posted on 2021-02-24, 16:06authored byZihua Li, Ziyi Wu, Xuecong Cen, Yu Liu, Ye Zhang, Dehua Liu, Zhen Chen
1,3-Propanediol (1,3-PDO) is a promising
platform chemical used
to manufacture various polyesters, polyethers, and polyurethanes.
Microbial production of 1,3-PDO using non-natural producers often
requires adding expensive cofactors such as vitamin B12, which increases the whole production cost. In this study, we proposed
and engineered a non-natural 1,3-PDO synthetic pathway derived from
acetyl-CoA, enabling efficient accumulation of 1,3-PDO in Escherichia coli without adding expensive cofactors. This
functional pathway was established by introducing the malonyl-CoA-dependent
3-hydroxypropionic acid (3-HP) module and screening the key enzymes
to convert 3-HP to 1,3-PDO. The best engineered strain can produce
2.93 g/L 1,3-PDO with a yield of 0.35 mol/mol glucose in shake flask
cultivation (and 7.98 g/L in fed-batch fermentation), which is significantly
higher than previous reports based on homoserine- or malate-derived
non-natural pathways. We also demonstrated for the first time the
feasibility of producing 1,3-PDO from diverse carbohydrates including
xylose, glycerol, and acetate based on the same pathway. Thus, this
study provides an alternative route for 1,3-PDO production.