1
|
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.
Collapse
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
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Smaluch K, Wollenhaupt B, Steinhoff H, Kohlheyer D, Grünberger A, Dusny C. Assessing the growth kinetics and stoichiometry of Escherichia coli at the single-cell level. Eng Life Sci 2023; 23:e2100157. [PMID: 36619887 PMCID: PMC9815083 DOI: 10.1002/elsc.202100157] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/17/2022] [Accepted: 04/16/2022] [Indexed: 01/11/2023] Open
Abstract
Microfluidic cultivation and single-cell analysis are inherent parts of modern microbial biotechnology and microbiology. However, implementing biochemical engineering principles based on the kinetics and stoichiometry of growth in microscopic spaces remained unattained. We here present a novel integrated framework that utilizes distinct microfluidic cultivation technologies and single-cell analytics to make the fundamental math of process-oriented biochemical engineering applicable at the single-cell level. A combination of non-invasive optical cell mass determination with sub-pg sensitivity, microfluidic perfusion cultivations for establishing physiological steady-states, and picoliter batch reactors, enabled the quantification of all physiological parameters relevant to approximate a material balance in microfluidic reaction environments. We determined state variables (biomass concentration based on single-cell dry weight and mass density), biomass synthesis rates, and substrate affinities of cells grown in microfluidic environments. Based on this data, we mathematically derived the specific kinetics of substrate uptake and growth stoichiometry in glucose-grown Escherichia coli with single-cell resolution. This framework may initiate microscale material balancing beyond the averaged values obtained from populations as a basis for integrating heterogeneous kinetic and stoichiometric single-cell data into generalized bioprocess models and descriptions.
Collapse
Affiliation(s)
- Katharina Smaluch
- Department of Solar Materials – Microscale Analysis and EngineeringHelmholtz‐Centre for Environmental Research – UFZ LeipzigLeizpigGermany
| | - Bastian Wollenhaupt
- Microscale BioengineeringIBG‐1: BiotechnologyForschungszentrum Jülich GmbHJülichGermany
| | - Heiko Steinhoff
- Multiscale BioengineeringFaculty of TechnologyBielefeld UniversityBielefeldGermany
| | - Dietrich Kohlheyer
- Microscale BioengineeringIBG‐1: BiotechnologyForschungszentrum Jülich GmbHJülichGermany
| | - Alexander Grünberger
- Multiscale BioengineeringFaculty of TechnologyBielefeld UniversityBielefeldGermany
| | - Christian Dusny
- Department of Solar Materials – Microscale Analysis and EngineeringHelmholtz‐Centre for Environmental Research – UFZ LeipzigLeizpigGermany
| |
Collapse
|
4
|
Properties and Mechanisms of Flavin-Dependent Monooxygenases and Their Applications in Natural Product Synthesis. Int J Mol Sci 2022; 23:ijms23052622. [PMID: 35269764 PMCID: PMC8910399 DOI: 10.3390/ijms23052622] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/21/2022] [Accepted: 02/25/2022] [Indexed: 11/17/2022] Open
Abstract
Natural products are usually highly complicated organic molecules with special scaffolds, and they are an important resource in medicine. Natural products with complicated structures are produced by enzymes, and this is still a challenging research field, its mechanisms requiring detailed methods for elucidation. Flavin adenine dinucleotide (FAD)-dependent monooxygenases (FMOs) catalyze many oxidation reactions with chemo-, regio-, and stereo-selectivity, and they are involved in the synthesis of many natural products. In this review, we introduce the mechanisms for different FMOs, with the classical FAD (C4a)-hydroperoxide as the major oxidant. We also summarize the difference between FMOs and cytochrome P450 (CYP450) monooxygenases emphasizing the advantages of FMOs and their specificity for substrates. Finally, we present examples of FMO-catalyzed synthesis of natural products. Based on these explanations, this review will expand our knowledge of FMOs as powerful enzymes, as well as implementation of the FMOs as effective tools for biosynthesis.
Collapse
|
5
|
Salamanca D, Bühler K, Engesser KH, Schmid A, Karande R. Whole-cell biocatalysis using the Acidovorax sp. CHX100 Δ6HX for the production of ω-hydroxycarboxylic acids from cycloalkanes. N Biotechnol 2020; 60:200-206. [PMID: 33127412 DOI: 10.1016/j.nbt.2020.10.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 10/22/2020] [Accepted: 10/22/2020] [Indexed: 11/17/2022]
Abstract
Omega hydroxycarboxylic acids (ω-HAs) possess two functional groups, a hydroxyl group and a carboxyl group, and are essential precursors for the production of biodegradable polyester polymers. In this work, an Acidovorax mutant was investigated as a whole-cell biocatalyst for the conversion of cycloalkanes to their respective ω-hydroxycarboxylic acids. This Acidovorax sp. strain CHX100 originated from a wastewater treatment plant and uses cyclohexane as the sole source of carbon and energy with excellent growth rates (0.199 h-1). The metabolic efficiency of Acidovorax CHX100 is based on a highly efficient enzyme cascade used for the mineralization of cyclohexane. A deletion of 6-hydroxyhexanoate dehydrogenase in the native cycloalkane pathway resulted in the Acidovorax sp. strain CHX100 Δ6HX mutant, which accumulated short ω-hydroxycarboxylic acids (C5 to C10) from cycloalkanes. This mutant transformed cyclopentane and cyclohexane (5 mM) to 5-hydroxypentanoic acid and 6-hydroxyhexanoic acid, respectively, with a molar conversion above 98% in 6 h. An elementary environmental and economical assessment based on E-factor and biocatalyst yield suggests the use of inexpensive electron donor and carbon sources, with subsequent efforts to minimize waste generation. Such an early-stage analysis highlights the main bottlenecks that need to be solved in developing a sustainable bioprocess.
Collapse
Affiliation(s)
- Diego Salamanca
- Helmholtz-Centre for Environmental Research - UFZ GmbH, Department of Solar Materials, Permoserstr. 15, 04318 Leipzig, Germany
| | - Katja Bühler
- Helmholtz-Centre for Environmental Research - UFZ GmbH, Department of Solar Materials, Permoserstr. 15, 04318 Leipzig, Germany
| | - Karl-Heinrich Engesser
- Department of Biological Waste Air Purification, Institute for Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Stuttgart, Germany
| | - Andreas Schmid
- Helmholtz-Centre for Environmental Research - UFZ GmbH, Department of Solar Materials, Permoserstr. 15, 04318 Leipzig, Germany
| | - Rohan Karande
- Helmholtz-Centre for Environmental Research - UFZ GmbH, Department of Solar Materials, Permoserstr. 15, 04318 Leipzig, Germany.
| |
Collapse
|
6
|
Cui C, Lin H, Pu W, Guo C, Liu Y, Pei XQ, Wu ZL. Asymmetric Epoxidation and Sulfoxidation Catalyzed by a New Styrene Monooxygenase from Bradyrhizobium. Appl Biochem Biotechnol 2020; 193:65-78. [PMID: 32808246 DOI: 10.1007/s12010-020-03413-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 08/12/2020] [Indexed: 10/23/2022]
Abstract
Asymmetric epoxidation catalyzed with styrene monooxygenase (SMO) is a powerful enzymatic process producing enantiopure styrene epoxide derivatives. To establish a more diversified reservoir of SMOs, a new SMO from Bradyrhizobium sp. ORS 375, named BrSMO, was mined from the database and characterized. BrSMO was constituted of an epoxygenase component of 415 amino acid residues and an NADH-dependent flavin reductase component of 175 residues. BrSMO catalyzed the epoxidation of styrene and 7 more styrene derivatives, yielding the corresponding (S)-epoxides with excellent enantiomeric excesses (95- > 99% ee), with the highest activity achieved for styrene. BrSMO also catalyzed the asymmetric sulfoxidation of 7 sulfides, producing the corresponding (R)-sulfoxides (20-90% ee) with good yields.
Collapse
Affiliation(s)
- Can Cui
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hui Lin
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China.
| | - Wei Pu
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chao Guo
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
| | - Yan Liu
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
| | - Xiao-Qiong Pei
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
| | - Zhong-Liu Wu
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.
| |
Collapse
|
7
|
Doukyu N, Iida S. Production of styrene oxide from styrene by a recombinant Escherichia coli with enhanced AcrAB-TolC efflux pump level in an aqueous-organic solvent two-phase system. Biosci Biotechnol Biochem 2020; 84:1513-1520. [PMID: 32310021 DOI: 10.1080/09168451.2020.1755219] [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] [Indexed: 10/24/2022]
Abstract
The AcrAB-TolC efflux pump is involved in the organic solvent tolerance of Escherichia coli. Most E. coli strains are highly sensitive to organic solvents such as n-hexane and cyclohexane. Here, a recombinant E. coli transformed with an expression plasmid containing acrAB and tolC became tolerant to n-hexane and cyclohexane. The levels of AcrA, AcrB, and TolC in the recombinant increased by 3- to 5-fold compared to those in the control strain without the plasmid for acrAB or tolC. To investigate the usability of the recombinant as a biocatalyst in an aqueous-organic solvent two-phase system, we further introduced xylMA xylene monooxygenase genes from Pseudomonas putida mt-2 into the recombinant and examined the production of styrene oxide from styrene. The resulting recombinant produced 1.8 mg and 1.0 mg styrene oxide mL-1 of medium in a medium overlaid with a 25% volume of n-hexane and cyclohexane containing 10% (wt vol-1) styrene, respectively.
Collapse
Affiliation(s)
- Noriyuki Doukyu
- Department of Life Science, Toyo University , Gunma, Japan.,Bio-Nano Electronic Research Center, Toyo University , Kawagoe, Saitama, Japan
| | - Shinichiro Iida
- Department of Life Science, Toyo University , Gunma, Japan.,Bio-Nano Electronic Research Center, Toyo University , Kawagoe, Saitama, Japan
| |
Collapse
|
8
|
Schäfer L, Karande R, Bühler B. Maximizing Biocatalytic Cyclohexane Hydroxylation by Modulating Cytochrome P450 Monooxygenase Expression in P. taiwanensis VLB120. Front Bioeng Biotechnol 2020; 8:140. [PMID: 32175317 PMCID: PMC7056670 DOI: 10.3389/fbioe.2020.00140] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/11/2020] [Indexed: 01/31/2023] Open
Abstract
Cytochrome P450 monooxygenases (Cyps) effectively catalyze the regiospecific oxyfunctionalization of inert C-H bonds under mild conditions. Due to their cofactor dependency and instability in isolated form, oxygenases are preferably applied in living microbial cells with Pseudomonas strains constituting potent host organisms for Cyps. This study presents a holistic genetic engineering approach, considering gene dosage, transcriptional, and translational levels, to engineer an effective Cyp-based whole-cell biocatalyst, building on recombinant Pseudomonas taiwanensis VLB120 for cyclohexane hydroxylation. A lac-based regulation system turned out to be favorable in terms of orthogonality to the host regulatory network and enabled a remarkable specific whole-cell activity of 34 U gCDW -1. The evaluation of different ribosomal binding sites (RBSs) revealed that a moderate translation rate was favorable in terms of the specific activity. An increase in gene dosage did only slightly elevate the hydroxylation activity, but severely impaired growth and resulted in a large fraction of inactive Cyp. Finally, the introduction of a terminator reduced leakiness. The optimized strain P. taiwanensis VLB120 pSEVA_Cyp allowed for a hydroxylation activity of 55 U gCDW -1. Applying 5 mM cyclohexane, molar conversion and biomass-specific yields of 82.5% and 2.46 mmolcyclohexanol gbiomass -1 were achieved, respectively. The strain now serves as a platform to design in vivo cascades and bioprocesses for the production of polymer building blocks such as ε-caprolactone.
Collapse
Affiliation(s)
- Lisa Schäfer
- Department of Solar Materials, Helmholtz-Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Rohan Karande
- Department of Solar Materials, Helmholtz-Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Bruno Bühler
- Department of Solar Materials, Helmholtz-Centre for Environmental Research-UFZ, Leipzig, Germany
| |
Collapse
|
9
|
Fabara AN, Fraaije MW. An overview of microbial indigo-forming enzymes. Appl Microbiol Biotechnol 2019; 104:925-933. [PMID: 31834440 PMCID: PMC6962290 DOI: 10.1007/s00253-019-10292-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/23/2019] [Accepted: 11/28/2019] [Indexed: 11/03/2022]
Abstract
Indigo is one of the oldest textile dyes and was originally prepared from plant material. Nowadays, indigo is chemically synthesized at a large scale to satisfy the demand for dyeing jeans. The current indigo production processes are based on fossil feedstocks; therefore, it is highly attractive to develop a more sustainable and environmentally friendly biotechnological process for the production of this popular dye. In the past decades, a number of natural and engineered enzymes have been identified that can be used for the synthesis of indigo. This mini-review provides an overview of the various microbial enzymes which are able to produce indigo and discusses the advantages and disadvantages of each biocatalytic system.
Collapse
Affiliation(s)
- Andrea N Fabara
- Molecular Enzymology group, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Marco W Fraaije
- Molecular Enzymology group, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
| |
Collapse
|
10
|
Heine T, Scholtissek A, Hofmann S, Koch R, Tischler D. Accessing Enantiopure Epoxides and Sulfoxides: Related Flavin‐Dependent Monooxygenases Provide Reversed Enantioselectivity. ChemCatChem 2019. [DOI: 10.1002/cctc.201901353] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Thomas Heine
- Institute of BiosciencesTU Bergakademie Freiberg Freiberg 09599 Germany
| | - Anika Scholtissek
- Institute of BiosciencesTU Bergakademie Freiberg Freiberg 09599 Germany
| | - Sarah Hofmann
- Institute of BiosciencesTU Bergakademie Freiberg Freiberg 09599 Germany
| | - Rainhard Koch
- Engineering & TechnologyBayer AG Leverkusen 51368 Germany
| | - Dirk Tischler
- Institute of BiosciencesTU Bergakademie Freiberg Freiberg 09599 Germany
- Microbial BiotechnologyRuhr University Bochum Bochum 44780 Germany
| |
Collapse
|
11
|
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
| |
Collapse
|
12
|
Heine T, van Berkel WJH, Gassner G, van Pée KH, Tischler D. Two-Component FAD-Dependent Monooxygenases: Current Knowledge and Biotechnological Opportunities. BIOLOGY 2018; 7:biology7030042. [PMID: 30072664 PMCID: PMC6165268 DOI: 10.3390/biology7030042] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/31/2018] [Accepted: 08/01/2018] [Indexed: 12/11/2022]
Abstract
Flavoprotein monooxygenases create valuable compounds that are of high interest for the chemical, pharmaceutical, and agrochemical industries, among others. Monooxygenases that use flavin as cofactor are either single- or two-component systems. Here we summarize the current knowledge about two-component flavin adenine dinucleotide (FAD)-dependent monooxygenases and describe their biotechnological relevance. Two-component FAD-dependent monooxygenases catalyze hydroxylation, epoxidation, and halogenation reactions and are physiologically involved in amino acid metabolism, mineralization of aromatic compounds, and biosynthesis of secondary metabolites. The monooxygenase component of these enzymes is strictly dependent on reduced FAD, which is supplied by the reductase component. More and more representatives of two-component FAD-dependent monooxygenases have been discovered and characterized in recent years, which has resulted in the identification of novel physiological roles, functional properties, and a variety of biocatalytic opportunities.
Collapse
Affiliation(s)
- Thomas Heine
- Institute of Biosciences, Environmental Microbiology, TU Bergakademie Freiberg, Leipziger Str. 29, 09599 Freiberg, Germany.
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - George Gassner
- Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA.
| | - Karl-Heinz van Pée
- Allgemeine Biochemie, Technische Universität Dresden, 01062 Dresden, Germany.
| | - Dirk Tischler
- Institute of Biosciences, Environmental Microbiology, TU Bergakademie Freiberg, Leipziger Str. 29, 09599 Freiberg, Germany.
- Microbial Biotechnology, Ruhr University Bochum, Universitätsstr. 150, 44780 Bochum, Germany.
| |
Collapse
|
13
|
Oelschlägel M, Zimmerling J, Tischler D. A Review: The Styrene Metabolizing Cascade of Side-Chain Oxygenation as Biotechnological Basis to Gain Various Valuable Compounds. Front Microbiol 2018; 9:490. [PMID: 29623070 PMCID: PMC5874493 DOI: 10.3389/fmicb.2018.00490] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/02/2018] [Indexed: 11/16/2022] Open
Abstract
Styrene is one of the most produced and processed chemicals worldwide and is released into the environment during widespread processing. But, it is also produced from plants and microorganisms. The natural occurrence of styrene led to several microbiological strategies to form and also to degrade styrene. One pathway designated as side-chain oxygenation has been reported as a specific route for the styrene degradation among microorganisms. It comprises the following enzymes: styrene monooxygenase (SMO; NADH-consuming and FAD-dependent, two-component system), styrene oxide isomerase (SOI; cofactor independent, membrane-bound protein) and phenylacetaldehyde dehydrogenase (PAD; NAD+-consuming) and allows an intrinsic cofactor regeneration. This specific way harbors a high potential for biotechnological use. Based on the enzymatic steps involved in this degradation route, important reactions can be realized from a large number of substrates which gain access to different interesting precursors for further applications. Furthermore, stereochemical transformations are possible, offering chiral products at high enantiomeric excess. This review provides an actual view on the microbiological styrene degradation followed by a detailed discussion on the enzymes of the side-chain oxygenation. Furthermore, the potential of the single enzyme reactions as well as the respective multi-step syntheses using the complete enzyme cascade are discussed in order to gain styrene oxides, phenylacetaldehydes, or phenylacetic acids (e.g., ibuprofen). Altered routes combining these putative biocatalysts with other enzymes are additionally described. Thus, the substrates spectrum can be enhanced and additional products as phenylethanols or phenylethylamines are reachable. Finally, additional enzymes with similar activities toward styrene and its metabolic intermediates are shown in order to modify the cascade described above or to use these enzyme independently for biotechnological application.
Collapse
Affiliation(s)
- Michel Oelschlägel
- Environmental Microbiology Group, Institute of Biosciences, Technische Universität Bergakademie Freiberg, Freiberg, Germany
| | - Juliane Zimmerling
- Environmental Microbiology Group, Institute of Biosciences, Technische Universität Bergakademie Freiberg, Freiberg, Germany
| | - Dirk Tischler
- Environmental Microbiology Group, Institute of Biosciences, Technische Universität Bergakademie Freiberg, Freiberg, Germany
- Microbial Biotechnology, Ruhr University Bochum, Bochum, Germany
| |
Collapse
|
14
|
Volmer J, Schmid A, Bühler B. The application of constitutively solvent-tolerantP. taiwanensisVLB120ΔCΔttgVfor stereospecific epoxidation of toxic styrene alleviates carrier solvent use. Biotechnol J 2017; 12. [DOI: 10.1002/biot.201600558] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/15/2017] [Accepted: 03/24/2017] [Indexed: 01/15/2023]
Affiliation(s)
- Jan Volmer
- Chair for Bioprocess engineering; Department of Biochemical and Chemical Engineering; TU Dortmund University; Dortmund Germany
| | - Andreas Schmid
- Department Solar Materials; Helmholtz Centre for Environmental Research GmbH - UFZ; Leipzig Germany
| | - Bruno Bühler
- Department Solar Materials; Helmholtz Centre for Environmental Research GmbH - UFZ; Leipzig Germany
| |
Collapse
|
15
|
Hintermayer SB, Weuster-Botz D. Experimental validation of in silico estimated biomass yields of Pseudomonas putida KT2440. Biotechnol J 2017; 12. [PMID: 28294579 DOI: 10.1002/biot.201600720] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/12/2017] [Accepted: 03/13/2017] [Indexed: 11/09/2022]
Abstract
Pseudomonas putida is rapidly becoming a microbial cell platform for biotechnological applications. In order to understand genotype-phenotype relationships genome scale models represent helpful tools. However, the validation of in silico predictions of genome scale models is a task that is rarely performed. In this study the theoretical biomass yields of Pseudomonas putida KT2440 were estimated for 57 different carbon sources based on a genome scale stoichiometric model applying flux balance analysis. The batch growth of P. putida KT2440 with six individual carbon sources covering the range of maximal to minimal in silico biomass yields (acetate, glycerol, citrate, succinate, malate and methanol, respectively) was studied in a defined mineral medium in a fully controlled stirred-tank bioreactor on a 3 L scale. The highest growth rate of P. putida KT2440 was measured with succinate as carbon source (0.51 h-1 ). Among the 57 carbon sources tested, glycerol resulted in the highest estimated biomass yield (0.61 molCBiomass molC-1Glycerol ) which was experimentally confirmed. The comparison of experimental determined biomass yields with a modified version of the model iJP815 showed deviations of only up to 10%. The experimental data generated in this study can also be used in future studies to further improve the genome scale models of P. putida KT2440. Improved models will then help to gain deeper insights in genotype-phenotype relationships.
Collapse
Affiliation(s)
| | - Dirk Weuster-Botz
- Institute of Biochemical Engineering, Technische Universität München, Garching, Germany
| |
Collapse
|
16
|
Lai B, Yu S, Bernhardt PV, Rabaey K, Virdis B, Krömer JO. Anoxic metabolism and biochemical production in Pseudomonas putida F1 driven by a bioelectrochemical system. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:39. [PMID: 26893611 PMCID: PMC4758010 DOI: 10.1186/s13068-016-0452-y] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/03/2016] [Indexed: 05/22/2023]
Abstract
BACKGROUND Pseudomonas putida is a promising host for the bioproduction of chemicals, but its industrial applications are significantly limited by its obligate aerobic character. The aim of this paper is to empower the anoxic metabolism of wild-type Pseudomonas putida to enable bioproduction anaerobically, with the redox power from a bioelectrochemical system (BES). RESULTS The obligate aerobe Pseudomonas putida F1 was able to survive and produce almost exclusively 2-Keto-gluconate from glucose under anoxic conditions due to redox balancing with electron mediators in a BES. 2-Keto-gluconate, a precursor for industrial anti-oxidant production, was produced at an overall carbon yield of over 90 % based on glucose. Seven different mediator compounds were tested, and only those with redox potential above 0.207 V (vs standard hydrogen electrode) showed interaction with the cells. The productivity increased with the increasing redox potential of the mediator, indicating this was a key factor affecting the anoxic production process. P. putida cells survived under anaerobic conditions, and limited biofilm formation could be observed on the anode's surface. Analysis of the intracellular pools of ATP, ADP and AMP showed that cells had an increased adenylate energy charge suggesting that cells were able to generate energy using the anode as terminal electron acceptor. The analysis of NAD(H) and NADP(H) showed that in the presence of specific extracellular electron acceptors, the NADP(H) pool was more oxidised, while the NAD(H) pool was unchanged. This implies a growth limitation under anaerobic conditions due to a shortage of NADPH and provides a way to limit biomass formation, while allowing cell maintenance and catalysis at high purity and yield. CONCLUSIONS For the first time, this study proved the principle that a BES-driven bioconversion of glucose can be achieved for a wild-type obligate aerobe. This non-growth bioconversion was in high yields, high purity and also could deliver the necessary metabolic energy for cell maintenance. By combining this approach with metabolic engineering strategies, this could prove to be a powerful new way to produce bio-chemicals and fuels from renewables in both high yield and high purity.
Collapse
Affiliation(s)
- Bin Lai
- />Centre for Microbial Electrochemical Systems (CEMES), The University of Queensland, Office 618, Gehrmann Building (60), St. Lucia, Brisbane, QLD 4072 Australia
- />Advanced Water Management Centre (AWMC), The University of Queensland, Brisbane, Australia
| | - Shiqin Yu
- />Centre for Microbial Electrochemical Systems (CEMES), The University of Queensland, Office 618, Gehrmann Building (60), St. Lucia, Brisbane, QLD 4072 Australia
- />Advanced Water Management Centre (AWMC), The University of Queensland, Brisbane, Australia
| | - Paul V. Bernhardt
- />School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Korneel Rabaey
- />Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Ghent, Belgium
| | - Bernardino Virdis
- />Centre for Microbial Electrochemical Systems (CEMES), The University of Queensland, Office 618, Gehrmann Building (60), St. Lucia, Brisbane, QLD 4072 Australia
- />Advanced Water Management Centre (AWMC), The University of Queensland, Brisbane, Australia
| | - Jens O. Krömer
- />Centre for Microbial Electrochemical Systems (CEMES), The University of Queensland, Office 618, Gehrmann Building (60), St. Lucia, Brisbane, QLD 4072 Australia
- />Advanced Water Management Centre (AWMC), The University of Queensland, Brisbane, Australia
| |
Collapse
|
17
|
Karande R, Schmid A, Buehler K. Applications of Multiphasic Microreactors for Biocatalytic Reactions. Org Process Res Dev 2016. [DOI: 10.1021/acs.oprd.5b00352] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Rohan Karande
- Helmholtz-Centre for Environmental Research—UFZ GmbH, Department of
Solar Materials, Permoserstrasse
15, 04318 Leipzig, Germany
| | - Andreas Schmid
- Helmholtz-Centre for Environmental Research—UFZ GmbH, Department of
Solar Materials, Permoserstrasse
15, 04318 Leipzig, Germany
| | - Katja Buehler
- Helmholtz-Centre for Environmental Research—UFZ GmbH, Department of
Solar Materials, Permoserstrasse
15, 04318 Leipzig, Germany
| |
Collapse
|
18
|
Sathesh-Prabu C, Lee SK. Production of Long-Chain α,ω-Dicarboxylic Acids by Engineered Escherichia coli from Renewable Fatty Acids and Plant Oils. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:8199-8208. [PMID: 26359801 DOI: 10.1021/acs.jafc.5b03833] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Long-chain α,ω-dicarboxylic acids (LDCAs, ≥ C12) are widely used as a raw material for preparing various commodities and polymers. In this study, a CYP450-monooxygenase-mediated ω-oxidation pathway system with high ω-regioselectivity was heterologously expressed in Escherichia coli to produce DCAs from fatty acids. The resulting engineered E. coli produced a maximum of 41 mg/L of C12 DCA and 163 mg/L of C14 DCA from fatty acids (1 g/L), following 20 h of whole cell biotransformation. Addition of a heme precursor and the hydroxyl radical scavenger, thiourea, increased product concentration (159 mg/L of C12 DCA and 410 mg/L of C14 DCA) in a shorter culture duration than that of the corresponding controls. DCAs of various chain lengths were synthesized from coconut oil hydrolysate using the engineered E. coli. This novel synthetic biocatalytic system could be applied to produce high value DCAs in a cost-effective manner from renewable plant oils.
Collapse
Affiliation(s)
- Chandran Sathesh-Prabu
- School of Energy and Chemical Engineering, and ‡School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, Republic of Korea
| | - Sung Kuk Lee
- School of Energy and Chemical Engineering, and ‡School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, Republic of Korea
| |
Collapse
|
19
|
Volmer J, Schmid A, Bühler B. Guiding bioprocess design by microbial ecology. Curr Opin Microbiol 2015; 25:25-32. [DOI: 10.1016/j.mib.2015.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/26/2015] [Accepted: 02/26/2015] [Indexed: 12/20/2022]
|
20
|
Lindmeyer M, Meyer D, Kuhn D, Bühler B, Schmid A. Making variability less variable: matching expression system and host for oxygenase-based biotransformations. ACTA ACUST UNITED AC 2015; 42:851-66. [DOI: 10.1007/s10295-015-1615-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 03/26/2015] [Indexed: 01/11/2023]
Abstract
Abstract
Variability in whole-cell biocatalyst performance represents a critical aspect for stable and productive bioprocessing. In order to investigate whether and how oxygenase-catalyzed reactions are affected by such variability issues in solvent-tolerant Pseudomonas, different inducers, expression systems, and host strains were tested for the reproducibility of xylene and styrene monooxygenase catalyzed hydroxylation and epoxidation reactions, respectively. Significantly higher activity variations were found for biocatalysts based on solvent-tolerant Pseudomonas putida DOT-TIE and S12 compared with solvent-sensitive P. putida KT2440, Escherichia coli JM101, and solvent-tolerant Pseudomonas taiwanensis VLB120. Specific styrene epoxidation rates corresponded to cellular styrene monooxygenase contents. Detected variations in activity strictly depended on the type of regulatory system employed, being high with the alk- and low with the lac-system. These results show that the occurrence of clonal variability in recombinant gene expression in Pseudomonas depends on the combination of regulatory system and host strain, does not correlate with a general phenotype such as solvent tolerance, and must be evaluated case by case.
Collapse
Affiliation(s)
- Martin Lindmeyer
- grid.5675.1 0000000104169637 Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering TU Dortmund University Emil-Figge-Strasse 66 44227 Dortmund Germany
| | - Daniel Meyer
- grid.5675.1 0000000104169637 Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering TU Dortmund University Emil-Figge-Strasse 66 44227 Dortmund Germany
- grid.5801.c 0000000121562780 Department of Biosystems Science and Engineering ETH Zürich Mattenstrasse 26 4058 Basel Switzerland
| | - Daniel Kuhn
- grid.5675.1 0000000104169637 Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering TU Dortmund University Emil-Figge-Strasse 66 44227 Dortmund Germany
- grid.419481.1 0000 0001 1515 9979 ESBATech, a Novartis company Wagistrasse 12 8952 Zürich-Schlieren Switzerland
| | - Bruno Bühler
- grid.5675.1 0000000104169637 Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering TU Dortmund University Emil-Figge-Strasse 66 44227 Dortmund Germany
- grid.7492.8 0000000404923830 Department Solar Materials Center for Environmental Research - UFZ GmbH Permoser Strasse 15 04318 Leipzig Germany
| | - Andreas Schmid
- grid.5675.1 0000000104169637 Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering TU Dortmund University Emil-Figge-Strasse 66 44227 Dortmund Germany
- grid.7492.8 0000000404923830 Department Solar Materials Center for Environmental Research - UFZ GmbH Permoser Strasse 15 04318 Leipzig Germany
| |
Collapse
|
21
|
Bayer T, Milker S, Wiesinger T, Rudroff F, Mihovilovic MD. Designer Microorganisms for Optimized Redox Cascade Reactions - Challenges and Future Perspectives. Adv Synth Catal 2015. [DOI: 10.1002/adsc.201500202] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
22
|
Toda H, Ohuchi T, Imae R, Itoh N. Microbial production of aliphatic (S)-epoxyalkanes by using Rhodococcus sp. strain ST-10 styrene monooxygenase expressed in organic-solvent-tolerant Kocuria rhizophila DC2201. Appl Environ Microbiol 2015; 81:1919-25. [PMID: 25556188 PMCID: PMC4345390 DOI: 10.1128/aem.03405-14] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 12/27/2014] [Indexed: 11/20/2022] Open
Abstract
We describe the development of biocatalysis for producing optically pure straight-chain (S)-epoxyalkanes using styrene monooxygenase of Rhodococcus sp. strain ST-10 (RhSMO). RhSMO was expressed in the organic solvent-tolerant microorganism Kocuria rhizophila DC2201, and the bioconversion reaction was performed in an organic solvent-water biphasic reaction system. The biocatalytic process enantioselectively converted linear terminal alkenes to their corresponding (S)-epoxyalkanes using glucose and molecular oxygen. When 1-heptene and 6-chloro-1-hexene were used as substrates (400 mM) under optimized conditions, 88.3 mM (S)-1,2-epoxyheptane and 246.5 mM (S)-1,2-epoxy-6-chlorohexane, respectively, accumulated in the organic phase with good enantiomeric excess (ee; 84.2 and 95.5%). The biocatalysis showed broad substrate specificity toward various aliphatic alkenes, including functionalized and unfunctionalized alkenes, with good to excellent ee. Here, we demonstrate that this biocatalytic system is environmentally friendly and useful for producing various enantiopure (S)-epoxyalkanes.
Collapse
Affiliation(s)
- Hiroshi Toda
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, Kurokawa, Imizu, Toyama, Japan
| | - Takuya Ohuchi
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, Kurokawa, Imizu, Toyama, Japan
| | - Ryouta Imae
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, Kurokawa, Imizu, Toyama, Japan
| | - Nobuya Itoh
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, Kurokawa, Imizu, Toyama, Japan
| |
Collapse
|
23
|
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.
Collapse
|
24
|
Going beyond E. coli: autotransporter based surface display on alternative host organisms. N Biotechnol 2015; 32:644-50. [PMID: 25579193 DOI: 10.1016/j.nbt.2014.12.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/19/2014] [Accepted: 12/31/2014] [Indexed: 11/21/2022]
Abstract
Autotransporters represent one of the most popular anchoring motifs used to display peptides, proteins or enzymes on the cell surface of a Gram-negative bacterium. Applications range from vaccine delivery to library screenings to biocatalysis and bioremediation. Although the underlying secretion mechanism is supposed to be available in most, if not all, Gram-negative bacteria, autotransporters have to date almost exclusively been used for surface display on Escherichia coli. However, for their utilisation beyond a laboratory scale, in particular for biocatalysis, host bacteria with specific features and industrial applicability are required. A few groups have addressed this issue and demonstrated that bacteria other than E. coli can also be used for autotransporter based surface display. We summarise these studies and discuss opportunities and challenges that arise from surface display of recombinant proteins using the autotransporter pathway in alternative hosts.
Collapse
|
25
|
Toda H, Imae R, Itoh N. Bioproduction of Chiral Epoxyalkanes using Styrene Monooxygenase fromRhodococcussp. ST-10 (RhSMO). Adv Synth Catal 2014. [DOI: 10.1002/adsc.201400383] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
26
|
Halan B, Letzel T, Schmid A, Buehler K. Solid support membrane-aerated catalytic biofilm reactor for the continuous synthesis of (S)-styrene oxide at gram scale. Biotechnol J 2014; 9:1339-49. [DOI: 10.1002/biot.201400341] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/27/2014] [Accepted: 08/07/2014] [Indexed: 11/09/2022]
|
27
|
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.
Collapse
|
28
|
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.
Collapse
Affiliation(s)
- Manfred Schrewe
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Strasse 66, 44227 Dortmund, Germany
| | | | | | | |
Collapse
|
29
|
Metabolic engineering of Pseudomonas sp. strain VLB120 as platform biocatalyst for the production of isobutyric acid and other secondary metabolites. Microb Cell Fact 2014; 13:2. [PMID: 24397404 PMCID: PMC3897908 DOI: 10.1186/1475-2859-13-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 12/29/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Over the recent years the production of Ehrlich pathway derived chemicals was shown in a variety of hosts such as Escherichia coli, Corynebacterium glutamicum, and yeast. Exemplarily the production of isobutyric acid was demonstrated in Escherichia coli with remarkable titers and yields. However, these examples suffer from byproduct formation due to the fermentative growth mode of the respective organism. We aim at establishing a new aerobic, chassis for the synthesis of isobutyric acid and other interesting metabolites using Pseudomonas sp. strain VLB120, an obligate aerobe organism, as host strain. RESULTS The overexpression of kivd, coding for a 2-ketoacid decarboxylase from Lactococcus lactis in Ps. sp. strain VLB120 enabled for the production of isobutyric acid and isobutanol via the valine synthesis route (Ehrlich pathway). This indicates the existence of chromosomally encoded alcohol and aldehyde dehydrogenases catalyzing the reduction and oxidation of isobutyraldehyde. In addition we showed that the strain possesses a complete pathway for isobutyric acid metabolization, channeling the compound via isobutyryl-CoA into valine degradation. Three key issues were addressed to allow and optimize isobutyric acid synthesis: i) minimizing isobutyric acid degradation by host intrinsic enzymes, ii) construction of suitable expression systems and iii) streamlining of central carbon metabolism finally leading to production of up to 26.8 ± 1.5 mM isobutyric acid with a carbon yield of 0.12 ± 0.01 g g(glc)⁻¹. CONCLUSION The combination of an increased flux towards isobutyric acid using a tailor-made expression system and the prevention of precursor and product degradation allowed efficient production of isobutyric acid in Ps. sp. strain VLB120. This will be the basis for the development of a continuous reaction process for this bulk chemicals.
Collapse
|
30
|
Scheps D, Honda Malca S, Richter SM, Marisch K, Nestl BM, Hauer B. Synthesis of ω-hydroxy dodecanoic acid based on an engineered CYP153A fusion construct. Microb Biotechnol 2013; 6:694-707. [PMID: 23941649 PMCID: PMC3815936 DOI: 10.1111/1751-7915.12073] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 06/07/2013] [Accepted: 06/08/2013] [Indexed: 01/09/2023] Open
Abstract
A bacterial P450 monooxygenase-based whole cell biocatalyst using Escherichia coli has been applied in the production of ω-hydroxy dodecanoic acid from dodecanoic acid (C12-FA) or the corresponding methyl ester. We have constructed and purified a chimeric protein where the fusion of the monooxygenase CYP153A from Marinobacter aquaeloei to the reductase domain of P450 BM3 from Bacillus megaterium ensures optimal protein expression and efficient electron coupling. The chimera was demonstrated to be functional and three times more efficient than other sets of redox components evaluated. The established fusion protein (CYP153AM. aq.-CPR) was used for the hydroxylation of C12-FA in in vivo studies. These experiments yielded 1.2 g l–1 ω-hydroxy dodecanoic from 10 g l–1 C12-FA with high regioselectivity (> 95%) for the terminal position. As a second strategy, we utilized C12-FA methyl ester as substrate in a two-phase system (5:1 aqueous/organic phase) configuration to overcome low substrate solubility and product toxicity by continuous extraction. The biocatalytic system was further improved with the coexpression of an additional outer membrane transport system (AlkL) to increase the substrate transfer into the cell, resulting in the production of 4 g l–1 ω-hydroxy dodecanoic acid. We further summarized the most important aspects of the whole-cell process and thereupon discuss the limits of the applied oxygenation reactions referring to hydrogen peroxide, acetate and P450 concentrations that impact the efficiency of the production host negatively.
Collapse
Affiliation(s)
- Daniel Scheps
- Institute of Technical Biochemistry, University of Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | | | | | | | | | | |
Collapse
|
31
|
Mirabal-Gallardo Y, Soriano MDPC, Santos LS. Stereoselective bioreduction of β-carboline imines through cell-free extracts from earthworms (Eisenia foetida). ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.tetasy.2013.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|