Acyl Transferase Domains of Putative Polyketide Synthase (PKS) Genes in Aspergillus and Penicillium Producers of Ochratoxin A and the Evaluation of PCR Primers to Amplify PKS Sequences in Black Aspergillus Species

Fungal polyketide synthases (PKS) are responsible for the biosynthesis of several mycotoxins and other secondary metabolites. PKS genes in ochratoxin producing species from Aspergillus and Penicillum genera have been identified using a degenerate primer pair developed for the acyl transferase (AT) domain of fungal PKSs. Sequences of AT domains were aligned and analyzed using phylogenetic methods. The AT domain sequences appeared to be specific for a particular type of fungal PKSs and were related to PKSs involved in different mycotoxin biosynthesis pathways, including ochratoxin A. We have also developed primers suitable for amplifying AT domain sequences in strains belonging to the A. nig…