College of Biology & Engineering, Hebei University of Economics & Business, Shijiazhuang 050061, PR China; William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA.
William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA.
Bioresour Technol. 2019 Oct;289:121749. doi: 10.1016/j.biortech.2019.121749. Epub 2019 Jul 3.
Acetone-butanol-ethanol fermentation suffers from high substrate cost and low butanol titer and yield. In this study, engineered Clostridium tyrobutyricum CtΔack-adhE2 immobilized in a fibrous-bed bioreactor was used for butanol production from glucose and xylose present in the hydrolysates of low-cost lignocellulosic biomass including corn fiber, cotton stalk, soybean hull, and sugarcane bagasse. The biomass hydrolysates obtained after acid pretreatment and enzymatic hydrolysis were supplemented with corn steep liquor and used in repeated-batch fermentations. Butanol production with high titer (∼15 g/L), yield (∼0.3 g/g), and productivity (∼0.3 g/L∙h) was obtained from cotton stalk, soybean hull, and sugarcane bagasse hydrolysates, while corn fiber hydrolysate with higher inhibitor contents gave somewhat inferior results. The fermentation process was stable for long-term operation without any noticeable degeneration, demonstrating its potential for industrial application. A techno-economic analysis showed that n-butanol could be produced from lignocellulosic biomass using this novel fermentation process at ∼$2.5/gal for biofuel application.
丙酮丁醇乙醇发酵存在底物成本高、丁醇得率和浓度低的问题。在本研究中，采用经工程改造的 Clostridium tyrobutyricum CtΔack-adhE2 固定在纤维床生物反应器中，从低成本木质纤维素生物质水解物中的葡萄糖和木糖生产丁醇，所述木质纤维素生物质包括玉米纤维、棉花秸秆、大豆皮和甘蔗渣。在用酸预处理和酶水解获得生物质水解物后，用玉米浆进行补充并用于重复批式发酵。从棉秸秆、大豆皮和甘蔗渣水解物中获得了高浓度（约 15g/L）、高收率（约 0.3g/g）和高生产效率（约 0.3g/L·h）的丁醇生产，而含有较高抑制剂含量的玉米纤维水解物则产生了稍差的结果。发酵过程稳定，可长期运行，没有明显的退化，显示出其在工业应用中的潜力。技术经济分析表明，使用这种新型发酵工艺，从木质纤维素生物质生产正丁醇的成本约为 2.5 美元/加仑，可用于生物燃料应用。
