Recent advances in the metabolic engineering of microorganisms for the production of 3-hydroxypropionic acid as C3 platform chemical.

Development of sustainable technologies for the production of 3-hydroxypropionic acid (3HP) as a platform chemical has recently been gaining much attention owing to its versatility in applications for the synthesis of other specialty chemicals. Several proposed biological synthesis routes and strategies for producing 3HP from glucose and glycerol are reviewed presently. Ten proposed routes for 3HP production from glucose are described and one of which was recently constructed successfully in Escherichia coli with malonyl-Coenzyme A as a precursor. This resulted in a yield still far from the required level for industrial application. On the other hand, strategies employing engineered E. coli and Klebsiella pneumoniae capable of producing 3HP from glycerol are also evaluated. The titers produced by these recombinant strains reached around 3 %. At its current state, it is evident that a bulk of engineering works is yet to be done to acquire a biosynthesis route for 3HP that is acceptable for industrial-scale production.