P-050. Detection of Additional Genes of the Patulin Biosynthetic Pathway in Penicillium griseofulvum

M. Dombrink-Kurtzman;
USDA/ARS/NCAUR, Peoria, IL.

Genes in the patulin biosynthetic pathway are likely to be arranged in a cluster as has been found for biosynthetic pathways of other mycotoxins. The mycotoxin patulin, common in apples and apple juice, is most often associated with Penicillium expansum. However, of 15 fungal species capable of synthesizing patulin, the biochemistry and molecular biology of patulin production has been most extensively studied in Penicillium griseofulvum, revealing the isoepoxydon dehydrogenase (idh) gene to be part of the patulin biosynthetic pathway. For determination of the genes contiguous with the idh gene of P. griseofulvum, GenomeWalker libraries were constructed for sequencing in both the 5’ and 3’ directions. When compared to the recently published genome of Aspergillus clavatus, an ABC transporter (Pea B1) gene was detected upstream of the idh gene and a putative isoamyl alcohol oxidase gene (iao) was located downstream of the idh gene, as expected. A putative C6 transcription factor gene was detected downstream of the iao gene, rather than upstream of the ABC transporter (Pea B1) gene, as in A. clavatus. Upstream of the ABC transporter (Pea B1) gene were located two genes, a putative acetate transporter gene and a carboxyl esterase family gene, which in the A. clavatus sequence are present eleven and twelve genes upstream of the ABC transporter gene. Interestingly, these two genes in P. griseofulvum had undergone inversion and are now in the opposite orientation. The genetic information determined in this study provides additional understanding of the patulin biosynthetic pathway and may enable development of methods for inhibition of patulin biosynthesis in fruit and fruit products.

180/P. Foodborne Pathogens - III

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