Yao Xiuqing, Zhang Quan, Fan Yixuan, Xu Xinyang, Liu Ziyong
School of Resources and Civil Engineering, Northeastern University, Shenyang, 110819, China.
School Environmental & Safety Engineering, Liaoning Petrochemical University, Fushun, 113001, China.
AMB Express. 2022 May 14;12(1):57. doi: 10.1186/s13568-022-01399-6.
Acetone-butanol-ethanol (ABE) fermentation is a traditional way for solvents production through bioconversion by Clostridium species. It is still a challenge to obtain metabolic engineering strains with high ABE yield. Screening strains with remarkable characteristics from nature and improving ABE yield by mutation are viable approaches. Clostridium beijerinckii XH 0906, a newly isolated strain, produces butanol and isopropanol (BI) as the main end-products (9.1 g/L BI) during fermentation with glucose as the sole carbon source. The screening process for this strain was performed under aerobic conditions rather than anaerobic environment. Thus, it is a robust stain capable of oxygen-tolerant BI fermentation. Furthermore, C. beijerinckii XH 0906 fermented xylose and glucose simultaneously to produce BI. A mutant strain obtained by ultraviolet (UV) mutagenesis, C. beijerinckii XH 29, had improved BI production capacity and could produce 17.0 g/L BI and 18.4 g/L BI using glucose or corn stover hydrolysate, respectively as the carbon source. Interestingly, C. beijerinckii XH 29 also produced up to 19.3 g/L isopropanol through fermentation of a glucose-acetone mix. These results indicate that C. beijerinckii XH 29 is an excellent BI producer with great potential for industrial applications.
丙酮-丁醇-乙醇（ABE）发酵是通过梭菌属生物转化生产溶剂的传统方法。获得高ABE产量的代谢工程菌株仍然是一项挑战。从自然界筛选具有显著特性的菌株并通过诱变提高ABE产量是可行的方法。拜氏梭菌XH 0906是一株新分离的菌株，在以葡萄糖为唯一碳源的发酵过程中，以丁醇和异丙醇（BI）作为主要终产物（9.1 g/L BI）。该菌株的筛选过程是在有氧条件下而非厌氧环境中进行的。因此，它是一种能够耐受氧气进行BI发酵的稳健菌株。此外，拜氏梭菌XH 0906能同时发酵木糖和葡萄糖以产生BI。通过紫外线（UV）诱变获得的突变株拜氏梭菌XH 29具有提高的BI生产能力，分别以葡萄糖或玉米秸秆水解液作为碳源时，能够产生17.0 g/L BI和18.4 g/L BI。有趣的是，拜氏梭菌XH 29通过葡萄糖-丙酮混合物发酵还能产生高达19.3 g/L的异丙醇。这些结果表明，拜氏梭菌XH 29是一种优秀的BI生产者，具有巨大的工业应用潜力。
