Development of a landing pad system for Aspergillus niger and its application in the overproduction of monacolin J.

Aspergillus niger is a powerful and efficient cell factory, with the potential to synthesize valuable products as chassis cells. The use of microbial cell factories to produce monacolin J, a precursor for statin synthesis, as an alternative to chemical synthesis could meet increasing market demand. However, the need for precise large fragment gene editing and the availability of suitable integration loci hinders the application of this strain. Herein, we identified neutral integration sites of A. niger based on the combination of ATAC-seq, H3K4me3 epigenetic datasets. Next, a landing pad system was developed for the one-step integration of the MJ biosynthesis gene cluster (BGC) in A. niger. Furthermore, we optimized the precursor module supply, the auxiliary factor supply module of NADPH, the module for eliminating oxidative stress pressure, and the transporter module to improve the production of MJ. Finally, a multi-copy integration strategy was applied to the rapid integration of MJ BGC, achieving MJ titer up to 1851.52 mg/L at the 500 mL shaker level.