Engineering a cyanobacterium as the catalyst for the photosynthetic conversion of CO2 to 1,2-propanediol.
Engineering a cyanobacterium as the catalyst for the photosynthetic conversion of CO2 to 1,2-propanediol.
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DOI：
10.1186/1475-2859-12-4
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发表时间：
2013-01-22
影响因子：
6.4
通讯作者：
Liao JC
中科院分区：
文献类型：
--
作者：
Li H;Liao JC
现代社会主要依靠石油和天然气生产燃料和化学品。在美国年产量超过50万吨的主要商品化学品之一1，2-丙二醇（1，2-PDO）目前是通过化学方法从石油衍生的环氧丙烷生产的，这是能源密集型的并且是不可持续的。在这项研究中，我们试图实现光合生产1，2-PDO从CO2使用基因工程蓝藻细长聚球藻PCC 7942。与以前报道的使用糖或甘油作为底物的生物1，2-PDO生产过程相比，在光合生物中从CO2直接化学生产可吸收大气中的CO2，并且不会与粮食作物竞争耕地。在这项研究中，我们报道了利用基因工程蓝藻细长聚球藻PCC 7942从CO2光合生产1，2-PDO。引入编码甲基乙二醛合酶（mgsA）、甘油脱氢酶（gldA）和醛还原酶（yqhD）的基因导致从CO2产生约22 mg/L的1，2-PDO。然而，也产生了相当数量的途径中间体丙酮醇，特别是在稳定期。1，2-PDO的产生需要来自细胞代谢的还原当量的强输入。为了利用蓝藻的NADPH库，1，2-PDO的合成途径被改造成NADPH依赖性的，通过利用NADPH特异性仲醇脱氢酶，这在以前没有报道用于1，2-PDO的生产。这种优化策略导致1，2-PDO的产量约为150 mg/L，并最大限度地减少了不完全还原产物丙酮醇的积累。这项工作表明，蓝细菌可以被改造为催化剂的光合作用转化CO2为1，2-PDO。这项工作还表征了两种NADPH依赖性sADH在1，2-PDO形成中的催化能力，并表明它们可能是光合生物中还原化学物质可再生生产的有用工具。
The modern society primarily relies on petroleum and natural gas for the production of fuels and chemicals. One of the major commodity chemicals 1,2-propanediol (1,2-PDO), which has an annual production of more than 0.5 million tons in the United States, is currently produced by chemical processes from petroleum derived propylene oxide, which is energy intensive and not sustainable. In this study, we sought to achieve photosynthetic production of 1,2-PDO from CO2 using a genetically engineered cyanobacterium Synechococcus elongatus PCC 7942. Compared to the previously reported biological 1,2-PDO production processes which used sugar or glycerol as the substrates, direct chemical production from CO2 in photosynthetic organisms recycles the atmospheric CO2 and will not compete with food crops for arable land. In this study, we reported photosynthetic production of 1,2-PDO from CO2 using a genetically engineered cyanobacterium Synechococcus elongatus PCC 7942. Introduction of the genes encoding methylglyoxal synthase (mgsA), glycerol dehydrogenase (gldA), and aldehyde reductase (yqhD) resulted in the production of ~22mg/L 1,2-PDO from CO2. However, a comparable amount of the pathway intermediate acetol was also produced, especially during the stationary phase. The production of 1,2-PDO requires a robust input of reducing equivalents from cellular metabolism. To take advantage of cyanobacteria’s NADPH pool, the synthetic pathway of 1,2-PDO was engineered to be NADPH-dependent by exploiting the NADPH-specific secondary alcohol dehydrogenases which have not been reported for 1,2-PDO production previously. This optimization strategy resulted in the production of ~150mg/L 1,2-PDO and minimized the accumulation of the incomplete reduction product, acetol. This work demonstrated that cyanobacteria can be engineered as a catalyst for the photosynthetic conversion of CO2 to 1,2-PDO. This work also characterized two NADPH-dependent sADHs for their catalytic capacity in 1,2-PDO formation, and suggested that they may be useful tools for renewable production of reduced chemicals in photosynthetic organisms.
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影响因子：
48
作者：
Gibson, Daniel G.;Young, Lei;Smith, Hamilton O.
通讯作者：
Smith, Hamilton O.
影响因子：
56.9
作者：
Li, Han;Opgenorth, Paul H.;Liao, James C.
通讯作者：
Liao, James C.
影响因子：
3.8
作者：
Clomburg, James M.;Gonzalez, Ramon
通讯作者：
Gonzalez, Ramon
DOI：
10.1073/pnas.1200074109
发表时间：
2012-04-17
影响因子：
11.1
作者：
Lan, Ethan I.;Liao, James C.
通讯作者：
Liao, James C.
影响因子：
4.1
作者：
Marx, A;Hans, S;de Graaf, AA
通讯作者：
de Graaf, AA