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Gemünde A, Rossini E, Lenz O, Frielingsdorf S, Holtmann D. Chemoorganotrophic electrofermentation by Cupriavidus necator using redox mediators. Bioelectrochemistry 2024; 158:108694. [PMID: 38518507 DOI: 10.1016/j.bioelechem.2024.108694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 03/13/2024] [Accepted: 03/16/2024] [Indexed: 03/24/2024]
Abstract
The non-pathogenic β-proteobacterium Cupriavidus necator has the ability to switch between chemoorganotrophic, chemolithoautotrophic and electrotrophic growth modes, making this microorganism a widely used host for cellular bioprocesses. Oxygen usually acts as the terminal electron acceptor in all growth modes. However, several challenges are associated with aeration, such as foam formation, oxygen supply costs, and the formation of an explosive gas mixture in chemolithoautotrophic cultivation with H2, CO2 and O2. Bioelectrochemical systems in which O2 is replaced by an electrode as a terminal electron acceptor offer a promising solution to these problems. The aim of this study was to establish a mediated electron transfer between the anode and the metabolism of living cells, i.e. anodic respiration, using fructose as electron and carbon source. Since C. necator is not able to transfer electrons directly to an electrode, redox mediators are required for this process. Based on previous observations on the extracellular electron transfer enabled by a polymeric mediator, we tested 11 common biological and non-biological redox mediators for their functionality and inhibitory effect for anodic electron transfer in a C. necator-based bioelectrochemical system. The use of ferricyanide at a concentration of 15 mM resulted in the highest current density of 260.75µAcm-2 and a coulombic efficiency of 64.1 %.
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Affiliation(s)
- André Gemünde
- Institute of Bioprocess Engineering and Pharmaceutical Technology and Competence Centre for Sustainable Engineering and Environmental Systems, University of Applied Sciences Mittelhessen, 35390 Giessen, Germany
| | - Elena Rossini
- Institute of Chemistry, Biophysical Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Oliver Lenz
- Institute of Chemistry, Biophysical Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Stefan Frielingsdorf
- Institute of Chemistry, Biophysical Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany.
| | - Dirk Holtmann
- Institute of Bioprocess Engineering and Pharmaceutical Technology and Competence Centre for Sustainable Engineering and Environmental Systems, University of Applied Sciences Mittelhessen, 35390 Giessen, Germany; Institute of Process Engineering in Life Sciences, Karlsruhe Institute of Technology, Kaiserstraße 12, 76131 Karlsruhe, Germany.
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2
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Harnisch F, Deutzmann JS, Boto ST, Rosenbaum MA. Microbial electrosynthesis: opportunities for microbial pure cultures. Trends Biotechnol 2024; 42:1035-1047. [PMID: 38431514 PMCID: PMC11310912 DOI: 10.1016/j.tibtech.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/05/2024] [Accepted: 02/05/2024] [Indexed: 03/05/2024]
Abstract
Microbial electrosynthesis (MES) is an emerging technology that couples renewable electricity to microbial production processes. Although advances in MES performance have been driven largely by microbial mixed cultures, we see a great limitation in the diversity, and hence value, of products that can be achieved in undefined mixed cultures. By contrast, metabolic control of pure cultures and genetic engineering could greatly expand the scope of MES, and even of broader electrobiotechnology, to include targeted high-value products. To leverage this potential, we advocate for more efforts and activities to develop engineered electroactive microbes for synthesis, and we highlight the need for a standardized electrobioreactor infrastructure that allows the establishment and engineering of electrobioprocesses with these novel biocatalysts.
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Affiliation(s)
- Falk Harnisch
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research GmbH, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Jörg S Deutzmann
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Santiago T Boto
- Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Adolf Reichwein Strasse 23, 07745 Jena, Germany; Institute of Microbiology, Faculty for Biological Sciences, Friedrich-Schiller-University Jena, Neugasse 23, 07743 Jena, Germany
| | - Miriam A Rosenbaum
- Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Adolf Reichwein Strasse 23, 07745 Jena, Germany; Institute of Microbiology, Faculty for Biological Sciences, Friedrich-Schiller-University Jena, Neugasse 23, 07743 Jena, Germany.
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3
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Meng H, Köbbing S, Blank LM. Establishing a straightforward I-SceI-mediated recombination one-plasmid system for efficient genome editing in P. putida KT2440. Microb Biotechnol 2024; 17:e14531. [PMID: 39031514 PMCID: PMC11258999 DOI: 10.1111/1751-7915.14531] [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: 01/24/2024] [Accepted: 07/04/2024] [Indexed: 07/22/2024] Open
Abstract
Pseudomonas putida has become an increasingly important chassis for producing valuable bioproducts. This development is not least due to the ever-improving genetic toolbox, including gene and genome editing techniques. Here, we present a novel, one-plasmid design of a critical genetic tool, the pEMG/pSW system, guaranteeing one engineering cycle to be finalized in 3 days. The pEMG/pSW system proved in the last decade to be valuable for targeted genome engineering in Pseudomonas, as it enables the deletion of large regions of the genome, the integration of heterologous gene clusters or the targeted generation of point mutations. Here, to expedite genetic engineering, two alternative plasmids were constructed: (1) The sacB gene from Bacillus subtilis was integrated into the I-SceI expressing plasmid pSW-2 as a counterselection marker to accelerated plasmid curing; (2) double-strand break introducing gene I-sceI and sacB counterselection marker were integrated into the backbone of the original pEMG vector, named pEMG-RIS. The single plasmid of pEMG-RIS allows rapid genome editing despite the low transcriptional activity of a single copy of the I-SceI encoding gene. Here, the usability of the pEMG-RIS is shown in P. putida KT2440 by integrating an expression cassette including an msfGFP gene in 3 days. In addition, a large fragment of 12.1 kb was also integrated. In summary, we present an updated pEMG/pSW genome editing system that allows efficient and rapid genome editing in P. putida. All plasmids designed in this study will be available via the Addgene platform.
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Affiliation(s)
- Hao Meng
- iAMB—Institute of Applied Microbiology, ABBt—Aachen Biology and BiotechnologyRWTH Aachen UniversityAachenGermany
| | - Sebastian Köbbing
- iAMB—Institute of Applied Microbiology, ABBt—Aachen Biology and BiotechnologyRWTH Aachen UniversityAachenGermany
| | - Lars M. Blank
- iAMB—Institute of Applied Microbiology, ABBt—Aachen Biology and BiotechnologyRWTH Aachen UniversityAachenGermany
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4
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Qi X, Gao X, Wang X, Xu P. Harnessing Pseudomonas putida in bioelectrochemical systems. Trends Biotechnol 2024; 42:877-894. [PMID: 38184440 DOI: 10.1016/j.tibtech.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/02/2023] [Accepted: 12/04/2023] [Indexed: 01/08/2024]
Abstract
Bioelectrochemical systems (BESs), a group of promising integrated systems that combine the advantages of biotechnology and electrochemical techniques, offer new opportunities to address environmental and energy challenges. Exoelectrogens capable of extracellular electron transfer (EET) are the critical factor enabling electrocatalytic activity in BESs. Pseudomonas putida, an aerobe widely used in environmental bioremediation, the biosynthesis of valuable chemicals, and energy bioproduction, has attracted much attention due to its unique application potential in BESs. This review provides a comprehensive understanding of the working principles, key factors, and applications of BESs using P. putida as the exoelectrogen. The challenges and perspectives for the development of BESs with P. putida as the exoelectrogen are also proposed and discussed.
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Affiliation(s)
- Xiaoyan Qi
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, PR China
| | - Xinyu Gao
- College of Arts and Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA
| | - Xia Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, PR China.
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, PR China.
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5
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Franco A, Chukwubuikem A, Meiners C, Rosenbaum MA. Exploring phenazine electron transfer interaction with elements of the respiratory pathways of Pseudomonas putida and Pseudomonas aeruginosa. Bioelectrochemistry 2024; 157:108636. [PMID: 38181591 DOI: 10.1016/j.bioelechem.2023.108636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/20/2023] [Accepted: 12/23/2023] [Indexed: 01/07/2024]
Abstract
Pseudomonas aeruginosa phenazines contribute to survival under microaerobic and anaerobic conditions by extracellular electron discharge to regulate cellular redox balances. This electron discharge is also attractive to be used for bioelectrochemical applications. However, elements of the respiratory pathways that interact with phenazines are not well understood. Five terminal oxidases are involved in the aerobic electron transport chain (ETC) of Pseudomonas putida and P. aeruginosa. The latter bacterium also includes four reductases that allow for denitrification. Here, we explored if phenazine-1-carboxylic acid interacts with those elements to enhance anodic electron discharge and drive bacterial growth in oxygen-limited conditions. Bioelectrochemical evaluations of terminal oxidase-deficient mutants of both Pseudomonas strains and P. aeruginosa with stimulated denitrification pathways indicated no direct beneficial interaction of phenazines with ETC elements for extracellular electron discharge. However, the single usage of the Cbb3-2 oxidase increased phenazine production, electron discharge, and cell growth. Assays with purified periplasmic cytochromes NirM and NirS indicated that pyocyanin acts as their electron donor. We conclude that phenazines play an important role in electron transfer to, between, and from terminal oxidases under oxygen-limiting conditions and their modulation might enhance EET. However, the phenazine-anode interaction cannot replace oxygen respiration to deliver energy for biomass formation.
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Affiliation(s)
- Angel Franco
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Anthony Chukwubuikem
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University (FSU), Fürstengraben 1, 07743 Jena, Germany
| | - Carina Meiners
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University (FSU), Fürstengraben 1, 07743 Jena, Germany
| | - Miriam A Rosenbaum
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University (FSU), Fürstengraben 1, 07743 Jena, Germany.
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6
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Dvořák P, Burýšková B, Popelářová B, Ebert BE, Botka T, Bujdoš D, Sánchez-Pascuala A, Schöttler H, Hayen H, de Lorenzo V, Blank LM, Benešík M. Synthetically-primed adaptation of Pseudomonas putida to a non-native substrate D-xylose. Nat Commun 2024; 15:2666. [PMID: 38531855 DOI: 10.1038/s41467-024-46812-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 03/11/2024] [Indexed: 03/28/2024] Open
Abstract
To broaden the substrate scope of microbial cell factories towards renewable substrates, rational genetic interventions are often combined with adaptive laboratory evolution (ALE). However, comprehensive studies enabling a holistic understanding of adaptation processes primed by rational metabolic engineering remain scarce. The industrial workhorse Pseudomonas putida was engineered to utilize the non-native sugar D-xylose, but its assimilation into the bacterial biochemical network via the exogenous xylose isomerase pathway remained unresolved. Here, we elucidate the xylose metabolism and establish a foundation for further engineering followed by ALE. First, native glycolysis is derepressed by deleting the local transcriptional regulator gene hexR. We then enhance the pentose phosphate pathway by implanting exogenous transketolase and transaldolase into two lag-shortened strains and allow ALE to finetune the rewired metabolism. Subsequent multilevel analysis and reverse engineering provide detailed insights into the parallel paths of bacterial adaptation to the non-native carbon source, highlighting the enhanced expression of transaldolase and xylose isomerase along with derepressed glycolysis as key events during the process.
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Affiliation(s)
- Pavel Dvořák
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic.
| | - Barbora Burýšková
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Barbora Popelářová
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Birgitta E Ebert
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Cnr College Rd & Cooper Rd, St Lucia, QLD, QLD 4072, Australia
| | - Tibor Botka
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Dalimil Bujdoš
- APC Microbiome Ireland, University College Cork, College Rd, Cork, T12 YT20, Ireland
- School of Microbiology, University College Cork, College Rd, Cork, T12 Y337, Ireland
| | - Alberto Sánchez-Pascuala
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Straße 10, 35043, Marburg, Germany
| | - Hannah Schöttler
- Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstraße 48, 48149, Münster, Germany
| | - Heiko Hayen
- Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstraße 48, 48149, Münster, Germany
| | - Víctor de Lorenzo
- Systems and Synthetic Biology Program, Centro Nacional de Biotecnología CNB-CSIC, Cantoblanco, Darwin 3, 28049, Madrid, Spain
| | - Lars M Blank
- Institute of Applied Microbiology, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany
| | - Martin Benešík
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
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7
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Zhang J, Li F, Liu D, Liu Q, Song H. Engineering extracellular electron transfer pathways of electroactive microorganisms by synthetic biology for energy and chemicals production. Chem Soc Rev 2024; 53:1375-1446. [PMID: 38117181 DOI: 10.1039/d3cs00537b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The excessive consumption of fossil fuels causes massive emission of CO2, leading to climate deterioration and environmental pollution. The development of substitutes and sustainable energy sources to replace fossil fuels has become a worldwide priority. Bio-electrochemical systems (BESs), employing redox reactions of electroactive microorganisms (EAMs) on electrodes to achieve a meritorious combination of biocatalysis and electrocatalysis, provide a green and sustainable alternative approach for bioremediation, CO2 fixation, and energy and chemicals production. EAMs, including exoelectrogens and electrotrophs, perform extracellular electron transfer (EET) (i.e., outward and inward EET), respectively, to exchange energy with the environment, whose rate determines the efficiency and performance of BESs. Therefore, we review the synthetic biology strategies developed in the last decade for engineering EAMs to enhance the EET rate in cell-electrode interfaces for facilitating the production of electricity energy and value-added chemicals, which include (1) progress in genetic manipulation and editing tools to achieve the efficient regulation of gene expression, knockout, and knockdown of EAMs; (2) synthetic biological engineering strategies to enhance the outward EET of exoelectrogens to anodes for electricity power production and anodic electro-fermentation (AEF) for chemicals production, including (i) broadening and strengthening substrate utilization, (ii) increasing the intracellular releasable reducing equivalents, (iii) optimizing c-type cytochrome (c-Cyts) expression and maturation, (iv) enhancing conductive nanowire biosynthesis and modification, (v) promoting electron shuttle biosynthesis, secretion, and immobilization, (vi) engineering global regulators to promote EET rate, (vii) facilitating biofilm formation, and (viii) constructing cell-material hybrids; (3) the mechanisms of inward EET, CO2 fixation pathway, and engineering strategies for improving the inward EET of electrotrophic cells for CO2 reduction and chemical production, including (i) programming metabolic pathways of electrotrophs, (ii) rewiring bioelectrical circuits for enhancing inward EET, and (iii) constructing microbial (photo)electrosynthesis by cell-material hybridization; (4) perspectives on future challenges and opportunities for engineering EET to develop highly efficient BESs for sustainable energy and chemical production. We expect that this review will provide a theoretical basis for the future development of BESs in energy harvesting, CO2 fixation, and chemical synthesis.
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Affiliation(s)
- Junqi Zhang
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Feng Li
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Dingyuan Liu
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Qijing Liu
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Hao Song
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
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8
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Pause L, Weimer A, Wirth NT, Nguyen AV, Lenz C, Kohlstedt M, Wittmann C, Nikel PI, Lai B, Krömer JO. Anaerobic glucose uptake in Pseudomonas putida KT2440 in a bioelectrochemical system. Microb Biotechnol 2024; 17:e14375. [PMID: 37990843 PMCID: PMC10832537 DOI: 10.1111/1751-7915.14375] [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: 07/29/2023] [Revised: 11/01/2023] [Accepted: 11/07/2023] [Indexed: 11/23/2023] Open
Abstract
Providing an anodic potential in a bio-electrochemical system to the obligate aerobe Pseudomonas putida enables anaerobic survival and allows the cells to overcome redox imbalances. In this setup, the bacteria could be exploited to produce chemicals via oxidative pathways at high yield. However, the absence of anaerobic growth and low carbon turnover rates remain as obstacles for the application of such an electro-fermentation technology. Growth and carbon turnover start with carbon uptake into the periplasm and cytosol. P. putida KT2440 has three native transporting systems for glucose, each differing in energy and redox demand. This architecture previously led to the hypothesis that internal redox and energy constraints ultimately limit cytoplasmic carbon utilization in a bio-electrochemical system. However, it remains largely unclear which uptake route is predominantly used by P. putida under electro-fermentative conditions. To elucidate this, we created three gene deletion mutants of P. putida KT2440, forcing the cells to exclusively utilize one of the routes. When grown in a bio-electrochemical system, the pathway mutants were heavily affected in terms of sugar consumption, current output and product formation. Surprisingly, however, we found that about half of the acetate formed in the cytoplasm originated from carbon that was put into the system via the inoculation biomass, while the other half came from the consumption of substrate. The deletion of individual sugar uptake routes did not alter significantly the secreted acetate concentrations among different strains even with different carbon sources. This means that the stoichiometry of the sugar uptake routes is not a limiting factor during electro-fermentation and that the low rates might be caused by other reasons, for example energy limitations or a yet-to-be-identified oxygen-dependent regulatory mechanism.
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Affiliation(s)
- Laura Pause
- Systems Biotechnology groupHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Anna Weimer
- Institute of Systems BiotechnologySaarland UniversitySaarbrückenGermany
| | - Nicolas T. Wirth
- Systems Environmental Microbiology Group, The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkLyngbyDenmark
| | - Anh Vu Nguyen
- Systems Biotechnology groupHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Claudius Lenz
- Systems Biotechnology groupHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Michael Kohlstedt
- Institute of Systems BiotechnologySaarland UniversitySaarbrückenGermany
| | | | - Pablo I. Nikel
- Systems Environmental Microbiology Group, The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkLyngbyDenmark
| | - Bin Lai
- BMBF Junior Research Group BiophotovoltaicsHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Jens O. Krömer
- Systems Biotechnology groupHelmholtz Centre for Environmental Research – UFZLeipzigGermany
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9
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Bitzenhofer NL, Höfel C, Thies S, Weiler AJ, Eberlein C, Heipieper HJ, Batra‐Safferling R, Sundermeyer P, Heidler T, Sachse C, Busche T, Kalinowski J, Belthle T, Drepper T, Jaeger K, Loeschcke A. Exploring engineered vesiculation by Pseudomonas putida KT2440 for natural product biosynthesis. Microb Biotechnol 2024; 17:e14312. [PMID: 37435812 PMCID: PMC10832525 DOI: 10.1111/1751-7915.14312] [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: 01/04/2023] [Accepted: 06/25/2023] [Indexed: 07/13/2023] Open
Abstract
Pseudomonas species have become promising cell factories for the production of natural products due to their inherent robustness. Although these bacteria have naturally evolved strategies to cope with different kinds of stress, many biotechnological applications benefit from engineering of optimised chassis strains with specially adapted tolerance traits. Here, we explored the formation of outer membrane vesicles (OMV) of Pseudomonas putida KT2440. We found OMV production to correlate with the recombinant production of a natural compound with versatile beneficial properties, the tripyrrole prodigiosin. Further, several P. putida genes were identified, whose up- or down-regulated expression allowed controlling OMV formation. Finally, genetically triggering vesiculation in production strains of the different alkaloids prodigiosin, violacein, and phenazine-1-carboxylic acid, as well as the carotenoid zeaxanthin, resulted in up to three-fold increased product yields. Consequently, our findings suggest that the construction of robust strains by genetic manipulation of OMV formation might be developed into a useful tool which may contribute to improving limited biotechnological applications.
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Affiliation(s)
- Nora Lisa Bitzenhofer
- Institute of Molecular Enzyme Technology (IMET)Heinrich Heine University DüsseldorfDüsseldorfGermany
| | - Carolin Höfel
- Institute of Molecular Enzyme Technology (IMET)Heinrich Heine University DüsseldorfDüsseldorfGermany
| | - Stephan Thies
- Institute of Molecular Enzyme Technology (IMET)Heinrich Heine University DüsseldorfDüsseldorfGermany
| | - Andrea Jeanette Weiler
- Institute of Molecular Enzyme Technology (IMET)Heinrich Heine University DüsseldorfDüsseldorfGermany
| | - Christian Eberlein
- Department of Environmental BiotechnologyHelmholtz Centre for Environmental Research (UFZ)LeipzigGermany
| | - Hermann J. Heipieper
- Department of Environmental BiotechnologyHelmholtz Centre for Environmental Research (UFZ)LeipzigGermany
| | - Renu Batra‐Safferling
- Institute of Biological Information Processing – Structural Biochemistry (IBI‐7: Structural Biochemistry)Forschungszentrum JülichJülichGermany
| | - Pia Sundermeyer
- Ernst‐Ruska Centre for Microscopy and Spectroscopy with Electrons (ER‐C‐3/Structural Biology)Forschungszentrum JülichJülichGermany
- Institute for Biological Information Processing 6 (IBI‐6/ Structural Cellular Biology)Forschungszentrum JülichJülichGermany
| | - Thomas Heidler
- Ernst‐Ruska Centre for Microscopy and Spectroscopy with Electrons (ER‐C‐3/Structural Biology)Forschungszentrum JülichJülichGermany
- Institute for Biological Information Processing 6 (IBI‐6/ Structural Cellular Biology)Forschungszentrum JülichJülichGermany
| | - Carsten Sachse
- Ernst‐Ruska Centre for Microscopy and Spectroscopy with Electrons (ER‐C‐3/Structural Biology)Forschungszentrum JülichJülichGermany
- Institute for Biological Information Processing 6 (IBI‐6/ Structural Cellular Biology)Forschungszentrum JülichJülichGermany
- Department of BiologyHeinrich Heine University DüsseldorfDüsseldorfGermany
| | - Tobias Busche
- Center for Biotechnology (CeBiTec)Bielefeld UniversityBielefeldGermany
- Bielefeld University, Medical School East Westphalia‐LippeBielefeld UniversityBielefeldGermany
| | - Jörn Kalinowski
- Center for Biotechnology (CeBiTec)Bielefeld UniversityBielefeldGermany
| | - Thomke Belthle
- DWI─Leibniz‐Institute for Interactive MaterialsAachenGermany
- Functional and Interactive Polymers, Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityAachenGermany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology (IMET)Heinrich Heine University DüsseldorfDüsseldorfGermany
| | - Karl‐Erich Jaeger
- Institute of Molecular Enzyme Technology (IMET)Heinrich Heine University DüsseldorfDüsseldorfGermany
- Institute of Bio‐ and Geosciences IBG‐1: BiotechnologyForschungszentrum JülichJülichGermany
| | - Anita Loeschcke
- Institute of Molecular Enzyme Technology (IMET)Heinrich Heine University DüsseldorfDüsseldorfGermany
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10
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Xu W, Lu X, Tang X, Xu J, Ye Z. Mechanism of quinone mediators modified polyurethane foam for enhanced nitrobenzene reduction and denitrification. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:131830. [PMID: 37506643 DOI: 10.1016/j.jhazmat.2023.131830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/03/2023] [Accepted: 06/09/2023] [Indexed: 07/30/2023]
Abstract
The nitrobenzene (NB) reduction and denitrification performance of the immobilized biofilm (I-BF) reactors based on 9,10-anthraquinone-2-sulfonyl chloride (ASC) modified polyurethane foam (PUF-ASC) carriers were investigated. Experiments demonstrated that the quinone mediators enhanced NB reduction and denitrification performance. The NB reduction rates increased by 1.46, while the NO3--N removal rates increased by 1.55 times in the PUF-0.1ASC system. The quinone mediators promote extracellular polymeric substances (EPS) secretion. Electrochemical tests indicated that quinone mediators enhanced the electron transfer of biofilm systems. NADH generation was accelerated and microbial electron transport system activity (ETSA) was promoted. The abundance of genera with electrochemical activity, NB degradation and denitrification ability (Pseudomonas sp., Diaphorobate sp., and Acinetobacter sp.) increased. Metabolic pathways relating to NO3--N and NB reduction were uploaded. In conclusion, electron acquisition by NO3--N and NB was facilitated, bacterial community structure and metabolic pathways were affected by the quinone mediators.
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Affiliation(s)
- Wenjie Xu
- School of Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China; Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China
| | - Xinyue Lu
- Technical research and development center, CNOOC Gas and Power Group Co., Ltd, Beijing 100028, China
| | - Xiaohui Tang
- No. 1 Engineering Design Institute, Academy of Environmental Planning and Design, Co., Ltd. Nanjing University, Nanjing 210003, China
| | - Jin Xu
- School of Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China
| | - Zhengfang Ye
- Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
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11
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Pous N, Bañeras L, Corvini PFX, Liu SJ, Puig S. Direct ammonium oxidation to nitrogen gas (Dirammox) in Alcaligenes strain HO-1: The electrode role. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2023; 15:100253. [PMID: 36896143 PMCID: PMC9988695 DOI: 10.1016/j.ese.2023.100253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 02/07/2023] [Accepted: 02/13/2023] [Indexed: 05/14/2023]
Abstract
It has been recently suggested that Alcaligenes use a previously unknown pathway to convert ammonium into dinitrogen gas (Dirammox) via hydroxylamine (NH2OH). This fact alone already implies a significant decrease in the aeration requirements for the process, but the process would still be dependent on external aeration. This work studied the potential use of a polarised electrode as an electron acceptor for ammonium oxidation using the recently described Alcaligenes strain HO-1 as a model heterotrophic nitrifier. Results indicated that Alcaligenes strain HO-1 requires aeration for metabolism, a requirement that cannot be replaced for a polarised electrode alone. However, concomitant elimination of succinate and ammonium was observed when operating a previously grown Alcaligenes strain HO-1 culture in the presence of a polarised electrode and without aeration. The usage of a polarised electrode together with aeration did not increase the succinate nor the nitrogen removal rates observed with aeration alone. However, current density generation was observed along a feeding batch test representing an electron share of 3% of the ammonium removed in the presence of aeration and 16% without aeration. Additional tests suggested that hydroxylamine oxidation to dinitrogen gas could have a relevant role in the electron discharge onto the anode. Therefore, the presence of a polarised electrode supported the metabolic functions of Alcaligenes strain HO-1 on the simultaneous oxidation of succinate and ammonium.
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Affiliation(s)
- Narcís Pous
- Laboratory of Chemical and Environmental Engineering (LEQUiA), Institute of the Environment, University of Girona, Carrer Maria Aurèlia Capmany, 69, E-17003, Girona, Spain
| | - Lluis Bañeras
- Group of Environmental Microbial Ecology, Institute of Aquatic Ecology, University of Girona, C/Maria Aurèlia Capmany, 40, E-17003, Girona, Spain
| | - Philippe F.-X. Corvini
- School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, 4132, Switzerland
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Resource at Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Sebastià Puig
- Laboratory of Chemical and Environmental Engineering (LEQUiA), Institute of the Environment, University of Girona, Carrer Maria Aurèlia Capmany, 69, E-17003, Girona, Spain
- Corresponding author.
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12
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Al-Mamun A, Ahmed W, Jafary T, Nayak JK, Al-Nuaimi A, Sana A. Recent advances in microbial electrosynthesis system: Metabolic investigation and process optimization. Biochem Eng J 2023. [DOI: 10.1016/j.bej.2023.108928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
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13
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Franco A, Elbahnasy M, Rosenbaum MA. Screening of natural phenazine producers for electroactivity in bioelectrochemical systems. Microb Biotechnol 2023; 16:579-594. [PMID: 36571174 PMCID: PMC9948232 DOI: 10.1111/1751-7915.14199] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 12/27/2022] Open
Abstract
Mediated extracellular electron transfer (EET) might be a great vehicle to connect microbial bioprocesses with electrochemical control in stirred-tank bioreactors. However, mediated electron transfer to date is not only much less efficient but also much less studied than microbial direct electron transfer to an anode. For example, despite the widespread capacity of pseudomonads to produce phenazine natural products, only Pseudomonas aeruginosa has been studied for its use of phenazines in bioelectrochemical applications. To provide a deeper understanding of the ecological potential for the bioelectrochemical exploitation of phenazines, we here investigated the potential electroactivity of over 100 putative diverse native phenazine producers and the performance within bioelectrochemical systems. Five species from the genera Pseudomonas, Streptomyces, Nocardiopsis, Brevibacterium and Burkholderia were identified as new electroactive bacteria. Electron discharge to the anode and electric current production correlated with the phenazine synthesis of Pseudomonas chlororaphis subsp. aurantiaca. Phenazine-1-carboxylic acid was the dominant molecule with a concentration of 86.1 μg/ml mediating an anodic current of 15.1 μA/cm2 . On the other hand, Nocardiopsis chromatogenes used a wider range of phenazines at low concentrations and likely yet-unknown redox compounds to mediate EET, achieving an anodic current of 9.5 μA/cm2 . Elucidating the energetic and metabolic usage of phenazines in these and other species might contribute to improving electron discharge and respiration. In the long run, this may enhance oxygen-limited bioproduction of value-added compounds based on mediated EET mechanisms.
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Affiliation(s)
- Angel Franco
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany
| | - Mahmoud Elbahnasy
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University (FSU), Jena, Germany
| | - Miriam A Rosenbaum
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University (FSU), Jena, Germany
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14
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Lai B, Krömer J, Aulenta F, Wu H, Nikel PI. Exploiting synergies between microbial electrochemical technologies and synthetic biology. Microb Biotechnol 2023; 16:485-488. [PMID: 36622031 PMCID: PMC9948174 DOI: 10.1111/1751-7915.14208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 12/22/2022] [Indexed: 01/10/2023] Open
Affiliation(s)
- Bin Lai
- BMBF Junior Research Group Biophotovoltaics, Helmholtz Center for Environmental Research - UFZ, Leipzig, Germany
| | - Jens Krömer
- Systems Biotechnology Group, Helmholtz Center for Environmental Research - UFZ, Leipzig, Germany
| | - Federico Aulenta
- Water Research Institute (IRSA), National Research Council (CNR), Rome, Italy
| | - Hui Wu
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Pablo Ivan Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark - Kgs, Lyngby, Denmark
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15
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The two faces of pyocyanin - why and how to steer its production? World J Microbiol Biotechnol 2023; 39:103. [PMID: 36864230 PMCID: PMC9981528 DOI: 10.1007/s11274-023-03548-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 02/13/2023] [Indexed: 03/04/2023]
Abstract
The ambiguous nature of pyocyanin was noted quite early after its discovery. This substance is a recognized Pseudomonas aeruginosa virulence factor that causes problems in cystic fibrosis, wound healing, and microbiologically induced corrosion. However, it can also be a potent chemical with potential use in a wide variety of technologies and applications, e.g. green energy production in microbial fuel cells, biocontrol in agriculture, therapy in medicine, or environmental protection. In this mini-review, we shortly describe the properties of pyocyanin, its role in the physiology of Pseudomonas and show the ever-growing interest in it. We also summarize the possible ways of modulating pyocyanin production. We underline different approaches of the researchers that aim either at lowering or increasing pyocyanin production by using different culturing methods, chemical additives, physical factors (e.g. electromagnetic field), or genetic engineering techniques. The review aims to present the ambiguous character of pyocyanin, underline its potential, and signalize the possible further research directions.
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16
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Gemünde A, Lai B, Pause L, Krömer J, Holtmann D. Redox mediators in microbial electrochemical systems. ChemElectroChem 2022. [DOI: 10.1002/celc.202200216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- André Gemünde
- Technische Hochschule Mittelhessen Institute of Bioprocess Engineering and Pharmaceutical Technology Wiesenstraße 14 35390 Gießen GERMANY
| | - Bin Lai
- Helmholtz Centre for Environmental Research UFZ Department of Environmental Microbiology: Helmholtz-Zentrum fur Umweltforschung UFZ Abteilung Umweltmikrobiologie Systems Biotechnology 04318 Leipzig GERMANY
| | - Laura Pause
- Helmholtz Centre for Environmental Research UFZ Environmental Engineering and Biotechnology Research Unit: Helmholtz-Zentrum fur Umweltforschung UFZ Themenbereich Umwelt- und Biotechnologie Systems Biotechnology 04318 Leipzig GERMANY
| | - Jens Krömer
- Helmholtz Centre for Environmental Research UFZ Environmental Engineering and Biotechnology Research Unit: Helmholtz-Zentrum fur Umweltforschung UFZ Themenbereich Umwelt- und Biotechnologie Systems Biotechnology 04318 Leipzig GERMANY
| | - Dirk Holtmann
- Technische Hochschule Mittelhessen IBPT Wiesenstrasse 14 35390 Giessen GERMANY
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17
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Pötschke L, Huber P, Stegschuster G, Schriever S, Kroppen N, Schmatz J, Gries T, Blank LM, Farber P, Rosenbaum MA. Customized Woven Carbon Fiber Electrodes for Bioelectrochemical Systems—A Study of Structural Parameters. FRONTIERS IN CHEMICAL ENGINEERING 2022. [DOI: 10.3389/fceng.2022.765682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Commercial carbon fiber (CF) fabrics are popular electrode materials for bioelectrochemical systems (BES), but are usually not optimized for the specific application. This study investigates BES-relevant material characteristics on fabric level, such as weave types and weave parameters. The two contrasting weave types plain and leno weave were characterized with respect to their envisaged application types: 1) BES with mainly advective flow regimes and 2) stirred systems, which could benefit from fluid flow through a fabric electrode. Experiments with batch and continuously fed pure cultures of Geobacter sulfurreducens PCA and Shewanella oneidensis MR-1 reveal that µm-scale electrode topologies are of limited use for the thick biofilms of G. sulfurreducens, but can boost S. oneidensis’ current generation especially in batch and fed-batch reactors. For advective flow regimes, deeper layers of biofilm inside microporous electrodes are often mass transport limited, even with thin biofilms of S. oneidensis. Therefore, low porosity plain weave electrodes for advective flow operation as in wastewater treating BES should be thin and flat. A trade-off between maximized current density and electrode material utilization exists, which is optimized exemplarily for an advective flow operation. For stirred BES of biotechnological applications, a flow-through of electrolyte is desired. For this, leno weave fabrics with pores at cm-scale are produced from 100% CF for the first time. In a preliminary evaluation, they outperform plain weave fabrics. Mass transfer investigations in stirred BES demonstrate that the large pores enable efficient electrode utilization at lower power input in terms of stirring speed.
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18
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Lai B, Glaven S, Song H. Editorial: Electrobiotechnology Towards Sustainable Bioeconomy: Fundamental, Optimization and Applications. Front Bioeng Biotechnol 2022; 10:901072. [PMID: 35557869 PMCID: PMC9086240 DOI: 10.3389/fbioe.2022.901072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Bin Lai
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Sarah Glaven
- Naval Research Laboratory, Center for Bio/Molecular Science and Engineering, Washington, DC, United States
| | - Hao Song
- Key Laboratory of Systems Bioengineering, Frontier Science Center for Synthetic Biology, Ministry of Education, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
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19
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Khandelwal H, Mutyala S, Kim M, Eun Song Y, Li S, Jang M, Oh SE, Rae Kim J. Colorimetric isolation of a novel electrochemically active Pseudomonas strain using tungsten nanorods for bioelectrochemical applications. Bioelectrochemistry 2022; 146:108136. [DOI: 10.1016/j.bioelechem.2022.108136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/15/2022] [Accepted: 04/15/2022] [Indexed: 11/29/2022]
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20
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Virdis B, Hoelzle R, Marchetti A, Boto ST, Rosenbaum MA, Blasco-Gómez R, Puig S, Freguia S, Villano M. Electro-fermentation: Sustainable bioproductions steered by electricity. Biotechnol Adv 2022; 59:107950. [PMID: 35364226 DOI: 10.1016/j.biotechadv.2022.107950] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 02/22/2022] [Accepted: 03/24/2022] [Indexed: 01/06/2023]
Abstract
The market of biobased products obtainable via fermentation processes is steadily increasing over the past few years, driven by the need to create a decarbonized economy. To date, industrial fermentation (IF) employs either pure or mixed microbial cultures (MMC) whereby the type of the microbial catalysts and the used feedstock affect metabolic pathways and, in turn, the type of product(s) generated. In many cases, especially when dealing with MMC, the economic viability of IF is hindered by factors such as the low attained product titer and selectivity, which ultimately challenge the downstream recovery and purification steps. In this context, electro-fermentation (EF) represents an innovative approach, based on the use of a polarized electrode interface to trigger changes in the rate, yield, titer or product distribution deriving from traditional fermentation processes. In principle, the electrode in EF can act as an electron acceptor (i.e., anodic electro-fermentation, AEF) or donor (i.e., cathodic electro-fermentation, CEF), or simply as a mean to control the oxidation-reduction potential of the fermentation broth. However, the molecular and biochemical basis underlying the EF process are still largely unknown. This review paper provides a comprehensive overview of recent literature studies including both AEF and CEF examples with either pure or mixed microbial cultures. A critical analysis of biochemical, microbiological, and engineering aspects which presently hamper the transition of the EF technology from the laboratory to the market is also presented.
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Affiliation(s)
- Bernardino Virdis
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane, QLD 4072, Australia
| | - Robert Hoelzle
- School of Earth and Environmental Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Angela Marchetti
- Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Santiago T Boto
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), 07745 Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University (FSU), 07743 Jena, Germany
| | - Miriam A Rosenbaum
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), 07745 Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University (FSU), 07743 Jena, Germany
| | - Ramiro Blasco-Gómez
- LEQUIA, Institute of the Environment, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
| | - Sebastià Puig
- LEQUIA, Institute of the Environment, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
| | - Stefano Freguia
- Department of Chemical Engineering, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Marianna Villano
- Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
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21
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Nitrogen Metabolism in Pseudomonas putida: Functional Analysis Using Random Barcode Transposon Sequencing. Appl Environ Microbiol 2022; 88:e0243021. [PMID: 35285712 DOI: 10.1128/aem.02430-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas putida KT2440 has long been studied for its diverse and robust metabolisms, yet many genes and proteins imparting these growth capacities remain uncharacterized. Using pooled mutant fitness assays, we identified genes and proteins involved in the assimilation of 52 different nitrogen containing compounds. To assay amino acid biosynthesis, 19 amino acid drop-out conditions were also tested. From these 71 conditions, significant fitness phenotypes were elicited in 672 different genes including 100 transcriptional regulators and 112 transport-related proteins. We divide these conditions into 6 classes, and propose assimilatory pathways for the compounds based on this wealth of genetic data. To complement these data, we characterize the substrate range of three promiscuous aminotransferases relevant to metabolic engineering efforts in vitro. Furthermore, we examine the specificity of five transcriptional regulators, explaining some fitness data results and exploring their potential to be developed into useful synthetic biology tools. In addition, we use manifold learning to create an interactive visualization tool for interpreting our BarSeq data, which will improve the accessibility and utility of this work to other researchers. IMPORTANCE Understanding the genetic basis of P. putida's diverse metabolism is imperative for us to reach its full potential as a host for metabolic engineering. Many target molecules of the bioeconomy and their precursors contain nitrogen. This study provides functional evidence linking hundreds of genes to their roles in the metabolism of nitrogenous compounds, and provides an interactive tool for visualizing these data. We further characterize several aminotransferases, lactamases, and regulators, which are of particular interest for metabolic engineering.
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22
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Cockell CS. Bridging the gap between microbial limits and extremes in space: space microbial biotechnology in the next 15 years. Microb Biotechnol 2022; 15:29-41. [PMID: 34534397 PMCID: PMC8719799 DOI: 10.1111/1751-7915.13927] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 09/05/2021] [Indexed: 12/01/2022] Open
Abstract
The establishment of a permanent human settlement in space is one of humanity's ambitions. To achieve this, microorganisms will be used to carry out many functions such as recycling, food and pharmaceutical production, mining and other processes. However, the physical and chemical extremes in all locations beyond Earth exceed known growth limits of microbial life. Making microbes more tolerant of a greater range of extraterrestrial extremes will not produce organisms that can grow in unmodified extraterrestrial environments since in many of them not even liquid water can exist. However, by narrowing the gap, the engineering demands on bioindustrial processes can be reduced and greater robustness can be incorporated into the biological component. I identify and describe these required microbial biotechnological modifications and speculate on long-term possibilities such as microbial biotechnology on Saturn's moon Titan to support a human presence in the outer Solar System and bioprocessing of asteroids. A challenge for space microbial biotechnology in the coming decades is to narrow the microbial gap by systemically identifying the genes required to do this and incorporating them into microbial systems that can be used to carry out bioindustrial processes of interest.
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Affiliation(s)
- Charles S. Cockell
- UK Centre for AstrobiologySchool of Physics and AstronomyUniversity of EdinburghEdinburghUK
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23
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Rhodes Z, Simoska O, Dantanarayana A, Stevenson KJ, Minteer SD. Using structure-function relationships to understand the mechanism of phenazine-mediated extracellular electron transfer in Escherichia coli. iScience 2021; 24:103033. [PMID: 34522869 PMCID: PMC8426270 DOI: 10.1016/j.isci.2021.103033] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/19/2021] [Accepted: 08/20/2021] [Indexed: 10/26/2022] Open
Abstract
Phenazines are redox-active nitrogen-containing heterocyclic compounds that can be produced by either bacteria or synthetic approaches. As an electron shuttles (mediators), phenazines are involved in several biological processes facilitating extracellular electron transfer (EET). Therefore, it is of great importance to understand the structural and electronic properties of phenazines that promote EET in microbial electrochemical systems. Our previous study experimentally investigated a phenazine-based library as an exogenous mediator system to facilitate EET in Escherichia coli. Herein, we combine our experimental data with density functional theory (DFT) calculations and multivariate linear regression modeling to understand the structure-function relationships in phenazine-based mediated EET. These calculations demonstrate that the computed redox properties of phenazines in lipophilic environments (e.g., cell membrane) correlate to experimental mediated current densities. Additional DFT-derived molecular properties were considered to develop a predictive model, which could be used in metabolic engineering approaches to introduce phenazines as endogenous mediators into bacteria.
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Affiliation(s)
- Zayn Rhodes
- Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Olja Simoska
- Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | | | - Keith J Stevenson
- Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Bolshoi Boulevard 30 Bld. 1, Moscow 121205, Russia
| | - Shelley D Minteer
- Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA
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Demling P, Ankenbauer A, Klein B, Noack S, Tiso T, Takors R, Blank LM. Pseudomonas putida KT2440 endures temporary oxygen limitations. Biotechnol Bioeng 2021; 118:4735-4750. [PMID: 34506651 DOI: 10.1002/bit.27938] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 01/26/2023]
Abstract
The obligate aerobic nature of Pseudomonas putida, one of the most prominent whole-cell biocatalysts emerging for industrial bioprocesses, questions its ability to be cultivated in large-scale bioreactors, which exhibit zones of low dissolved oxygen tension. P. putida KT2440 was repeatedly subjected to temporary oxygen limitations in scale-down approaches to assess the effect on growth and an exemplary production of rhamnolipids. At those conditions, the growth and production of P. putida KT2440 were decelerated compared to well-aerated reference cultivations, but remarkably, final biomass and rhamnolipid titers were similar. The robust growth behavior was confirmed across different cultivation systems, media compositions, and laboratories, even when P. putida KT2440 was repeatedly exposed to dual carbon and oxygen starvation. Quantification of the nucleotides ATP, ADP, and AMP revealed a decrease of intracellular ATP concentrations with increasing duration of oxygen starvation, which can, however, be restored when re-supplied with oxygen. Only small changes in the proteome were detected when cells encountered oscillations in dissolved oxygen tensions. Concluding, P. putida KT2440 appears to be able to cope with repeated oxygen limitations as they occur in large-scale bioreactors, affirming its outstanding suitability as a whole-cell biocatalyst for industrial-scale bioprocesses.
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Affiliation(s)
- Philipp Demling
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Andreas Ankenbauer
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Bianca Klein
- Institute of Bio- and Geosciences (IBG-1): Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Stephan Noack
- Institute of Bio- and Geosciences (IBG-1): Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Till Tiso
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Ralf Takors
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Lars M Blank
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
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25
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Dong H, Ma J, Chen Q, Chen B, Liang L, Liao Y, Song Y, Wang H, Cronan JE. A cryptic long-chain 3-ketoacyl-ACP synthase in the Pseudomonas putida F1 unsaturated fatty acid synthesis pathway. J Biol Chem 2021; 297:100920. [PMID: 34181948 PMCID: PMC8319022 DOI: 10.1016/j.jbc.2021.100920] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/08/2021] [Accepted: 06/23/2021] [Indexed: 11/30/2022] Open
Abstract
The Pseudomonas putida F1 genome contains five genes annotated as encoding 3-ketoacyl-acyl carrier protein (ACP) synthases. Four are annotated as encoding FabF (3-ketoacyl-ACP synthase II) proteins, and the fifth is annotated as encoding a FabB (3-ketoacyl-ACP synthase I) protein. Expression of one of the FabF proteins, FabF2, is cryptic in the native host and becomes physiologically important only when the repressor controlling fabF2 transcription is inactivated. When derepressed, FabF2 can functionally replace FabB, and when expressed from a foreign promoter, had weak FabF activity. Complementation of Escherichia coli fabB and fabF mutant strains with high expression showed that P. putida fabF1 restored E. coli fabF function, whereas fabB restored E. coli fabB function and fabF2 restored the functions of both E. coli fabF and fabB. The P. putida ΔfabF1 deletion strain was almost entirely defective in synthesis of cis-vaccenic acid, whereas the ΔfabB strain is an unsaturated fatty acid (UFA) auxotroph that accumulated high levels of spontaneous suppressors in the absence of UFA supplementation. This was due to increased expression of fabF2 that bypasses loss of fabB because of the inactivation of the regulator, Pput_2425, encoded in the same operon as fabF2. Spontaneous suppressor accumulation was decreased by high levels of UFA supplementation, whereas competition by the P. putida β-oxidation pathway gave increased accumulation. The ΔfabB ΔfabF2 strain is a stable UFA auxotroph indicating that suppressor accumulation requires FabF2 function. However, at low concentrations of UFA supplementation, the ΔfabF2 ΔPput_2425 double-mutant strain still accumulated suppressors at low UFA concentrations.
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Affiliation(s)
- Huijuan Dong
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China; Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jincheng Ma
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China
| | - Qunyi Chen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China
| | - Bo Chen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China
| | - Lujie Liang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China
| | - Yuling Liao
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China
| | - Yulu Song
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China
| | - Haihong Wang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China.
| | - John E Cronan
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA; Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
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Chukwubuikem A, Berger C, Mady A, Rosenbaum MA. Role of phenazine-enzyme physiology for current generation in a bioelectrochemical system. Microb Biotechnol 2021; 14:1613-1626. [PMID: 34000093 PMCID: PMC8313257 DOI: 10.1111/1751-7915.13827] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/14/2021] [Accepted: 04/27/2021] [Indexed: 02/06/2023] Open
Abstract
Pseudomonas aeruginosa produces phenazine-1-carboxylic acid (PCA) and pyocyanin (PYO), which aid its anaerobic survival by mediating electron transfer to distant oxygen. These natural secondary metabolites are being explored in biotechnology to mediate electron transfer to the anode of bioelectrochemical systems. A major challenge is that only a small fraction of electrons from microbial substrate conversion is recovered. It remained unclear whether phenazines can re-enter the cell and thus, if the electrons accessed by the phenazines arise mainly from cytoplasmic or periplasmic pathways. Here, we prove that the periplasmic glucose dehydrogenase (Gcd) of P. aeruginosa and P. putida is involved in the reduction of natural phenazines. PYO displayed a 60-fold faster enzymatic reduction than PCA; PCA was, however, more stable for long-term electron shuttling to the anode. Evaluation of a Gcd knockout and overexpression strain showed that up to 9% of the anodic current can be designated to this enzymatic reaction. We further assessed phenazine uptake with the aid of two molecular biosensors, which experimentally confirm the phenazines' ability to re-enter the cytoplasm. These findings significantly advance the understanding of the (electro) physiology of phenazines for future tailoring of phenazine electron discharge in biotechnological applications.
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Affiliation(s)
- Anthony Chukwubuikem
- Bio Pilot PlantLeibniz Institute for Natural Product Research and Infection Biology – Hans‐Knöll‐Institute (HKI)JenaGermany
- Faculty of Biological SciencesFriedrich Schiller University (FSU)JenaGermany
| | - Carola Berger
- Faculty of Biological SciencesFriedrich Schiller University (FSU)JenaGermany
| | - Ahmed Mady
- Faculty of Biological SciencesFriedrich Schiller University (FSU)JenaGermany
| | - Miriam A. Rosenbaum
- Bio Pilot PlantLeibniz Institute for Natural Product Research and Infection Biology – Hans‐Knöll‐Institute (HKI)JenaGermany
- Faculty of Biological SciencesFriedrich Schiller University (FSU)JenaGermany
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28
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Nguyen AV, Lai B, Adrian L, Krömer JO. The anoxic electrode-driven fructose catabolism of Pseudomonas putida KT2440. Microb Biotechnol 2021; 14:1784-1796. [PMID: 34115443 PMCID: PMC8313287 DOI: 10.1111/1751-7915.13862] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/20/2021] [Indexed: 11/29/2022] Open
Abstract
Pseudomonas putida (P. putida) is a microorganism of interest for various industrial processes, yet its strictly aerobic nature limits application. Despite previous attempts to adapt P. putida to anoxic conditions via genetic engineering or the use of a bioelectrochemical system (BES), the problem of energy shortage and internal redox imbalance persists. In this work, we aimed to provide the cytoplasmic metabolism with different monosaccharides, other than glucose, and explored the physiological response in P. putida KT2440 during bioelectrochemical cultivation. The periplasmic oxidation cascade was found to be able to oxidize a wide range of aldoses to their corresponding (keto-)aldonates. Unexpectedly, isomerization of the ketose fructose to mannose also enabled oxidation by glucose dehydrogenase, a new pathway uncovered for fructose metabolism in P. putida KT2440 in BES. Besides the isomerization, the remainder of fructose was imported into the cytoplasm and metabolized. This resulted in a higher NADPH/NADP+ ratio, compared to glucose. Comparative proteomics further revealed the upregulation of proteins in the lower central carbon metabolism during the experiment. These findings highlight that the choice of a substrate in BES can target cytosolic and periplasmic oxidation pathways, and that electrode-driven redox balancing can drive these pathways in P. putida under anaerobic conditions.
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Affiliation(s)
- Anh Vu Nguyen
- Department of Solar MaterialsHelmholtz Centre for Environmental Research ‐ UFZLeipzigGermany
| | - Bin Lai
- Department of Solar MaterialsHelmholtz Centre for Environmental Research ‐ UFZLeipzigGermany
| | - Lorenz Adrian
- Department of Environmental BiotechnologyHelmholtz Centre for Environmental Research ‐ UFZLeipzigGermany
- Chair of GeobiotechnologyTechnische Universität BerlinBerlinGermany
| | - Jens O. Krömer
- Department of Solar MaterialsHelmholtz Centre for Environmental Research ‐ UFZLeipzigGermany
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29
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Ankenbauer A, Nitschel R, Teleki A, Müller T, Favilli L, Blombach B, Takors R. Micro-aerobic production of isobutanol with engineered Pseudomonas putida. Eng Life Sci 2021; 21:475-488. [PMID: 34257629 PMCID: PMC8258000 DOI: 10.1002/elsc.202000116] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/14/2021] [Accepted: 02/16/2021] [Indexed: 11/29/2022] Open
Abstract
Pseudomonas putida KT2440 is emerging as a promising microbial host for biotechnological industry due to its broad range of substrate affinity and resilience to physicochemical stresses. Its natural tolerance towards aromatics and solvents qualifies this versatile microbe as promising candidate to produce next generation biofuels such as isobutanol. In this study, we scaled-up the production of isobutanol with P. putida from shake flask to fed-batch cultivation in a 30 L bioreactor. The design of a two-stage bioprocess with separated growth and production resulted in 3.35 gisobutanol L-1. Flux analysis revealed that the NADPH expensive formation of isobutanol exceeded the cellular catabolic supply of NADPH finally causing growth retardation. Concomitantly, the cell counteracted to the redox imbalance by increased formation of 2-ketogluconic thereby providing electrons for the respiratory ATP generation. Thus, P. putida partially uncoupled ATP formation from the availability of NADH. The quantitative analysis of intracellular pyridine nucleotides NAD(P)+ and NAD(P)H revealed elevated catabolic and anabolic reducing power during aerobic production of isobutanol. Additionally, the installation of micro-aerobic conditions during production doubled the integral glucose-to-isobutanol conversion yield to 60 mgisobutanol gglucose -1 while preventing undesired carbon loss as 2-ketogluconic acid.
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Affiliation(s)
- Andreas Ankenbauer
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Robert Nitschel
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Attila Teleki
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Tobias Müller
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Lorenzo Favilli
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Bastian Blombach
- Microbial BiotechnologyCampus Straubing for Biotechnology and SustainabilityTechnical University of MunichStraubingGermany
| | - Ralf Takors
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
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30
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Vassilev I, Averesch NJH, Ledezma P, Kokko M. Anodic electro-fermentation: Empowering anaerobic production processes via anodic respiration. Biotechnol Adv 2021; 48:107728. [PMID: 33705913 DOI: 10.1016/j.biotechadv.2021.107728] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 01/31/2021] [Accepted: 03/03/2021] [Indexed: 11/24/2022]
Abstract
In nature as well as in industrial microbiology, all microorganisms need to achieve redox balance. Their redox state and energy conservation highly depend on the availability of a terminal electron acceptor, for example oxygen in aerobic production processes. Under anaerobic conditions in the absence of an electron acceptor, redox balance is achieved via the production of reduced carbon-compounds (fermentation). An alternative strategy to artificially stabilize microbial redox and energy state is the use of anodic electro-fermentation (AEF). This emerging biotechnology empowers respiration under anaerobic conditions using the anode of a bioelectrochemical system as an undepletable terminal electron acceptor. Electrochemical control of redox metabolism and energy conservation via AEF can steer the carbon metabolism towards a product of interest and avoid the need for continuous and cost-inefficient supply of oxygen as well as the production of mixed reduced by-products, as is the case in aerobic production and fermentation processes, respectively. The great challenge for AEF is to establish efficient extracellular electron transfer (EET) from the microbe to the anode and link it to central carbon metabolism to enhance the synthesis of a target product. This article reviews the advantages and challenges of AEF, EET mechanisms, microbial energy gain, and discusses the rational choice of substrate-product couple as well as the choice of microbial catalyst. Besides, it discusses the potential of the industrial model-organism Bacillus subtilis as a promising candidate for AEF, which has not been yet considered for such an application. This prospective review contributes to a better understanding of how industrial microbiology can benefit from AEF and analyses key-factors required to successfully implement AEF processes. Overall, this work aims to advance the young research field especially by critically revisiting the fundamental aspects of AEF.
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Affiliation(s)
- Igor Vassilev
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland.
| | - Nils J H Averesch
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, United States.
| | - Pablo Ledezma
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, Australia.
| | - Marika Kokko
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland.
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31
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Chandrasekhar K, Naresh Kumar A, Kumar G, Kim DH, Song YC, Kim SH. Electro-fermentation for biofuels and biochemicals production: Current status and future directions. BIORESOURCE TECHNOLOGY 2021; 323:124598. [PMID: 33401164 DOI: 10.1016/j.biortech.2020.124598] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/16/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
Electro-fermentation is an emerging bioporcess that could regulate the metabolism of electrochemically active microorganisms. The provision of electrodes for the fermentation process that functions as an electron acceptor and supports the formation and transportation of electrons and protons, consequently producing bioelectricity and value-added chemicals. The traditional method of fermentation has several limitations in usability and economic feasibility. Subsequently, a series of metabolic processes occurring in conventional fermentation processes are most often redox misaligned. In this regard, electro-fermentation emerged as a hybrid technology which can regulate a series of metabolic processes occurring in a bioreactor by regulating the redox instabilities and boosting the overall metabolic process towards high biomass yield and enhanced product formation. The present article deals with microorganisms-electrode interactions, various types of electro-fermentation systems, comparative evaluation of pure and mixed culture electro-fermentation application, and value-added fuels and chemical synthesis.
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Affiliation(s)
- K Chandrasekhar
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - A Naresh Kumar
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Gopalakrishnan Kumar
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea; Institute of Chemistry, Bioscience and Environmental Engineering, Faculty of Science and Technology, University of Stavanger, 4036 Stavanger, Norway
| | - Dong-Hoon Kim
- Department of Civil Engineering, Inha University, 100 Inha-ro, Nam-gu, Incheon 22212, Republic of Korea
| | - Young-Chae Song
- Department of Environmental Engineering, Korea Maritime and Ocean University, Busan 49112, Republic of Korea
| | - Sang-Hyoun Kim
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea.
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32
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Kampers LFC, Koehorst JJ, van Heck RJA, Suarez-Diez M, Stams AJM, Schaap PJ. A metabolic and physiological design study of Pseudomonas putida KT2440 capable of anaerobic respiration. BMC Microbiol 2021; 21:9. [PMID: 33407113 PMCID: PMC7789669 DOI: 10.1186/s12866-020-02058-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 12/02/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Pseudomonas putida KT2440 is a metabolically versatile, HV1-certified, genetically accessible, and thus interesting microbial chassis for biotechnological applications. However, its obligate aerobic nature hampers production of oxygen sensitive products and drives up costs in large scale fermentation. The inability to perform anaerobic fermentation has been attributed to insufficient ATP production and an inability to produce pyrimidines under these conditions. Addressing these bottlenecks enabled growth under micro-oxic conditions but does not lead to growth or survival under anoxic conditions. RESULTS Here, a data-driven approach was used to develop a rational design for a P. putida KT2440 derivative strain capable of anaerobic respiration. To come to the design, data derived from a genome comparison of 1628 Pseudomonas strains was combined with genome-scale metabolic modelling simulations and a transcriptome dataset of 47 samples representing 14 environmental conditions from the facultative anaerobe Pseudomonas aeruginosa. CONCLUSIONS The results indicate that the implementation of anaerobic respiration in P. putida KT2440 would require at least 49 additional genes of known function, at least 8 genes encoding proteins of unknown function, and 3 externally added vitamins.
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Affiliation(s)
- Linde F C Kampers
- Laboratory of Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708, WE, Wageningen, The Netherlands
| | - Jasper J Koehorst
- Laboratory of Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708, WE, Wageningen, The Netherlands
| | - Ruben J A van Heck
- Laboratory of Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708, WE, Wageningen, The Netherlands
| | - Maria Suarez-Diez
- Laboratory of Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708, WE, Wageningen, The Netherlands
| | - Alfons J M Stams
- Laboratory of Microbiology, Wageningen University and Research Centre, Stippeneng 4, 6708, WE, Wageningen, The Netherlands
| | - Peter J Schaap
- Laboratory of Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708, WE, Wageningen, The Netherlands.
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33
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Schmitz S, Rosenbaum MA. Controlling the Production of Pseudomonas Phenazines by Modulating the Genetic Repertoire. ACS Chem Biol 2020; 15:3244-3252. [PMID: 33258592 DOI: 10.1021/acschembio.0c00805] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microbial phenazines are getting increasing attention for antimicrobial and biotechnological applications. Phenazine production of the most well-known producer Pseudomonas aeruginosa is subject to a highly complex regulation network involving both quorum sensing and catabolite repression. These networks affect the expression of the two redundant phz gene operons responsible for phenazine-1-carboxylate (PCA) production and two specific genes phzM and phzS necessary for pyocyanin production. To decipher the specific functionality of these genes, in this study, specific phenazine gene deletion mutants of P. aeruginosa PA14 were generated and characterized in glucose and 2,3-butanediol media. Phenazine concentration and expression levels of the remaining genes were analyzed in parallel experiments. The findings suggest a strong dominance of operon phzA2-G2 resulting in a 10-fold higher expression of phz2 compared to phzA1-G1 and almost exclusive production of PCA from this operon. The genes phzM and phzS seem to exhibit antagonistic function in phenazine production. An upregulation of phzM explains the documented enhanced pyocyanin production in a 2,3-butanediol medium. Applied to a bioelectrochemical system, the altered phenazine production of the mutant strains is directly translated into current generation. Additionally, the deletion of the phenazine genes induced the activation of alternative energy pathways, which resulted in the accumulation of various fermentation products. Overall, modulating the genetic repertoire of the phenazine genes tremendously affects phenazine production levels, which are naturally kept in tight homeostasis in the P. aeruginosa wildtype. This important information can be directly utilized for ongoing efforts of heterologous biotechnological phenazine production.
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Affiliation(s)
- Simone Schmitz
- Institute of Applied Microbiology iAMB, Aachen Biology and Biotechnology ABBt, RWTH Aachen University, Aachen, Germany
| | - Miriam A. Rosenbaum
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology − Hans-Knöll-Institute, Beutenbergstrasse 11a, Jena, Germany
- Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
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34
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Coupling an Electroactive Pseudomonas putida KT2440 with Bioelectrochemical Rhamnolipid Production. Microorganisms 2020; 8:microorganisms8121959. [PMID: 33322018 PMCID: PMC7763313 DOI: 10.3390/microorganisms8121959] [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: 11/20/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 12/16/2022] Open
Abstract
Sufficient supply of oxygen is a major bottleneck in industrial biotechnological synthesis. One example is the heterologous production of rhamnolipids using Pseudomonas putida KT2440. Typically, the synthesis is accompanied by strong foam formation in the reactor vessel hampering the process. It is caused by the extensive bubbling needed to sustain the high respirative oxygen demand in the presence of the produced surfactants. One way to reduce the oxygen requirement is to enable the cells to use the anode of a bioelectrochemical system (BES) as an alternative sink for their metabolically derived electrons. We here used a P. putida KT2440 strain that interacts with the anode using mediated extracellular electron transfer via intrinsically produced phenazines, to perform heterologous rhamnolipid production under oxygen limitation. The strain P. putida RL-PCA successfully produced 30.4 ± 4.7 mg/L mono-rhamnolipids together with 11.2 ± 0.8 mg/L of phenazine-1-carboxylic acid (PCA) in 500-mL benchtop BES reactors and 30.5 ± 0.5 mg/L rhamnolipids accompanied by 25.7 ± 8.0 mg/L PCA in electrode containing standard 1-L bioreactors. Hence, this study marks a first proof of concept to produce glycolipid surfactants in oxygen-limited BES with an industrially relevant strain.
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35
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Mutyala S, Kim C, Song YE, Khandelwal H, Baek J, Seol E, Oh YK, Kim JR. Enabling anoxic acetate assimilation by electrode-driven respiration in the obligate aerobe, Pseudomonas putida. Bioelectrochemistry 2020; 138:107690. [PMID: 33190096 DOI: 10.1016/j.bioelechem.2020.107690] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 10/17/2020] [Accepted: 10/20/2020] [Indexed: 10/23/2022]
Abstract
This study examined the obligate aerobe, Pseudomonas putida, using acetate as the sole carbon and energy source, and respiration via an anode as the terminal electron acceptor under anoxic conditions. P. putida showed significantly different acetate assimilation in a closed-circuit microbial fuel cell (CC-MFC) compared to an open circuit MFC (OC-MFC). More than 72% (2.6 mmol) of acetate was consumed during 84 hrs in the CC-MFC in contrast to the no acetate consumption observed in the OC-MFC. The CC-MFC produced 150 μA (87 C) from acetate metabolization. Electrode-based respiration reduced the NADH/NAD+ ratio anaerobically, which is similar to the aerobic condition. The CC-MFC showed significantly higher acetyl-CoA synthetase activity than the OC-MFC (0.028 vs. 0.001 μmol/min/mg), which was comparable to the aerobic condition (circa 60%). Overall, electrode-based respiration enables P. putida to metabolize acetate under anoxic conditions and provide a platform to regulate the bacterial redox balance without oxygen.
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Affiliation(s)
- Sakuntala Mutyala
- School of Chemical Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - Changman Kim
- Advanced Biofuel and Bioproducts Process Development Unit, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, USA
| | - Young Eun Song
- School of Chemical Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - Himanshu Khandelwal
- School of Chemical Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - Jiyun Baek
- School of Chemical Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - Eunhee Seol
- School of Chemical Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - You-Kwan Oh
- School of Chemical Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - Jung Rae Kim
- School of Chemical Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea.
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36
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Schwanemann T, Otto M, Wierckx N, Wynands B. Pseudomonasas Versatile Aromatics Cell Factory. Biotechnol J 2020; 15:e1900569. [DOI: 10.1002/biot.201900569] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/08/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Tobias Schwanemann
- Institute of Bio‐ and Geosciences, IBG‐1: Biotechnology Forschungszentrum Jülich, GmbH 52425 Jülich Germany
| | - Maike Otto
- Institute of Bio‐ and Geosciences, IBG‐1: Biotechnology Forschungszentrum Jülich, GmbH 52425 Jülich Germany
| | - Nick Wierckx
- Institute of Bio‐ and Geosciences, IBG‐1: Biotechnology Forschungszentrum Jülich, GmbH 52425 Jülich Germany
| | - Benedikt Wynands
- Institute of Bio‐ and Geosciences, IBG‐1: Biotechnology Forschungszentrum Jülich, GmbH 52425 Jülich Germany
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37
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Chen H, Simoska O, Lim K, Grattieri M, Yuan M, Dong F, Lee YS, Beaver K, Weliwatte S, Gaffney EM, Minteer SD. Fundamentals, Applications, and Future Directions of Bioelectrocatalysis. Chem Rev 2020; 120:12903-12993. [DOI: 10.1021/acs.chemrev.0c00472] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Hui Chen
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Olja Simoska
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Koun Lim
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Matteo Grattieri
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Mengwei Yuan
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Fangyuan Dong
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Yoo Seok Lee
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Kevin Beaver
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Samali Weliwatte
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Erin M. Gaffney
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Shelley D. Minteer
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
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Abstract
Electro-fermentation (EF) is an upcoming technology that can control the metabolism of exoelectrogenic bacteria (i.e., bacteria that transfer electrons using an extracellular mechanism). The fermenter consists of electrodes that act as sink and source for the production and movement of electrons and protons, thus generating electricity and producing valuable products. The conventional process of fermentation has several drawbacks that restrict their application and economic viability. Additionally, metabolic reactions taking place in traditional fermenters are often redox imbalanced. Almost all metabolic pathways and microbial strains have been studied, and EF can electrochemically control this. The process of EF can be used to optimize metabolic processes taking place in the fermenter by controlling the redox and pH imbalances and by stimulating carbon chain elongation or breakdown to improve the overall biomass yield and support the production of a specific product. This review briefly discusses microbe-electrode interactions, electro-fermenter designs, mixed-culture EF, and pure culture EF in industrial applications, electro methanogenesis, and the various products that could be hence generated using this process.
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39
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VanArsdale E, Pitzer J, Payne GF, Bentley WE. Redox Electrochemistry to Interrogate and Control Biomolecular Communication. iScience 2020; 23:101545. [PMID: 33083771 PMCID: PMC7516135 DOI: 10.1016/j.isci.2020.101545] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cells often communicate by the secretion, transport, and perception of molecules. Information conveyed by molecules is encoded, transmitted, and decoded by cells within the context of the prevailing microenvironments. Conversely, in electronics, transmission reliability and message validation are predictable, robust, and less context dependent. In turn, many transformative advances have resulted by the formal consideration of information transfer. One way to explore this potential for biological systems is to create bio-device interfaces that facilitate bidirectional information transfer between biology and electronics. Redox reactions enable this linkage because reduction and oxidation mediate communication within biology and can be coupled with electronics. By manipulating redox reactions, one is able to combine the programmable features of electronics with the ability to interrogate and modulate biological function. In this review, we examine methods to electrochemically interrogate the various components of molecular communication using redox chemistry and to electronically control cell communication using redox electrogenetics.
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Affiliation(s)
- Eric VanArsdale
- Fischell Department of Bioengineering, University of Maryland, 3102 A. James Clark Hall 8278 Paint Branch Drive, College Park, MD 20742, USA.,Institute of Bioscience and Biotechnology Research, University of Maryland, 5115 Plant Sciences Building, College Park, MD 20742, USA.,Robert E. Fischell Institute for Biomedical Devices, University of Maryland, Room 5102, A. James Clark Hall, College Park, MD 20742, USA
| | - Juliana Pitzer
- Fischell Department of Bioengineering, University of Maryland, 3102 A. James Clark Hall 8278 Paint Branch Drive, College Park, MD 20742, USA
| | - Gregory F Payne
- Institute of Bioscience and Biotechnology Research, University of Maryland, 5115 Plant Sciences Building, College Park, MD 20742, USA.,Robert E. Fischell Institute for Biomedical Devices, University of Maryland, Room 5102, A. James Clark Hall, College Park, MD 20742, USA
| | - William E Bentley
- Fischell Department of Bioengineering, University of Maryland, 3102 A. James Clark Hall 8278 Paint Branch Drive, College Park, MD 20742, USA.,Institute of Bioscience and Biotechnology Research, University of Maryland, 5115 Plant Sciences Building, College Park, MD 20742, USA.,Robert E. Fischell Institute for Biomedical Devices, University of Maryland, Room 5102, A. James Clark Hall, College Park, MD 20742, USA
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40
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Weimer A, Kohlstedt M, Volke DC, Nikel PI, Wittmann C. Industrial biotechnology of Pseudomonas putida: advances and prospects. Appl Microbiol Biotechnol 2020; 104:7745-7766. [PMID: 32789744 PMCID: PMC7447670 DOI: 10.1007/s00253-020-10811-9] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/23/2020] [Accepted: 08/02/2020] [Indexed: 11/17/2022]
Abstract
Pseudomonas putida is a Gram-negative, rod-shaped bacterium that can be encountered in diverse ecological habitats. This ubiquity is traced to its remarkably versatile metabolism, adapted to withstand physicochemical stress, and the capacity to thrive in harsh environments. Owing to these characteristics, there is a growing interest in this microbe for industrial use, and the corresponding research has made rapid progress in recent years. Hereby, strong drivers are the exploitation of cheap renewable feedstocks and waste streams to produce value-added chemicals and the steady progress in genetic strain engineering and systems biology understanding of this bacterium. Here, we summarize the recent advances and prospects in genetic engineering, systems and synthetic biology, and applications of P. putida as a cell factory. KEY POINTS: • Pseudomonas putida advances to a global industrial cell factory. • Novel tools enable system-wide understanding and streamlined genomic engineering. • Applications of P. putida range from bioeconomy chemicals to biosynthetic drugs.
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Affiliation(s)
- Anna Weimer
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany
| | - Daniel C Volke
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany.
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41
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Fruehauf HM, Enzmann F, Harnisch F, Ulber R, Holtmann D. Microbial Electrosynthesis—An Inventory on Technology Readiness Level and Performance of Different Process Variants. Biotechnol J 2020; 15:e2000066. [DOI: 10.1002/biot.202000066] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/29/2020] [Indexed: 01/01/2023]
Affiliation(s)
- Hanna M. Fruehauf
- Industrial Biotechnology DECHEMA Research Institute Theodor‐Heuss‐Allee 25 Frankfurt am Main 60486 Germany
| | - Franziska Enzmann
- Technology and Infrastructure Evonik Industries Rodenbacher Chaussee 4 Hanau 63457 Germany
| | - Falk Harnisch
- Department of Environmental Microbiology Helmholtz‐Centre for Environmental Research GmbH ‐ UFZ Permoserstraße 15 Leipzig 04318 Germany
| | - Roland Ulber
- Bioprocess Engineering University of Kaiserslautern Erwin‐Schrödinger‐Straße 52 Kaiserslautern 64663 Germany
| | - Dirk Holtmann
- Institute of Bioprocess Engineering and Pharmaceutical Technology University of Applied Sciences Mittelhessen Wiesenstraße 14 Giessen 35390 Germany
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42
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Tiso T, Ihling N, Kubicki S, Biselli A, Schonhoff A, Bator I, Thies S, Karmainski T, Kruth S, Willenbrink AL, Loeschcke A, Zapp P, Jupke A, Jaeger KE, Büchs J, Blank LM. Integration of Genetic and Process Engineering for Optimized Rhamnolipid Production Using Pseudomonas putida. Front Bioeng Biotechnol 2020; 8:976. [PMID: 32974309 PMCID: PMC7468518 DOI: 10.3389/fbioe.2020.00976] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/27/2020] [Indexed: 12/27/2022] Open
Abstract
Rhamnolipids are biosurfactants produced by microorganisms with the potential to replace synthetic compounds with petrochemical origin. To promote industrial use of rhamnolipids, recombinant rhamnolipid production from sugars needs to be intensified. Since this remains challenging, the aim of the presented research is to utilize a multidisciplinary approach to take a step toward developing a sustainable rhamnolipid production process. Here, we developed expression cassettes for stable integration of the rhamnolipid biosynthesis genes into the genome outperformed plasmid-based expression systems. Furthermore, the genetic stability of the production strain was improved by using an inducible promoter. To enhance rhamnolipid synthesis, energy- and/or carbon-consuming traits were removed: mutants negative for the synthesis of the flagellar machinery or the storage polymer PHA showed increased production by 50%. Variation of time of induction resulted in an 18% increase in titers. A scale-up from shake flasks was carried out using a 1-L bioreactor. By recycling of the foam, biomass loss could be minimized and a rhamnolipid titer of up to 1.5 g/L was achieved without using mechanical foam destroyers or antifoaming agents. Subsequent liquid-liquid extraction was optimized by using a suitable minimal medium during fermentation to reduce undesired interphase formation. A technical-scale production process was designed and evaluated by a life-cycle assessment (LCA). Different process chains and their specific environmental impact were examined. It was found that next to biomass supply, the fermentation had the biggest environmental impact. The present work underlines the need for multidisciplinary approaches to address the challenges associated with achieving sustainable production of microbial secondary metabolites. The results are discussed in the context of the challenges of microbial biosurfactant production using hydrophilic substrates on an industrial scale.
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Affiliation(s)
- Till Tiso
- iAMB – Institute of Applied Microbiology, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Nina Ihling
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Aachen, Germany
| | - Sonja Kubicki
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Andreas Biselli
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Fluid Process Engineering (AVT.FVT), RWTH Aachen University, Aachen, Germany
| | - Andreas Schonhoff
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Energy and Climate Research – Systems Analysis and Technology Evaluation (IEK-STE), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Isabel Bator
- iAMB – Institute of Applied Microbiology, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Stephan Thies
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Tobias Karmainski
- iAMB – Institute of Applied Microbiology, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Sebastian Kruth
- iAMB – Institute of Applied Microbiology, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Anna-Lena Willenbrink
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Fluid Process Engineering (AVT.FVT), RWTH Aachen University, Aachen, Germany
| | - Anita Loeschcke
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Petra Zapp
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Energy and Climate Research – Systems Analysis and Technology Evaluation (IEK-STE), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Andreas Jupke
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Fluid Process Engineering (AVT.FVT), RWTH Aachen University, Aachen, Germany
| | - Karl-Erich Jaeger
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
- Institute of Bio- and Geosciences IBG 1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Jochen Büchs
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Aachen, Germany
| | - Lars M. Blank
- iAMB – Institute of Applied Microbiology, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich GmbH, Jülich, Germany
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43
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Su L, Fukushima T, Ajo-Franklin CM. A hybrid cyt c maturation system enhances the bioelectrical performance of engineered Escherichia coli by improving the rate-limiting step. Biosens Bioelectron 2020; 165:112312. [PMID: 32729471 DOI: 10.1016/j.bios.2020.112312] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/15/2020] [Accepted: 05/18/2020] [Indexed: 12/26/2022]
Abstract
Bioelectronic devices can use electron flux to enable communication between biotic components and abiotic electrodes. We have modified Escherichia coli to electrically interact with electrodes by expressing the cytochrome c from Shewanella oneidensis MR-1. However, we observe inefficient electrical performance, which we hypothesize is due to the limited compatibility of the E. coli cytochrome c maturation (Ccm) systems with MR-1 cytochrome c. Here we test whether the bioelectronic performance of E. coli can be improved by constructing hybrid Ccm systems containing protein domains from both E. coli and S. oneidensis MR-1. The hybrid CcmH increased cytochrome c expression by increasing the abundance of CymA 60%, while only slightly changing the abundance of the other cytochromes c. Electrochemical measurements showed that the overall current from the hybrid ccm strain increased 121% relative to the wildtype ccm strain, with an electron flux per cell of 12.3 ± 0.3 fA·cell-1. Additionally, the hybrid ccm strain doubled its electrical response with the addition of exogenous flavin, and quantitative analysis of this demonstrates CymA is the rate-limiting step in this electron conduit. These results demonstrate that this hybrid Ccm system can enhance the bioelectrical performance of the cyt c expressing E. coli, allowing the construction of more efficient bioelectronic devices.
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Affiliation(s)
- Lin Su
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210018, China; Department of BioSciences, Rice University, Houston, TX, 77005, USA; Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Tatsuya Fukushima
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Caroline M Ajo-Franklin
- Department of BioSciences, Rice University, Houston, TX, 77005, USA; Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Molecular Biophysics and Integrated Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Institute for Biosciences and Bioengineering, Rice University, Houston, TX, 77005, USA.
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44
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Loeschcke A, Thies S. Engineering of natural product biosynthesis in Pseudomonas putida. Curr Opin Biotechnol 2020; 65:213-224. [PMID: 32498036 DOI: 10.1016/j.copbio.2020.03.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/01/2020] [Accepted: 03/30/2020] [Indexed: 01/03/2023]
Affiliation(s)
- Anita Loeschcke
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Germany.
| | - Stephan Thies
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Germany.
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45
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Philipp LA, Edel M, Gescher J. Genetic engineering for enhanced productivity in bioelectrochemical systems. ADVANCES IN APPLIED MICROBIOLOGY 2020; 111:1-31. [PMID: 32446410 DOI: 10.1016/bs.aambs.2020.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
A shift from petrochemical processes toward a bio-based economy is one of the most advocated developments for a sustainable future. To achieve this will require the biotechnological production of platform chemicals that can be further processed by chemical engineering. Bioelectrochemical systems (BESs) are a novel tool within the biotechnology field. In BESs, microbes serve as biocatalysts for the production of biofuels and value-added compounds, as well as for the production of electricity. Although the general feasibility of bioelectrochemical processes has been demonstrated in recent years, much research has been conducted to develop biocatalysts better suited to meet industrial demands. Initially, mainly natural exoelectrogenic organisms were investigated for their performance in BESs. Driven by possibilities of recent developments in genetic engineering and synthetic biology, the spectrum of microbial catalysts and their versatility (substrate and product range) have expanded significantly. Despite these developments, there is still a tremendous gap between currently achievable space-time yields and current densities on the one hand and the theoretical limits of BESs on the other. It will be necessary to move the performance of the biocatalysts closer to the theoretical possibilities in order to establish viable production routines. This review summarizes the status quo of engineering microbial biocatalysts for anode-applications with high space-time yields. Furthermore, we will address some of the theoretical limitations of these processes exemplarily and discuss which of the present strategies might be combined to achieve highly synergistic effects and, thus, meet industrial demands.
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Affiliation(s)
- Laura-Alina Philipp
- Karlsruhe Institute of Technology, Institute for Applied Biosciences-Department of Applied Biology, Karlsruhe, Germany
| | - Miriam Edel
- Karlsruhe Institute of Technology, Institute for Applied Biosciences-Department of Applied Biology, Karlsruhe, Germany
| | - Johannes Gescher
- Karlsruhe Institute of Technology, Institute for Applied Biosciences-Department of Applied Biology, Karlsruhe, Germany; Karlsruhe Institute of Technology, Institute for Biological Interfaces, Eggenstein-Leopoldshafen, Germany.
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46
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Yee MO, Deutzmann J, Spormann A, Rotaru AE. Cultivating electroactive microbes-from field to bench. NANOTECHNOLOGY 2020; 31:174003. [PMID: 31931483 DOI: 10.1088/1361-6528/ab6ab5] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electromicrobiology is an emerging field investigating and exploiting the interaction of microorganisms with insoluble electron donors or acceptors. Some of the most recently categorized electroactive microorganisms became of interest to sustainable bioengineering practices. However, laboratories worldwide typically maintain electroactive microorganisms on soluble substrates, which often leads to a decrease or loss of the ability to effectively exchange electrons with solid electrode surfaces. In order to develop future sustainable technologies, we cannot rely solely on existing lab-isolates. Therefore, we must develop isolation strategies for environmental strains with electroactive properties superior to strains in culture collections. In this article, we provide an overview of the studies that isolated or enriched electroactive microorganisms from the environment using an anode as the sole electron acceptor (electricity-generating microorganisms) or a cathode as the sole electron donor (electricity-consuming microorganisms). Next, we recommend a selective strategy for the isolation of electroactive microorganisms. Furthermore, we provide a practical guide for setting up electrochemical reactors and highlight crucial electrochemical techniques to determine electroactivity and the mode of electron transfer in novel organisms.
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Affiliation(s)
- Mon Oo Yee
- Nordcee, Department of Biology, University of Southern Denmark, Odense, DK-5230, Denmark
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47
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Pasternak G, Askitosari TD, Rosenbaum MA. Biosurfactants and Synthetic Surfactants in Bioelectrochemical Systems: A Mini-Review. Front Microbiol 2020; 11:358. [PMID: 32231644 PMCID: PMC7082750 DOI: 10.3389/fmicb.2020.00358] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/18/2020] [Indexed: 12/15/2022] Open
Abstract
Bioelectrochemical systems (BESs) are ruled by a complex combination of biological and abiotic factors. The interplay of these factors determines the overall efficiency of BES in generating electricity and treating waste. The recent progress in bioelectrochemistry of BESs and electrobiotechnology exposed an important group of compounds, which have a significant contribution to operation and efficiency: surface-active agents, also termed surfactants. Implementation of the interfacial science led to determining several effects of synthetic and natural surfactants on BESs operation. In high pH, these amphiphilic compounds prevent the cathode electrodes from biodeterioration. Through solubilization, their presence leads to increased catabolism of hydrophobic compounds. They interfere with the surface of the electrodes leading to improved biofilm formation, while affecting its microarchitecture and composition. Furthermore, they may act as quorum sensing activators and induce the synthesis of electron shuttles produced by electroactive bacteria. On the other hand, the bioelectrochemical activity can be tailored for new, improved biosurfactant production processes. Herein, the most recent knowledge on the effects of these promising compounds in BESs is discussed.
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Affiliation(s)
- Grzegorz Pasternak
- Laboratory of Microbial Electrochemical Systems, Department of Process Engineering and Technology of Polymer and Carbon Materials, Wrocław University of Science and Technology, Wrocław, Poland
| | - Theresia D Askitosari
- Laboratory of Microorganism Biotechnology, Faculty of Technobiology, University of Surabaya, Surabaya, Indonesia
| | - Miriam A Rosenbaum
- Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
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48
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Neves D, Vos S, Blank LM, Ebert BE. Pseudomonas mRNA 2.0: Boosting Gene Expression Through Enhanced mRNA Stability and Translational Efficiency. Front Bioeng Biotechnol 2020; 7:458. [PMID: 32039175 PMCID: PMC6993053 DOI: 10.3389/fbioe.2019.00458] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 12/19/2019] [Indexed: 11/14/2022] Open
Abstract
High gene expression of enzymes partaking in recombinant production pathways is a desirable trait among cell factories belonging to all different kingdoms of life. High enzyme abundance is generally aimed for by utilizing strong promoters, which ramp up gene transcription and mRNA levels. Increased protein abundance can alternatively be achieved by optimizing the expression on the post-transcriptional level. Here, we evaluated protein synthesis with a previously proposed optimized gene expression architecture, in which mRNA stability and translation initiation are modulated by genetic parts such as self-cleaving ribozymes and a bicistronic design, which have initially been described to support the standardization of gene expression. The optimized gene expression architecture was tested in Pseudomonas taiwanensis VLB120, a promising, novel microbial cell factory. The expression cassette was employed on a plasmid basis and after single genomic integration. We used three constitutive and two inducible promoters to drive the expression of two fluorescent reporter proteins and a short acetoin biosynthesis pathway. The performance was confronted with that of a traditional expression cassette harboring the same promoter and gene of interest but lacking the genetic parts for increased expression efficiency. The optimized expression cassette granted higher protein abundance independently of the expression basis or promoter used proving its value for applications requiring high protein abundance.
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Affiliation(s)
- Dário Neves
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Stefan Vos
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Lars M Blank
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Birgitta E Ebert
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany.,Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia.,CSIRO Synthetic Biology Future Science Platform, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Brisbane, QLD, Australia
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49
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Su L, Fukushima T, Prior A, Baruch M, Zajdel TJ, Ajo-Franklin CM. Modifying Cytochrome c Maturation Can Increase the Bioelectronic Performance of Engineered Escherichia coli. ACS Synth Biol 2020; 9:115-124. [PMID: 31880923 DOI: 10.1021/acssynbio.9b00379] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Genetic circuits that encode extracellular electron transfer (EET) pathways allow the intracellular state of Escherichia coli to be electronically monitored and controlled. However, relatively low electron flux flows through these pathways, limiting the degree of control by these circuits. Since the EET pathway is composed of multiple multiheme cytochromes c (cyts c) from Shewanella oneidensis MR-1, we hypothesized that lower expression levels of cyt c may explain this low EET flux and may be caused by the differences in the cyt c maturation (ccm) machinery between these two species. Here, we constructed random mutations within ccmH by error-prone PCR and screened for increased cyt c production. We identified two ccmH mutants, ccmH-132 and ccmH-195, that exhibited increased heterologous cyt c expression, but had different effects on EET. The ccmH-132 strain reduced WO3 nanoparticles faster than the parental control, whereas the ccmH-195 strain reduced more slowly. The same trend is reflected in electrical current generation: ccmH-132, which has only a single mutation from WT, drastically increased current production by 77%. The percentage of different cyt c proteins in these two mutants suggests that the stoichiometry of the S. oneidensis cyts c is a key determinant of current production by Mtr-expressing E. coli. Thus, we conclude that modulating cyt c maturation effectively improves genetic circuits governing EET in engineered biological systems, enabling better bioelectronic control of E. coli.
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Affiliation(s)
- Lin Su
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210018, China
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Tatsuya Fukushima
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Andrew Prior
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Moshe Baruch
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Tom J. Zajdel
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Caroline M. Ajo-Franklin
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Molecular Biophysics and Integrated Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Synthetic Biology Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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50
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Bator I, Wittgens A, Rosenau F, Tiso T, Blank LM. Comparison of Three Xylose Pathways in Pseudomonas putida KT2440 for the Synthesis of Valuable Products. Front Bioeng Biotechnol 2020; 7:480. [PMID: 32010683 PMCID: PMC6978631 DOI: 10.3389/fbioe.2019.00480] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/23/2019] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas putida KT2440 is a well-established chassis in industrial biotechnology. To increase the substrate spectrum, we implemented three alternative xylose utilization pathways, namely the Isomerase, Weimberg, and Dahms pathways. The synthetic operons contain genes from Escherichia coli and Pseudomonas taiwanensis. For isolating the Dahms pathway in P. putida KT2440 two genes (PP_2836 and PP_4283), encoding an endogenous enzyme of the Weimberg pathway and a regulator for glycolaldehyde degradation, were deleted. Before and after adaptive laboratory evolution, these strains were characterized in terms of growth and synthesis of mono-rhamnolipids and pyocyanin. The engineered strain using the Weimberg pathway reached the highest maximal growth rate of 0.30 h-1. After adaptive laboratory evolution the lag phase was reduced significantly. The highest titers of 720 mg L-1 mono-rhamnolipids and 30 mg L-1 pyocyanin were reached by the evolved strain using the Weimberg or an engineered strain using the Isomerase pathway, respectively. The different stoichiometries of the three xylose utilization pathways may allow engineering of tailored chassis for valuable bioproduct synthesis.
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Affiliation(s)
- Isabel Bator
- iAMB - Institute of Applied Microbiology, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Andreas Wittgens
- Institute for Pharmaceutical Biotechnology, Ulm-University, Ulm, Germany
- Ulm Center for Peptide Pharmaceuticals, Ulm, Germany
- Max-Planck-Institute for Polymer Research Mainz, Synthesis of Macromolecules, Mainz, Germany
| | - Frank Rosenau
- Institute for Pharmaceutical Biotechnology, Ulm-University, Ulm, Germany
- Ulm Center for Peptide Pharmaceuticals, Ulm, Germany
- Max-Planck-Institute for Polymer Research Mainz, Synthesis of Macromolecules, Mainz, Germany
| | - Till Tiso
- iAMB - Institute of Applied Microbiology, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Lars M. Blank
- iAMB - Institute of Applied Microbiology, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany
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