Abstract:Pyrroloquinoline quinone (PQQ), the third oxidoreductase coenzyme discovered in the nature after nicotinamide and riboflavin, is ubiquitous in bacteria, fungi, plants, and animals. PQQ participates in a variety of life activities and has anti-inflammation, anti-oxidation, cell metabolism-enhancing, and cardioprotective activities, demonstrating broad application prospects in pharmaceuticals, agriculture, food and other fields. Therefore, the large-scale production of PQQ is the primary problem that needs to be solved at present. Microbial fermentation is a primary production method of PQQ. Deciphering the biosynthesis pathway and regulatory mechanism of PQQ is essential for the screening and breeding of strains with short production periods and high yields by metabolic engineering, which has been a hot topic in this field. This paper summarizes the synthesis pathways, strain screening and breeding, microbial production, and purification processes of PQQ, aiming to provide a reference for further research and application of PQQ.