GS Caltex corporation
Title: Fermentative production of 2,3-butanediol and its recovery by electrodialysis-ion exchange and alcohol precipitation
Sangjun Jeon has completed his Ph.D study regarding mass transfer behavior in extraction process from Korea Advanced Institute of Science and Technology in South Korea. He has started his working career at GS Caltex corporation, one of the biggest petroleum company in South Korea, since 2009 and his research interest has been on the downstream process development for biochemical production. For now, he’s working on the purification of 2,3-butanediol produced by fermentation.
This study presents an integrated fermentation and downstream process for 2,3-butanediol (2,3-BD) production. Klebsiella oxytoca producing a large amount of 2,3-BD was isolated, and its ΔldhA ΔpflB mutant was constructed by metabolic engineering. A two-stage fed-batch fermentation allowed to produce more than 120 g/L of 2,3-BD with a yield of 0.45 g/g in 50 h. Two 2,3-BD recovery processes, electrodialysis-ion exchange and alcohol precipitation, were developed and their performance was evaluated. The impurities in the cell-free fermentation broth, including organic acids and inorganic salts, were removed by electrodialys-ion exchange. Then two sequential vacuum distillation was performed to remove water and recover 2,3-BD, respectively. For alcohol precipitation, the cell-free fermentation broth was firstly concentrated until 2,3-BD reached around 500 g/L by vacuum evaporation. The concentrated solution was further treated using isopropanol for the precipitation of the impurities followed by a vacuum distillation. We could obtain 2,3-BD with more than 98% purity by the above two recovery processes. Although the alcohol precipitation based process is more cost effective, electrodialysis-ion exchange based process is preferred for the use of 2,3-BD in eco-friendly industries such as cosmetics and personal cares.