ABSTRACT
Propionic acid as an important C3 platform chemical has been widely used in food, pharmaceutical, and chemical fields. The chemical synthesis of propionic acid from petroleum and other chemical products has serious environmental pollution and is not sustainable. In recent years, the production of propionic acid by microbial transformation of renewable resources has received extensive attention. Focusing on the biomanufacturing of propionic acid, this paper firstly reviews the studies about the metabolic engineering of Propionibacterium and the pathway reconstruction in heterogeneous hosts such as Escherichia coli and Saccharomyces cerevisiae. Secondly, this paper reviews the recent progress in the synthesis of high-purity propionic acid from L-threonine or bio-based 1, 2-propanediol by the design and modification of the pathway of Pseudomonas putida KT2440 based on synthetic biology.