1
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Bertelmann C, Bühler B. Strategies found not to be suitable for stabilizing high steroid hydroxylation activities of CYP450 BM3-based whole-cell biocatalysts. PLoS One 2024; 19:e0309965. [PMID: 39240904 PMCID: PMC11379211 DOI: 10.1371/journal.pone.0309965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Accepted: 08/21/2024] [Indexed: 09/08/2024] Open
Abstract
The implementation of biocatalytic steroid hydroxylation processes plays a crucial role in the pharmaceutical industry due to a plethora of medicative effects of hydroxylated steroid derivatives and their crucial role in drug approval processes. Cytochrome P450 monooxygenases (CYP450s) typically constitute the key enzymes catalyzing these reactions, but commonly entail drawbacks such as poor catalytic rates and the dependency on additional redox proteins for electron transfer from NAD(P)H to the active site. Recently, these bottlenecks were overcome by equipping Escherichia coli cells with highly active variants of the self-sufficient single-component CYP450 BM3 together with hydrophobic outer membrane proteins facilitating cellular steroid uptake. The combination of the BM3 variant KSA14m and the outer membrane pore AlkL enabled exceptionally high testosterone hydroxylation rates of up to 45 U gCDW-1 for resting (i.e., living but non-growing) cells. However, a rapid loss of specific activity heavily compromised final product titers and overall space-time yields. In this study, several stabilization strategies were evaluated on enzyme-, cell-, and reaction level. However, neither changes in biocatalyst configuration nor variation of cultivation media, expression systems, or inducer concentrations led to considerable improvement. This qualified the so-far used genetic construct pETM11-ksa14m-alkL, M9 medium, and the resting-cell state as the best options enabling comparatively efficient activity along with fast growth prior to biotransformation. In summary, we report several approaches not enabling a stabilization of the high testosterone hydroxylation rates, providing vital guidance for researchers tackling similar CYP450 stability issues. A comparison with more stable natively steroid-hydroxylating CYP106A2 and CYP154C5 in equivalent setups further highlighted the high potential of the investigated CYP450 BM3-based whole-cell biocatalysts. The immense and continuously developing repertoire of enzyme engineering strategies provides promising options to stabilize the highly active biocatalysts.
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Affiliation(s)
- Carolin Bertelmann
- Department of Solar Materials Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Saxony, Germany
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Saxony, Germany
| | - Bruno Bühler
- Department of Solar Materials Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Saxony, Germany
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Saxony, Germany
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2
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Bertelmann C, Mock M, Schmid A, Bühler B. Efficiency aspects of regioselective testosterone hydroxylation with highly active CYP450-based whole-cell biocatalysts. Microb Biotechnol 2024; 17:e14378. [PMID: 38018939 PMCID: PMC10832557 DOI: 10.1111/1751-7915.14378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 11/12/2023] [Indexed: 11/30/2023] Open
Abstract
Steroid hydroxylations belong to the industrially most relevant reactions catalysed by cytochrome P450 monooxygenases (CYP450s) due to the pharmacological relevance of hydroxylated derivatives. The implementation of respective bioprocesses at an industrial scale still suffers from several limitations commonly found in CYP450 catalysis, that is low turnover rates, enzyme instability, inhibition and toxicity related to the substrate(s) and/or product(s). Recently, we achieved a new level of steroid hydroxylation rates by introducing highly active testosterone-hydroxylating CYP450 BM3 variants together with the hydrophobic outer membrane protein AlkL into Escherichia coli-based whole-cell biocatalysts. However, the activity tended to decrease, which possibly impedes overall productivities and final product titres. In this study, a considerable instability was confirmed and subject to a systematic investigation regarding possible causes. In-depth evaluation of whole-cell biocatalyst kinetics and stability revealed a limitation in substrate availability due to poor testosterone solubility as well as inhibition by the main product 15β-hydroxytestosterone. Instability of CYP450 BM3 variants was disclosed as another critical factor, which is of general significance for CYP450-based biocatalysis. Presented results reveal biocatalyst, reaction and process engineering strategies auguring well for industrial implementation of the developed steroid hydroxylation platform.
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Affiliation(s)
| | - Magdalena Mock
- Department of Solar MaterialsLeipzigGermany
- Present address:
Department of Mechanical Engineering and Material SciencesGeorg Agricola University of Applied SciencesBochumGermany
| | | | - Bruno Bühler
- Department of Solar MaterialsLeipzigGermany
- Department of Microbial BiotechnologyHelmholtz Centre for Environmental Research GmbH–UFZLeipzigGermany
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3
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Rinaldi MA, Tait S, Toogood HS, Scrutton NS. Bioproduction of Linalool From Paper Mill Waste. Front Bioeng Biotechnol 2022; 10:892896. [PMID: 35711639 PMCID: PMC9195575 DOI: 10.3389/fbioe.2022.892896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/09/2022] [Indexed: 11/18/2022] Open
Abstract
A key challenge in chemicals biomanufacturing is the maintenance of stable, highly productive microbial strains to enable cost-effective fermentation at scale. A “cookie-cutter” approach to microbial engineering is often used to optimize host stability and productivity. This can involve identifying potential limitations in strain characteristics followed by attempts to systematically optimize production strains by targeted engineering. Such targeted approaches however do not always lead to the desired traits. Here, we demonstrate both ‘hit and miss’ outcomes of targeted approaches in attempts to generate a stable Escherichia coli strain for the bioproduction of the monoterpenoid linalool, a fragrance molecule of industrial interest. First, we stabilized linalool production strains by eliminating repetitive sequences responsible for excision of pathway components in plasmid constructs that encode the pathway for linalool production. These optimized pathway constructs were then integrated within the genome of E. coli in three parts to eliminate a need for antibiotics to maintain linalool production. Additional strategies were also employed including: reduction in cytotoxicity of linalool by adaptive laboratory evolution and modification or homologous gene replacement of key bottleneck enzymes GPPS/LinS. Our study highlights that a major factor influencing linalool titres in E. coli is the stability of the genetic construct against excision or similar recombination events. Other factors, such as decreasing linalool cytotoxicity and changing pathway genes, did not lead to improvements in the stability or titres obtained. With the objective of reducing fermentation costs at scale, the use of minimal base medium containing paper mill wastewater secondary paper fiber as sole carbon source was also investigated. This involved simultaneous saccharification and fermentation using either supplemental cellulase blends or by co-expressing secretable cellulases in E. coli containing the stabilized linalool production pathway. Combined, this study has demonstrated a stable method for linalool production using an abundant and low-cost feedstock and improved production strains, providing an important proof-of-concept for chemicals production from paper mill waste streams. For scaled production, optimization will be required, using more holistic approaches that involve further rounds of microbial engineering and fermentation process development.
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Affiliation(s)
- Mauro A Rinaldi
- Future Biomanufacturing Research Hub, Manchester, United Kingdom.,Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | - Shirley Tait
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | - Helen S Toogood
- Future Biomanufacturing Research Hub, Manchester, United Kingdom.,Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | - Nigel S Scrutton
- Future Biomanufacturing Research Hub, Manchester, United Kingdom.,Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom.,C3 Biotechnologies (Maritime and Aerospace) Ltd, Lancaster, United Kingdom
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4
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Theodosiou E, Tüllinghoff A, Toepel J, Bühler B. Exploitation of Hetero- and Phototrophic Metabolic Modules for Redox-Intensive Whole-Cell Biocatalysis. Front Bioeng Biotechnol 2022; 10:855715. [PMID: 35497353 PMCID: PMC9043136 DOI: 10.3389/fbioe.2022.855715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 03/09/2022] [Indexed: 11/13/2022] Open
Abstract
The successful realization of a sustainable manufacturing bioprocess and the maximization of its production potential and capacity are the main concerns of a bioprocess engineer. A main step towards this endeavor is the development of an efficient biocatalyst. Isolated enzyme(s), microbial cells, or (immobilized) formulations thereof can serve as biocatalysts. Living cells feature, beside active enzymes, metabolic modules that can be exploited to support energy-dependent and multi-step enzyme-catalyzed reactions. Metabolism can sustainably supply necessary cofactors or cosubstrates at the expense of readily available and cheap resources, rendering external addition of costly cosubstrates unnecessary. However, for the development of an efficient whole-cell biocatalyst, in depth comprehension of metabolic modules and their interconnection with cell growth, maintenance, and product formation is indispensable. In order to maximize the flux through biosynthetic reactions and pathways to an industrially relevant product and respective key performance indices (i.e., titer, yield, and productivity), existing metabolic modules can be redesigned and/or novel artificial ones established. This review focuses on whole-cell bioconversions that are coupled to heterotrophic or phototrophic metabolism and discusses metabolic engineering efforts aiming at 1) increasing regeneration and supply of redox equivalents, such as NAD(P/H), 2) blocking competing fluxes, and 3) increasing the availability of metabolites serving as (co)substrates of desired biosynthetic routes.
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Affiliation(s)
- Eleni Theodosiou
- Institute of Applied Biosciences, Centre for Research and Technology Hellas, Thessaloniki, Greece
| | - Adrian Tüllinghoff
- Department of Solar Materials, Helmholtz Centre for Environmental Research GmbH—UFZ, Leipzig, Germany
| | - Jörg Toepel
- Department of Solar Materials, Helmholtz Centre for Environmental Research GmbH—UFZ, Leipzig, Germany
| | - Bruno Bühler
- Department of Solar Materials, Helmholtz Centre for Environmental Research GmbH—UFZ, Leipzig, Germany
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5
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Dusny C, Schmid A. The Metabolic Flux Probe (MFP)-Secreted Protein as a Non-Disruptive Information Carrier for 13C-Based Metabolic Flux Analysis. Int J Mol Sci 2021; 22:ijms22179438. [PMID: 34502345 PMCID: PMC8430588 DOI: 10.3390/ijms22179438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 11/29/2022] Open
Abstract
Novel cultivation technologies demand the adaptation of existing analytical concepts. Metabolic flux analysis (MFA) requires stable-isotope labeling of biomass-bound protein as the primary information source. Obtaining the required protein in cultivation set-ups where biomass is inaccessible due to low cell densities and cell immobilization is difficult to date. We developed a non-disruptive analytical concept for 13C-based metabolic flux analysis based on secreted protein as an information carrier for isotope mapping in the protein-bound amino acids. This “metabolic flux probe” (MFP) concept was investigated in different cultivation set-ups with a recombinant, protein-secreting yeast strain. The obtained results grant insight into intracellular protein turnover dynamics. Experiments under metabolic but isotopically nonstationary conditions in continuous glucose-limited chemostats at high dilution rates demonstrated faster incorporation of isotope information from labeled glucose into the recombinant reporter protein than in biomass-bound protein. Our results suggest that the reporter protein was polymerized from intracellular amino acid pools with higher turnover rates than biomass-bound protein. The latter aspect might be vital for 13C-flux analyses under isotopically nonstationary conditions for analyzing fast metabolic dynamics.
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6
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Lemke P, Zoheir AE, Rabe KS, Niemeyer CM. Microfluidic cultivation and analysis of productive biofilms. Biotechnol Bioeng 2021; 118:3860-3870. [PMID: 34133021 DOI: 10.1002/bit.27861] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/25/2021] [Accepted: 06/11/2021] [Indexed: 01/09/2023]
Abstract
We here report the application of a machine-based microfluidic biofilm cultivation and analysis platform for studying the performance of biocatalytically active biofilms. By using robotic sampling, we succeeded in spatially resolving the productivity of three microfluidic reactors containing biocatalytically active biofilms that inducibly overexpress recombinant enzymes. Escherichia coli biofilms expressing two stereoselective oxidoreductases, the (R)-selective alcohol dehydrogenase LbADH and the (S)-selective ketoreductase Gre2p, as well as the phenolic acid decarboxylase EsPAD were used. The excellent reproducibility of the cultivation and analysis methods observed for all three systems underlines the usefulness of the new technical platform for the investigation of biofilms. In addition, we demonstrated that the analytical platform also opens up new opportunities to perform in-depth spatially resolved studies on the biomass growth in a reactor channel and its biochemical productivity. Since the platform not only offers the detailed biochemical characterization but also broad capabilities for the morphological study of living biofilms, we believe that our approach can also be performed on many other natural and artificial biofilms to systematically investigate a wide range of process parameters in a highly parallel manner using miniaturized model systems, thus advancing the harnessing of microbial communities for technical purposes.
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Affiliation(s)
- Phillip Lemke
- Karlsruhe Institute for Technology (KIT), Institute for Biological Interfaces (IBG 1), Eggenstein-Leopoldshafen, Germany
| | - Ahmed E Zoheir
- Karlsruhe Institute for Technology (KIT), Institute for Biological Interfaces (IBG 1), Eggenstein-Leopoldshafen, Germany.,Department of Genetics and Cytology, National Research Centre (NRC), Cairo, Egypt
| | - Kersten S Rabe
- Karlsruhe Institute for Technology (KIT), Institute for Biological Interfaces (IBG 1), Eggenstein-Leopoldshafen, Germany
| | - Christof M Niemeyer
- Karlsruhe Institute for Technology (KIT), Institute for Biological Interfaces (IBG 1), Eggenstein-Leopoldshafen, Germany
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7
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Systems Analysis of NADH Dehydrogenase Mutants Reveals Flexibility and Limits of Pseudomonas taiwanensis VLB120's Metabolism. Appl Environ Microbiol 2020; 86:AEM.03038-19. [PMID: 32245760 DOI: 10.1128/aem.03038-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/18/2020] [Indexed: 12/14/2022] Open
Abstract
Obligate aerobic organisms rely on a functional electron transport chain for energy conservation and NADH oxidation. Because of this essential requirement, the genes of this pathway are likely constitutively and highly expressed to avoid a cofactor imbalance and energy shortage under fluctuating environmental conditions. We here investigated the essentiality of the three NADH dehydrogenases of the respiratory chain of the obligate aerobe Pseudomonas taiwanensis VLB120 and the impact of the knockouts of corresponding genes on its physiology and metabolism. While a mutant lacking all three NADH dehydrogenases seemed to be nonviable, the single or double knockout mutant strains displayed no, or only a weak, phenotype. Only the mutant deficient in both type 2 dehydrogenases showed a clear phenotype with biphasic growth behavior and a strongly reduced growth rate in the second phase. In-depth analyses of the metabolism of the generated mutants, including quantitative physiological experiments, transcript analysis, proteomics, and enzyme activity assays revealed distinct responses to type 2 and type 1 dehydrogenase deletions. An overall high metabolic flexibility enables P. taiwanensis to cope with the introduced genetic perturbations and maintain stable phenotypes, likely by rerouting of metabolic fluxes. This metabolic adaptability has implications for biotechnological applications. While the phenotypic robustness is favorable in large-scale applications with inhomogeneous conditions, the possible versatile redirecting of carbon fluxes upon genetic interventions can thwart metabolic engineering efforts.IMPORTANCE While Pseudomonas has the capability for high metabolic activity and the provision of reduced redox cofactors important for biocatalytic applications, exploitation of this characteristic might be hindered by high, constitutive activity of and, consequently, competition with the NADH dehydrogenases of the respiratory chain. The in-depth analysis of NADH dehydrogenase mutants of Pseudomonas taiwanensis VLB120 presented here provides insight into the phenotypic and metabolic response of this strain to these redox metabolism perturbations. This high degree of metabolic flexibility needs to be taken into account for rational engineering of this promising biotechnological workhorse toward a host with a controlled and efficient supply of redox cofactors for product synthesis.
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8
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Microfluidic Single-Cell Analytics. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2020; 179:159-189. [PMID: 32737554 DOI: 10.1007/10_2020_134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
What is the impact of cellular heterogeneity on process performance? How do individual cells contribute to averaged process productivity? Single-cell analysis is a key technology for answering such key questions of biotechnology, beyond bulky measurements with populations. The analysis of cellular individuality, its origins, and the dependency of process performance on cellular heterogeneity has tremendous potential for optimizing biotechnological processes in terms of metabolic, reaction, and process engineering. Microfluidics offer unmatched environmental control of the cellular environment and allow massively parallelized cultivation of single cells. However, the analytical accessibility to a cell's physiology is of crucial importance for obtaining the desired information on the single-cell production phenotype. Highly sensitive analytics are required to detect and quantify the minute amounts of target analytes and small physiological changes in a single cell. For their application to biotechnological questions, single-cell analytics must evolve toward the measurement of kinetics and specific rates of the smallest catalytic unit, the single cell. In this chapter, we focus on an introduction to the latest single-cell analytics and their application for obtaining physiological parameters in a biotechnological context from single cells. We present and discuss recent advancements in single-cell analytics that enable the analysis of cell-specific growth, uptake, and production kinetics, as well as the gene expression and regulatory mechanisms at a single-cell level.
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9
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Song JW, Seo JH, Oh DK, Bornscheuer UT, Park JB. Design and engineering of whole-cell biocatalytic cascades for the valorization of fatty acids. Catal Sci Technol 2020. [DOI: 10.1039/c9cy01802f] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This review presents the key factors to construct a productive whole-cell biocatalytic cascade exemplified for the biotransformation of renewable fatty acids.
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Affiliation(s)
- Ji-Won Song
- Department of Food Science and Engineering
- Ewha Womans University
- Seoul 03760
- Republic of Korea
| | - Joo-Hyun Seo
- Department of Bio and Fermentation Convergence Technology
- Kookmin University
- Seoul 02707
- Republic of Korea
| | - Doek-Kun Oh
- Department of Bioscience and Biotechnology
- Konkuk University
- Seoul 143-701
- Republic of Korea
| | - Uwe T. Bornscheuer
- Institute of Biochemistry
- Department of Biotechnology & Enzyme Catalysis
- Greifswald University
- 17487 Greifswald
- Germany
| | - Jin-Byung Park
- Department of Food Science and Engineering
- Ewha Womans University
- Seoul 03760
- Republic of Korea
- Institute of Molecular Microbiology and Biosystems Engineering
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10
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Kim D, Sathesh-Prabu C, JooYeon Y, Lee SK. High-Level Production of 4-Hydroxyvalerate from Levulinic Acid via Whole-Cell Biotransformation Decoupled from Cell Metabolism. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:10678-10684. [PMID: 31475535 DOI: 10.1021/acs.jafc.9b04304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
γ-Hydroxyvalerate (4HV) is an important monomer used to produce various valuable polymers and products. In this study, an engineered 3-hydroxybutyrate dehydrogenase that can convert levulinic acid (LA) into 4HV was co-expressed with a cofactor (NADH) regeneration system mediated by an NAD+-dependent formate dehydrogenase (CbFDH) in the Escherichia coli strain, MG1655. The resulting strain produced 23-fold more 4HV in a shake flask. The 4HV production was not dependent on ATP and required low aeration; all of these are considered beneficial characteristics for the production of target compounds, especially at an industrial scale. Under optimized conditions in a 5 L fermenter, the titer, productivity, and molar conversion efficiency for 4HV reached 100 g/L, 4.2 g/L/h, and 92%, respectively. Our system could prove to be a promising method for the large-scale production of 4HV from LA at low-cost and using a renewable biomass source.
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Affiliation(s)
| | | | - Young JooYeon
- Department of Biochemical Engineering , Gangneung-Wonju National University , Gangneung 25457 , Republic of Korea
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11
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Schmitz LM, Schäper J, Rosenthal K, Lütz S. Accessing the Biocatalytic Potential for C−H‐Activation by Targeted Genome Mining and Screening. ChemCatChem 2019. [DOI: 10.1002/cctc.201901273] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Lisa Marie Schmitz
- Chair for Bioprocess Engineering Department of Biochemical and Chemical EngineeringTU Dortmund University Emil-Figge-Straße 66 Dortmund 44227 Germany
| | - Jonas Schäper
- Chair for Bioprocess Engineering Department of Biochemical and Chemical EngineeringTU Dortmund University Emil-Figge-Straße 66 Dortmund 44227 Germany
| | - Katrin Rosenthal
- Chair for Bioprocess Engineering Department of Biochemical and Chemical EngineeringTU Dortmund University Emil-Figge-Straße 66 Dortmund 44227 Germany
| | - Stephan Lütz
- Chair for Bioprocess Engineering Department of Biochemical and Chemical EngineeringTU Dortmund University Emil-Figge-Straße 66 Dortmund 44227 Germany
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12
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Li W, Jayakody LN, Franden MA, Wehrmann M, Daun T, Hauer B, Blank LM, Beckham GT, Klebensberger J, Wierckx N. Laboratory evolution reveals the metabolic and regulatory basis of ethylene glycol metabolism by
Pseudomonas putida
KT2440. Environ Microbiol 2019; 21:3669-3682. [DOI: 10.1111/1462-2920.14703] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 05/29/2019] [Accepted: 06/03/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Wing‐Jin Li
- Institute of Applied Microbiology‐iAMB, Aachen Biology and Biotechnology‐ABBt RWTH Aachen University Worringerweg 1, 52074 Aachen Germany
| | - Lahiru N. Jayakody
- National Bioenergy Center National Renewable Energy Laboratory Golden CO 80401 USA
| | - Mary Ann Franden
- National Bioenergy Center National Renewable Energy Laboratory Golden CO 80401 USA
| | - Matthias Wehrmann
- University of Stuttgart Institute of Biochemistry and Technical Biochemistry Allmandring 31, 70569 Stuttgart Germany
| | - Tristan Daun
- Institute of Applied Microbiology‐iAMB, Aachen Biology and Biotechnology‐ABBt RWTH Aachen University Worringerweg 1, 52074 Aachen Germany
| | - Bernhard Hauer
- University of Stuttgart Institute of Biochemistry and Technical Biochemistry Allmandring 31, 70569 Stuttgart Germany
| | - Lars M. Blank
- Institute of Applied Microbiology‐iAMB, Aachen Biology and Biotechnology‐ABBt RWTH Aachen University Worringerweg 1, 52074 Aachen Germany
| | - Gregg T. Beckham
- National Bioenergy Center National Renewable Energy Laboratory Golden CO 80401 USA
| | - Janosch Klebensberger
- University of Stuttgart Institute of Biochemistry and Technical Biochemistry Allmandring 31, 70569 Stuttgart Germany
| | - Nick Wierckx
- Institute of Applied Microbiology‐iAMB, Aachen Biology and Biotechnology‐ABBt RWTH Aachen University Worringerweg 1, 52074 Aachen Germany
- Institute of Bio‐ and Geosciences IBG‐1: Biotechnology Forschungszentrum Jülich, 52425 Jülich Germany
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13
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Volmer J, Lindmeyer M, Seipp J, Schmid A, Bühler B. Constitutively solvent‐tolerantPseudomonas taiwanensisVLB120∆C∆ttgVsupports particularly high‐styrene epoxidation activities when grown under glucose excess conditions. Biotechnol Bioeng 2019; 116:1089-1101. [DOI: 10.1002/bit.26924] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/17/2018] [Accepted: 01/06/2019] [Indexed: 01/08/2023]
Affiliation(s)
- Jan Volmer
- Department of Biochemical and Chemical EngineeringTU Dortmund UniversityDortmund Germany
| | - Martin Lindmeyer
- Department of Biochemical and Chemical EngineeringTU Dortmund UniversityDortmund Germany
- Department of Solar MaterialsHelmholtz Centre for Environmental Research GmbH–UFZLeipzig Germany
| | - Julia Seipp
- Department of Biochemical and Chemical EngineeringTU Dortmund UniversityDortmund Germany
| | - Andreas Schmid
- Department of Solar MaterialsHelmholtz Centre for Environmental Research GmbH–UFZLeipzig Germany
| | - Bruno Bühler
- Department of Solar MaterialsHelmholtz Centre for Environmental Research GmbH–UFZLeipzig Germany
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14
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Liu C, Zhao J, Liu J, Guo X, Rao D, Liu H, Zheng P, Sun J, Ma Y. Simultaneously improving the activity and thermostability of a new proline 4-hydroxylase by loop grafting and site-directed mutagenesis. Appl Microbiol Biotechnol 2018; 103:265-277. [DOI: 10.1007/s00253-018-9410-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/14/2018] [Accepted: 09/19/2018] [Indexed: 02/03/2023]
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15
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Thermodynamic favorability and pathway yield as evolutionary tradeoffs in biosynthetic pathway choice. Proc Natl Acad Sci U S A 2018; 115:11339-11344. [PMID: 30309961 DOI: 10.1073/pnas.1805367115] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The structure of the metabolic network contains myriad organism-specific variations across the tree of life, but the selection basis for pathway choices in different organisms is not well understood. Here, we examined the metabolic capabilities with respect to cofactor use and pathway thermodynamics of all sequenced organisms in the Kyoto Encyclopedia of Genes and Genomes Database. We found that (i) many biomass precursors have alternate synthesis routes that vary substantially in thermodynamic favorability and energy cost, creating tradeoffs that may be subject to selection pressure; (ii) alternative pathways in amino acid synthesis are characteristically distinguished by the use of biosynthetically unnecessary acyl-CoA cleavage; (iii) distinct choices preferring thermodynamic-favorable or cofactor-use-efficient pathways exist widely among organisms; (iv) cofactor-use-efficient pathways tend to have a greater yield advantage under anaerobic conditions specifically; and (v) lysine biosynthesis in particular exhibits temperature-dependent thermodynamics and corresponding differential pathway choice by thermophiles. These findings present a view on the evolution of metabolic network structure that highlights a key role of pathway thermodynamics and cofactor use in determining organism pathway choices.
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Hartmann SK, Stockdreher Y, Wandrey G, Hosseinpour Tehrani H, Zambanini T, Meyer AJ, Büchs J, Blank LM, Schwarzländer M, Wierckx N. Online in vivo monitoring of cytosolic NAD redox dynamics in Ustilago maydis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:1015-1024. [DOI: 10.1016/j.bbabio.2018.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 04/06/2018] [Accepted: 05/20/2018] [Indexed: 12/20/2022]
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17
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Zhang HL, Zhang C, Pei CH, Han MN, Xu ZD, Li CH, Li W. Efficient production of trans
-4-Hydroxy-l
-proline from glucose by metabolic engineering of recombinant Escherichia coli. Lett Appl Microbiol 2018; 66:400-408. [DOI: 10.1111/lam.12864] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/28/2018] [Accepted: 02/04/2018] [Indexed: 01/16/2023]
Affiliation(s)
- H.-L. Zhang
- Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of Education; College of Chemistry and Environmental Science; Hebei University; Baoding China
| | - C. Zhang
- Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of Education; College of Chemistry and Environmental Science; Hebei University; Baoding China
| | - C.-H. Pei
- Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of Education; College of Chemistry and Environmental Science; Hebei University; Baoding China
| | - M.-N. Han
- Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of Education; College of Chemistry and Environmental Science; Hebei University; Baoding China
| | - Z.-D. Xu
- Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of Education; College of Chemistry and Environmental Science; Hebei University; Baoding China
| | - C.-H. Li
- HeBei Brant Pharmaceutical Co., Ltd.; Shingjiazhuang China
| | - W. Li
- Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of Education; College of Chemistry and Environmental Science; Hebei University; Baoding China
- HeBei Brant Pharmaceutical Co., Ltd.; Shingjiazhuang China
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Kelly W, Veigne S, Li X, Subramanian SS, Huang Z, Schaefer E. Optimizing performance of semi-continuous cell culture in an ambr15™ microbioreactor using dynamic flux balance modeling. Biotechnol Prog 2017; 34:420-431. [DOI: 10.1002/btpr.2585] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 11/05/2017] [Indexed: 12/29/2022]
Affiliation(s)
- William Kelly
- Villanova University, Chemical Engineering; Villanova PA 19085
| | - Sorelle Veigne
- Janssen R&D, cAPI Large Molecule Pharmaceutical, Development and Manufacturing Sciences; Malvern PA
| | - Xianhua Li
- Villanova University, Chemical Engineering; Villanova PA 19085
| | | | - Zuyi Huang
- Villanova University, Chemical Engineering; Villanova PA 19085
| | - Eugene Schaefer
- Janssen R&D, cAPI Large Molecule Pharmaceutical, Development and Manufacturing Sciences; Malvern PA
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Wang P, Yang X, Lin B, Huang J, Tao Y. Cofactor self-sufficient whole-cell biocatalysts for the production of 2-phenylethanol. Metab Eng 2017; 44:143-149. [DOI: 10.1016/j.ymben.2017.09.013] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/11/2017] [Accepted: 09/19/2017] [Indexed: 11/24/2022]
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20
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Theodosiou E, Breisch M, Julsing MK, Falcioni F, Bühler B, Schmid A. An artificial TCA cycle selects for efficient α-ketoglutarate dependent hydroxylase catalysis in engineered Escherichia coli. Biotechnol Bioeng 2017; 114:1511-1520. [PMID: 28266022 DOI: 10.1002/bit.26281] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/13/2017] [Accepted: 03/01/2017] [Indexed: 01/24/2023]
Abstract
Amino acid hydroxylases depend directly on the cellular TCA cycle via their cosubstrate α-ketoglutarate (α-KG) and are highly useful for the selective biocatalytic oxyfunctionalization of amino acids. This study evaluates TCA cycle engineering strategies to force and increase α-KG flux through proline-4-hydroxylase (P4H). The genes sucA (α-KG dehydrogenase E1 subunit) and sucC (succinyl-CoA synthetase β subunit) were alternately deleted together with aceA (isocitrate lyase) in proline degradation-deficient Escherichia coli strains (ΔputA) expressing the p4h gene. Whereas, the ΔsucCΔaceAΔputA strain grew in minimal medium in the absence of P4H, relying on the activity of fumarate reductase, growth of the ΔsucAΔaceAΔputA strictly depended on P4H activity, thus coupling growth to proline hydroxylation. P4H restored growth, even when proline was not externally added. However, the reduced succinyl-CoA pool caused a 27% decrease of the average cell size compared to the wildtype strain. Medium supplementation partially restored the morphology and, in some cases, enhanced proline hydroxylation activity. The specific proline hydroxylation rate doubled when putP, encoding the Na+ /l-proline transporter, was overexpressed in the ΔsucAΔaceAΔputA strain. This is in contrast to wildtype and ΔputA single-knock out strains, in which α-KG availability obviously limited proline hydroxylation. Such α-KG limitation was relieved in the ΔsucAΔaceAΔputA strain. Furthermore, the ΔsucAΔaceAΔputA strain was used to demonstrate an agar plate-based method for the identification and selection of active α-KG dependent hydroxylases. This together with the possibility to waive selection pressure and overcome α-KG limitation in respective hydroxylation processes based on living cells emphasizes the potential of TCA cycle engineering for the productive application of α-KG dependent hydroxylases. Biotechnol. Bioeng. 2017;114: 1511-1520. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Eleni Theodosiou
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, Leipzig 04318, Germany
| | - Marina Breisch
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Mattijs K Julsing
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Francesco Falcioni
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Bruno Bühler
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, Leipzig 04318, Germany
| | - Andreas Schmid
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, Leipzig 04318, Germany
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21
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Hydrolase BioH knockout in E. coli enables efficient fatty acid methyl ester bioprocessing. ACTA ACUST UNITED AC 2017; 44:339-351. [DOI: 10.1007/s10295-016-1890-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 12/16/2016] [Indexed: 01/19/2023]
Abstract
Abstract
Fatty acid methyl esters (FAMEs) originating from plant oils are most interesting renewable feedstocks for biofuels and bio-based materials. FAMEs can also be produced and/or functionalized by engineered microbes to give access to, e.g., polymer building blocks. Yet, they are often subject to hydrolysis yielding free fatty acids, which typically are degraded by microbes. We identified BioH as the key enzyme responsible for the hydrolysis of medium-chain length FAME derivatives in different E. coli K-12 strains. E. coli ΔbioH strains showed up to 22-fold reduced FAME hydrolysis rates in comparison with respective wild-type strains. Knockout strains showed, beside the expected biotin auxotrophy, unchanged growth behavior and biocatalytic activity. Thus, high specific rates (~80 U gCDW −1) for terminal FAME oxyfunctionalization catalyzed by a recombinant alkane monooxygenase could be combined with reduced hydrolysis. Biotransformations in process-relevant two-liquid phase systems profited from reduced fatty acid accumulation and/or reduced substrate loss via free fatty acid metabolization. The BioH knockout strategy was beneficial in all tested strains, although its effect was found to differ according to specific strain properties, such as FAME hydrolysis and FFA degradation activities. BioH or functional analogs can be found in virtually all microorganisms, making bioH deletion a broadly applicable strategy for efficient microbial bioprocessing involving FAMEs.
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Kadisch M, Julsing MK, Schrewe M, Jehmlich N, Scheer B, von Bergen M, Schmid A, Bühler B. Maximization of cell viability rather than biocatalyst activity improves whole-cell ω-oxyfunctionalization performance. Biotechnol Bioeng 2016; 114:874-884. [PMID: 27883174 DOI: 10.1002/bit.26213] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 07/11/2016] [Accepted: 10/31/2016] [Indexed: 11/11/2022]
Abstract
It is a common misconception in whole-cell biocatalysis to refer to an enzyme as the biocatalyst, thereby neglecting the structural and metabolic framework provided by the cell. Here, the low whole-cell biocatalyst stability, that is, the stability of specific biocatalyst activity, in a process for the terminal oxyfunctionalization of renewable fatty acid methyl esters was investigated. This reaction, which is difficult to achieve by chemical means, is catalyzed by Escherichia coli featuring the monooxygenase system AlkBGT and the uptake facilitator AlkL from Pseudomonas putida GPo1. Corresponding products, that is, terminal alcohols, aldehydes, and acids, constitute versatile bifunctional building blocks, which are of special interest for polymer synthesis. It could clearly be shown that extensive dodecanoic acid methyl ester uptake mediated by high AlkL levels leads to whole-cell biocatalyst toxification. Thus, cell viability constitutes the primary factor limiting biocatalyst stability and, as a result, process durability. Hence, a compromise had to be found between low biocatalyst activity due to restricted substrate uptake and poor biocatalyst stability due to AlkL-mediated toxification. This was achieved by the fine-tuning of heterologous alkL expression, which, furthermore, enabled the identification of the alkBGT expression level as another critical factor determining biocatalyst stability. Controlled synthesis of AlkL and reduced alkBGT expression finally enabled an increase of product titers by a factor of 4.3 up to 229 g Lorg-1 in a two-liquid phase bioprocess setup. Clearly, ω-oxyfunctionalization process performance was determined by cell viability and thus biocatalyst stability rather than the maximally achievable specific biocatalyst activity. Biotechnol. Bioeng. 2017;114: 874-884. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Marvin Kadisch
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318, Leipzig, Germany
| | - Mattijs K Julsing
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Manfred Schrewe
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318, Leipzig, Germany
| | - Nico Jehmlich
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Benjamin Scheer
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Martin von Bergen
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Andreas Schmid
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318, Leipzig, Germany
| | - Bruno Bühler
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318, Leipzig, Germany
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Zobel S, Kuepper J, Ebert B, Wierckx N, Blank LM. Metabolic response of Pseudomonas putida to increased NADH regeneration rates. Eng Life Sci 2016; 17:47-57. [PMID: 32624728 DOI: 10.1002/elsc.201600072] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 07/19/2016] [Accepted: 08/10/2016] [Indexed: 11/08/2022] Open
Abstract
Pseudomonas putida efficiently utilizes many different carbon sources without the formation of byproducts even under conditions of stress. This implies a high degree of flexibility to cope with conditions that require a significantly altered distribution of carbon to either biomass or energy in the form of NADH. In the literature, co-feeding of the reduced C1 compound formate to Escherichia coli heterologously expressing the NAD+-dependent formate dehydrogenase of the yeast Candida boidinii was demonstrated to boost various NADH-demanding applications. Pseudomonas putida as emerging biotechnological workhorse is inherently equipped with an NAD+-dependent formate dehydrogenase encouraging us to investigate the use of formate and its effect on P. putida's metabolism. Hence, this study provides a detailed insight into the co-utilization of formate and glucose by P. putida. Our results show that the addition of formate leads to a high increase in the NADH regeneration rate resulting in a very high biomass yield on glucose. Metabolic flux analysis revealed a significant flux rerouting from catabolism to anabolism. These metabolic insights argue further for P. putida as a host for redox cofactor demanding bioprocesses.
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Affiliation(s)
- Sebastian Zobel
- Institute of Applied Microbiology - iAMB RWTH Aachen University - ABBt Aachen Germany
| | - Jannis Kuepper
- Institute of Applied Microbiology - iAMB RWTH Aachen University - ABBt Aachen Germany
| | - Birgitta Ebert
- Institute of Applied Microbiology - iAMB RWTH Aachen University - ABBt Aachen Germany
| | - Nick Wierckx
- Institute of Applied Microbiology - iAMB RWTH Aachen University - ABBt Aachen Germany
| | - Lars M Blank
- Institute of Applied Microbiology - iAMB RWTH Aachen University - ABBt Aachen Germany
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24
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Kuepper J, Zobel S, Wierckx N, Blank LM. A rapid method to estimate NADH regeneration rates in living cells. J Microbiol Methods 2016; 130:92-94. [PMID: 27592588 DOI: 10.1016/j.mimet.2016.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 09/01/2016] [Indexed: 02/05/2023]
Abstract
We introduce a rapid whole cell assay for the estimation of NADH regeneration rates based on the fluorescent dye resazurin. A co-feed of formate and glucose, known to increase the intrinsic NADH regeneration rate of P. putida KT2440, was chosen as model system for the validation of this assay.
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Affiliation(s)
- Jannis Kuepper
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Sebastian Zobel
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Nick Wierckx
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
| | - Lars M Blank
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
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25
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Ladkau N, Assmann M, Schrewe M, Julsing MK, Schmid A, Bühler B. Efficient production of the Nylon 12 monomer ω-aminododecanoic acid methyl ester from renewable dodecanoic acid methyl ester with engineered Escherichia coli. Metab Eng 2016; 36:1-9. [PMID: 26969251 DOI: 10.1016/j.ymben.2016.02.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 01/21/2016] [Accepted: 02/23/2016] [Indexed: 01/02/2023]
Abstract
The expansion of microbial substrate and product scopes will be an important brick promoting future bioeconomy. In this study, an orthogonal pathway running in parallel to native metabolism and converting renewable dodecanoic acid methyl ester (DAME) via terminal alcohol and aldehyde to 12-aminododecanoic acid methyl ester (ADAME), a building block for the high-performance polymer Nylon 12, was engineered in Escherichia coli and optimized regarding substrate uptake, substrate requirements, host strain choice, flux, and product yield. Efficient DAME uptake was achieved by means of the hydrophobic outer membrane porin AlkL increasing maximum oxygenation and transamination activities 8.3 and 7.6-fold, respectively. An optimized coupling to the pyruvate node via a heterologous alanine dehydrogenase enabled efficient intracellular L-alanine supply, a prerequisite for self-sufficient whole-cell transaminase catalysis. Finally, the introduction of a respiratory chain-linked alcohol dehydrogenase enabled an increase in pathway flux, the minimization of undesired overoxidation to the respective carboxylic acid, and thus the efficient formation of ADAME as main product. The completely synthetic orthogonal pathway presented in this study sets the stage for Nylon 12 production from renewables. Its effective operation achieved via fine tuning the connectivity to native cell functionalities emphasizes the potential of this concept to expand microbial substrate and product scopes.
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Affiliation(s)
- Nadine Ladkau
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Strasse 66, 44227 Dortmund, Germany
| | - Miriam Assmann
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Strasse 66, 44227 Dortmund, Germany
| | - Manfred Schrewe
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Strasse 66, 44227 Dortmund, Germany; Department of Solar Materials, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Mattijs K Julsing
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Strasse 66, 44227 Dortmund, Germany
| | - Andreas Schmid
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Strasse 66, 44227 Dortmund, Germany; Department of Solar Materials, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
| | - Bruno Bühler
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Strasse 66, 44227 Dortmund, Germany; Department of Solar Materials, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
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26
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Willrodt C, Hoschek A, Bühler B, Schmid A, Julsing MK. Decoupling production from growth by magnesium sulfate limitation boosts de novo limonene production. Biotechnol Bioeng 2015; 113:1305-14. [PMID: 26574166 DOI: 10.1002/bit.25883] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/08/2015] [Indexed: 01/23/2023]
Abstract
The microbial production of isoprenoids has recently developed into a prime example for successful bottom-up synthetic biology or top-down systems biology strategies. Respective fermentation processes typically rely on growing recombinant microorganisms. However, the fermentative production of isoprenoids has to compete with cellular maintenance and growth for carbon and energy. Non-growing but metabolically active E. coli cells were evaluated in this study as alternative biocatalyst configurations to reduce energy and carbon loss towards biomass formation. The use of non-growing cells in an optimized fermentation medium resulted in more than fivefold increased specific limonene yields on cell dry weight and glucose, as compared to the traditional growing-cell-approach. Initially, the stability of the resting-cell activity was limited. This instability was overcome via the optimization of the minimal fermentation medium enabling high and stable limonene production rates for up to 8 h and a high specific yield of ≥50 mg limonene per gram cell dry weight. Omitting MgSO4 from the fermentation medium was very promising to prohibit growth and allow high productivities. Applying a MgSO4 -limitation also improved limonene formation by growing cells during non-exponential growth involving a reduced biomass yield on glucose and a fourfold increase in specific limonene yields on biomass as compared to non-limited cultures. The control of microbial growth via the medium composition was identified as a key but yet underrated strategy for efficient isoprenoid production. Biotechnol. Bioeng. 2016;113: 1305-1314. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Christian Willrodt
- Department Solar Materials, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany.,Department of Biochemical and Chemical Engineering, Laboratory of Chemical Biotechnology, TU Dortmund University, Dortmund, Germany
| | - Anna Hoschek
- Department of Biochemical and Chemical Engineering, Laboratory of Chemical Biotechnology, TU Dortmund University, Dortmund, Germany
| | - Bruno Bühler
- Department of Biochemical and Chemical Engineering, Laboratory of Chemical Biotechnology, TU Dortmund University, Dortmund, Germany
| | - Andreas Schmid
- Department Solar Materials, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany.
| | - Mattijs K Julsing
- Department of Biochemical and Chemical Engineering, Laboratory of Chemical Biotechnology, TU Dortmund University, Dortmund, Germany
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27
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Lindmeyer M, Jahn M, Vorpahl C, Müller S, Schmid A, Bühler B. Variability in subpopulation formation propagates into biocatalytic variability of engineered Pseudomonas putida strains. Front Microbiol 2015; 6:1042. [PMID: 26483771 PMCID: PMC4589675 DOI: 10.3389/fmicb.2015.01042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/14/2015] [Indexed: 01/01/2023] Open
Abstract
Pivotal challenges in industrial biotechnology are the identification and overcoming of cell-to-cell heterogeneity in microbial processes. While the development of subpopulations of isogenic cells in bioprocesses is well described (intra-population variability), a possible variability between genetically identical cultures growing under macroscopically identical conditions (clonal variability) is not. A high such clonal variability has been found for the recombinant expression of the styrene monooxygenase genes styAB from Pseudomonas taiwanensis VLB120 in solvent-tolerant Pseudomonas putida DOT-T1E using the alk-regulatory system from P. putida GPo1. In this study, the oxygenase subunit StyA fused to eGFP was used as readout tool to characterize the population structure in P. putida DOT-T1E regarding recombinant protein content. Flow cytometric analyses revealed that in individual cultures, at least two subpopulations with highly differing recombinant StyA-eGFP protein contents appeared (intra-population variability). Interestingly, subpopulation sizes varied from culture-to-culture correlating with the specific styrene epoxidation activity of cells derived from respective cultures (clonal variability). In addition, flow cytometric cell sorting coupled to plasmid copy number (PCN) determination revealed that detected clonal variations cannot be correlated to the PCN, but depend on the combination of the regulatory system and the host strain employed. This is, to the best of our knowledge, the first work reporting that intra-population variability (with differing protein contents in the presented case study) causes clonal variability of genetically identical cultures. Respective impacts on bioprocess reliability and performance and strategies to overcome respective reliability issues are discussed.
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Affiliation(s)
- Martin Lindmeyer
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University Dortmund, Germany
| | - Michael Jahn
- Helmholtz Centre for Environmental Research - UFZ, Department for Environmental Microbiology Leipzig, Germany
| | - Carsten Vorpahl
- Helmholtz Centre for Environmental Research - UFZ, Department for Environmental Microbiology Leipzig, Germany
| | - Susann Müller
- Helmholtz Centre for Environmental Research - UFZ, Department for Environmental Microbiology Leipzig, Germany
| | - Andreas Schmid
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University Dortmund, Germany ; Helmholtz Centre for Environmental Research - UFZ, Department of Solar Materials Leipzig, Germany
| | - Bruno Bühler
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University Dortmund, Germany ; Helmholtz Centre for Environmental Research - UFZ, Department of Solar Materials Leipzig, Germany
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28
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Kratzer R, Woodley JM, Nidetzky B. Rules for biocatalyst and reaction engineering to implement effective, NAD(P)H-dependent, whole cell bioreductions. Biotechnol Adv 2015; 33:1641-52. [PMID: 26343336 PMCID: PMC5414839 DOI: 10.1016/j.biotechadv.2015.08.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 08/21/2015] [Accepted: 08/31/2015] [Indexed: 12/27/2022]
Abstract
Access to chiral alcohols of high optical purity is today frequently provided by the enzymatic reduction of precursor ketones. However, bioreductions are complicated by the need for reducing equivalents in the form of NAD(P)H. The high price and molecular weight of NAD(P)H necessitate in situ recycling of catalytic quantities, which is mostly accomplished by enzymatic oxidation of a cheap co-substrate. The coupled oxidoreduction can be either performed by free enzymes in solution or by whole cells. Reductase selection, the decision between cell-free and whole cell reduction system, coenzyme recycling mode and reaction conditions represent design options that strongly affect bioreduction efficiency. In this paper, each option was critically scrutinized and decision rules formulated based on well-described literature examples. The development chain was visualized as a decision-tree that can be used to identify the most promising route towards the production of a specific chiral alcohol. General methods, applications and bottlenecks in the set-up are presented and key experiments required to "test" for decision-making attributes are defined. The reduction of o-chloroacetophenone to (S)-1-(2-chlorophenyl)ethanol was used as one example to demonstrate all the development steps. Detailed analysis of reported large scale bioreductions identified product isolation as a major bottleneck in process design.
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Affiliation(s)
- Regina Kratzer
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/I, 8010 Graz, Austria.
| | - John M Woodley
- CAPEC-PROCESS Research Center, Department of Chemical and Biochemical Engineering, Technical University of Denmark, Søltofts Plads Building 229, 2800 Kgs. Lyngby, Denmark.
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/I, 8010 Graz, Austria.
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Theodosiou E, Frick O, Bühler B, Schmid A. Metabolic network capacity of Escherichia coli for Krebs cycle-dependent proline hydroxylation. Microb Cell Fact 2015. [PMID: 26215086 PMCID: PMC4517350 DOI: 10.1186/s12934-015-0298-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Background Understanding the metabolism of the microbial host is essential for the development and optimization of whole-cell based biocatalytic processes, as it dictates production efficiency. This is especially true for redox biocatalysis where metabolically active cells are employed because of the cofactor/cosubstrate regenerative capacity endogenous in the host. Recombinant Escherichia coli was used for overproducing proline-4-hydroxylase (P4H), a dioxygenase catalyzing the hydroxylation of free l-proline into trans-4-hydroxy-l-proline with a-ketoglutarate (a-KG) as cosubstrate. In this whole-cell biocatalyst, central carbon metabolism provides the required cosubstrate a-KG, coupling P4H biocatalytic performance directly to carbon metabolism and metabolic activity. By applying both experimental and computational biology tools, such as metabolic engineering and 13C-metabolic flux analysis (13C-MFA), we investigated and quantitatively described the physiological, metabolic, and bioenergetic response of the whole-cell biocatalyst to the targeted bioconversion and identified possible metabolic bottlenecks for further rational pathway engineering. Results A proline degradation-deficient E. coli strain was constructed by deleting the putA gene encoding proline dehydrogenase. Whole-cell biotransformations with this mutant strain led not only to quantitative proline hydroxylation but also to a doubling of the specific trans-4-l-hydroxyproline (hyp) formation rate, compared to the wild type. Analysis of carbon flux through central metabolism of the mutant strain revealed that the increased a-KG demand for P4H activity did not enhance the a-KG generating flux, indicating a tightly regulated TCA cycle operation under the conditions studied. In the wild type strain, P4H synthesis and catalysis caused a reduction in biomass yield. Interestingly, the ΔputA strain additionally compensated the associated ATP and NADH loss by reducing maintenance energy demands at comparably low glucose uptake rates, instead of increasing the TCA activity. Conclusions The putA knockout in recombinant E. coli BL21(DE3)(pLysS) was found to be promising for productive P4H catalysis not only in terms of biotransformation yield, but also regarding the rates for biotransformation and proline uptake and the yield of hyp on the energy source. The results indicate that, upon a putA knockout, the coupling of the TCA-cycle to proline hydroxylation via the cosubstrate a-KG becomes a key factor constraining and a target to further improve the efficiency of a-KG-dependent biotransformations. Electronic supplementary material The online version of this article (doi:10.1186/s12934-015-0298-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eleni Theodosiou
- Department of Biochemical and Chemical Engineering, Laboratory of Chemical Biotechnology, TU Dortmund University, Emil-Figge-Strasse 66, 44227, Dortmund, Germany. .,Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany.
| | - Oliver Frick
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany.
| | - Bruno Bühler
- Department of Biochemical and Chemical Engineering, Laboratory of Chemical Biotechnology, TU Dortmund University, Emil-Figge-Strasse 66, 44227, Dortmund, Germany. .,Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany.
| | - Andreas Schmid
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany.
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Willrodt C, Hoschek A, Bühler B, Schmid A, Julsing MK. Coupling limonene formation and oxyfunctionalization by mixed-culture resting cell fermentation. Biotechnol Bioeng 2015; 112:1738-50. [PMID: 25786991 DOI: 10.1002/bit.25592] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/13/2015] [Accepted: 03/10/2015] [Indexed: 01/11/2023]
Abstract
Metabolic engineering strategies mark a milestone for the fermentative production of bulk and fine chemicals. Yet, toxic products and volatile reaction intermediates with low solubilities remain challenging. Prominent examples are artificial multistep pathways like the production of perillyl acetate (POHAc) from glucose via limonene. For POHAc, these limitations can be overcome by mixed-culture fermentations. A limonene biosynthesis pathway and cytochrome P450 153A6 (CYP153A6) as regioselective hydroxylase are used in two distinct recombinant E. coli. POHAc formation from glucose in one recombinant cell was hindered by ineffective coupling of limonene synthesis and low rates of oxyfunctionalization. The optimization of P450 gene expression led to the formation of 6.20 ± 0.06 mg gcdw (-1) POHAc in a biphasic batch cultivation with glucose as sole carbon and energy source. Increasing the spatial proximity between limonene synthase and CYP153A6 by a genetic fusion of both enzymes changed the molar limonene/POHAc ratio from 3.2 to 1.6. Spatial separation of limonene biosynthesis from its oxyfunctionalization improved POHAc concentration 3.3-fold to 21.7 mg L(-1) as compared to a biphasic fermentation. Mixed-cultures of E. coli BL21 (DE3) containing the limonene biosynthesis pathway and E. coli MG1655 harboring either CYP153A6, or alternatively a cymene monooxygenase, showed POHAc formation rates of 0.06 or 0.11 U gcdw (-1) , respectively. This concept provides a novel framework for fermentative syntheses involving toxic, volatile, or barely soluble compounds or pathway intermediates.
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Affiliation(s)
- Christian Willrodt
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany.,Department Solar Materials, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
| | - Anna Hoschek
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Bruno Bühler
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Andreas Schmid
- Department Solar Materials, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany.
| | - Mattijs K Julsing
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
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Holtmann D, Fraaije MW, Arends IWCE, Opperman DJ, Hollmann F. The taming of oxygen: biocatalytic oxyfunctionalisations. Chem Commun (Camb) 2015; 50:13180-200. [PMID: 24902635 DOI: 10.1039/c3cc49747j] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The scope and limitations of oxygenases as catalysts for preparative organic synthesis is discussed.
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Affiliation(s)
- Dirk Holtmann
- DECHEMA Research Institute, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany
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Guidelines for development and implementation of biocatalytic P450 processes. Appl Microbiol Biotechnol 2015; 99:2465-83. [PMID: 25652652 DOI: 10.1007/s00253-015-6403-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 01/17/2023]
Abstract
Biocatalytic reactions performed by cytochrome P450 monooxygenases are interesting in pharmaceutical research since they are involved in human drug metabolism. Furthermore, they are potentially interesting as biocatalysts for synthetic chemistry because of the exquisite selectivity of the chemistry they undertake. For example, selective hydroxylation can be undertaken on a highly functionalized molecule without the need for functional group protection. Recent progress in the discovery of novel P450s as well as protein engineering of these enzymes strongly encourages further development of their application, including use in synthetic processes. The biological characteristics of P450s (e.g., cofactor dependence) motivate the use of whole-cell systems for synthetic processes, and those processes implemented in industry are so far dominated by growing cells and native host systems. However, for an economically feasible process, the expression of P450 systems in a heterologous host with sufficient biocatalyst yield (g/g cdw) for non-growing systems or space-time yield (g/L/h) for growing systems remains a major challenge. This review summarizes the opportunities to improve P450 whole-cell processes and strategies in order to apply and implement them in industrial processes, both from a biological and process perspective. Indeed, a combined approach of host selection and cell engineering, integrated with process engineering, is suggested as the most effective route to implementation.
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Biooxidation of n-butane to 1-butanol by engineered P450 monooxygenase under increased pressure. J Biotechnol 2014; 191:86-92. [DOI: 10.1016/j.jbiotec.2014.08.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 08/06/2014] [Accepted: 08/19/2014] [Indexed: 01/09/2023]
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Falcioni F, Bühler B, Schmid A. Efficient hydroxyproline production from glucose in minimal media byCorynebacterium glutamicum. Biotechnol Bioeng 2014; 112:322-30. [DOI: 10.1002/bit.25442] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 08/06/2014] [Accepted: 08/18/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Francesco Falcioni
- Department of Biochemical and Chemical Engineering; Laboratory of Chemical Biotechnology; TU Dortmund University; Emil-Figge-Strasse 66 Dortmund 44227 Germany
| | - Bruno Bühler
- Department of Biochemical and Chemical Engineering; Laboratory of Chemical Biotechnology; TU Dortmund University; Emil-Figge-Strasse 66 Dortmund 44227 Germany
| | - Andreas Schmid
- Department of Biochemical and Chemical Engineering; Laboratory of Chemical Biotechnology; TU Dortmund University; Emil-Figge-Strasse 66 Dortmund 44227 Germany
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Tarlak F, Sadıkoğlu H, Çakır T. The role of flexibility and optimality in the prediction of intracellular fluxes of microbial central carbon metabolism. MOLECULAR BIOSYSTEMS 2014; 10:2459-65. [DOI: 10.1039/c4mb00117f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Müller CA, Dennig A, Welters T, Winkler T, Ruff AJ, Hummel W, Gröger H, Schwaneberg U. Whole-cell double oxidation of n-heptane. J Biotechnol 2014; 191:196-204. [PMID: 24925696 DOI: 10.1016/j.jbiotec.2014.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 05/25/2014] [Accepted: 06/02/2014] [Indexed: 10/25/2022]
Abstract
Biocascades allow one-pot synthesis of chemical building blocks omitting purification of reaction intermediates and expenses for downstream processing. Here we show the first whole cell double oxidation of n-heptane to produce chiral alcohols and heptanones. The concept of an artificial operon for co-expression of a monooxygenase from Bacillus megaterium (P450 BM3) and an alcohol dehydrogenase (RE-ADH) from Rhodococcus erythropolis is reported and compared to the widely used two-plasmid or Duet-vector expression systems. Both catalysts are co-expressed on a polycistronic constructs (single mRNA) that reduces recombinant DNA content and metabolic burden for the host cell, therefore increasing growth rate and expression level. Using the artificial operon system, the expression of P450 BM3 reached 81mgg(-1) cell dry weight. In addition, in situ cofactor regeneration through the P450 BM3/RE-ADH couple was enhanced by coupling to glucose oxidation by E. coli. Under optimized reaction conditions the artificial operon system displayed a product formation of 656mgL(-1) (5.7mM) of reaction products (heptanols+heptanones), which is 3-fold higher than the previously reported values for an in vitro oxidation cascade. In conjunction with the high product concentrations it was possible to obtain ee values of >99% for (S)-3-heptanol. Coexpression of a third alcohol dehydrogenase from Lactobacillus brevis (Lb-ADH) in the same host yielded complete oxidation of all heptanol isomers. Introduction of a second ADH enabled further to utilize both cofactors in the host cell (NADH and NADPH) which illustrates the simplicity and modular character of the whole cell oxidation concept employing an artificial operon system.
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Affiliation(s)
- Christina A Müller
- Institute of Biotechnology, RWTH Aachen, Worringerweg 3, 52074 Aachen, Germany
| | - Alexander Dennig
- Institute of Biotechnology, RWTH Aachen, Worringerweg 3, 52074 Aachen, Germany
| | - Tim Welters
- Institute of Biotechnology, RWTH Aachen, Worringerweg 3, 52074 Aachen, Germany
| | - Till Winkler
- Institute of Molecular Enzyme Technology at the Heinrich-Heine-University of Düsseldorf, Research Centre Jülich, Stetternicher Forst, 52426 Jülich, Germany
| | - Anna Joelle Ruff
- Institute of Biotechnology, RWTH Aachen, Worringerweg 3, 52074 Aachen, Germany
| | - Werner Hummel
- Institute of Molecular Enzyme Technology at the Heinrich-Heine-University of Düsseldorf, Research Centre Jülich, Stetternicher Forst, 52426 Jülich, Germany
| | - Harald Gröger
- Faculty of Chemistry, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen, Worringerweg 3, 52074 Aachen, Germany.
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Engineering the productivity of recombinantEscherichia colifor limonene formation from glycerol in minimal media. Biotechnol J 2014; 9:1000-12. [DOI: 10.1002/biot.201400023] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 03/10/2014] [Accepted: 04/21/2014] [Indexed: 01/18/2023]
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Schrewe M, Julsing MK, Lange K, Czarnotta E, Schmid A, Bühler B. Reaction and catalyst engineering to exploit kinetically controlled whole-cell multistep biocatalysis for terminal FAME oxyfunctionalization. Biotechnol Bioeng 2014; 111:1820-30. [DOI: 10.1002/bit.25248] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 02/18/2014] [Accepted: 03/24/2014] [Indexed: 01/14/2023]
Affiliation(s)
- Manfred Schrewe
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering; TU Dortmund University; Emil-Figge-Strasse 66 Dortmund 44227 Germany
| | - Mattijs K. Julsing
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering; TU Dortmund University; Emil-Figge-Strasse 66 Dortmund 44227 Germany
| | - Kerstin Lange
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering; TU Dortmund University; Emil-Figge-Strasse 66 Dortmund 44227 Germany
| | - Eik Czarnotta
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering; TU Dortmund University; Emil-Figge-Strasse 66 Dortmund 44227 Germany
| | - Andreas Schmid
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering; TU Dortmund University; Emil-Figge-Strasse 66 Dortmund 44227 Germany
| | - Bruno Bühler
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering; TU Dortmund University; Emil-Figge-Strasse 66 Dortmund 44227 Germany
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Klatte S, Wendisch VF. Redox self-sufficient whole cell biotransformation for amination of alcohols. Bioorg Med Chem 2014; 22:5578-85. [PMID: 24894767 DOI: 10.1016/j.bmc.2014.05.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/02/2014] [Accepted: 05/09/2014] [Indexed: 10/25/2022]
Abstract
Whole cell biotransformation is an upcoming tool to replace common chemical routes for functionalization and modification of desired molecules. In the approach presented here the production of various non-natural (di)amines was realized using the designed whole cell biocatalyst Escherichia coli W3110/pTrc99A-ald-adh-ta with plasmid-borne overexpression of genes for an l-alanine dehydrogenase, an alcohol dehydrogenase and a transaminase. Cascading alcohol oxidation with l-alanine dependent transamination and l-alanine dehydrogenase allowed for redox self-sufficient conversion of alcohols to the corresponding amines. The supplementation of the corresponding (di)alcohol precursors as well as amino group donor l-alanine and ammonium chloride were sufficient for amination and redox cofactor recycling in a resting buffer system. The addition of the transaminase cofactor pyridoxal-phosphate and the alcohol dehydrogenase cofactor NAD(+) was not necessary to obtain complete conversion. Secondary and cyclic alcohols, for example, 2-hexanol and cyclohexanol were not aminated. However, efficient redox self-sufficient amination of aliphatic and aromatic (di)alcohols in vivo was achieved with 1-hexanol, 1,10-decanediol and benzylalcohol being aminated best.
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Affiliation(s)
- Stephanie Klatte
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitaetsstr. 25, 33615 Bielefeld, Germany
| | - Volker F Wendisch
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitaetsstr. 25, 33615 Bielefeld, Germany.
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Schrewe M, Julsing MK, Bühler B, Schmid A. Whole-cell biocatalysis for selective and productive C-O functional group introduction and modification. Chem Soc Rev 2014; 42:6346-77. [PMID: 23475180 DOI: 10.1039/c3cs60011d] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
During the last decades, biocatalysis became of increasing importance for chemical and pharmaceutical industries. Regarding regio- and stereospecificity, enzymes have shown to be superior compared to traditional chemical synthesis approaches, especially in C-O functional group chemistry. Catalysts established on a process level are diverse and can be classified along a functional continuum starting with single-step biotransformations using isolated enzymes or microbial strains towards fermentative processes with recombinant microorganisms containing artificial synthetic pathways. The complex organization of respective enzymes combined with aspects such as cofactor dependency and low stability in isolated form often favors the use of whole cells over that of isolated enzymes. Based on an inventory of the large spectrum of biocatalytic C-O functional group chemistry, this review focuses on highlighting the potentials, limitations, and solutions offered by the application of self-regenerating microbial cells as biocatalysts. Different cellular functionalities are discussed in the light of their (possible) contribution to catalyst efficiency. The combined achievements in the areas of protein, genetic, metabolic, and reaction engineering enable the development of whole-cell biocatalysts as powerful tools in organic synthesis.
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Affiliation(s)
- Manfred Schrewe
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Strasse 66, 44227 Dortmund, Germany
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41
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Klatte S, Lorenz E, Wendisch VF. Whole cell biotransformation for reductive amination reactions. Bioengineered 2013; 5:56-62. [PMID: 24406456 DOI: 10.4161/bioe.27151] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Whole cell biotransformation systems with enzyme cascading increasingly find application in biocatalysis to complement or replace established chemical synthetic routes for production of, e.g., fine chemicals. Recently, we established an Escherichia coli whole cell biotransformation system for reductive amination by coupling a transaminase and an amino acid dehydrogenase with glucose catabolism for cofactor recycling. Transformation of 2-keto-3-methylvalerate to l-isoleucine by E. coli cells was improved by genetic engineering of glucose metabolism for improved cofactor regeneration. Here, we compare this system with different strategies for cofactor regeneration such as cascading with alcohol dehydrogenases, with alternative production hosts such as Pseudomonas species or Corynebacterium glutamicum, and with improving whole cell biotransformation systems by metabolic engineering of NADPH regeneration.
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Affiliation(s)
- Stephanie Klatte
- Chair of Genetics of Prokaryotes; Faculty of Biology & CeBiTec; Bielefeld University; Bielefeld, Germany
| | - Elisabeth Lorenz
- Chair of Genetics of Prokaryotes; Faculty of Biology & CeBiTec; Bielefeld University; Bielefeld, Germany
| | - Volker F Wendisch
- Chair of Genetics of Prokaryotes; Faculty of Biology & CeBiTec; Bielefeld University; Bielefeld, Germany
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Lorenz E, Klatte S, Wendisch VF. Reductive amination by recombinant Escherichia coli: whole cell biotransformation of 2-keto-3-methylvalerate to L-isoleucine. J Biotechnol 2013; 168:289-94. [PMID: 23831557 DOI: 10.1016/j.jbiotec.2013.06.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 06/17/2013] [Accepted: 06/24/2013] [Indexed: 10/26/2022]
Abstract
A whole cell biotransformation system for reductive amination has been studied in recombinant Escherichia coli cells. Reductive amination of 2-keto-3-methylvalerate to L-isoleucine by a two-enzyme-cascade was achieved by overproduction of endogenous L-alanine dependent transaminase AvtA and heterologous L-alanine dehydrogenase from Bacillus subtilis in recombinant E. coli. Up to 100 mM L-isoleucine were produced from 100 mM 2-keto-3-methylvalerate and 100 mM ammonium sulfate. Regeneration of NADH as cofactor in the whole cell system was driven by glucose catabolism. The effects of defined gene deletions in the central carbon metabolism on biotransformation were tested. Strains lacking the NuoG subunit of NADH:ubiquinone oxidoreductase (complex I) or aceA encoding the glyoxylate cycle enzyme isocitrate lyase exhibited increased biotransformation rates.
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Affiliation(s)
- Elisabeth Lorenz
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, D-33615 Bielefeld, Germany
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Proline availability regulates proline-4-hydroxylase synthesis and substrate uptake in proline-hydroxylating recombinant Escherichia coli. Appl Environ Microbiol 2013; 79:3091-100. [PMID: 23455348 DOI: 10.1128/aem.03640-12] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial physiology plays a crucial role in whole-cell biotransformation, especially for redox reactions that depend on carbon and energy metabolism. In this study, regio- and enantio-selective proline hydroxylation with recombinant Escherichia coli expressing proline-4-hydroxylase (P4H) was investigated with respect to its interconnectivity to microbial physiology and metabolism. P4H production was found to depend on extracellular proline availability and on codon usage. Medium supplementation with proline did not alter p4h mRNA levels, indicating that P4H production depends on the availability of charged prolyl-tRNAs. Increasing the intracellular levels of soluble P4H did not result in an increase in resting cell activities above a certain threshold (depending on growth and assay temperature). Activities up to 5-fold higher were reached with permeabilized cells, confirming that host physiology and not the intracellular level of active P4H determines the achievable whole-cell proline hydroxylation activity. Metabolic flux analysis revealed that tricarboxylic acid cycle fluxes in growing biocatalytically active cells were significantly higher than proline hydroxylation rates. Remarkably, a catalysis-induced reduction of substrate uptake was observed, which correlated with reduced transcription of putA and putP, encoding proline dehydrogenase and the major proline transporter, respectively. These results provide evidence for a strong interference of catalytic activity with the regulation of proline uptake and metabolism. In terms of whole-cell biocatalyst efficiency, proline uptake and competition of P4H with proline catabolism are considered the most critical factors.
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Olaofe OA, Fenner CJ, Gudiminchi RK, Smit MS, Harrison STL. The influence of microbial physiology on biocatalyst activity and efficiency in the terminal hydroxylation of n-octane using Escherichia coli expressing the alkane hydroxylase, CYP153A6. Microb Cell Fact 2013; 12:8. [PMID: 23351575 PMCID: PMC3598389 DOI: 10.1186/1475-2859-12-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 01/17/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Biocatalyst improvement through molecular and recombinant means should be complemented with efficient process design to facilitate process feasibility and improve process economics. This study focused on understanding the bioprocess limitations to identify factors that impact the expression of the terminal hydroxylase CYP153A6 and also influence the biocatalytic transformation of n-octane to 1-octanol using resting whole cells of recombinant E. coli expressing the CYP153A6 operon which includes the ferredoxin (Fdx) and the ferredoxin reductase (FdR). RESULTS Specific hydroxylation activity decreased with increasing protein expression showing that the concentration of active biocatalyst is not the sole determinant of optimum process efficiency. Process physiological conditions including the medium composition, temperature, glucose metabolism and product toxicity were investigated. A fed-batch system with intermittent glucose feeding was necessary to ease overflow metabolism and improve process efficiency while the introduction of a product sink (BEHP) was required to alleviate octanol toxicity. Resting cells cultivated on complex LB and glucose-based defined medium with similar CYP level (0.20 μmol gDCW-1) showed different biocatalyst activity and efficiency in the hydroxylation of octane over a period of 120 h. This was influenced by differing glucose uptake rate which is directly coupled to cofactor regeneration and cell energy in whole cell biocatalysis. The maximum activity and biocatalyst efficiency achieved presents a significant improvement in the use of CYP153A6 for alkane activation. This biocatalyst system shows potential to improve productivity if substrate transfer limitation across the cell membrane and enzyme stability can be addressed especially at higher temperature. CONCLUSION This study emphasises that the overall process efficiency is primarily dependent on the interaction between the whole cell biocatalyst and bioprocess conditions.
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Affiliation(s)
- Oluwafemi A Olaofe
- Centre for Bioprocess Engineering Research (CeBER), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch 7701, Cape Town, South Africa
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Kuhn D, Fritzsch FSO, Zhang X, Wendisch VF, Blank LM, Bühler B, Schmid A. Subtoxic product levels limit the epoxidation capacity of recombinant E. coli by increasing microbial energy demands. J Biotechnol 2012; 163:194-203. [PMID: 22922011 DOI: 10.1016/j.jbiotec.2012.07.194] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 07/12/2012] [Accepted: 07/27/2012] [Indexed: 10/28/2022]
Abstract
The utilization of the cellular metabolism for cofactor regeneration is a common motivation for the application of whole cells in redox biocatalysis. Introduction of an active oxidoreductase into a microorganism has profound consequences on metabolism, potentially affecting metabolic and biotransformation efficiency. An ambitious goal of systems biotechnology is to design process-relevant and knowledge-based engineering strategies to improve biocatalyst performance. Metabolic flux analysis (MFA) has shown that the competition for NAD(P)H between redox biocatalysis and the energy metabolism becomes critical during asymmetric styrene epoxidation catalyzed by growing Escherichia coli containing recombinant styrene monooxygenase. Engineering TCA-cycle regulation allowed increased TCA-cycle activities, a delay of acetate formation, and enhanced NAD(P)H yields during batch cultivation. However, at low biomass and product concentrations, the cellular metabolism of both the mutants as well as the native host strains could cope with increased NADH demands during continuous two-liquid phase biotransformations, whereas elevated but still subtoxic product concentrations were found to cause a significantly increased NAD(P)H demand and a compromised efficiency of metabolic operation. In conclusion, operational conditions determine cellular energy and NAD(P)H demands and thus the biocatalytic efficiency of whole-cell redox biocatalysts.
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Affiliation(s)
- Daniel Kuhn
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Str. 66, D-44227 Dortmund, Germany
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Production host selection for asymmetric styrene epoxidation: Escherichia coli vs. solvent-tolerant Pseudomonas. ACTA ACUST UNITED AC 2012; 39:1125-33. [DOI: 10.1007/s10295-012-1126-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 03/28/2012] [Indexed: 10/28/2022]
Abstract
Abstract
Selection of the ideal microbe is crucial for whole-cell biotransformations, especially if the target reaction intensively interacts with host cell functions. Asymmetric styrene epoxidation is an example of a reaction which is strongly dependent on the host cell owing to its requirement for efficient cofactor regeneration and stable expression of the styrene monooxygenase genes styAB. On the other hand, styrene epoxidation affects the whole-cell biocatalyst, because it involves toxic substrate and products besides the burden of additional (recombinant) enzyme synthesis. With the aim to compare two fundamentally different strain engineering strategies, asymmetric styrene epoxidation by StyAB was investigated using the engineered wild-type strain Pseudomonas sp. strain VLB120ΔC, a styrene oxide isomerase (StyC) knockout strain able to accumulate (S)-styrene oxide, and recombinant E. coli JM101 carrying styAB on the plasmid pSPZ10. Their performance was analyzed during fed-batch cultivation in two-liquid phase biotransformations with respect to specific activity, volumetric productivity, product titer, tolerance of toxic substrate and products, by-product formation, and product yield on glucose. Thereby, Pseudomonas sp. strain VLB120ΔC proved its great potential by tolerating high styrene oxide concentrations and by the absence of by-product formation. The E. coli-based catalyst, however, showed higher specific activities and better yields on glucose. The results not only show the importance but also the complexity of host cell selection and engineering. Finding the optimal strain engineering strategy requires profound understanding of bioprocess and biocatalyst operation. In this respect, a possible negative influence of solvent tolerance on yield and activity is discussed.
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Outer membrane protein AlkL boosts biocatalytic oxyfunctionalization of hydrophobic substrates in Escherichia coli. Appl Environ Microbiol 2012; 78:5724-33. [PMID: 22685130 DOI: 10.1128/aem.00949-12] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The outer membrane of microbial cells forms an effective barrier for hydrophobic compounds, potentially causing an uptake limitation for hydrophobic substrates. Low bioconversion activities (1.9 U g(cdw)(-1)) have been observed for the ω-oxyfunctionalization of dodecanoic acid methyl ester by recombinant Escherichia coli containing the alkane monooxygenase AlkBGT of Pseudomonas putida GPo1. Using fatty acid methyl ester oxygenation as the model reaction, this study investigated strategies to improve bacterial uptake of hydrophobic substrates. Admixture of surfactants and cosolvents to improve substrate solubilization did not result in increased oxygenation rates. Addition of EDTA increased the initial dodecanoic acid methyl ester oxygenation activity 2.8-fold. The use of recombinant Pseudomonas fluorescens CHA0 instead of E. coli resulted in a similar activity increase. However, substrate mass transfer into cells was still found to be limiting. Remarkably, the coexpression of the alkL gene of P. putida GPo1 encoding an outer membrane protein with so-far-unknown function increased the dodecanoic acid methyl ester oxygenation activity of recombinant E. coli 28-fold. In a two-liquid-phase bioreactor setup, a 62-fold increase to a maximal activity of 87 U g(cdw)(-1) was achieved, enabling the accumulation of high titers of terminally oxyfunctionalized products. Coexpression of alkL also increased oxygenation activities toward the natural AlkBGT substrates octane and nonane, showing for the first time clear evidence for a prominent role of AlkL in alkane degradation. This study demonstrates that AlkL is an efficient tool to boost productivities of whole-cell biotransformations involving hydrophobic aliphatic substrates and thus has potential for broad applicability.
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Whole-cell hydroxylation of n-octane by Escherichia coli strains expressing the CYP153A6 operon. Appl Microbiol Biotechnol 2012; 96:1507-16. [PMID: 22410745 DOI: 10.1007/s00253-012-3984-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 02/11/2012] [Accepted: 02/17/2012] [Indexed: 10/28/2022]
Abstract
CYP153A6 is a well-studied terminal alkane hydroxylase which has previously been expressed in Pseudomonas putida and Escherichia coli by using the pCom8 plasmid. In this study, CYP153A6 was successfully expressed in E. coli BL21(DE3) by cloning the complete operon from Mycobacterium sp. HXN-1500, also encoding the ferredoxin reductase and ferredoxin, into pET28b(+). LB medium with IPTG as well as auto-induction medium was used to express the proteins under the T7 promoter. A maximum concentration of 1.85 μM of active CYP153A6 was obtained when using auto-induction medium, while with IPTG induction of LB cultures, the P450 concentration peaked at 0.6-0.8 μM. Since more biomass was produced in auto-induction medium, the specific P450 content was often almost the same, 0.5-1.0 μmol P450 g (DCW)⁻¹, for both methods. Analytical scale whole-cell biotransformations of n-octane were conducted with resting cells, and it was found that high P450 content in biomass did not necessarily result in high octanol production. Whole cells from LB cultures induced with IPTG gave higher specific and volumetric octanol formation rates than biomass from auto-induction medium. A maximum of 8.7 g octanol L (BRM)⁻¹ was obtained within 24 h (0.34 g L (BRM)⁻¹ h⁻¹) with IPTG-induced cells containing only 0.20 μmol P450 g (DCW)⁻¹, when glucose (22 g L (BRM)⁻¹) was added for cofactor regeneration.
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Escapa IF, García JL, Bühler B, Blank LM, Prieto MA. The polyhydroxyalkanoate metabolism controls carbon and energy spillage in Pseudomonas putida. Environ Microbiol 2012; 14:1049-63. [PMID: 22225632 DOI: 10.1111/j.1462-2920.2011.02684.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The synthesis and degradation of polyhydroxyalkanoates (PHAs), the storage polymer of many bacteria, is linked to the operation of central carbon metabolism. To rationalize the impact of PHA accumulation on central carbon metabolism of the prototype bacterium Pseudomonas putida, we have revisited PHA production in quantitative physiology experiments in the wild-type strain vs. a PHA negative mutant growing under low nitrogen conditions. When octanoic acid was used as PHA precursor and as carbon and energy source, we have detected higher intracellular flux via acetyl-CoA in the mutant strain than in the wild type, which correlates with the stimulation of the TCA cycle and glyoxylate shunt observed on the transcriptional level. The mutant defective in carbon and energy storage spills the additional resources, releasing CO(2) instead of generating biomass. Hence, P. putida operates the metabolic network to optimally exploit available resources and channels excess carbon and energy to storage via PHA, without compromising growth. These findings demonstrate that the PHA metabolism plays a critical role in synchronizing global metabolism to availability of resources in PHA-producing microorganisms.
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Affiliation(s)
- I F Escapa
- Environmental Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid, Spain
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Julsing MK, Kuhn D, Schmid A, Bühler B. Resting cells of recombinant E. coli show high epoxidation yields on energy source and high sensitivity to product inhibition. Biotechnol Bioeng 2011; 109:1109-19. [DOI: 10.1002/bit.24404] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 10/24/2011] [Accepted: 11/28/2011] [Indexed: 11/07/2022]
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