Evaluation of Extractants for Bio-butanol Extraction Fermentation Using Organic Solvents and Ionic Liquids

• Published in: Korean Society for Biotechnology and Bioengineering Journal Vol. 24; no. 5
• Main Authors: Cho, M.O., Korea Institute of Science and Technology, Seoul, Republic of Korea, Lee, S.M., Korea Institute of Science and Technology, Seoul, Republic of Korea, Sang, B.I., Korea Institute of Science and Technology, Seoul, Republic of Korea, Um, Y.S., Korea Institute of Science and Technology, Seoul, Republic of Korea
• Format: Journal Article
• Language: Korean
• Published: 01.10.2009
• Subjects: BUTANOL; extractive fermentation; in-situ removal; ionic liquid; oleyl alcohol
• ISSN: 1225-7117

Oleyl alcohol, butyl butyrate, and two different ionic liquids were evaluated for the extraction of butanol from culture broth without toxic effect to cells. The tested solvents showed more than 50% extraction efficiency, and oleyl alcohol was chosen as the best extractant for butanol among the used extractants with a partition coefficient of 2.89. When oleyl alcohol was used as an extractant, more than 80% of butanol was extracted in the wide range of butanol concentrations (1-20 g/L) and pH values (pH 4-5.5). In extractive fermentation using oleyl alcohol only, there was 11% more butanol production and glucose consumption when compared to that without extractive fermentation, implicating a reduced inhibitory effect of butanol due to butanol removal to the oleyl alcohol phase. In addition, oleyl alcohol did not inhibit cell growth, while a mixture of oleyl alcohol and butyl butyrate with the volume ratio of 9：1~7：3 inhibited either butanol production or cell growth significantly due to the toxicity of butyl butyrate to cells. In conclusion, oleyl alcohol can be used as an efficient and non-toxic solvent for extractive fermentation for butanol production.