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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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2
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Abufalgha AA, Pott RWM, Clarke KG. Quantification of oxygen transfer coefficients in simulated hydrocarbon-based bioprocesses in a bubble column bioreactor. Bioprocess Biosyst Eng 2021; 44:1913-1921. [PMID: 33893834 DOI: 10.1007/s00449-021-02571-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 04/09/2021] [Indexed: 12/01/2022]
Abstract
This study investigates the overall volumetric oxygen transfer coefficient (KLa) in multiphase hydrocarbon-based bioprocess under a range of hydrocarbon concentrations (HC), solid loadings (deactivated yeast) (SL) and superficial gas velocities (UG) in a bubble column reactor (BCR). KLa increased with increasing UG in the air-water system; due to an increase in the number of small bubbles which enhanced gas holdup. In air-water-yeast systems, the initial addition of yeast increased KLa significantly. Further increases in SL reduced KLa, due to increases in the bubble size with increasing SL. KLa decreased when HC was added in air-water-hydrocarbon systems. However, UG, SL and HC affected KLa differently in air-water-yeast-hydrocarbon systems: an indication of the complex interactions between the yeast and hydrocarbon phases which changed the system's hydrodynamics and therefore affected KL. This work illustrates the effect of the operating conditions (SL, HC and UG) on oxygen transfer behaviour in multiphase systems.
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Affiliation(s)
- Ayman A Abufalgha
- DST-NRF Centre of Excellence in Catalysis (c* Change), Pretoria, South Africa.,Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600, South Africa
| | - Robert W M Pott
- DST-NRF Centre of Excellence in Catalysis (c* Change), Pretoria, South Africa. .,Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600, South Africa.
| | - Kim G Clarke
- DST-NRF Centre of Excellence in Catalysis (c* Change), Pretoria, South Africa.,Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600, South Africa
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3
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Engineering substrate recognition sites of cytochrome P450 monooxygenase CYP116B3 from Rhodococcus ruber for enhanced regiospecific naphthalene hydroxylation. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.111089] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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4
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Buergler MB, Dennig A, Nidetzky B. Process intensification for cytochrome P450 BM3-catalyzed oxy-functionalization of dodecanoic acid. Biotechnol Bioeng 2020; 117:2377-2388. [PMID: 32369187 PMCID: PMC7384007 DOI: 10.1002/bit.27372] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 01/15/2023]
Abstract
Selective oxy‐functionalization of nonactivated C‐H bonds is a long‐standing “dream reaction” of organic synthesis for which chemical methodology is not well developed. Mono‐oxygenase enzymes are promising catalysts for such oxy‐functionalization to establish. Limitation on their applicability arises from low reaction output. Here, we showed an integrated approach of process engineering to the intensification of the cytochrome P450 BM3‐catalyzed hydroxylation of dodecanoic acid (C12:0). Using P450 BM3 together with glucose dehydrogenase for regeneration of nicotinamide adenine dinucleotide phosphate (NADPH), we compared soluble and co‐immobilized enzymes in O2‐gassed and pH‐controlled conversions at high final substrate concentrations (≥40mM). We identified the main engineering parameters of process output (i.e., O2 supply; mixing correlated with immobilized enzyme stability; foam control correlated with product isolation; substrate solubilization) and succeeded in disentangling their complex interrelationship for systematic process optimization. Running the reaction at O2‐limited conditions at up to 500‐ml scale (10% dimethyl sulfoxide; silicone antifoam), we developed a substrate feeding strategy based on O2 feedback control. Thus, we achieved high reaction rates of 1.86g·L−1·hr−1 and near complete conversion (≥90%) of 80mM (16g/L) C12:0 with good selectivity (≤5% overoxidation). We showed that “uncoupled reaction” of the P450 BM3 (~95% utilization of NADPH and O2 not leading to hydroxylation) with the C12:0 hydroxylated product limited the process efficiency at high product concentration. Hydroxylated product (~7g; ≥92% purity) was recovered from 500ml reaction in 82% yield using ethyl‐acetate extraction. Collectively, these results demonstrate key engineering parameters for the biocatalytic oxy‐functionalization and show their integration into a coherent strategy for process intensification.
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Affiliation(s)
- Moritz B Buergler
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Graz, Austria
| | - Alexander Dennig
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Graz, Austria.,Austrian Centre of Industrial Biotechnology, Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Graz, Austria.,Austrian Centre of Industrial Biotechnology, Graz, Austria
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5
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Gakingo G, Clarke K, Louw T. A numerical investigation of the hydrodynamics and mass transfer in a three-phase gas-liquid-liquid stirred tank reactor. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107522] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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6
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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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7
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Sakkos JK, Wackett LP, Aksan A. Enhancement of biocatalyst activity and protection against stressors using a microbial exoskeleton. Sci Rep 2019; 9:3158. [PMID: 30816335 PMCID: PMC6395662 DOI: 10.1038/s41598-019-40113-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 02/08/2019] [Indexed: 12/18/2022] Open
Abstract
Whole cell biocatalysts can perform numerous industrially-relevant chemical reactions. While they are less expensive than purified enzymes, whole cells suffer from inherent reaction rate limitations due to transport resistance imposed by the cell membrane. Furthermore, it is desirable to immobilize the biocatalysts to enable ease of separation from the reaction mixture. In this study, we used a layer-by-layer (LbL) self-assembly process to create a microbial exoskeleton which, simultaneously immobilized, protected, and enhanced the reactivity of a whole cell biocatalyst. As a proof of concept, we used Escherichia coli expressing homoprotocatechuate 2,3-dioxygenase (HPCD) as a model biocatalyst and coated it with up to ten alternating layers of poly(diallyldimethylammonium chloride) (PDADMAC) and silica. The microbial exoskeleton also protected the biocatalyst against a variety of external stressors including: desiccation, freeze/thaw, exposure to high temperatures, osmotic shock, as well as against enzymatic attack by lysozyme, and predation by protozoa. While we observed increased permeability of the outer membrane after exoskeleton deposition, this had a moderate effect on the reaction rate (up to two-fold enhancement). When the exoskeleton construction was followed by detergent treatment to permeabilize the cytoplasmic membrane, up to 15-fold enhancement in the reaction rate was reached. With the exoskeleton, we increased in the reaction rate constants as much as 21-fold by running the biocatalyst at elevated temperatures ranging from 40 °C to 60 °C, a supraphysiologic temperature range not accessible by unprotected bacteria.
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Affiliation(s)
- Jonathan K Sakkos
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Lawrence P Wackett
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
- The BioTechnology Institute, University of Minnesota, St. Paul, MN, 55108, USA
| | - Alptekin Aksan
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA.
- The BioTechnology Institute, University of Minnesota, St. Paul, MN, 55108, USA.
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8
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Dong J, Fernández‐Fueyo E, Hollmann F, Paul CE, Pesic M, Schmidt S, Wang Y, Younes S, Zhang W. Biocatalytic Oxidation Reactions: A Chemist's Perspective. Angew Chem Int Ed Engl 2018; 57:9238-9261. [PMID: 29573076 PMCID: PMC6099261 DOI: 10.1002/anie.201800343] [Citation(s) in RCA: 276] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Indexed: 01/25/2023]
Abstract
Oxidation chemistry using enzymes is approaching maturity and practical applicability in organic synthesis. Oxidoreductases (enzymes catalysing redox reactions) enable chemists to perform highly selective and efficient transformations ranging from simple alcohol oxidations to stereoselective halogenations of non-activated C-H bonds. For many of these reactions, no "classical" chemical counterpart is known. Hence oxidoreductases open up shorter synthesis routes based on a more direct access to the target products. The generally very mild reaction conditions may also reduce the environmental impact of biocatalytic reactions compared to classical counterparts. In this Review, we critically summarise the most important recent developments in the field of biocatalytic oxidation chemistry and identify the most pressing bottlenecks as well as promising solutions.
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Affiliation(s)
- JiaJia Dong
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Elena Fernández‐Fueyo
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Frank Hollmann
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Caroline E. Paul
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Milja Pesic
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Sandy Schmidt
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Yonghua Wang
- School of Food Science and EngineeringSouth China University of TechnologyGuangzhou510640P. R. China
| | - Sabry Younes
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Wuyuan Zhang
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
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9
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Dong J, Fernández-Fueyo E, Hollmann F, Paul CE, Pesic M, Schmidt S, Wang Y, Younes S, Zhang W. Biokatalytische Oxidationsreaktionen - aus der Sicht eines Chemikers. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800343] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- JiaJia Dong
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Elena Fernández-Fueyo
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Frank Hollmann
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Caroline E. Paul
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Milja Pesic
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Sandy Schmidt
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Yonghua Wang
- School of Food Science and Engineering; South China University of Technology; Guangzhou 510640 P. R. China
| | - Sabry Younes
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Wuyuan Zhang
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
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10
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White BE, Fenner CJ, Smit MS, Harrison STL. Effect of cell permeability and dehydrogenase expression on octane activation by CYP153A6-based whole cell Escherichia coli catalysts. Microb Cell Fact 2017; 16:156. [PMID: 28931395 PMCID: PMC5607502 DOI: 10.1186/s12934-017-0763-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 09/07/2017] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND The regeneration of cofactors and the supply of alkane substrate are key considerations for the biocatalytic activation of hydrocarbons by cytochrome P450s. This study focused on the biotransformation of n-octane to 1-octanol using resting Escherichia coli cells expressing the CYP153A6 operon, which includes the electron transport proteins ferredoxin and ferredoxin reductase. Glycerol dehydrogenase was co-expressed with the CYP153A6 operon to investigate the effects of boosting cofactor regeneration. In order to overcome the alkane supply bottleneck, various chemical and physical approaches to membrane permeabilisation were tested in strains with or without additional dehydrogenase expression. RESULTS Dehydrogenase co-expression in whole cells did not improve product formation and reduced the stability of the system at high cell densities. Chemical permeabilisation resulted in initial hydroxylation rates that were up to two times higher than the whole cell system, but severely impacted biocatalyst stability. Mechanical cell breakage led to improved enzyme stability, but additional dehydrogenase expression was necessary to improve product formation. The best-performing system (in terms of final titres) consisted of mechanically ruptured cells expressing additional dehydrogenase. This system had an initial activity of 1.67 ± 0.12 U/gDCW (32% improvement on whole cells) and attained a product concentration of 34.8 ± 1.6 mM after 24 h (22% improvement on whole cells). Furthermore, the system was able to maintain activity when biotransformation was extended to 72 h, resulting in a final product titre of 60.9 ± 1.1 mM. CONCLUSIONS This study suggests that CYP153A6 in whole cells is limited by coupling efficiencies rather than cofactor supply. However, the most significant limitation in the current system is hydrocarbon transport, with substrate import being the main determinant of hydroxylation rates, and product export playing a key role in system stability.
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Affiliation(s)
- Bronwyn E White
- Centre for Bioprocess Engineering Research (CeBER), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, Cape Town, 7701, South Africa.,South African DST-NRF Centre of Excellence in Catalysis, c*change, University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa
| | - Caryn J Fenner
- Centre for Bioprocess Engineering Research (CeBER), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, Cape Town, 7701, South Africa.,South African DST-NRF Centre of Excellence in Catalysis, c*change, University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa
| | - Martha S Smit
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa.,South African DST-NRF Centre of Excellence in Catalysis, c*change, University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa
| | - Susan T L Harrison
- Centre for Bioprocess Engineering Research (CeBER), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, Cape Town, 7701, South Africa. .,South African DST-NRF Centre of Excellence in Catalysis, c*change, University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa.
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11
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Kadisch M, Willrodt C, Hillen M, Bühler B, Schmid A. Maximizing the stability of metabolic engineering-derived whole-cell biocatalysts. Biotechnol J 2017; 12. [DOI: 10.1002/biot.201600170] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 05/22/2017] [Accepted: 06/08/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Marvin Kadisch
- Department Solar Materials; Helmholtz Centre for Environmental Research - UFZ; Leipzig Germany
| | - Christian Willrodt
- Department Solar Materials; Helmholtz Centre for Environmental Research - UFZ; Leipzig Germany
| | - Michael Hillen
- Department Solar Materials; Helmholtz Centre for Environmental Research - UFZ; Leipzig Germany
| | - Bruno Bühler
- Department Solar Materials; Helmholtz Centre for Environmental Research - UFZ; Leipzig Germany
| | - Andreas Schmid
- Department Solar Materials; Helmholtz Centre for Environmental Research - UFZ; Leipzig Germany
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12
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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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13
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Enhancing the productivity of the bi-enzymatic convergent cascade for ɛ-caprolactone synthesis through design of experiments and a biphasic system. Tetrahedron 2016. [DOI: 10.1016/j.tet.2015.11.054] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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14
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Glonke S, Sadowski G, Brandenbusch C. Applied catastrophic phase inversion: a continuous non-centrifugal phase separation step in biphasic whole-cell biocatalysis. J Ind Microbiol Biotechnol 2016; 43:1527-1535. [PMID: 27650629 DOI: 10.1007/s10295-016-1837-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 09/11/2016] [Indexed: 11/25/2022]
Abstract
Biphasic whole-cell biotransformations are known to be efficient alternatives to common chemical synthesis routes, especially for the production of, e.g. apolar enantiopure organic compounds. They provide high stereoselectivity combined with high product concentrations owing to the presence of an organic phase serving as substrate reservoir and product sink. Industrial implementation suffers from the formation of stable Pickering emulsions caused by the presence of cells. State-of-the-art downstream processing includes inefficient strategies such as excessive centrifugation, use of de-emulsifiers or thermal stress. In contrast, using the catastrophic phase inversion (CPI) phenomenon (sudden switch of emulsion type caused by addition of dispersed phase), Pickering-type emulsions can be destabilized efficiently. Within this work a model system using bis(2-ethylhexyl) phthalate (BEHP) as organic phase in combination with E. coli, JM101 was successfully separated using a continuous mixer settler setup. Compared to the state-of-the-art centrifugal separations, this process allows complete phase separation with no detectable water content or cells in the organic phase with no utilities/additives required. Furthermore, the concentration of the product is not affected by the separation. It is therefore a simple applicable method that can be used for separation of stable Pickering-type emulsions based on the knowledge of the point of inversion.
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Affiliation(s)
- Sebastian Glonke
- Laboratory of Thermodynamics, TU Dortmund University, 44227, Dortmund, Germany
| | - Gabriele Sadowski
- Laboratory of Thermodynamics, TU Dortmund University, 44227, Dortmund, Germany
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15
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Ramesh H, Mayr T, Hobisch M, Borisov S, Klimant I, Krühne U, Woodley JM. Measurement of oxygen transfer from air into organic solvents. JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY (OXFORD, OXFORDSHIRE : 1986) 2016; 91:832-836. [PMID: 27773958 PMCID: PMC5064614 DOI: 10.1002/jctb.4862] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/25/2015] [Accepted: 11/25/2015] [Indexed: 06/06/2023]
Abstract
BACKGROUND The use of non-aqueous organic media is becoming increasingly important in many biotechnological applications in order to achieve process intensification. Such media can be used, for example, to directly extract poorly water-soluble toxic products from fermentations. Likewise many biological reactions require the supply of oxygen, most normally from air. However, reliable online measurements of oxygen concentration in organic solvents (and hence oxygen transfer rates from air to the solvent) has to date proven impossible due to limitations in the current analytical methods. RESULTS For the first time, online oxygen measurements in non-aqueous media using a novel optical sensor are demonstrated. The sensor was used to measure oxygen concentration in various organic solvents including toluene, THF, isooctane, DMF, heptane and hexane (which have all been shown suitable for several biological applications). Subsequently, the oxygen transfer rates from air into these organic solvents were measured. CONCLUSION The measurement of oxygen transfer rates from air into organic solvents using the dynamic method was established using the solvent resistant optical sensor. The feasibility of online oxygen measurements in organic solvents has also been demonstrated, paving the way for new opportunities in process control. © 2015 The Authors. Journal of Chemical Technology & Biotechnology published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Hemalata Ramesh
- Department of Chemical and Biochemical Engineering Technical University of Denmark DK-2800 Kgs Lyngby Denmark
| | - Torsten Mayr
- Institute of Analytical Chemistry and Food Chemistry Graz University of Technology 8010 Graz Austria
| | - Mathias Hobisch
- Institute of Analytical Chemistry and Food Chemistry Graz University of Technology 8010 Graz Austria
| | - Sergey Borisov
- Institute of Analytical Chemistry and Food Chemistry Graz University of Technology 8010 Graz Austria
| | - Ingo Klimant
- Institute of Analytical Chemistry and Food Chemistry Graz University of Technology 8010 Graz Austria
| | - Ulrich Krühne
- Department of Chemical and Biochemical Engineering Technical University of Denmark DK-2800 Kgs Lyngby Denmark
| | - John M Woodley
- Department of Chemical and Biochemical Engineering Technical University of Denmark DK-2800 Kgs Lyngby Denmark
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Eichler A, Gricman Ł, Herter S, Kelly PP, Turner NJ, Pleiss J, Flitsch SL. Enantioselective Benzylic Hydroxylation Catalysed by P450 Monooxygenases: Characterisation of a P450cam Mutant Library and Molecular Modelling. Chembiochem 2016; 17:426-32. [DOI: 10.1002/cbic.201500536] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Indexed: 12/30/2022]
Affiliation(s)
- Anja Eichler
- School of Chemistry; Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
| | - Łukasz Gricman
- Institute for Technical Biochemistry; University of Stuttgart; Allmandring 31 70569 Stuttgart Germany
| | - Susanne Herter
- School of Chemistry; Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
| | - Paul P. Kelly
- School of Chemistry; Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
| | - Nicholas J. Turner
- School of Chemistry; Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
| | - Jürgen Pleiss
- Institute for Technical Biochemistry; University of Stuttgart; Allmandring 31 70569 Stuttgart Germany
| | - Sabine L. Flitsch
- School of Chemistry; Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
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Molina-Espeja P, Cañellas M, Plou FJ, Hofrichter M, Lucas F, Guallar V, Alcalde M. Synthesis of 1-Naphthol by a Natural Peroxygenase Engineered by Directed Evolution. Chembiochem 2016; 17:341-9. [DOI: 10.1002/cbic.201500493] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Patricia Molina-Espeja
- Department of Biocatalysis; Institute of Catalysis; CSIC; C/Marie Curie n° 2L10 28049 Madrid Spain
| | | | - Francisco J. Plou
- Department of Biocatalysis; Institute of Catalysis; CSIC; C/Marie Curie n° 2L10 28049 Madrid Spain
| | - Martin Hofrichter
- TU Dresden; International Institute Zittau; Department of Bio- and Environmental Sciences; Markt 23 02763 Zittau Germany
| | - Fatima Lucas
- Anaxomics Biotech; Balmes 89 08008 Barcelona Spain
- Joint BSC-CRG-IRB Research Program in Computational Biology; Barcelona Supercomputing Center; Jordi Girona 29 08034 Barcelona Spain
| | - Victor Guallar
- Joint BSC-CRG-IRB Research Program in Computational Biology; Barcelona Supercomputing Center; Jordi Girona 29 08034 Barcelona Spain
- ICREA: Institució Catalana de Recerca i Estudis Avançats; Passeig Lluís Companys 23 08010 Barcelona Spain
| | - Miguel Alcalde
- Department of Biocatalysis; Institute of Catalysis; CSIC; C/Marie Curie n° 2L10 28049 Madrid Spain
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Brandenbusch C, Glonke S, Collins J, Hoffrogge R, Grunwald K, Bühler B, Schmid A, Sadowski G. Process boundaries of irreversible scCO2-assisted phase separation in biphasic whole-cell biocatalysis. Biotechnol Bioeng 2015; 112:2316-23. [DOI: 10.1002/bit.25655] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 05/04/2015] [Accepted: 05/11/2015] [Indexed: 11/05/2022]
Affiliation(s)
| | - Sebastian Glonke
- Laboratory of Thermodynamics; Emil-Figge-Str. 70; 44227 Dortmund; Germany
| | - Jonathan Collins
- Laboratory of Chemical Biotechnology; TU Dortmund University; Dortmund Germany
| | - Raimund Hoffrogge
- Institute of Cell Culture Technology; Bielefeld University; Bielefeld Germany
| | - Klaudia Grunwald
- Institute of Cell Culture Technology; Bielefeld University; Bielefeld Germany
| | - Bruno Bühler
- Laboratory of Chemical Biotechnology; TU Dortmund University; Dortmund Germany
| | - Andreas Schmid
- Laboratory of Chemical Biotechnology; TU Dortmund University; Dortmund Germany
| | - Gabriele Sadowski
- Laboratory of Thermodynamics; Emil-Figge-Str. 70; 44227 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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Zeynalov E, Nagiev T. Enzymatic Catalysis of Hydrocarbons Oxidation “in vitro” (Review). CHEMISTRY & CHEMICAL TECHNOLOGY 2015. [DOI: 10.23939/chcht09.02.157] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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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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Engineering of Pseudomonas taiwanensis VLB120 for constitutive solvent tolerance and increased specific styrene epoxidation activity. Appl Environ Microbiol 2014; 80:6539-48. [PMID: 25128338 DOI: 10.1128/aem.01940-14] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The application of whole cells as biocatalysts is often limited by the toxicity of organic solvents, which constitute interesting substrates/products or can be used as a second phase for in situ product removal and as tools to control multistep biocatalysis. Solvent-tolerant bacteria, especially Pseudomonas strains, are proposed as promising hosts to overcome such limitations due to their inherent solvent tolerance mechanisms. However, potential industrial applications suffer from tedious, unproductive adaptation processes, phenotypic variability, and instable solvent-tolerant phenotypes. In this study, genes described to be involved in solvent tolerance were identified in Pseudomonas taiwanensis VLB120, and adaptive solvent tolerance was proven by cultivation in the presence of 1% (vol/vol) toluene. Deletion of ttgV, coding for the specific transcriptional repressor of solvent efflux pump TtgGHI gene expression, led to constitutively solvent-tolerant mutants of P. taiwanensis VLB120 and VLB120ΔC. Interestingly, the increased amount of solvent efflux pumps enhanced not only growth in the presence of toluene and styrene but also the biocatalytic performance in terms of stereospecific styrene epoxidation, although proton-driven solvent efflux is expected to compete with the styrene monooxygenase for metabolic energy. Compared to that of the P. taiwanensis VLB120ΔC parent strain, the maximum specific epoxidation activity of P. taiwanensis VLB120ΔCΔttgV doubled to 67 U/g of cells (dry weight). This study shows that solvent tolerance mechanisms, e.g., the solvent efflux pump TtgGHI, not only allow for growth in the presence of organic compounds but can also be used as tools to improve redox biocatalysis involving organic solvents.
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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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High-cell-density cultivation of recombinant Escherichia coli, purification and characterization of a self-sufficient biosynthetic octane ω-hydroxylase. Appl Microbiol Biotechnol 2014; 98:6275-83. [PMID: 24687750 DOI: 10.1007/s00253-014-5671-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/04/2014] [Accepted: 03/05/2014] [Indexed: 01/07/2023]
Abstract
We have recently described the biocatalytic characterization of a self-sufficent biosynthetic alkane hydroxylase based on CYP153A13a from Alcanivorax borkumensis SK2 (thereafter A13-Red). Despite remarkable regio- and chemo-selectivity, A13-Red suffers of a difficult-to-reproduce expression and moderate operational stability. In this study, we focused our efforts on the production of A13-Red using high-cell-density cultivation (HCDC) of recombinant Escherichia coli. We achieved 455 mg (5,000 nmol) of functional enzyme per liter of culture. Tight control of cultivation parameters rendered the whole process highly reproducible compared with flask cultivations. We optimized the purification of the biocatalyst that can be performed in either two or three steps depending on the application needed to afford A13-Red up to 95 % homogeneous. We investigated different reaction conditions and found that the total turnover numbers of A13-Red during the in vitro hydroxylation of n-octane could reach up to 3,250 to produce 1-octanol (1.6 mM) over a period of 78 h.
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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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Müller CA, Akkapurathu B, Winkler T, Staudt S, Hummel W, Gröger H, Schwaneberg U. In VitroDouble Oxidation ofn-Heptane with Direct Cofactor Regeneration. Adv Synth Catal 2013. [DOI: 10.1002/adsc.201300143] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Hibino A, Ohtake H. Use of hydrophobic bacterium Rhodococcus rhodochrous NBRC15564 expressed thermophilic alcohol dehydrogenases as whole-cell catalyst in solvent-free organic media. Process Biochem 2013. [DOI: 10.1016/j.procbio.2013.03.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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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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Cornelissen S, Julsing MK, Volmer J, Riechert O, Schmid A, Bühler B. Whole-cell-based CYP153A6-catalyzed (S)-limonene hydroxylation efficiency depends on host background and profits from monoterpene uptake via AlkL. Biotechnol Bioeng 2013; 110:1282-92. [PMID: 23239244 DOI: 10.1002/bit.24801] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 11/23/2012] [Accepted: 11/28/2012] [Indexed: 11/09/2022]
Abstract
Living microbial cells are considered to be the catalyst of choice for selective terpene functionalization. However, such processes often suffer from side product formation and poor substrate mass transfer into cells. For the hydroxylation of (S)-limonene to (S)-perillyl alcohol by Pseudomonas putida KT2440 (pGEc47ΔB)(pCom8-PFR1500), containing the cytochrome P450 monooxygenase CYP153A6, the side products perillyl aldehyde and perillic acid constituted up to 26% of the total amount of oxidized terpenes. In this study, it is shown that the reaction rate is substrate-limited in the two-liquid phase system used and that host intrinsic dehydrogenases and not CYP153A6 are responsible for the formation of the undesired side products. In contrast to P. putida KT2440, E. coli W3110 was found to catalyze perillyl aldehyde reduction to the alcohol and no oxidation to the acid. Furthermore, E. coli W3110 harboring CYP153A6 showed high limonene hydroxylation activities (7.1 U g CDW-1). The outer membrane protein AlkL was found to enhance hydroxylation activities of E. coli twofold in aqueous single-phase and fivefold in two-liquid phase biotransformations. In the latter system, E. coli harboring CYP153A6 and AlkL produced up to 39.2 mmol (S)-perillyl alcohol L tot-1 within 26 h, whereas no perillic acid and minor amounts of perillyl aldehyde (8% of the total products) were formed. In conclusion, undesired perillyl alcohol oxidation was reduced by choosing E. coli's enzymatic background as a reaction environment and co-expression of the alkL gene in E. coli represents a promising strategy to enhance terpene bioconversion rates.
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Affiliation(s)
- Sjef Cornelissen
- Department of Biochemical and Chemical Engineering, Laboratory of Chemical Biotechnology, TU Dortmund University, Emil-Figge-Strasse 66, 44227 Dortmund, Germany
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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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Dror A, Fishman A. Engineering non-heme mono- and dioxygenases for biocatalysis. Comput Struct Biotechnol J 2012; 2:e201209011. [PMID: 24688652 PMCID: PMC3962191 DOI: 10.5936/csbj.201209011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Revised: 10/02/2012] [Accepted: 10/12/2012] [Indexed: 11/25/2022] Open
Abstract
Oxygenases are ubiquitous enzymes that catalyze the introduction of one or two oxygen atoms to unreactive chemical compounds. They require reduction equivalents from NADH or NADPH and comprise metal ions, metal ion complexes, or coenzymes in their active site. Thus, for industrial purposes, oxygenases are most commonly employed using whole cell catalysis, to alleviate the need for co-factor regeneration. Biotechnological applications include bioremediation, chiral synthesis, biosensors, fine chemicals, biofuels, pharmaceuticals, food ingredients and polymers. Controlling activity and selectivity of oxygenases is therefore of great importance and of growing interest to the scientific community. This review focuses on protein engineering of non-heme monooxygenases and dioxygenases for generating improved or novel functionalities. Rational mutagenesis based on x-ray structures and sequence alignment, as well as random methods such as directed evolution, have been utilized. It is concluded that knowledge-based protein engineering accompanied with targeted libraries, is most efficient for the design and tuning of biocatalysts towards novel substrates and enhanced catalytic activity while minimizing the screening efforts.
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Affiliation(s)
- Adi Dror
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Ayelet Fishman
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, 32000, Israel
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Bordeaux M, Galarneau A, Drone J. Catalytic, Mild, and Selective Oxyfunctionalization of Linear Alkanes: Current Challenges. Angew Chem Int Ed Engl 2012; 51:10712-23. [DOI: 10.1002/anie.201203280] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Indexed: 02/02/2023]
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Bordeaux M, Galarneau A, Drone J. Katalytische, milde und selektive Oxyfunktionalisierung von linearen Alkanen: aktuelle Herausforderungen. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201203280] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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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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Braun A, Geier M, Bühler B, Schmid A, Mauersberger S, Glieder A. Steroid biotransformations in biphasic systems with Yarrowia lipolytica expressing human liver cytochrome P450 genes. Microb Cell Fact 2012; 11:106. [PMID: 22876969 PMCID: PMC3544689 DOI: 10.1186/1475-2859-11-106] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 07/25/2012] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Yarrowia lipolytica efficiently metabolizes and assimilates hydrophobic compounds such as n-alkanes and fatty acids. Efficient substrate uptake is enabled by naturally secreted emulsifiers and a modified cell surface hydrophobicity and protrusions formed by this yeast. We were examining the potential of recombinant Y. lipolytica as a biocatalyst for the oxidation of hardly soluble hydrophobic steroids. Furthermore, two-liquid biphasic culture systems were evaluated to increase substrate availability. While cells, together with water soluble nutrients, are maintained in the aqueous phase, substrates and most of the products are contained in a second water-immiscible organic solvent phase. RESULTS For the first time we have co-expressed the human cytochromes P450 2D6 and 3A4 genes in Y. lipolytica together with human cytochrome P450 reductase (hCPR) or Y. lipolytica cytochrome P450 reductase (YlCPR). These whole-cell biocatalysts were used for the conversion of poorly soluble steroids in biphasic systems.Employing a biphasic system with the organic solvent and Y. lipolytica carbon source ethyl oleate for the whole-cell bioconversion of progesterone, the initial specific hydroxylation rate in a 1.5 L stirred tank bioreactor was further increased 2-fold. Furthermore, the product formation was significantly prolonged as compared to the aqueous system. Co-expression of the human CPR gene led to a 4-10-fold higher specific activity, compared to the co-overexpression of the native Y. lipolytica CPR gene. Multicopy transformants showed a 50-70-fold increase of activity as compared to single copy strains. CONCLUSIONS Alkane-assimilating yeast Y. lipolytica, coupled with the described expression strategies, demonstrated its high potential for biotransformations of hydrophobic substrates in two-liquid biphasic systems. Especially organic solvents which can be efficiently taken up and/or metabolized by the cell might enable more efficient bioconversion as compared to aqueous systems and even enable simple, continuous or at least high yield long time processes.
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Affiliation(s)
- Andreas Braun
- Institute of Molecular Biotechnology, Graz University of Technology, ACIB GmbH, Petersgasse 14, Graz, Austria
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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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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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Schrewe M, Magnusson AO, Willrodt C, Bühler B, Schmid A. Kinetic Analysis of Terminal and Unactivated CH Bond Oxyfunctionalization in Fatty Acid Methyl Esters by Monooxygenase-Based Whole-Cell Biocatalysis. Adv Synth Catal 2011. [DOI: 10.1002/adsc.201100440] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Enzyme-Catalyzed Laurolactam Synthesis via Intramolecular Amide Bond Formation in Aqueous Solution. Adv Synth Catal 2011. [DOI: 10.1002/adsc.201100396] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Response of Pseudomonas putida KT2440 to increased NADH and ATP demand. Appl Environ Microbiol 2011; 77:6597-605. [PMID: 21803911 DOI: 10.1128/aem.05588-11] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adenosine phosphate and NAD cofactors play a vital role in the operation of cell metabolism, and their levels and ratios are carefully regulated in tight ranges. Perturbations of the consumption of these metabolites might have a great impact on cell metabolism and physiology. Here, we investigated the impact of increased ATP hydrolysis and NADH oxidation rates on the metabolism of Pseudomonas putida KT2440 by titration of 2,4-dinitrophenol (DNP) and overproduction of a water-forming NADH oxidase, respectively. Both perturbations resulted in a reduction of the biomass yield and, as a consequence of the uncoupling of catabolic and anabolic activities, in an amplification of the net NADH regeneration rate. However, a stimulation of the specific carbon uptake rate was observed only when P. putida was challenged with very high 2,4-dinitrophenol concentrations and was comparatively unaffected by recombinant NADH oxidase activity. This behavior contrasts with the comparably sensitive performance described, for example, for Escherichia coli or Saccharomyces cerevisiae. The apparent robustness of P. putida metabolism indicates that it possesses a certain buffering capacity and a high flexibility to adapt to and counteract different stresses without showing a distinct phenotype. These findings are important, e.g., for the development of whole-cell redox biocatalytic processes that impose equivalent burdens on the cell metabolism: stoichiometric consumption of (reduced) redox cofactors and increased energy expenditures, due to the toxicity of the biocatalytic compounds.
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Cell physiology rather than enzyme kinetics can determine the efficiency of cytochrome P450-catalyzed C–H-oxyfunctionalization. J Ind Microbiol Biotechnol 2011; 38:1359-70. [DOI: 10.1007/s10295-010-0919-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 11/18/2010] [Indexed: 11/26/2022]
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El Ouarradi A, Lombard M, Buisson D. Biooxidation of methyl group: Part 2. Evidences for the involvement of cytochromes P450 in microbial multistep oxidation of terfenadine. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcatb.2010.07.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ütkür FÖ, Gaykawad S, Bühler B, Schmid A. Regioselective aromatic hydroxylation of quinaldine by water using quinaldine 4-oxidase in recombinant Pseudomonas putida. J Ind Microbiol Biotechnol 2010; 38:1067-77. [DOI: 10.1007/s10295-010-0883-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 09/17/2010] [Indexed: 11/24/2022]
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Mallick S, Chakraborty J, Dutta TK. Role of oxygenases in guiding diverse metabolic pathways in the bacterial degradation of low-molecular-weight polycyclic aromatic hydrocarbons: a review. Crit Rev Microbiol 2010; 37:64-90. [PMID: 20846026 DOI: 10.3109/1040841x.2010.512268] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Widespread environmental pollution by polycyclic aromatic hydrocarbons (PAHs) poses an immense risk to the environment. Bacteria-mediated attenuation has a great potential for the restoration of PAH-contaminated environment in an ecologically accepted manner. Bacterial degradation of PAHs has been extensively studied and mining of biodiversity is ever expanding the biodegradative potentials with intelligent manipulation of catabolic genes and adaptive evolution to generate multiple catabolic pathways. The present review of bacterial degradation of low-molecular-weight (LMW) PAHs describes the current knowledge about the diverse metabolic pathways depicting novel metabolites, enzyme-substrate/metabolite relationships, the role of oxygenases and their distribution in phylogenetically diverse bacterial species.
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Affiliation(s)
- Somnath Mallick
- Department of Chemistry, Saldiha College, Bankura, West Bengal, India
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Abstract
Whole-cell biocatalysis utilizes native or recombinant enzymes produced by cellular metabolism to perform synthetically interesting reactions. Besides hydrolases, oxidoreductases represent the most applied enzyme class in industry. Oxidoreductases are attributed a high future potential, especially for applications in the chemical and pharmaceutical industries, as they enable highly interesting chemistry (e.g., the selective oxyfunctionalization of unactivated C-H bonds). Redox reactions are characterized by electron transfer steps that often depend on redox cofactors as additional substrates. Their regeneration typically is accomplished via the metabolism of whole-cell catalysts. Traditionally, studies towards productive redox biocatalysis focused on the biocatalytic enzyme, its activity, selectivity, and specificity, and several successful examples of such processes are running commercially. However, redox cofactor regeneration by host metabolism was hardly considered for the optimization of biocatalytic rate, yield, and/or titer. This article reviews molecular mechanisms of oxidoreductases with synthetic potential and the host redox metabolism that fuels biocatalytic reactions with redox equivalents. The tools discussed in this review for investigating redox metabolism provide the basis for studies aiming at a deeper understanding of the interplay between synthetically active enzymes and metabolic networks. The ultimate goal of rational whole-cell biocatalyst engineering and use for fine chemical production is discussed.
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Khatri Y, Girhard M, Romankiewicz A, Ringle M, Hannemann F, Urlacher VB, Hutter MC, Bernhardt R. Regioselective hydroxylation of norisoprenoids by CYP109D1 from Sorangium cellulosum So ce56. Appl Microbiol Biotechnol 2010; 88:485-95. [PMID: 20645086 DOI: 10.1007/s00253-010-2756-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 06/29/2010] [Accepted: 06/29/2010] [Indexed: 11/26/2022]
Abstract
Sesquiterpenes are particularly interesting as flavorings and fragrances or as pharmaceuticals. Regio- or stereoselective functionalizations of terpenes are one of the main goals of synthetic organic chemistry, which are possible through radical reactions but are not selective enough to introduce the desired chiral alcohol function into those compounds. Cytochrome P450 monooxygenases are versatile biocatalysts and are capable of performing selective oxidations of organic molecules. We were able to demonstrate that CYP109D1 from Sorangium cellulosum So ce56 functions as a biocatalyst for the highly regioselective hydroxylation of norisoprenoids, alpha- and beta-ionone, which are important aroma compounds of floral scents. The substrates alpha- and beta-ionone were regioselectively hydroxylated to 3-hydroxy-alpha-ionone and 4-hydroxy-beta-ionone, respectively, which was confirmed by (1)H NMR and (13)C NMR. The results of docking alpha- and beta-ionone into a homology model of CYP109D1 gave a rational explanation for the regio-selectivity of the hydroxylation. Kinetic studies revealed that alpha- and beta-ionone can be hydroxylated with nearly identical V (max) and K (m) values. This is the first comprehensive investigation of the regioselective hydroxylation of norisoprenoids by CYP109D1.
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Affiliation(s)
- Yogan Khatri
- Department of Biochemistry, Saarland University, Saarbrücken, Germany
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Brandenbusch C, Bühler B, Hoffmann P, Sadowski G, Schmid A. Efficient phase separation and product recovery in organic-aqueous bioprocessing using supercritical carbon dioxide. Biotechnol Bioeng 2010; 107:642-51. [DOI: 10.1002/bit.22846] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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50
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Catalytic activity of aryl alcohol oxidase immobilized in 3D-mesoporous silicates. J Biosci Bioeng 2009; 108:310-3. [DOI: 10.1016/j.jbiosc.2009.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 04/07/2009] [Accepted: 04/07/2009] [Indexed: 11/18/2022]
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