Functional Analysis of the Cyclopiazonic Acid Biosynthesis Gene Cluster in Aspergillus oryzae RIB 40

Abstract

The cyclopiazonic acid (CPA) nonproducing strain, Aspergillus oryzae RIB 40, does not biosynthesize cyclo-acetoacetyl-L-tryptophan (cAATrp) due to a truncation in the responsible PKS-NRPS gene. We found that RIB 40 converted cAATrp to 2-oxocyclopiazonic acid, the final product of CPA biosynthesis in A. oryzae. This indicates that the CPA biosynthesis gene cluster, except for the PKS-NRPS gene, is functional in RIB 40.