Progresses of Propionic Acid Production by Microbial Fermentation
Zhang Huafeng,Kang Hui
Propionic acid and its salts are important feed preservatives. Propio nic acid production by microbial fermentation is one of focuses in modern fermen tation processes. Because propionic acid fermentation is inhibited by its end pr oducts,microbial fermentation is both low productive and expensive,and it is d ifficult to compete with chemical synthesis. Both the propionic acid metabolism mechanism and culture conditions of propionic-acid-producing bacteria are disc ussed. Present situation on the selective breeding of propionic-acid-tolerant mutant strains is introduced. Advances in applications of fed-batch fermentatio n,immobilized cell bioreactor and extractive fermentation to propionic acid fer mentation are summarized emphatically. After problems in propionic acid producti on by microbial fermentation are analyzed,strategies for propionic acid ferment ation are discussed. Both the selective breeding of superior strains and the app lication of extractive fermentation should be attached great importance to. The route of the extractive fermentation for propionic acid using ion-exchange resi n is demonstrated.