Genetic background of ochratoxin A production in Penicillium.

A part of the gene cluster responsible for the production of ochratoxin A in P. nordicum has been characterised recently. The analysed DNA region contains three putative genes: an alcaline proteinase ( aspPN), a non-ribosomal peptide synthetase ( npsPN) and an polyketide synthase ( otapksPN). The last two genes are putative genes of the ochratoxin A biosynthetic pathway. Interestingly the otapksPN gene is present in this form only in P. nordicum but not in P. verrucosum indicating genetic differences between both ochratoxin A producing Penicillium species. The genes in ochratoxin A producing Aspergillus species seems to be completely different. It has been demonstrated that the npsPN gene is actively transcribed in P. nordicum under ochratoxin A producing conditions, indicating that this gene is involved in ochratoxin A biosynthesis. [ABSTRACT FROM AUTHOR]