With the high tolerance for acetic acid and abundant multifunctional enzymes, acetic acid bacteria (AAB), as valuable biocatalysts, exhibit great advantages during industrial acetic acid production and value-added chemical fermentation. However, low biomass and a low production rates arising from acid stress remains major hurdles in industrial processes. Engineering AAB with excellent properties is expected to obtain economically viable production and facilitates their biotechnological applications. Here, the investigation of acetic acid-tolerance mechanisms and metabolic features is discussed, and effective targets are provided for the metabolic engineering of AAB. Next, we review the advances in improving AAB and compare these advances with improvement to other model acid-tolerant microorganisms. Furthermore, future directions involving the combination of systems biology and synthetic biology to achieve efficient biomanufacturing in AAB are highlighted.
Keywords: Acetic acid bacteria; acetic acid-tolerance mechanism; biocatalyst; enzymes; fine chemicals; metabolic engineering; production.