents, fungicides and 2-deoxy-D-glucose (DOG), on a mycotoxin, patulin, production by strains of Penicillium expansum. Fungicides and DOG were added individually to agar on which the fungus was then grown. In an initial screen of six fungicides, three indicated that patulin was stimulated. These were tested further at a range of concentrations and colony diameters (cd) and patulin production were measured. Although patulin production appeared similar at each concentration in most cases, cd were reduced by fungicide in two out of three cases. So patulin was stimulated in relation to the diameter of the fungal colonies. This is interesting from an academic standpoint and also has applied relevance to fruit producers. In addition, the growth inhibitor and biocontrol-enhancer DOG appeared to stimulate patulin production although results were not statistically significant. The effect of fungal control agents on mycotoxin production requires consideration.Fundação para a Ciência e a Tecnologia (FCT). Cabi Bioscience, UK

Fungal mutants not solved by internal amplification controls

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The isoepoxydon dehydrogenase gene PCR profile is useful in fungal taxonomy

This study evaluates the specificity of PCR isoepoxydon dehydrogenase (idh) primers on fungi associated with patulin production. The DNAs of 93 strains were extracted and analysed by PCR using primers of the idh gene of patulin biosynthesis. A single band at 620 bp was obtained on 17% of the analysed strains. Different molecular weight amplicons were observed in other strains. These were employed as binary characters for numerical analysis to obtain a dendrogram. Clusters were observed, which corresponded to morphological identifications in some cases. Amplicons at 400 and/or 500 bp were related to patulin non-detection for strains, whereas a 450 bp amplicon was associated with some Aspergillus and both of the Byssochlamys nivea strains tested. Hence, the idh primers are not specific for the gene and provide other amplicon products in other species. These results were useful providing (a) profiles of DNA to identify and classify fungi and (b) insights into patulin production. The DNA profiles in this study may be useful for determining patulin producing fungi. Obtaining multiple bands in culture-independent PCR of environmental samples by using the primers could indicate that more than one species is present.El interés del presente estudio fue investigar la especificidad de los cebadores para la PCR del gen de la isoepoxydon deshidrogenasa en hongos asociados a la producción de patulina. El DNA de 93 cepas fue extraído y analizado mediante PCR utilizando cebadores del gen idh implicado en la biosíntesis de la patulina. Se obtuvo una banda simple de 620 pb en un 17% de las cepas y bandas de peso molecular variable para el resto. Estos datos fueron utilizados como caracteres binarios en un análisis numérico. Se pudo comprobar que los diferentes clusters que aparecían en el correspondiente dendograma a veces se correspondían con determinados caracteres morfológicos de las cepas. Amplificados de de 400 y/o 500 pb se relacionaron con cepas no productoras de patulina y una banda de 450 pb se asoció con algunos Aspergillus y con las dos cepas de Byssochlamys nivea incluidas en el estudio. Ello demostraba que los cebadores no eran específicos para el gen y amplificaban otras regiones en algunas especies. Estos resultados demostraron ser útiles en para la identificación y clasificación de hongos y para un mejor conocimiento de la producción de patulina. Determinados patrones de DNA pueden ser útiles para detectar hongos potenciales productores de patulina. La obtención de múltiples bandas en una PCR de muestras ambientales no cultivadas puede indicar que más de una especie está presente.Fundação para a Ciência e a Tecnologia (FCT)

Self inhibitors and mutagens affect fungal PCR

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