The isoepoxydon dehydrogenase gene PCR profile is useful in fungal taxonomy

El interés del presente estudio fue investigar la especificidad de los cebadorespara la PCR del gen de la isoepoxydon deshidrogenasa en hongos asociadosa la producción de patulina. El DNA de 93 cepas fue extraído y analizadomediante PCR utilizando cebadores del gen idh implicado en la biosíntesis dela patulina. Se obtuvo una banda simple de 620 pb en un 17% de las cepas ybandas de peso molecular variable para el resto. Estos datos fueron utilizadoscomo caracteres binarios en un análisis numérico. Se pudo comprobar quelos diferentes clusters que aparecían en el correspondiente dendograma aveces se correspondían con determinados caracteres morfológicos de lascepas. Amplificados de de 400 y/o 500 pb se relacionaron con cepas noproductoras de patulina y una banda de 450 pb se asoció con algunosAspergillus y con las dos cepas de Byssochlamys nivea incluidas en elestudio. Ello demostraba que los cebadores no eran específicos para el geny amplificaban otras regiones en algunas especies. Estos resultadosdemostraron ser útiles en para la identificación y clasificación de hongos ypara un mejor conocimiento de la producción de patulina. Determinadospatrones de DNA pueden ser útiles para detectar hongos potencialesproductores de patulina. La obtención de múltiples bandas en una PCR demuestras ambientales no cultivadas puede indicar que más de una especieestá presente(AU)

This study evaluates the specificity of PCR isoepoxydon dehydrogenase (idh)primers on fungi associated with patulin production. The DNAs of 93 strainswere extracted and analysed by PCR using primers of the idh gene of patulinbiosynthesis. A single band at 620 bp was obtained on 17% of the analysedstrains. Different molecular weight amplicons were observed in other strains.These were employed as binary characters for numerical analysis to obtain adendrogram. Clusters were observed, which corresponded to morphologicalidentifications in some cases. Amplicons at 400 and/or 500 bp were related topatulin non-detection for strains, whereas a 450 bp amplicon was associatedwith some Aspergillus and both of the Byssochlamys nivea strains tested.Hence, the idh primers are not specific for the gene and provide otheramplicon products in other species. These results were useful providing (a)profiles of DNA to identify and classify fungi and (b) insights into patulinproduction. The DNA profiles in this study may be useful for determiningpatulin producing fungi. Obtaining multiple bands in culture-independent PCRof environmental samples by using the primers could indicate that more thanone species is present(AU)

A practical approach for identifications based on mycotoxin characters of Penicillium

The taxonomy of the penicillia is unstable particularly in the important antibiotic and mycotoxin-producing subgenus Penicillium. There are difficulties relating identifications to mycotoxin production. Also, the validity of dual nomenclature for pleomorphic fungi is under discussion increasingly. Patulin is an important mycotoxin produced by various fungi and has strict limits in the European Union. The mycotoxin and/or the isoepoxydon dehydrogenase (IDH) gene of the metabolic pathway have been assessed in 318 strains predominately of subgenus Penicillium. These data were used to classify the isolates. Subgenus Penicillium contained most of the IDH and patulin positives. The species and varieties in subgenus Penicillium which were associated with patulin detection can be reduced to one name, viz. Penicillium Pen p+ (p = patulin). This has been extended to other mycotoxin producing penicillia to indicate the scope of the scheme. The classification will lead to the number of taxa being reduced, while avoiding species names and hence dual nomenclature. Culture independent analysis of environmental samples is mentioned. The scheme could be used with advantage for other fungi(AU)