Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria.
Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria.
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DOI：
10.1073/pnas.2021523118
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发表时间：
2021-03-16
影响因子：
11.1
通讯作者：
Ducat DC
中科院分区：
文献类型：
--
作者：
Santos-Merino M;Torrado A;Davis GA;Röttig A;Bibby TS;Kramer DM;Ducat DC
蓝细菌作为一种生物技术平台得到了越来越多的探索，尽管其经济可行性部分取决于最大限度地提高其光合作用、太阳能到生物质的能量转换效率的能力。在这里，我们表明，蓝藻光合能力可以增加转向细胞资源对异源，能量储存代谢途径，并通过减少电子流的光保护，但能量耗散，氧还原反应。我们进一步表明，这些异源汇可以部分地有助于光系统I（PSI）氧化，这表明了一种工程策略，以提高能量储存能力和鲁棒性的选择性转移过剩的光合能力生产过程。蓝细菌必须防止吸收的光能（源）和代谢能力（汇）之间的不平衡，以利用它来保护其光合机构免受损害。许多光保护机制有助于消散多余的吸收能量，包括呼吸末端氧化酶和黄二铁蛋白，但本质上降低光合效率。最近，有人假设，一些工程代谢途径可能会改善光合性能，纠正源/库的不平衡。在这一主题的背景下，我们探讨了内源性电子阀之间的相互联系，以及一个或多个异源代谢汇的激活。我们共表达了两种异源代谢途径，这两种途径先前已被证明对蓝细菌的光合活性有积极影响，一种是蔗糖生产途径（消耗ATP和还原剂），另一种是仅消耗细胞色素P450的还原剂。蔗糖出口与光系统II（PSII）和增强的电子传递链通量的量子产率提高，特别是在较低的光照水平，而细胞色素P450活性导致光合作用增强主要观察到在强光下。此外，这两个异源汇的共表达显示出对光合作用的加性影响，表明单独的汇都不能利用电子传递链的全部“过剩能力”。我们发现，异源汇可以部分补偿损失的光系统I（PSI）的氧化机制，即使在快速光照变化，虽然这种补偿是不完整的。我们的研究结果提供了支持的理论，异源代谢可以作为一个光合水槽，并表现出一些重叠的功能与光保护机制，同时可能保存有用的代谢产物，否则可能会“丢失”的能量。
Cyanobacteria have been increasingly explored as a biotechnological platform, although their economic feasibility relies in part on the capacity to maximize their photosynthetic, solar-to-biomass energy conversion efficiency. Here we show that cyanobacterial photosynthetic capacity can be increased by diverting cellular resources toward heterologous, energy-storing metabolic pathways and by reducing electron flow to photoprotective, but energy-dissipating, oxygen reduction reactions. We further show that these heterologous sinks can partially contribute to photosystem I (PSI) oxidation, suggesting an engineering strategy to improve both energy storage capacity and robustness by selective diversion of excess photosynthetic capacity to productive processes. Cyanobacteria must prevent imbalances between absorbed light energy (source) and the metabolic capacity (sink) to utilize it to protect their photosynthetic apparatus against damage. A number of photoprotective mechanisms assist in dissipating excess absorbed energy, including respiratory terminal oxidases and flavodiiron proteins, but inherently reduce photosynthetic efficiency. Recently, it has been hypothesized that some engineered metabolic pathways may improve photosynthetic performance by correcting source/sink imbalances. In the context of this subject, we explored the interconnectivity between endogenous electron valves, and the activation of one or more heterologous metabolic sinks. We coexpressed two heterologous metabolic pathways that have been previously shown to positively impact photosynthetic activity in cyanobacteria, a sucrose production pathway (consuming ATP and reductant) and a reductant-only consuming cytochrome P450. Sucrose export was associated with improved quantum yield of phtotosystem II (PSII) and enhanced electron transport chain flux, especially at lower illumination levels, while cytochrome P450 activity led to photosynthetic enhancements primarily observed under high light. Moreover, coexpression of these two heterologous sinks showed additive impacts on photosynthesis, indicating that neither sink alone was capable of utilizing the full “overcapacity” of the electron transport chain. We find that heterologous sinks may partially compensate for the loss of photosystem I (PSI) oxidizing mechanisms even under rapid illumination changes, although this compensation is incomplete. Our results provide support for the theory that heterologous metabolism can act as a photosynthetic sink and exhibit some overlapping functionality with photoprotective mechanisms, while potentially conserving energy within useful metabolic products that might otherwise be “lost.”
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影响因子：
2.7
作者：
Cordara A;Re A;Pagliano C;Van Alphen P;Pirone R;Saracco G;Branco Dos Santos F;Hellingwerf K;Vasile N
通讯作者：
Vasile N
影响因子：
9.2
作者：
Helman, Y;Tchernov, D;Kaplan, A
通讯作者：
Kaplan, A
影响因子：
4.6
作者：
Graham PJ;Nguyen B;Burdyny T;Sinton D
通讯作者：
Sinton D
DOI：
10.1073/pnas.1221194110
发表时间：
2013-03-05
影响因子：
11.1
作者：
Allahverdiyeva, Yagut;Mustila, Henna;Aro, Eva-Mari
通讯作者：
Aro, Eva-Mari
影响因子：
7.4
作者：
Chaux, Frederic;Burlacot, Adrien;Peltier, Gilles
通讯作者：
Peltier, Gilles