| 1. |
- Chen, Xiulai, et al.
(författare)
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DCEO Biotechnology: Tools to Design, Construct, Evaluate, and Optimize the Metabolic Pathway for Biosynthesis of Chemicals
- 2018
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Ingår i: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 118:1, s. 4-72
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Forskningsöversikt (refereegranskat)abstract
- Chemical synthesis is a well established route for producing many chemicals on a large scale, but some drawbacks still exist in this process, such as unstable intermediates, multistep reactions, complex process control, etc. Biobased production provides an attractive alternative to these challenges, but how to make cells into efficient factories is challenging. As a key enabling technology to develop efficient cell factories, design-construction-evaluation-optimization (DCEO) biotechnology, which incorporates the concepts and techniques of pathway design, pathway construction, pathway evaluation, and pathway optimization at the systems level, offers a conceptual and technological framework to exploit potential pathways, modify existing pathways and create new pathways for the optimal production of desired chemicals. Here, we summarize recent progress of DCEO biotechnology and examples of its application, and provide insights as to when, what and how different strategies should be taken. In addition, we highlight future perspectives of DCEO biotechnology for the successful establishment of biorefineries.
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| 2. |
- Hou, Jianshen, et al.
(författare)
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Rewiring carbon flux in Escherichia coli using a bifunctional molecular switch
- 2020
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Ingår i: Metabolic Engineering. - : Elsevier BV. - 1096-7176 .- 1096-7184. ; 61, s. 47-57
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Tidskriftsartikel (refereegranskat)abstract
- The unbalanced distribution of carbon flux in microbial cell factories can lead to inefficient production and poor cell growth. Uncoupling cell growth and chemical synthesis can therefore improve microbial cell factory efficiency. Such uncoupling, which requires precise manipulation of carbon fluxes, can be achieved by up-regulating or down-regulating the expression of enzymes of various pathways. In this study, a dynamic turn-off switch (dTFS) and a dynamic turn-on switch (dTNS) were constructed using growth phase-dependent promoters and degrons. By combining the dTFS and dTNS, a bifunctional molecular switch that could orthogonally regulate two target proteins was introduced. This bifunctional molecular switch was used to uncouple cell growth from shikimic acid and D-glucaric acid synthesis, resulting in the production of 14.33 g/L shikimic acid and the highest reported productivity of D-glucaric acid (0.0325 g/L/h) in Escherichia coli MG1655. This proved that the bifunctional molecular switch could rewire carbon fluxes by controlling target protein abundance.
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| 3. |
- Yang, Song, et al.
(författare)
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Regulating the Tautomerization in Covalent Organic Frameworks for Efficient Sacrificial Agent-Free Photocatalytic H2O2 Production
- 2024
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Ingår i: Macromolecules. - 0024-9297 .- 1520-5835. ; 57:5, s. 2039-2047
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Tidskriftsartikel (refereegranskat)abstract
- The efficiency of photocatalytic production of H2O2 is constrained by the low selectivity toward oxygen reduction, and the active sites are still under debate. Herein, analogous covalent organic framework photocatalysts were synthesized from triformylphloroglucinol (Tp) and predesigned diamines, in which a molecular engineering strategy was employed to manipulate the energy barrier for the targeted proton transfers. The tautomerization of enol-imine to keto-enamine introduced abundant alkene bonds (C═C), which serve as the primary adsorption sites and have a lower energy barrier for the reduction of the O2 reduction. DHAA-Tp COF displayed a remarkable photocatalytic H2O2 production rate of 219.5 μmol h–1 g–1 without any sacrificial reagent, which stands out among the structure-related materials. A switch from a concerted one-step 2e– to a two-step single e– process in O2 reduction was observed in TCNAQ-Tp COF, which is presumably ascribed to the suppressed tautomerization mediated by the strong electron-withdrawing cyano groups. The results demonstrate a novel concept for the photocatalytic production of H2O2 using an efficient, stable, and recyclable metal-free photocatalytic system.
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