Global crude oil price have risen dramatically over the past decades, which opens new opportunities as well as challenges for the biofuel industry. As a biofuel, butanol is a fuel superior to ethanol with respect to gasoline blending, distribution, and refueling. Besides, it is also an excellent chemical in the plastics industry and a foodgrade extractant in the food and flavor industry. Presently, the most important economic restriction on the viability of ABE production is the cost of the substrate (corn, molasses, etc.), which makes up about 60% of the overall cost. Although inexpensively available agricultural residues (e.g. straw, corn stover) have been investigated for their potential application, low butanol production caused by fermentation inhibitors from ligno-cellulosic biomasses remains a challenging problem.

Researchers from the Institute of Process Engineering, Chinese Academy of Sciences (IPE-CAS) reported that the use of Kudzu, planted on marginal farming land and widely distributed in Asia and America, could be a viable option for reducing butanol production cost. Kudzu is a rapid-growing and high-climbing perennial leguminous vine, and its main active compounds (namely isoflavones) are reported to have many important physiological Activities. They developed a new process of butanol production integrated with isoflavone extraction. Batch culture containing 140 g kudzu/L produced 17.99 ± 1.08 g/L solvent (acetone, butanol and ethanol) with a productivity of 0.19 g/ (L/h) and a yield of 0.33 after 96h of fermentation. Isoflavone yield extracted from kudzu fermentation residues was approximately 48% higher compared with that extracted from raw kudzu.

This work has been published on Biotechnology and Bioprocess Engineering, (Volume 16, issue 4, 739-745, 2011). The technology of this work is protected by Chinese invention patents No. 200910090098.3. This work was financially supported by the Important National Basic Research Program of China (No. 2011CB707401) and the Knowledge Innovation Program of the Chinese Academy of Sciences (Nos. KSCX1-YW- 11A and KGCX2-YW-328).

Contact:

Prof. CHEN Hongzhang (hzchen@home.ipe.ac.cn)

Institute of Process Engineering, Chinese Academy of Sciences.