Xue Chuang, Zhang Xiaotong, Wang Jufang, Xiao Min, Chen Lijie, Bai Fengwu
School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024 China.
School of Bioscience & Bioengineering, South China University of Technology, Guangzhou, 510006 China.
Biotechnol Biofuels. 2017 Jun 10;10:148. doi: 10.1186/s13068-017-0836-7. eCollection 2017.
Butanol as an important chemical and potential fuel could be produced via ABE fermentation from lignocellulosic biomass. The use of food-related feedstocks such as maize and sugar cane may not be a sustainable solution to world's energy needs. Recently, Jerusalem artichoke tubers containing inulin have been used as feedstock for butanol production, but this bioprocess is not commercially feasible due to the great value of inulin as functional food. Till now, there is a gap on the utilization of Jerusalem artichoke stalk (JAS) as feedstock for microbial butanol production.
Biobutanol production from JAS was investigated in order to improve cellulose digestibility and efficient biobutanol fermentation. Compared with 9.0 g/L butanol (14.7 g/L ABE) production by 2% NaOH pretreatment of JAS, 11.8 g/L butanol (17.6 g/L ABE) was produced in the best scenario conditions of NaOH-HO pretreatment, washing times and citrate buffer strengths etc. Furthermore, more than >64% water in washing pretreated JAS process could be saved, with improving butanol production by >25.0%. To mimic in situ product recovery for ABE fermentation, the vapor stripping-vapor permeation (VSVP) process steadily produced 323.4-348.7 g/L butanol (542.7-594.0 g/L ABE) in condensate, which showed more potentials than pervaporation for butanol recovery.
Therefore, the present study demonstrated an effective strategy on efficient biobutanol production using lignocellulosic biomass. The process optimization could contribute to significant reduction of wastewater emission and the improvement of lignocellulosic biomass digestibility and biobutanol production, which makes biobutanol production more efficient using JAS.
丁醇作为一种重要的化学品和潜在燃料，可以通过木质纤维素生物质的ABE发酵来生产。使用玉米和甘蔗等与食品相关的原料可能无法持续满足全球能源需求。最近，含有菊粉的菊芋块茎已被用作丁醇生产的原料，但由于菊粉作为功能性食品具有很高的价值，这种生物过程在商业上并不可行。到目前为止，在利用菊芋秸秆（JAS）作为微生物丁醇生产原料方面还存在空白。
为了提高纤维素的消化率和高效生物丁醇发酵，对JAS生产生物丁醇进行了研究。与用2%NaOH预处理JAS生产9.0g/L丁醇（14.7g/L ABE）相比，在NaOH-HO预处理、洗涤次数和柠檬酸盐缓冲液强度等最佳条件下，丁醇产量为11.8g/L（17.6g/L ABE）。此外，在洗涤预处理JAS过程中可以节省超过64%的水，同时丁醇产量提高超过25.0%。为了模拟ABE发酵的原位产物回收，汽提-蒸汽渗透（VSVP）过程在冷凝液中稳定地产生了323.4-348.7g/L丁醇（542.7-594.0g/L ABE），这表明在丁醇回收方面比渗透汽化更具潜力。
因此，本研究展示了一种利用木质纤维素生物质高效生产生物丁醇的有效策略。工艺优化有助于显著减少废水排放，提高木质纤维素生物质的消化率和生物丁醇产量，使得使用JAS生产生物丁醇更加高效。
