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Zhou Y, Zhou S, Lyons S, Sun H, Sweedler JV, Lu Y. Enhancing 2-Pyrone Synthase Efficiency by High-Throughput Mass-Spectrometric Quantification and In Vitro/In Vivo Catalytic Performance Correlation. Chembiochem 2024; 25:e202300849. [PMID: 38116888 DOI: 10.1002/cbic.202300849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 12/21/2023]
Abstract
Engineering efficient biocatalysts is essential for metabolic engineering to produce valuable bioproducts from renewable resources. However, due to the complexity of cellular metabolic networks, it is challenging to translate success in vitro into high performance in cells. To meet such a challenge, an accurate and efficient quantification method is necessary to screen a large set of mutants from complex cell culture and a careful correlation between the catalysis parameters in vitro and performance in cells is required. In this study, we employed a mass-spectrometry based high-throughput quantitative method to screen new mutants of 2-pyrone synthase (2PS) for triacetic acid lactone (TAL) biosynthesis through directed evolution in E. coli. From the process, we discovered two mutants with the highest improvement (46 fold) in titer and the fastest kcat (44 fold) over the wild type 2PS, respectively, among those reported in the literature. A careful examination of the correlation between intracellular substrate concentration, Michaelis-Menten parameters and TAL titer for these two mutants reveals that a fast reaction rate under limiting intracellular substrate concentrations is important for in-cell biocatalysis. Such properties can be tuned by protein engineering and synthetic biology to adopt these engineered proteins for the maximum activities in different intracellular environments.
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Affiliation(s)
- Yu Zhou
- Department of Chemistry, The University of Texas at Austin, 105 E 24th St, Austin, TX 78712, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, 1206 W Gregory Dr, Urbana, IL, 61801, USA
| | - Shuaizhen Zhou
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, 1206 W Gregory Dr, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W Gregory Dr, Urbana, IL, 61801, USA
| | - Scott Lyons
- Department of Molecular Bioscience, The University of Texas at Austin, 100 E 24th St, Austin, TX 78712, USA
| | - Haoran Sun
- Department of Molecular Bioscience, The University of Texas at Austin, 100 E 24th St, Austin, TX 78712, USA
| | - Jonathan V Sweedler
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, 1206 W Gregory Dr, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W Gregory Dr, Urbana, IL, 61801, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, 505 S Mathews Avenue, Urbana, IL, 61801, USA
| | - Yi Lu
- Department of Chemistry, The University of Texas at Austin, 105 E 24th St, Austin, TX 78712, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, 1206 W Gregory Dr, Urbana, IL, 61801, USA
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Teter J, Yeh S, Khanna M, Berndes G. Water impacts of U.S. biofuels: Insights from an assessment combining economic and biophysical models. PLoS One 2018; 13:e0204298. [PMID: 30265704 PMCID: PMC6161887 DOI: 10.1371/journal.pone.0204298] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 09/06/2018] [Indexed: 11/18/2022] Open
Abstract
Biofuels policies induce land use changes (LUC), including cropland expansion and crop switching, and this in turn alters water and soil management practices. Policies differ in the extent and type of land use changes they induce and therefore in their impact on water resources. We quantify and compare the spatially varying water impacts of biofuel crops stemming from LUC induced by two different biofuels policies by coupling a biophysical model with an economic model to simulate the economically viable mix of crops, land uses, and crop management choices under alternative policy scenarios. We assess the outputs of an economic model with a high-resolution crop-water model for major agricultural crops and potential cellulosic feedstocks in the US to analyze the impacts of three alternative policy scenarios on water balances: a counterfactual 'no-biofuels policy' (BAU) scenario, a volumetric mandate (Mandate) scenario, and a clean fuel-intensity standard (CFS) scenario incentivizing fuels based on their carbon intensities. While both biofuel policies incentivize more biofuels than in the counterfactual, they differ in the mix of corn ethanol and advanced biofuels from miscanthus and switchgrass (more corn ethanol in Mandate and more cellulosic biofuels in CFS). The two policies differ in their impact on irrigated acreage, irrigation demand, groundwater use and runoff. Net irrigation requirements increase 0.7% in Mandate and decrease 3.8% in CFS, but in both scenarios increases are concentrated in regions of Kansas and Nebraska that rely upon the Ogallala aquifer for irrigation water. Our study illustrates the importance of accounting for the overall LUC and shifts in agricultural production and management practices in response to policies when assessing the water impacts of biofuels.
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Affiliation(s)
- Jacob Teter
- International Energy Agency, Sustainable Technology Outlooks, Paris, France
| | - Sonia Yeh
- Department of Space, Earth and Environment, Chalmers University of Technology, Gothenburg, Sweden
| | - Madhu Khanna
- Department of Agricultural and Consumer Economics, University of Illinois at Urbana Champaign, Urbana, Illinois, United States of America
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana Illinois, United States of America
| | - Göran Berndes
- Department of Space, Earth and Environment, Chalmers University of Technology, Gothenburg, Sweden
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