School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea.
Department of Biological Science, College of Natural Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.
Sci Rep. 2017 Mar 14;7:44323. doi: 10.1038/srep44323.
Although aerobic CO dehydrogenases (CODHs) might be applicable in various fields, their practical applications have been hampered by low activity and no heterologous expression. We, for the first time, could functionally express recombinant PsCODH in E. coli and obtained a highly concentrated recombinant enzyme using an easy and convenient method. Its electron acceptor spectra, optimum conditions (pH 6.5 and 30 °C), and kinetic parameters (k of 12.97 s, K of 0.065 mM, and specific activity of 0.86 Umg) were examined. Blast furnace gas (BFG) containing 20% CO, which is a waste gas from the steel-making process, was tested as a substrate for PsCODH. Even with BFG, the recombinant PsCODH retained 88.2% and 108.4% activity compared with those of pure CO and 20% CO, respectively. The results provide not only a promising strategy to utilize CO-containing industrial waste gases as cheap, abundant, and renewable resources but also significant information for further studies about cascade reactions producing value-added chemicals via CO as an intermediate produced by a CODH-based CO-utilization system, which would ultimately expand the versatility of CODH.
虽然有氧 CO 脱氢酶（CODHs）可能在各个领域都有应用，但由于其活性低和无法异源表达，其实际应用受到了阻碍。我们首次成功地在大肠杆菌中功能性表达了重组 PsCODH，并采用简单便捷的方法获得了高浓度的重组酶。我们检测了其电子受体谱、最佳条件（pH6.5 和 30°C）和动力学参数（k 值为 12.97s，K 值为 0.065mM，比活性为 0.86Umg）。我们还以含有 20%CO 的高炉气（BFG）作为 PsCODH 的底物进行了测试，BFG 是炼钢过程中的废气。即使在 BFG 存在的情况下，与纯 CO 和 20%CO 相比，重组 PsCODH 的活性分别保留了 88.2%和 108.4%。这些结果不仅为利用 CO 含量高的工业废气作为廉价、丰富和可再生资源提供了一种很有前景的策略，也为进一步研究利用 CODH 基 CO 利用系统产生的 CO 作为中间体的级联反应生产增值化学品提供了重要信息，这将最终扩大 CODH 的多功能性。
