PROPIONIC-ACID PRODUCTION BY EXTRACTIVE FERMENTATION - I - SOLVENT CONSIDERATIONS

Solvent selection for extractive fermentation for propionic acid was c onducted with three systems: Alamine(R) 304-1 (trilaurylamine) in 2-oc tanol, 1-dodecanol, and Witcohol(R) 85 NF (oleyl alcohol). Among them, the solvent containing 2-octanol exhibited the highest partition coef ficient in acid extraction, but it was also toxic to propionibacteria. The most solvent-resistant strain among five strains of the microorga nism was selected. Solvent toxicity was eliminated via two strategies: entrapment of dissolved toxic solvent in the culture growth medium wi th vegetable oils such as corn, olive, or soybean oils; or replacement of the toxic 2-octanol with nontoxic Witcohol 85 NF. The complete rec overy of acids from the Alamine 304-1/Witcohol 85 NF was also realized with vacuum distillation. (C) 1998 John Wiley & Sons, Inc.