Reconstitution of the Early Stage of Chetomin Biosynthesis in Aspergillus fumigatus Leads to the Production of Epipolythiodioxopiperazines.

Using CRISPR-Cas9 technology and a microhomology-mediated end-joining repair system, we substituted genes of the gliotoxin pathway in Aspergillus fumigatus with genes responsible for chetomin biosynthesis from Chaetomium cochliodes , leading to the production of three new epipolythiodioxopiperazines (ETPs). This work represents the first successful endeavor to produce ETPs in a non-native host. Additionally, the simultaneous disruption of five genes in a single transformation marks the most extensive gene knockout event in filamentous fungi to date.