1] Department of Chemistry, University of California, Berkeley, California, USA. [2] Energy Biosciences Institute, University of California, Berkeley, California, USA.
1] Energy Biosciences Institute, University of California, Berkeley, California, USA. [2] Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, USA.
Nat Protoc. 2015 Mar;10(3):528-37. doi: 10.1038/nprot.2015.029. Epub 2015 Feb 26.
Clostridium acetobutylicum is a bacterial species that ferments sugar to a mixture of organic solvents (acetone, butanol and ethanol). This protocol delineates a methodology to combine solventogenic clostridial fermentation and chemical catalysis via extractive fermentation for the production of biofuel blendstocks. Extractive fermentation of C. acetobutylicum is operated in fed-batch mode with a concentrated feed solution (500 grams per liter glucose and 50 grams per liter yeast extract) for 60 h, producing in excess of 40 g of solvents (acetone, butanol and ethanol) between the completely immiscible extractant and aqueous phases of the bioreactor. After distillation of the extractant phase, the acetone, butanol and ethanol mixture is upgraded to long-chain ketones over a palladium-hydrotalcite (Pd-HT) catalyst. This reaction is generally carried out in batch with a high-pressure Q-tube for 20 h at 250 °C. Following this protocol enables the production of ∼0.5 g of high-value biofuel precursors from a 1.7-g portion of fermentation solvents.
丙酮丁醇梭菌是一种能够将糖发酵为有机溶剂（丙酮、丁醇和乙醇）混合物的细菌物种。本方案描述了一种通过萃取发酵将溶剂生成梭菌发酵和化学催化相结合生产生物燃料调合原料的方法。采用浓进料溶液（每升葡萄糖 500 克，酵母提取物 50 克）以分批补料方式对丙酮丁醇梭菌进行萃取发酵 60 小时，在生物反应器完全不混溶的萃取相与水相之间产生超过 40 克的溶剂（丙酮、丁醇和乙醇）。萃取相蒸馏后，将丙酮、丁醇和乙醇混合物在钯-水滑石（Pd-HT）催化剂上升级为长链酮。该反应通常在高压 Q 管中进行 20 小时，温度为 250°C。按照本方案，可从 1.7 克发酵溶剂中生产约 0.5 克高价值生物燃料前体。
