Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Road 189, Qingdao 266101, China; University of Chinese Academy of Sciences, Yuquan Road 19A, Beijing 100049, China.
Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Songling Road 189, Qingdao 266101, China.
Bioresour Technol. 2015 Feb;177:302-7. doi: 10.1016/j.biortech.2014.11.101. Epub 2014 Dec 2.
In this study, cell growth, gene expression and ethanol production were monitored under different fermentation conditions. Like its heterotrophical ABE-producing relatives, a switch from acidogenesis to solventogenesis of Clostridium ljungdahlii during the autotrophic fermentation with CO/CO2 could be observed, which occurred surprisingly in the late-log phase rather than in the transition phase. The gene expression profiles indicated that aor1, one of the putative aldehyde oxidoreductases in its genome played a critical role in the formation of ethanol, and its transcription could be induced by external acids. Moreover, a low amount of CaCO3 was proved to have positive influences on the cell density and substrate utilization, followed by an increase of over 40% ethanol and 30% acetate formation.
在这项研究中，在不同的发酵条件下监测了细胞生长、基因表达和乙醇生成。与它的异养ABE 生产相关物一样，在使用 CO/CO2 的自养发酵中，Clostridium ljungdahlii 可以从产酸阶段切换到产溶剂阶段，这一过程令人惊讶地发生在对数后期，而不是在过渡阶段。基因表达谱表明，其基因组中假定的醛氧化还原酶之一 aor1 在乙醇的形成中起着关键作用，其转录可以被外部酸诱导。此外，证明少量的 CaCO3 对细胞密度和底物利用有积极影响，随后乙醇生成增加超过 40%，乙酸生成增加 30%。
