Biosynthetic pathways for 3-hydroxypropionic acid production

Biobased platform chemicals have attracted growing interest recently. Among them, 3-hydroxypropionic acid receives significant attention due to its applications in the synthesis of novel polymer materials and other derivatives. To establish a biotechnology route instead of the problematic chemical synthesis of 3-hydroxypropionic acid, biosynthetic pathway is required, and the strategies of how to engineer a microbe to produce this product should be considered. In the present review, we summarize and review all known pathways, which could be potentially constructed for 3-hydroxypropionic acid production. Mass and redox balances are discussed in detail. Thermodynamic favorability is evaluated by standard Gibbs free energy. The assembly of pathways and possible solutions are proposed. Several new techniques and future research needs are also covered.