discrimination of the main ochratoxin a-producing species in aspergillus section circumdati by specific pcr assays.ochratoxin a (ota) is one of the most important mycotoxins because of its high toxicity to both humans and animals and its occurrence in a number of basic foods and agro-products. some of the main ota-producing species belong to aspergillus section circumdati, whose taxonomy has been lately revised with the description of new species. the high morphological similarity of these species (aspergillus ochraceus, aspergillus steynii and aspergillus westerdijkiae) makes difficult discrimination among ...200919819579
clustered array of ochratoxin a biosynthetic genes in aspergillus steynii and their expression patterns in permissive conditions.aspergillus steynii is probably the most relevant species of section circumdati producing ochratoxin a (ota). this mycotoxin contaminates a wide number of commodities and it is highly toxic for humans and animals. little is known on the biosynthetic genes and their regulation in aspergillus species. in this work, we identified and analysed three contiguous genes in a. steynii using 5'-race and genome walking approaches which predicted a cytochrome p450 monooxygenase (p450ste), a non-ribosomal pe ...201526256718
aspergillus steynii and aspergillus westerdijkiae as potential risk of ota contamination in food products in warm climates.aspergillus steynii and aspergillus westerdijkiae are the main ochratoxin a (ota) producing species of aspergillus section circumdati. due to its recent description, few data are available about the influence of ecophysiological factors on their growth and ota production profiles. in this work, the effect of temperature (20, 24 and 28 °c) and water activity (aw) (0.928, 0.964 and 0.995) on growth, sporulation and ota production by these fungi was examined in cya and media prepared from paprika, ...201525475281
effect of preharvest anti-fungal compounds on aspergillus steynii and a. carbonarius under fluctuating and extreme environmental conditions.ochratoxin a (ota) has been found in pre-harvest and freshly harvested wheat. spanish climatic conditions point to aspergillus species as probably responsible for this ota. in this study the effectiveness of 5 non-specific antifungal chemicals used on wheat fields (25.9% tebuconazole+60.0% n,n-capramide dimethyl; 12.70% tebuconazole+12.7% prothioconazole+59.5% n,n-amide dimethyldecane; 12.5% epoxiconazole; 12.5% tetraconazole; and 70% thiophanate methyl) and an extract from equisetum arvense wer ...201222947301
benzopyrone coumarin leads to an inhibition of ochratoxin biosynthesis in representatives of aspergillus and penicillium spp. via a type of feedback response mechanism.growth and mycotoxin biosynthesis of the ochratoxin-producing fungal strains aspergillus carbonarius, aspergillus steynii, penicillium verrucosum, and penicillium nordium were analyzed on standard laboratory growth medium supplemented with different amounts of coumarin, an organic compound of the benzopyrone class. neither the growth nor the phenotypic morphology of the filamentous fungi analyzed was affected by using coumarin concentrations equivalent to 2.5 to 25 μg/ml of medium. in contrast, ...201424680079
a new in vitro method to detect growth and ochratoxin a-producing ability of multiple fungal species commonly found in food commodities.the aim of the study was to develop a new screening method to detect growth and ochratoxin a (ota) production by multiple fungi growing in a small quantity of culture media, using microtiter plates. eight ochratoxigenic species were included in the study. the strains were inoculated in sterile 96-well flat-bottom microtiter plates containing yeast extract sucrose broth and czapek yeast extract broth and incubated at 25 °c. growth was daily monitored by absorbance measurements for 4 days and exte ...201425084669
efficacy of different caffeine concentrations on growth and ochratoxin a production by aspergillus species.the objective of this study was to evaluate the effect of different caffeine concentrations (0-4%) on (i) lag phase prior to growth, (ii) growth rates and (iii) ochratoxin a (ota) production by strains from the aspergillus section circumdati and aspergillus section nigri groups, isolated from coffee, when grown on a conducive medium at 0·98 water activity and 30°c. the lag phases prior to growth increased with caffeine concentration. a strain of aspergillus niger and aspergillus carbonarius were ...201627203680
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