PDF(Pubmed)
Abstract：
BACKGROUND: Biotransformation of CO2 into high-value-added carbon-based products is a promising process for reducing greenhouse gas emissions. To realize the green transformation of CO2, we use fatty acids as carbon source to drive CO2 fixation to produce succinate through a portion of the 3-hydroxypropionate (3HP) cycle in Cupriavidus necator H16.
RESULTS: This work can achieve the production of a single succinate molecule from one acetyl-CoA molecule and two CO2 molecules. It was verified using an isotope labeling experiment utilizing NaH13CO3. This implies that 50% of the carbon atoms present in succinate are derived from CO2, resulting in a twofold increase in efficiency compared to prior methods of succinate biosynthesis that relied on the carboxylation of phosphoenolpyruvate or pyruvate. Meanwhile, using fatty acid as a carbon source has a higher theoretical yield than other feedstocks and also avoids carbon loss during acetyl-CoA and succinate production. To further optimize succinate production, different approaches including the optimization of ATP and NADPH supply, optimization of metabolic burden, and optimization of carbon sources were used. The resulting strain was capable of producing succinate to a level of 3.6 g/L, an increase of 159% from the starting strain.
CONCLUSIONS: This investigation established a new method for the production of succinate by the implementation of two CO2 fixation reactions and demonstrated the feasibility of ATP, NADPH, and metabolic burden regulation strategies in biological carbon fixation.
RESULTS: This work can achieve the production of a single succinate molecule from one acetyl-CoA molecule and two CO2 molecules. It was verified using an isotope labeling experiment utilizing NaH13CO3. This implies that 50% of the carbon atoms present in succinate are derived from CO2, resulting in a twofold increase in efficiency compared to prior methods of succinate biosynthesis that relied on the carboxylation of phosphoenolpyruvate or pyruvate. Meanwhile, using fatty acid as a carbon source has a higher theoretical yield than other feedstocks and also avoids carbon loss during acetyl-CoA and succinate production. To further optimize succinate production, different approaches including the optimization of ATP and NADPH supply, optimization of metabolic burden, and optimization of carbon sources were used. The resulting strain was capable of producing succinate to a level of 3.6 g/L, an increase of 159% from the starting strain.
CONCLUSIONS: This investigation established a new method for the production of succinate by the implementation of two CO2 fixation reactions and demonstrated the feasibility of ATP, NADPH, and metabolic burden regulation strategies in biological carbon fixation.
摘要：
背景：将CO2生物转化为高附加值的碳基产品是减少温室气体排放的有前途的过程。为了实现CO2的绿色转化，我们使用脂肪酸作为碳源来驱动CO2固定，以通过CupriavidusnecatorH16中的3-羟基丙酸酯（3HP）循环的一部分产生琥珀酸酯。
结果：这项工作可以实现从一个乙酰辅酶A分子和两个CO2分子生产单个琥珀酸酯分子。使用利用NaH13CO3的同位素标记实验来验证。这意味着琥珀酸酯中存在的50%的碳原子源自CO2,导致与依赖于磷酸烯醇丙酮酸或丙酮酸的羧化的琥珀酸酯生物合成的现有方法相比效率提高两倍。同时,使用脂肪酸作为碳源具有比其他原料更高的理论产率,并且还避免了在乙酰辅酶A和琥珀酸酯生产期间的碳损失。为了进一步优化琥珀酸酯的生产，不同的方法，包括优化ATP和NADPH供应，优化代谢负担，并对碳源进行了优化。得到的菌株能够生产琥珀酸到3.6g/L的水平，从起始菌株增加159%。
结论：这项研究通过实施两个CO2固定反应建立了生产琥珀酸的新方法，并证明了ATP的可行性，NADPH,和生物碳固定中的代谢负担调控策略。
结果：这项工作可以实现从一个乙酰辅酶A分子和两个CO2分子生产单个琥珀酸酯分子。使用利用NaH13CO3的同位素标记实验来验证。这意味着琥珀酸酯中存在的50%的碳原子源自CO2,导致与依赖于磷酸烯醇丙酮酸或丙酮酸的羧化的琥珀酸酯生物合成的现有方法相比效率提高两倍。同时,使用脂肪酸作为碳源具有比其他原料更高的理论产率,并且还避免了在乙酰辅酶A和琥珀酸酯生产期间的碳损失。为了进一步优化琥珀酸酯的生产，不同的方法，包括优化ATP和NADPH供应，优化代谢负担，并对碳源进行了优化。得到的菌株能够生产琥珀酸到3.6g/L的水平，从起始菌株增加159%。
结论：这项研究通过实施两个CO2固定反应建立了生产琥珀酸的新方法，并证明了ATP的可行性，NADPH,和生物碳固定中的代谢负担调控策略。
