Clostridium ljungdahlii as a biocatalyst in microbial electrosynthesis - Effect of culture conditions on product formation
Clostridium ljungdahlii as a biocatalyst in microbial electrosynthesis - Effect of culture conditions on product formation
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DOI：
10.1016/j.biteb.2022.101156
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发表时间：
2022-09-01
影响因子：
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通讯作者：
Nygard, Yvonne
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文献类型：
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作者：
Im, Chaeho;Valgepea, Kaspar;Nygard, Yvonne
微生物电合成能够从CO2和电极提供的电子生产增值化学品。扬氏梭菌是一种具有电活性的产乙酸菌，可用于微生物电合成系统。然而，利用C. ljungdahlii是未知的。在这里，我们探讨了酵母提取物，pH值和阴极电位的影响。低的初始pH值增加了血清瓶培养物中CO2和H2的乙酸盐生产速率。当在生物电化学系统中培养时，在-0.8V和-1.0V之间的阴极电位下观察到最佳库仑效率（即接近100%），而在-1.0V下达到最高生产率。需要向培养基中添加酵母提取物以确保可再现的结果。利用循环伏安法检测了氢介导的C. ljungdahlii在生物电化学系统中在CO2上生长期间。这些结果表明，操作参数应仔细选择，以最大限度地提高微生物电合成的效率。
Microbial electrosynthesis enables the production of value-added chemicals from CO2 and electrons provided by an electrode. Clostridium ljungdahlii is an electroactive acetogen that potentially could be used in microbial electrosynthesis systems. However, the optimal operational parameters for microbial electrosynthesis using C. ljungdahlii are not known. Here, we explored the effects of yeast extract, pH, and cathode potential. A low initial pH increased the rate of acetate production from CO2 and H2 in serum bottle cultures. When cultivated in bioelectrochemical systems, the optimal coulombic efficiency (i.e. close to 100 %) was observed at a cathode potential between -0.8 V and -1.0 V, while the highest productivity was reached at -1.0 V. Addition of yeast extract to the medium was needed to ensure reproducible results. Using cyclic voltammetry, we detected hydrogen-mediated extracellular electron transfer of C. ljungdahlii during growth on CO2 in a bioelectrochemical system. These results show that operational parameters should be chosen carefully to maximise the efficiency of microbial electrosynthesis.