In this study, the production of aflatoxin B1 (AFB1) and cyclopiazonic acid (CPA) was investigated in toxigenic and non-toxigenic Aspergillus flavus with respect to expression of aflR, veA and laeA genes that are involved to toxins production. A. flavus strains were cultured in YES broth at 28 °C for 4 days and the presence of (AFB1) and (CPA) was confirmed and measured by TLC and HPLC. The exp...

Transformants of Aspergillus flavus containing the Aequorea victoria gfp gene fused to a viral promoter or the promoter region and 483 bp of the coding region of A. flavus aflR expressed green fluorescence detectable without a microscope or filters. Expression of green fluorescent protein fluorescence was correlated with resistance to aflatoxin accumulation in five corn genotypes inoculated wit...

Aflatoxins (AFs) are carcinogenic secondary metabolites of Aspergillus parasiticus. In previous studies, non-toxigenic A. parasiticus sec- (for secondary metabolism negative) variants were generated through serial transfer of mycelia from their toxigenic sec+ (for secondary metabolism positive) parents for genetic and physiological analysis for understanding regulation of AF biosynthesis. Previ...

BACKGROUND The effect of probiotic bacteria (Lactobacillus acidophilus and L. casei) as safe organisms was examined on fungal growth and aflatoxin gene regulation in Aspergillus parasiticus. METHODS The fungus was cultured in presence of two different concentrations of L. acidophilus and L. casei in MRS broth medium. Mycelia dry weight is indicated as criteria to evaluate fungal growth. Besid...

Production of carcinogenic aflatoxins has been reported from members of Aspergillus section Flavi, Aspergillus section Nidulantes and a newly proposed Aspergillus section Ochraceorosei that consists of Aspergillus ochraceoroseus and A. rambellii. Unlike members of section Flavi, A. ochraceoroseus and A. rambellii have been shown to accumulate both aflatoxin (AF) and the aflatoxin precursor ster...

Background: Aspergillus flavus is the second most important Aspergillus species causing human infections particularly fungal sinusitis. Since little is known about aflatoxin producing ability of clinical isolates, this study was undertaken to detect the aflatoxigenic isolates amongst these isolates. Methods: A total of 23 isolates of A. spp. which were recovered from patients proved to have fun...

BACKGROUND The effect of curcumin as a natural safe compound with different biological activities was examined on fungal growth and aflatoxin production in Aspergillus parasiticus NRRL 2999. METHODS The fungus was cultured in presence of serial two-fold concentrations of curcumin (125-2000 μg/ml) in yeast extract sucrose broth for 3 days at 28°C. Mycelia dry weight was determined as an index ...

Among the enzymatic steps in the aflatoxin biosynthetic pathway, the conversion of O-methylsterigmatocystin to aflatoxin has been proposed to be catalyzed by an oxidoreductase. Transformants of Aspergillus flavus 649WAF2 containing a 3.3-kb genomic DNA fragment and the aflatoxin biosynthesis regulatory gene aflR converted exogenously supplied O-methylsterigmatocystin to aflatoxin B1. A gene, or...

AIMS A relative quantification system (RQ-PCR) was used to monitor the correlations between the activity of the nor-1 (=aflD) gene of Aspergillus flavus using real-time PCR in relation to phenotypic aflatoxin B(1) (AFB(1) ) production and populations of A. flavus in stored peanuts at three water activity levels (a(w) , 0·95, 0·90 and 0·85) for 6 weeks. METHODS AND RESULTS Real-time PCR was us...