Research Progress on Caproic Acid-producing Bacteria in Chinese Strong-flavor Baijiu Fermentation Ecosystem

In the Chinese strong-flavor baijiu (CSFB) fermentation ecosystem, the caproic acid-anabolism of caproic acid-producing bacteria (CPBs) is very important for improving the fermentation quality of CSFB. Therefore, it is necessary to thoroughly understand the types of CPBs and their caproic acid-anabolism characteristics. This minireview introduces readers to the diversity, phylogenetic relationship, physiological and metabolic characteristics, and caproic acid synthesis mechanism of CPBs isolated from the CSFB fermentation ecosystem as well as their synergistic metabolic relationships with other CPBs or non-CPBs. This paper provides a reference for understanding the in-situ caproic acid-anabolism pattern of CPBs from the CSFB fermentation ecosystem, and further provides a theoretical basis for the future targeted application of CPBs in CSFB fermentation and for CPBs culture engineering for the synthesis of high value-added caproic acid.