Lin Zhangnan, Liu Hongjuan, Wu Jing, Patakova Petra, Branska Barbora, Zhang Jianan
1Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 China.
2Department of Biotechnology, University of Chemistry and Technology Prague, Technicka 5, 16628 Prague 6, Czech Republic.
Biotechnol Biofuels. 2019 Sep 16;12:219. doi: 10.1186/s13068-019-1561-1. eCollection 2019.
Butanol production by fermentation has recently attracted increasingly more attention because of its mild reaction conditions and environmentally friendly properties. However, traditional feedstocks, such as corn, are food supplies for human beings and are expensive and not suitable for butanol production at a large scale. In this study, acetone, butanol, and ethanol (ABE) fermentation with non-pretreated cassava using a symbiotic TSH06 was investigated.
In batch fermentation, the butanol concentration of 11.6 g/L was obtained with a productivity of 0.16 g/L/h, which was similar to that obtained from glucose system. A full utilization system of cassava was constructed to improve the fermentation performance, cassava flour was used as the substrate and cassava peel residue was used as the immobilization carrier. ABE fermentation with immobilized cells resulted in total ABE and butanol concentrations of 20 g/L and 13.3 g/L, which were 13.6% and 14.7% higher, respectively, than those of free cells. To further improve the solvent productivity, continuous fermentation was conducted with immobilized cells. In single-stage continuous fermentation, the concentrations of total ABE and butanol reached 9.3 g/L and 6.3 g/L with ABE and butanol productivities of 1.86 g/L/h and 1.26 g/L/h, respectively. In addition, both of the high product concentration and high solvent productivity were achieved in a three-stage continuous fermentation. The ABE productivity and concentration was 1.12 g/L/h and 16.8 g/L, respectively.
The results indicate that TSH06 could produce solvents from cassava effectively. This study shows that ABE fermentation with cassava as a substrate could be an efficient and economical method of butanol production.
由于发酵法生产丁醇的反应条件温和且具有环境友好特性，近年来其受到了越来越多的关注。然而，传统原料，如玉米，是人类的食物供应，价格昂贵且不适合大规模生产丁醇。在本研究中，对使用共生菌TSH06对未预处理木薯进行丙酮、丁醇和乙醇（ABE）发酵进行了研究。
在分批发酵中，丁醇浓度达到11.6 g/L，产率为0.16 g/L/h，这与在葡萄糖体系中获得的结果相似。构建了木薯的全利用系统以提高发酵性能，木薯粉用作底物，木薯皮渣用作固定化载体。固定化细胞的ABE发酵使总ABE和丁醇浓度分别达到20 g/L和13.3 g/L，分别比游离细胞高13.6%和14.7%。为进一步提高溶剂产率，对固定化细胞进行了连续发酵。在单级连续发酵中，总ABE和丁醇浓度分别达到9.3 g/L和6.3 g/L，ABE和丁醇产率分别为1.86 g/L/h和1.26 g/L/h。此外，在三级连续发酵中实现了高产物浓度和高溶剂产率。ABE产率和浓度分别为1.12 g/L/h和16.8 g/L。
结果表明TSH06能够有效地利用木薯生产溶剂。本研究表明以木薯为底物的ABE发酵可能是一种高效且经济的丁醇生产方法。
