|Dombrink kurtzman, Mary ann|
Submitted to: Mycological Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/19/2006
Publication Date: 9/21/2006
Citation: Dombrink Kurtzman, M., Engberg, A.E. 2006. Byssochlamys nivea with patulin producing capability has an isoepoxydon dehydrogenase gene (idh) with sequence homology to Penicillium expansum and Penicillium griseofulvum. Mycological Research. 110:1111-1118. Interpretive Summary: Total genomic DNA of the mold Byssochlamys nivea was analyzed to determine the presence of a certain gene that is part of the pathway for producing the mycotoxin patulin. The research was undertaken to identify a part of the gene of interest that would be present in all molds making patulin and but not present in other molds. This would make it possible to make a probe to test for the presence of these molds in fruit products, specifically apple juice and apple products. All of the strains tested contained the idh gene and it was similar to that in strains of Penicillium expansum and Penicillium griseofulvum that also make patulin. Patulin is one of two mycotoxins that are regulated by the US Food and Drug Administration.
Technical Abstract: Nucleotide sequences of the isoepoxydon dehydrogenase gene (idh) for eight strains of Byssochlamys nivea were determined by constructing GenomeWalker libraries. A striking finding was that all eight strains of B. nivea examined had identical nucleotide sequences, including those of the two introns present. The length of intron 2 was nearly three times the size of introns in strains of Penicillium expansum and P. griseofulvum, but intron 1 was comparable in size to the number of nucleotides present in introns 1 and 2 of P. expansum and P. griseofulvum. A high degree of amino acid homology (88 %) existed for the idh genes of the strains of B. nivea when compared to sequences of P. expansum and P.griseofulvum. There were many nucleotide differences present, but they did not affect the amino acid sequence because they were present in the third position. The identity of the B. nivea isolates was confirmed by sequencing the ITS/partial large subunit (28S) rDNA genes. Four B. nivea strains were analyzed for production of patulin, a mycotoxin found primarily in apple juice and other fruit products. The B. nivea strains produced patulin in amounts comparable to P. expansum strains. Interest in the genus Byssochlamys is related to the ability of its ascospores to survive pasteurization and cause spoilage of heat-processed fruit products worldwide.