# Reconstruction of a Genome-Scale Metabolic Model for Aspergillus oryzae Engineered Strain: A Potent Computational Tool for Enhancing Cordycepin Production

## TL;DR

A new computational model for a modified Aspergillus oryzae strain helps boost cordycepin production, a valuable compound for pharmaceuticals.

## Contribution

The first genome-scale metabolic model for a cordycepin-producing Aspergillus oryzae strain is reconstructed and validated.

## Key findings

- The GSMM iNR1684 includes 1684 genes and 1947 reactions with high coverage and was validated experimentally.
- In silico analysis identified key gene targets in pentose phosphate and one-carbon metabolism pathways for enhancing cordycepin production.
- Optimal carbon-to-nitrogen ratio of 11.6:1 was found to maximize cordycepin production in A. oryzae.

## Abstract

Cordycepin, a bioactive adenosine analog, holds promise in pharmaceutical and health product development. However, large-scale production remains constrained by the limitations of natural producers, Cordyceps spp. Herein, we report the reconstruction of the first genome-scale metabolic model (GSMM) for a cordycepin-producing strain of recombinant Aspergillus oryzae. The model, iNR1684, incorporated 1684 genes and 1947 reactions with 93% gene-protein-reaction coverage, which was validated by the experimental biomass composition and growth rate. In silico analyses identified key gene amplification targets in the pentose phosphate and one-carbon metabolism pathways, indicating that folate metabolism is crucial for enhancing cordycepin production. Nutrient optimization simulations revealed that chitosan, D-glucosamine, and L-aspartate preferentially supported cordycepin biosynthesis. Additionally, a carbon-to-nitrogen ratio of 11.6:1 was identified and experimentally validated to maximize production, higher than that reported for Cordyceps militaris. These findings correspond to a faster growth rate, enhanced carbon assimilation, and broader substrate utilization by A. oryzae. This study demonstrates the significant role of GSMM in uncovering rational engineering strategies and provides a quantitative framework for precision fermentation, offering scalable and sustainable solutions for industrial cordycepin production.