二氧化碳固定化是應對全球氣候變遷的重要策略，本研究通過適應性演化和合成生物學方法，改造大腸桿菌使其具備混營生長的能力，利用演化實驗提升2-酮戊二酸:鐵氧還蛋白氧化還原酶的活性，進而強化其二氧化碳吸收能力，也證明在厭氧呼吸時，硝酸鈉可以作為電子受體，在厭氧呼吸提供能量具有重要的影響力。透過自組設計的生物反應器，利用光密度偵測電路量測菌液的電壓值，藉由無線傳輸系統回傳到電腦，繪製出生長曲線並運算出生長速率，演化實驗過程以氫氣來輔助作為碳源的蘋果酸和作為電子接收者的硝酸鈉，最終得出結論演化後的菌株更適應蘋果酸與硝酸鈉的能量組合，也對二氧化碳的吸收有顯著提升，本研究提供了一種新穎且高效的碳固定途徑，擴展了大腸桿菌作為異營微生物的應用潛力，也為厭氧條件下的微生物代謝研究開創了新思路，特別是厭氧呼吸的能量作用和硝酸鹽及蘋果酸的應用。

Carbon fixation is a crucial strategy to address global climate change. This study utilizes adaptive evolution and synthetic biology to engineer Escherichia coli with the capability for mixotrophic growth. Through evolutionary experiments, the activity of OGOR was enhanced, thereby strengthening its ability to absorb carbon dioxide. The study also demonstrated that sodium nitrate can serve as an electron acceptor during anaerobic respiration, which has an important influence on providing energy during anaerobic respiration. Using a self-designed bioreactor equipped with an optical density detection circuit, the voltage values of the bacterial culture were measured and wirelessly transmitted to a computer. Growth curves were plotted, and growth rates were calculated. The evolutionary experiments used malic acid, supplemented by hydrogen as a carbon source, and sodium nitrate as an electron acceptor. The results showed that the evolved strains adapted better to the energy combination of malic acid and sodium nitrate and significantly improved carbon dioxide absorption. This research offers a novel and efficient carbon fixation pathway, expanding the application potential of E. coli as a heterotrophic microorganism. It also opens new avenues for microbial metabolism research under anaerobic conditions, particularly regarding the role of energy in anaerobic respiration and the applications of nitrate and malic acid.

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