Pan Haojie, Wang Jia, Wu Haoliang, Li Zhongjian, Lian Jiazhang
Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China.
Biotechnol Biofuels. 2021 Nov 4;14(1):212. doi: 10.1186/s13068-021-02063-0.
CO valorization is one of the effective methods to solve current environmental and energy problems, in which microbial electrosynthesis (MES) system has proved feasible and efficient. Cupriviadus necator (Ralstonia eutropha) H16, a model chemolithoautotroph, is a microbe of choice for CO conversion, especially with the ability to be employed in MES due to the presence of genes encoding [NiFe]-hydrogenases and all the Calvin-Benson-Basham cycle enzymes. The CO valorization strategy will make sense because the required hydrogen can be produced from renewable electricity independently of fossil fuels.
In this review, synthetic biology toolkit for C. necator H16, including genetic engineering vectors, heterologous gene expression elements, platform strain and genome engineering, and transformation strategies, is firstly summarized. Then, the review discusses how to apply these tools to make C. necator H16 an efficient cell factory for converting CO to value-added products, with the examples of alcohols, fatty acids, and terpenoids. The review is concluded with the limitation of current genetic tools and perspectives on the development of more efficient and convenient methods as well as the extensive applications of C. necator H16.
Great progress has been made on genetic engineering toolkit and synthetic biology applications of C. necator H16. Nevertheless, more efforts are expected in the near future to engineer C. necator H16 as efficient cell factories for the conversion of CO to value-added products.
一氧化碳（CO）转化是解决当前环境和能源问题的有效方法之一，其中微生物电合成（MES）系统已被证明是可行且高效的。嗜铜绿菌（Ralstonia eutropha）H16是一种典型的化能自养菌，是CO转化的首选微生物，特别是由于其存在编码[NiFe] - 氢化酶和所有卡尔文 - 本森 - 巴沙姆循环酶的基因，使其能够应用于MES。由于所需的氢气可以由可再生电力独立于化石燃料产生，因此CO转化策略具有重要意义。
在本综述中，首先总结了嗜铜绿菌H16的合成生物学工具包，包括基因工程载体、异源基因表达元件、平台菌株和基因组工程以及转化策略。然后，本综述讨论了如何应用这些工具使嗜铜绿菌H16成为将CO转化为增值产品的高效细胞工厂，并以醇类、脂肪酸和萜类化合物为例进行说明。本综述最后阐述了当前遗传工具的局限性以及对开发更高效便捷方法以及嗜铜绿菌H16广泛应用的展望。
嗜铜绿菌H16的基因工程工具包和合成生物学应用已取得了很大进展。然而，在不久的将来，仍需要做出更多努力，将嗜铜绿菌H16工程改造为将CO转化为增值产品的高效细胞工厂。
