posted on 2024-03-05, 16:38authored byYunhee Hwang, Hyun Gyu Hwang, Ji Yeon Lee, Gyoo Yeol Jung
Microbial
production of genistein, an isoflavonoid primarily found
in soybeans, is gaining prominence in the food industry due to its
significant nutritional and health benefits. However, challenges arise
in redesigning strains due to intricate regulatory nodes between cell
growth and genistein production and in systematically exploring core
enzymes involving genistein biosynthesis. To address this, this study
devised a strategy that simultaneously and precisely rewires flux
at both acetyl-CoA and malonyl-CoA nodes toward genistein synthesis.
In particular, naringenin, the primary precursor of genistein, was
accumulated 2.6 times more than the unoptimized strain through transcriptional
repressor-based genetic regulators. Building upon this, a combination
of isoflavone synthase and cytochrome P450 reductase with the remarkable
conversion of naringenin to genistein was screened from enzyme homologue
libraries. The integrated metabolic engineering strategy yields the
highest reported production (98 mg/L of genistein) to date, providing
a framework for the biosynthesis of diverse flavonoids, including
genistein.