The insight they had was to link part of the desired biosynthetic pathway to the cells pathway (but they don't explicitly show that this had been necessary EDIT - Fig 3f shows a 45X increase with their strategy over a similar strategy; however, it's not clear that their 'control' was the optimal strategy).
This is a standard approach in molecular biology. Here is the paper:
https://www.nature.com/articles/s41587-025-02867-7
Here is an explainer of this very typical technique: https://www.khanacademy.org/science/biology/biotech-dna-tech... and something more detailed: https://www.neb.com/en-us/tools-and-resources/feature-articl...
The insight they had was to link part of the desired biosynthetic pathway to the cells pathway (but they don't explicitly show that this had been necessary EDIT - Fig 3f shows a 45X increase with their strategy over a similar strategy; however, it's not clear that their 'control' was the optimal strategy).
relevant figure: https://www.nature.com/articles/s41587-025-02867-7/figures/1