Rewiring carbon flow in Synechocystis PCC 6803 for a high rate of CO2-to-ethanol under an atmospheric environment
Cyanobacteria are an excellent microbial photosynthetic platform for sustainable carbon dioxide fixation. One bottleneck to limit its application is that the natural carbon flow pathway almost transfers CO2 to glycogen/biomass other than designed biofuels such as ethanol. Here, we used engineered Sy...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-05-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmicb.2023.1211004/full |
| _version_ | 1797815226593181696 |
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| author | E-Bin Gao E-Bin Gao Junhua Wu Penglin Ye Haiyan Qiu Huayou Chen Zhen Fang |
| author_facet | E-Bin Gao E-Bin Gao Junhua Wu Penglin Ye Haiyan Qiu Huayou Chen Zhen Fang |
| author_sort | E-Bin Gao |
| collection | DOAJ |
| description | Cyanobacteria are an excellent microbial photosynthetic platform for sustainable carbon dioxide fixation. One bottleneck to limit its application is that the natural carbon flow pathway almost transfers CO2 to glycogen/biomass other than designed biofuels such as ethanol. Here, we used engineered Synechocystis sp. PCC 6803 to explore CO2-to-ethanol potential under atmospheric environment. First, we investigated the effects of two heterologous genes (pyruvate decarboxylase and alcohol dehydrogenase) on ethanol biosynthesis and optimized their promoter. Furthermore, the main carbon flow of the ethanol pathway was strengthened by blocking glycogen storage and pyruvate-to-phosphoenolpyruvate backflow. To recycle carbon atoms that escaped from the tricarboxylic acid cycle, malate was artificially guided back into pyruvate, which also created NADPH balance and promoted acetaldehyde conversion into ethanol. Impressively, we achieved high-rate ethanol production (248 mg/L/day at early 4 days) by fixing atmospheric CO2. Thus, this study exhibits the proof-of-concept that rewiring carbon flow strategies could provide an efficient cyanobacterial platform for sustainable biofuel production from atmospheric CO2. |
| first_indexed | 2024-03-13T08:19:31Z |
| format | Article |
| id | doaj.art-456a1671ea28493a8ffba49535eebb45 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-03-13T08:19:31Z |
| publishDate | 2023-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-456a1671ea28493a8ffba49535eebb452023-05-31T10:01:27ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2023-05-011410.3389/fmicb.2023.12110041211004Rewiring carbon flow in Synechocystis PCC 6803 for a high rate of CO2-to-ethanol under an atmospheric environmentE-Bin Gao0E-Bin Gao1Junhua Wu2Penglin Ye3Haiyan Qiu4Huayou Chen5Zhen Fang6School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, ChinaSchool of Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu, ChinaNingbo Women and Children's Hospital, Ningbo, ChinaSchool of Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu, ChinaNingbo Women and Children's Hospital, Ningbo, ChinaSchool of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, ChinaSchool of Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu, ChinaCyanobacteria are an excellent microbial photosynthetic platform for sustainable carbon dioxide fixation. One bottleneck to limit its application is that the natural carbon flow pathway almost transfers CO2 to glycogen/biomass other than designed biofuels such as ethanol. Here, we used engineered Synechocystis sp. PCC 6803 to explore CO2-to-ethanol potential under atmospheric environment. First, we investigated the effects of two heterologous genes (pyruvate decarboxylase and alcohol dehydrogenase) on ethanol biosynthesis and optimized their promoter. Furthermore, the main carbon flow of the ethanol pathway was strengthened by blocking glycogen storage and pyruvate-to-phosphoenolpyruvate backflow. To recycle carbon atoms that escaped from the tricarboxylic acid cycle, malate was artificially guided back into pyruvate, which also created NADPH balance and promoted acetaldehyde conversion into ethanol. Impressively, we achieved high-rate ethanol production (248 mg/L/day at early 4 days) by fixing atmospheric CO2. Thus, this study exhibits the proof-of-concept that rewiring carbon flow strategies could provide an efficient cyanobacterial platform for sustainable biofuel production from atmospheric CO2.https://www.frontiersin.org/articles/10.3389/fmicb.2023.1211004/fullcyanobacteriametabolic engineeringcofactor regenerationCO2 fixationphotosynthetic cell factory |
| spellingShingle | E-Bin Gao E-Bin Gao Junhua Wu Penglin Ye Haiyan Qiu Huayou Chen Zhen Fang Rewiring carbon flow in Synechocystis PCC 6803 for a high rate of CO2-to-ethanol under an atmospheric environment Frontiers in Microbiology cyanobacteria metabolic engineering cofactor regeneration CO2 fixation photosynthetic cell factory |
| title | Rewiring carbon flow in Synechocystis PCC 6803 for a high rate of CO2-to-ethanol under an atmospheric environment |
| title_full | Rewiring carbon flow in Synechocystis PCC 6803 for a high rate of CO2-to-ethanol under an atmospheric environment |
| title_fullStr | Rewiring carbon flow in Synechocystis PCC 6803 for a high rate of CO2-to-ethanol under an atmospheric environment |
| title_full_unstemmed | Rewiring carbon flow in Synechocystis PCC 6803 for a high rate of CO2-to-ethanol under an atmospheric environment |
| title_short | Rewiring carbon flow in Synechocystis PCC 6803 for a high rate of CO2-to-ethanol under an atmospheric environment |
| title_sort | rewiring carbon flow in synechocystis pcc 6803 for a high rate of co2 to ethanol under an atmospheric environment |
| topic | cyanobacteria metabolic engineering cofactor regeneration CO2 fixation photosynthetic cell factory |
| url | https://www.frontiersin.org/articles/10.3389/fmicb.2023.1211004/full |
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