1
|
Chen Y, Huang L, Yu T, Yao Y, Zhao M, Pang A, Zhou J, Zhang B, Liu Z, Zheng Y. Balancing the AspC and AspA Pathways of Escherichia coli by Systematic Metabolic Engineering Strategy for High-Efficient l-Homoserine Production. ACS Synth Biol 2024; 13:2457-2469. [PMID: 39042380 DOI: 10.1021/acssynbio.4c00208] [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] [Indexed: 07/24/2024]
Abstract
l-Homoserine is a promising C4 platform compound used in the agricultural, cosmetic, and pharmaceutical industries. Numerous works have been conducted to engineer Escherichia coli to be an excellent l-homoserine producer, but it is still unable to meet the industrial-scale demand. Herein, we successfully engineered a plasmid-free and noninducible E. coli strain with highly efficient l-homoserine production through balancing AspC and AspA synthesis pathways. First, an initial strain was constructed by increasing the accumulation of the precursor oxaloacetate and attenuating the organic acid synthesis pathway. To remodel the carbon flux toward l-aspartate, a balanced route prone to high yield based on TCA intensity regulation was designed. Subsequently, the main synthetic pathway and the cofactor system were strengthened to reinforce the l-homoserine synthesis. Ultimately, under two-stage DO control, strain HSY43 showed 125.07 g/L l-homoserine production in a 5 L fermenter in 60 h, with a yield of 0.62 g/g glucose and a productivity of 2.08 g/L/h. The titer, yield, and productivity surpassed the highest reported levels for plasmid-free strains in the literature. The strategies adopted in this study can be applied to the production of other l-aspartate family amino acids.
Collapse
Affiliation(s)
- Yuanyuan Chen
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Lianggang Huang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Tao Yu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Yuan Yao
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Mingming Zhao
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Aiping Pang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Junping Zhou
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Bo Zhang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Zhiqiang Liu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Yuguo Zheng
- The National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou 310014, PR China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| |
Collapse
|
2
|
Kumar V, Kumar P, Maity SK, Agrawal D, Narisetty V, Jacob S, Kumar G, Bhatia SK, Kumar D, Vivekanand V. Recent advances in bio-based production of top platform chemical, succinic acid: an alternative to conventional chemistry. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:72. [PMID: 38811976 PMCID: PMC11137917 DOI: 10.1186/s13068-024-02508-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 04/20/2024] [Indexed: 05/31/2024]
Abstract
Succinic acid (SA) is one of the top platform chemicals with huge applications in diverse sectors. The presence of two carboxylic acid groups on the terminal carbon atoms makes SA a highly functional molecule that can be derivatized into a wide range of products. The biological route for SA production is a cleaner, greener, and promising technological option with huge potential to sequester the potent greenhouse gas, carbon dioxide. The recycling of renewable carbon of biomass (an indirect form of CO2), along with fixing CO2 in the form of SA, offers a carbon-negative SA manufacturing route to reduce atmospheric CO2 load. These attractive attributes compel a paradigm shift from fossil-based to microbial SA manufacturing, as evidenced by several commercial-scale bio-SA production in the last decade. The current review article scrutinizes the existing knowledge and covers SA production by the most efficient SA producers, including several bacteria and yeast strains. The review starts with the biochemistry of the major pathways accumulating SA as an end product. It discusses the SA production from a variety of pure and crude renewable sources by native as well as engineered strains with details of pathway/metabolic, evolutionary, and process engineering approaches for enhancing TYP (titer, yield, and productivity) metrics. The review is then extended to recent progress on separation technologies to recover SA from fermentation broth. Thereafter, SA derivatization opportunities via chemo-catalysis are discussed for various high-value products, which are only a few steps away. The last two sections are devoted to the current scenario of industrial production of bio-SA and associated challenges, along with the author's perspective.
Collapse
Affiliation(s)
- Vinod Kumar
- School of Water, Energy and Environment, Cranfield University, Cranfield, MK43 0AL, UK.
- Department of Bioscience and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India.
| | - Pankaj Kumar
- Department of Chemical Engineering, School of Studies of Engineering and Technology, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh, 495009, India
| | - Sunil K Maity
- Department of Chemical Engineering, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Hyderabad, Telangana, 502284, India.
| | - Deepti Agrawal
- Biochemistry and Biotechnology Area, Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Dehradun, Uttarakhand, 248005, India
| | - Vivek Narisetty
- School of Water, Energy and Environment, Cranfield University, Cranfield, MK43 0AL, UK
| | - Samuel Jacob
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, 603203, India
| | - Gopalakrishnan Kumar
- School of Civil and Environmental Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Shashi Kant Bhatia
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, 05029, Republic of Korea
| | - Dinesh Kumar
- School of Bioengineering & Food Technology, Shoolini University of Biotechnology and Management Sciences, Solan, Himachal Pradesh, 173229, India
| | - Vivekanand Vivekanand
- Centre for Energy and Environment, Malaviya National Institute of Technology Jaipur, Jaipur, Rajasthan, 302017, India
| |
Collapse
|
3
|
de la Cruz M, Kunert F, Taymaz-Nikerel H, Sigala JC, Gosset G, Büchs J, Lara AR. Increasing the Pentose Phosphate Pathway Flux to Improve Plasmid DNA Production in Engineered E. coli. Microorganisms 2024; 12:150. [PMID: 38257977 PMCID: PMC10820320 DOI: 10.3390/microorganisms12010150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/03/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
The demand of plasmid DNA (pDNA) as a key element for gene therapy products, as well as mRNA and DNA vaccines, is increasing together with the need for more efficient production processes. An engineered E. coli strain lacking the phosphotransferase system and the pyruvate kinase A gene has been shown to produce more pDNA than its parental strain. With the aim of improving pDNA production in the engineered strain, several strategies to increase the flux to the pentose phosphate pathway (PPP) were evaluated. The simultaneous consumption of glucose and glycerol was a simple way to increase the growth rate, pDNA production rate, and supercoiled fraction (SCF). The overexpression of key genes from the PPP also improved pDNA production in glucose, but not in mixtures of glucose and glycerol. Particularly, the gene coding for the glucose 6-phosphate dehydrogenase (G6PDH) strongly improved the SCF, growth rate, and pDNA production rate. A linear relationship between the G6PDH activity and pDNA yield was found. A higher flux through the PPP was confirmed by flux balance analysis, which also estimates relevant differences in fluxes of the tricarboxylic acid cycle. These results are useful for developing further cell engineering strategies to increase pDNA production and quality.
Collapse
Affiliation(s)
- Mitzi de la Cruz
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Mexico City 05348, Mexico
| | - Flavio Kunert
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, 52074 Aachen, Germany
| | - Hilal Taymaz-Nikerel
- Department of Genetics and Bioengineering, Istanbul Bilgi University, 34060 Istanbul, Turkey
| | - Juan-Carlos Sigala
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Mexico City 05348, Mexico
| | - Guillermo Gosset
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico
| | - Jochen Büchs
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, 52074 Aachen, Germany
| | - Alvaro R. Lara
- Department of Biological and Chemical Engineering, Aarhus University, 8000 Aarhus, Denmark
| |
Collapse
|
4
|
Stegmüller J, Rodríguez Estévez M, Shu W, Gläser L, Myronovskyi M, Rückert-Reed C, Kalinowski J, Luzhetskyy A, Wittmann C. Systems metabolic engineering of the primary and secondary metabolism of Streptomyces albidoflavus enhances production of the reverse antibiotic nybomycin against multi-resistant Staphylococcus aureus. Metab Eng 2024; 81:123-143. [PMID: 38072358 DOI: 10.1016/j.ymben.2023.12.004] [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: 08/11/2023] [Revised: 11/17/2023] [Accepted: 12/01/2023] [Indexed: 01/23/2024]
Abstract
Nybomycin is an antibiotic compound with proven activity against multi-resistant Staphylococcus aureus, making it an interesting candidate for combating these globally threatening pathogens. For exploring its potential, sufficient amounts of nybomycin and its derivatives must be synthetized to fully study its effectiveness, safety profile, and clinical applications. As native isolates only accumulate low amounts of the compound, superior producers are needed. The heterologous cell factory S. albidoflavus 4N24, previously derived from the cluster-free chassis S. albidoflavus Del14, produced 860 μg L-1 of nybomycin, mainly in the stationary phase. A first round of strain development modulated expression of genes involved in supply of nybomycin precursors under control of the common Perm* promoter in 4N24, but without any effect. Subsequent studies with mCherry reporter strains revealed that Perm* failed to drive expression during the product synthesis phase but that use of two synthetic promoters (PkasOP* and P41) enabled strong constitutive expression during the entire process. Using PkasOP*, several rounds of metabolic engineering successively streamlined expression of genes involved in the pentose phosphate pathway, the shikimic acid pathway, supply of CoA esters, and nybomycin biosynthesis and export, which more than doubled the nybomycin titer to 1.7 mg L-1 in the sixth-generation strain NYB-6B. In addition, we identified the minimal set of nyb genes needed to synthetize the molecule using single-gene-deletion strains. Subsequently, deletion of the regulator nybW enabled nybomycin production to begin during the growth phase, further boosting the titer and productivity. Based on RNA sequencing along the created strain genealogy, we discovered that the nyb gene cluster was unfavorably downregulated in all advanced producers. This inspired removal of a part and the entire set of the four regulatory genes at the 3'-end nyb of the cluster. The corresponding mutants NYB-8 and NYB-9 exhibited marked further improvement in production, and the deregulated cluster was combined with all beneficial targets from primary metabolism. The best strain, S. albidoflavus NYB-11, accumulated up to 12 mg L-1 nybomycin, fifteenfold more than the basic strain. The absence of native gene clusters in the host and use of a lean minimal medium contributed to a selective production process, providing an important next step toward further development of nybomycin.
Collapse
Affiliation(s)
- Julian Stegmüller
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | | | - Wei Shu
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Lars Gläser
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Maksym Myronovskyi
- Department of Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany
| | | | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Andriy Luzhetskyy
- Department of Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
| |
Collapse
|
5
|
Ren X, Wei Y, Zhao H, Shao J, Zeng F, Wang Z, Li L. A comprehensive review and comparison of L-tryptophan biosynthesis in Saccharomyces cerevisiae and Escherichia coli. Front Bioeng Biotechnol 2023; 11:1261832. [PMID: 38116200 PMCID: PMC10729320 DOI: 10.3389/fbioe.2023.1261832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 11/22/2023] [Indexed: 12/21/2023] Open
Abstract
L-tryptophan and its derivatives are widely used in the chemical, pharmaceutical, food, and feed industries. Microbial fermentation is the most commonly used method to produce L-tryptophan, which calls for an effective cell factory. The mechanism of L-tryptophan biosynthesis in Escherichia coli, the widely used producer of L-tryptophan, is well understood. Saccharomyces cerevisiae also plays a significant role in the industrial production of biochemicals. Because of its robustness and safety, S. cerevisiae is favored for producing pharmaceuticals and food-grade biochemicals. However, the biosynthesis of L-tryptophan in S. cerevisiae has been rarely summarized. The synthetic pathways and engineering strategies of L-tryptophan in E. coli and S. cerevisiae have been reviewed and compared in this review. Furthermore, the information presented in this review pertains to the existing understanding of how L-tryptophan affects S. cerevisiae's stress fitness, which could aid in developing a novel plan to produce more resilient industrial yeast and E. coli cell factories.
Collapse
Affiliation(s)
- Xinru Ren
- College of Science and Technology, Hebei Agricultural University, Cangzhou, China
| | - Yue Wei
- College of Science and Technology, Hebei Agricultural University, Cangzhou, China
| | - Honglu Zhao
- College of Science and Technology, Hebei Agricultural University, Cangzhou, China
| | - Juanjuan Shao
- College of Science and Technology, Hebei Agricultural University, Cangzhou, China
| | - Fanli Zeng
- College of Life Sciences, Hebei Agricultural University, Baoding, China
- Hebei Key Laboratory of Analysis and Control of Zoonotic Pathogenic Microorganism, Baoding, China
| | - Zhen Wang
- College of Science and Technology, Hebei Agricultural University, Cangzhou, China
- Hebei Key Laboratory of Analysis and Control of Zoonotic Pathogenic Microorganism, Baoding, China
| | - Li Li
- College of Science and Technology, Hebei Agricultural University, Cangzhou, China
| |
Collapse
|
6
|
Singh A, Burns D, Sedinkin SL, Van Veller B, Potoyan DA, Venditti V. Protein Conformational Dynamics Underlie Selective Recognition of Thermophilic over Mesophilic Enzyme I by a Substrate Analogue. Biomolecules 2023; 13:biom13010160. [PMID: 36671545 PMCID: PMC9856155 DOI: 10.3390/biom13010160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/05/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Substrate selectivity is an important preventive measure to decrease the possibility of cross interactions between enzymes and metabolites that share structural similarities. In addition, understanding the mechanisms that determine selectivity towards a particular substrate increases the knowledge base for designing specific inhibitors for target enzymes. Here, we combine NMR, molecular dynamics (MD) simulations, and protein engineering to investigate how two substrate analogues, allylicphosphonate (cPEP) and sulfoenolpyruvate (SEP), recognize the mesophilic (eEIC) and thermophilic (tEIC) homologues of the receptor domain of bacterial Enzyme I, which has been proposed as a target for antimicrobial research. Chemical Shift Perturbation (CSP) experiments show that cPEP and SEP recognize tEIC over the mesophilic homologue. Combined Principal Component Analysis of half-microsecond-long MD simulations reveals that incomplete quenching of a breathing motion in the eEIC-ligand complex destabilizes the interaction and makes the investigated substrate analogues selective toward the thermophilic enzyme. Our results indicate that residual protein motions need to be considered carefully when optimizing small molecule inhibitors of EI. In general, our work demonstrates that protein conformational dynamics can be exploited in the rational design and optimization of inhibitors with subfamily selectivity.
Collapse
Affiliation(s)
- Aayushi Singh
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
| | - Daniel Burns
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | | | - Brett Van Veller
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
| | - Davit A. Potoyan
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
- Correspondence: (D.A.P.); (V.V.); Tel.: +515-294-9971 (D.A.P.); +515-294-1044 (V.V.); Fax: +515-294-7550 (D.A.P. & V.V.)
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
- Correspondence: (D.A.P.); (V.V.); Tel.: +515-294-9971 (D.A.P.); +515-294-1044 (V.V.); Fax: +515-294-7550 (D.A.P. & V.V.)
| |
Collapse
|
7
|
The Production of Pyruvate in Biological Technology: A Critical Review. Microorganisms 2022; 10:microorganisms10122454. [PMID: 36557706 PMCID: PMC9783380 DOI: 10.3390/microorganisms10122454] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/06/2022] [Accepted: 12/10/2022] [Indexed: 12/14/2022] Open
Abstract
Pyruvic acid has numerous applications in the food, chemical, and pharmaceutical industries. The high costs of chemical synthesis have prevented the extensive use of pyruvate for many applications. Metabolic engineering and traditional strategies for mutation and selection have been applied to microorganisms to enhance their ability to produce pyruvate. In the past decades, different microbial strains were generated to enhance their pyruvate production capability. In addition to the development of genetic engineering and metabolic engineering in recent years, the metabolic transformation of wild-type yeast, E. coli, and so on to produce high-yielding pyruvate strains has become a hot spot. The strategy and the understanding of the central metabolism directly related to pyruvate production could provide valuable information for improvements in fermentation products. One of the goals of this review was to collect information regarding metabolically engineered strains and the microbial fermentation processes used to produce pyruvate in high yield and productivity.
Collapse
|
8
|
Chan CCY, Lewis IA. Role of metabolism in uropathogenic Escherichia coli. Trends Microbiol 2022; 30:1174-1204. [PMID: 35941063 DOI: 10.1016/j.tim.2022.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 06/22/2022] [Accepted: 06/27/2022] [Indexed: 01/13/2023]
Abstract
Uropathogenic Escherichia coli (UPEC) is responsible for more than 75% of urinary tract infections (UTIs) and has been studied extensively to better understand the molecular underpinnings of infection and pathogenesis. Although the macromolecular adaptations UPEC employs - including the expression of virulence factors, adhesion molecules, and iron-acquisition systems - are well described, the role that metabolism plays in enabling infection is still unclear. However, a growing body of literature shows that metabolic function can have a profound impact on which strains can colonize the urinary tract. The goal of this review is to critically appraise this emerging body of literature to better understand the role that nutritional selection plays in enabling urinary tract colonization and the progression of UTIs.
Collapse
Affiliation(s)
- Carly C Y Chan
- Department of Biological Science, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Ian A Lewis
- Department of Biological Science, University of Calgary, Calgary, AB, T2N 1N4, Canada.
| |
Collapse
|
9
|
Re-designing Escherichia coli for high-yield production of β-alanine by metabolic engineering. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
10
|
Metabolic Engineering of Shikimic Acid Biosynthesis Pathway for the Production of Shikimic Acid and Its Branched Products in Microorganisms: Advances and Prospects. Molecules 2022; 27:molecules27154779. [PMID: 35897952 PMCID: PMC9332510 DOI: 10.3390/molecules27154779] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/10/2022] [Accepted: 07/12/2022] [Indexed: 02/06/2023] Open
Abstract
The shikimate pathway is a necessary pathway for the synthesis of aromatic compounds. The intermediate products of the shikimate pathway and its branching pathway have promising properties in many fields, especially in the pharmaceutical industry. Many important compounds, such as shikimic acid, quinic acid, chlorogenic acid, gallic acid, pyrogallol, catechol and so on, can be synthesized by the shikimate pathway. Among them, shikimic acid is the key raw material for the synthesis of GS4104 (Tamiflu®), an inhibitor of neuraminidase against avian influenza virus. Quininic acid is an important intermediate for synthesis of a variety of raw chemical materials and drugs. Gallic acid and catechol receive widespread attention as pharmaceutical intermediates. It is one of the hotspots to accumulate many kinds of target products by rationally modifying the shikimate pathway and its branches in recombinant strains by means of metabolic engineering. This review considers the effects of classical metabolic engineering methods, such as central carbon metabolism (CCM) pathway modification, key enzyme gene modification, blocking the downstream pathway on the shikimate pathway, as well as several expansion pathways and metabolic engineering strategies of the shikimate pathway, and expounds the synthetic biology in recent years in the application of the shikimate pathway and the future development direction.
Collapse
|
11
|
Xu Z, Wang L, Wang X, Wan M, Tang M, Ding Y. Characterizing the Effect of the Lysine Deacetylation Modification on Enzyme Activity of Pyruvate Kinase I and Pathogenicity of Vibrio alginolyticus. Front Vet Sci 2022; 9:877067. [PMID: 35795782 PMCID: PMC9252168 DOI: 10.3389/fvets.2022.877067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/28/2022] [Indexed: 01/22/2023] Open
Abstract
Pyruvate kinase I (PykF) is one of the key enzymes of glycolysis and plays a crucial role in bacterial metabolism. Several acetylation sites of Vibrio alginolyticus PykF were reported in previous studies and then 11 sites were first verified in this study, however, the specific roles of PykF acetylation remains unclear. Overlap-PCR and homologous recombination were implied to delete V. alginolyticus pykF gene and constructed complementary strains of site-directed mutagenesis for the further research focus on the deacetylation regulation on PykF. The results showed that the pyruvate kinase activity was sharply suppressed in the deacetylation status of K52, K68, and K317 of PykF, as well as the extracellular protease activity was significantly decreased in the deacetylation status of K52 and K68, but not induced with K317. Moreover, the growth rates of V. alginolyticus were not influenced with these three deacetylation sites. The ΔpykF mutant exhibited a 6-fold reduction in virulence to zebrafish. Site-directed mutations of K52R and K68R also showed reduced virulence while mutations of K317R didn't. The in vitro experiments showed that PykF was acetylated by acetyl phosphate (AcP), with the increase of incubation time by AcP, the acetylation level of PykF increased while the enzyme activity of PykF decreased correspondingly. Besides, PykF was deacetylated by CobB deacetylase and in result that the deacetylation was significantly down-regulated while the pyruvate kinase activity of PykF increased. Moreover, deletion of cobB gene had no significant difference in pyruvate kinase activity. These results confirm that CobB can regulate the acetylation level and pyruvate kinase activity of PykF. In summary, the results of this study provide a theoretical basis for further understanding of the deacetylation modification of PykF. It provides a new idea for the prevention and cure of vibriosis.
Collapse
Affiliation(s)
- Zhou Xu
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Key Laboratory of Control for Diseases of Aquatic Economic Animals, Zhanjiang, China
| | - Linjing Wang
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Key Laboratory of Control for Diseases of Aquatic Economic Animals, Zhanjiang, China
| | - Xudong Wang
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Key Laboratory of Control for Diseases of Aquatic Economic Animals, Zhanjiang, China
| | - Mingyue Wan
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Key Laboratory of Control for Diseases of Aquatic Economic Animals, Zhanjiang, China
| | - Mei Tang
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Key Laboratory of Control for Diseases of Aquatic Economic Animals, Zhanjiang, China
| | - Yu Ding
- Fisheries College, Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
- Guangdong Key Laboratory of Control for Diseases of Aquatic Economic Animals, Zhanjiang, China
- *Correspondence: Yu Ding
| |
Collapse
|
12
|
Liu Z, Xu J, Feng Z, Wang Y. Multi-strategy engineering unusual sugar TDP-l-mycarose biosynthesis to improve the production of 3-O-α-mycarosylerythronolide B in Escherichia coli. Synth Syst Biotechnol 2022; 7:756-764. [PMID: 35387229 PMCID: PMC8943214 DOI: 10.1016/j.synbio.2022.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/09/2022] [Accepted: 03/13/2022] [Indexed: 11/21/2022] Open
Abstract
The insufficient supply of sugar units is the key limitation for the biosynthesis of glycosylated products. The unusual sugar TDP-l-mycarose is initially attached to the C3 of the polyketide erythronolide B, resulting in 3-O-α-mycarosylerythronolide B (MEB). Here, we present the de novo biosynthesis of MEB in Escherichia coli and improve its production using multi-strategy metabolic engineering. Firstly, by blocking precursor glucose-1-phosphate competing pathways, the MEB titer of triple knockout strain QC13 was significantly enhanced to 41.2 mg/L, 9.8-fold to that produced by parental strain BAP230. Subsequently, the MEB production was further increased to 48.3 mg/L through overexpression of rfbA and rfbB. Moreover, the CRISPRi was implemented to promote the TDP-l-mycarose biosynthesis via repressing the glycolysis and TDP-l-rhamnose pathway. Our study paves the way for efficient production of erythromycins in E. coli and provides a promising platform that can be applied for biosynthesis of other glycosylated products with unusual sugars.
Collapse
|
13
|
Proteomic analysis of Aspergillus flavus reveals the antifungal action of Perilla frutescens essential oil by interfering with energy metabolism and defense function. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2021.112660] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
14
|
Vaud S, Pearcy N, Hanževački M, Van Hagen AMW, Abdelrazig S, Safo L, Ehsaan M, Jonczyk M, Millat T, Craig S, Spence E, Fothergill J, Bommareddy RR, Colin PY, Twycross J, Dalby PA, Minton NP, Jäger CM, Kim DH, Yu J, Maness PC, Lynch S, Eckert CA, Conradie A, Bryan SJ. Engineering improved ethylene production: Leveraging systems biology and adaptive laboratory evolution. Metab Eng 2021; 67:308-320. [PMID: 34245888 DOI: 10.1016/j.ymben.2021.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/26/2021] [Accepted: 07/02/2021] [Indexed: 10/20/2022]
Abstract
Ethylene is a small hydrocarbon gas widely used in the chemical industry. Annual worldwide production currently exceeds 150 million tons, producing considerable amounts of CO2 contributing to climate change. The need for a sustainable alternative is therefore imperative. Ethylene is natively produced by several different microorganisms, including Pseudomonas syringae pv. phaseolicola via a process catalyzed by the ethylene-forming enzyme (EFE), subsequent heterologous expression of EFE has led to ethylene production in non-native bacterial hosts including Escherichia coli and cyanobacteria. However, solubility of EFE and substrate availability remain rate-limiting steps in biological ethylene production. We employed a combination of genome-scale metabolic modelling, continuous fermentation, and protein evolution to enable the accelerated development of a high efficiency ethylene producing E. coli strain, yielding a 49-fold increase in production, the most significant improvement reported to date. Furthermore, we have clearly demonstrated that this increased yield resulted from metabolic adaptations that were uniquely linked to EFE (wild type versus mutant). Our findings provide a novel solution to deregulate metabolic bottlenecks in key pathways, which can be readily applied to address other engineering challenges.
Collapse
Affiliation(s)
- Sophie Vaud
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Nicole Pearcy
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Marko Hanževački
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Alexander M W Van Hagen
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Salah Abdelrazig
- Centre for Analytical Bioscience, Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, NG7 2RD, UK
| | - Laudina Safo
- Centre for Analytical Bioscience, Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, NG7 2RD, UK
| | - Muhammad Ehsaan
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Magdalene Jonczyk
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Thomas Millat
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Sean Craig
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Edward Spence
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - James Fothergill
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Rajesh Reddy Bommareddy
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Pierre-Yves Colin
- Department of Biochemical Engineering, Bernard Katz Building, University College London, WC1E 6BT, UK
| | - Jamie Twycross
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK; School of Computer Science, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, Bernard Katz Building, University College London, WC1E 6BT, UK
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Christof M Jäger
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Dong-Hyun Kim
- Centre for Analytical Bioscience, Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, NG7 2RD, UK
| | - Jianping Yu
- Biosciences Center, National Renewable Energy Laboratory (NREL), Golden, CO, USA
| | - Pin-Ching Maness
- Biosciences Center, National Renewable Energy Laboratory (NREL), Golden, CO, USA
| | - Sean Lynch
- Biosciences Center, National Renewable Energy Laboratory (NREL), Golden, CO, USA; Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, USA; Somalogic, Inc., Boulder, CO, USA
| | - Carrie A Eckert
- Biosciences Center, National Renewable Energy Laboratory (NREL), Golden, CO, USA; Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, USA
| | - Alex Conradie
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Samantha J Bryan
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK.
| |
Collapse
|
15
|
Liu Z, Zhang X, Lei D, Qiao B, Zhao GR. Metabolic engineering of Escherichia coli for de novo production of 3-phenylpropanol via retrobiosynthesis approach. Microb Cell Fact 2021; 20:121. [PMID: 34176467 PMCID: PMC8237410 DOI: 10.1186/s12934-021-01615-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/18/2021] [Indexed: 02/07/2023] Open
Abstract
Background 3-Phenylpropanol with a pleasant odor is widely used in foods, beverages and cosmetics as a fragrance ingredient. It also acts as the precursor and reactant in pharmaceutical and chemical industries. Currently, petroleum-based manufacturing processes of 3-phenypropanol is environmentally unfriendly and unsustainable. In this study, we aim to engineer Escherichia coli as microbial cell factory for de novo production of 3-phenypropanol via retrobiosynthesis approach. Results Aided by in silico retrobiosynthesis analysis, we designed a novel 3-phenylpropanol biosynthetic pathway extending from l-phenylalanine and comprising the phenylalanine ammonia lyase (PAL), enoate reductase (ER), aryl carboxylic acid reductase (CAR) and phosphopantetheinyl transferase (PPTase). We screened the enzymes from plants and microorganisms and reconstructed the artificial pathway for conversion of 3-phenylpropanol from l-phenylalanine. Then we conducted chromosome engineering to increase the supply of precursor l-phenylalanine and combined the upstream l-phenylalanine pathway and downstream 3-phenylpropanol pathway. Finally, we regulated the metabolic pathway strength and optimized fermentation conditions. As a consequence, metabolically engineered E. coli strain produced 847.97 mg/L of 3-phenypropanol at 24 h using glucose-glycerol mixture as co-carbon source. Conclusions We successfully developed an artificial 3-phenylpropanol pathway based on retrobiosynthesis approach, and highest titer of 3-phenylpropanol was achieved in E. coli via systems metabolic engineering strategies including enzyme sources variety, chromosome engineering, metabolic strength balancing and fermentation optimization. This work provides an engineered strain with industrial potential for production of 3-phenylpropanol, and the strategies applied here could be practical for bioengineers to design and reconstruct the microbial cell factory for high valuable chemicals. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01615-1.
Collapse
Affiliation(s)
- Zhenning Liu
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin, 300350, China
| | - Xue Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin, 300350, China
| | - Dengwei Lei
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin, 300350, China
| | - Bin Qiao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin, 300350, China
| | - Guang-Rong Zhao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin, 300350, China. .,Georgia Tech Shenzhen Institute, Tianjin University, Tangxing Road 133, Nanshan District, Shenzhen, 518071, China.
| |
Collapse
|
16
|
Wang S, Fu C, Liu K, Cui J, Hu H, Wang W, Zhang X. Engineering a Synthetic Pathway for Gentisate in Pseudomonas Chlororaphis P3. Front Bioeng Biotechnol 2021; 8:622226. [PMID: 33553126 PMCID: PMC7862547 DOI: 10.3389/fbioe.2020.622226] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/30/2020] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas chlororaphis P3 has been well-engineered as a platform organism for biologicals production due to enhanced shikimate pathway and excellent physiological and genetic characteristics. Gentisate displays high antiradical and antioxidant activities and is an important intermediate that can be used as a precursor for drugs. Herein, a plasmid-free biosynthetic pathway of gentisate was constructed by connecting the endogenous degradation pathway from 3-hydroxybenzoate in Pseudomonas for the first time. As a result, the production of gentisate reached 365 mg/L from 3-HBA via blocking gentisate conversion and enhancing the gentisate precursors supply through the overexpression of the rate-limiting step. With a close-up at the future perspectives, a series of bioactive compounds could be achieved by constructing synthetic pathways in conventional Pseudomonas to establish a cell factory.
Collapse
Affiliation(s)
- Songwei Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Cong Fu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Kaiquan Liu
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Jiajia Cui
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Hongbo Hu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Wei Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xuehong Zhang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
17
|
Enhancing microaerobic plasmid DNA production by chromosomal expression of Vitreoscilla hemoglobin in E. coli. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2020.107862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
18
|
Rivas-Astroza M, Conejeros R. Metabolic flux configuration determination using information entropy. PLoS One 2020; 15:e0243067. [PMID: 33275628 PMCID: PMC7717585 DOI: 10.1371/journal.pone.0243067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 11/14/2020] [Indexed: 11/20/2022] Open
Abstract
Constraint-based models use steady-state mass balances to define a solution space of flux configurations, which can be narrowed down by measuring as many fluxes as possible. Due to loops and redundant pathways, this process typically yields multiple alternative solutions. To address this ambiguity, flux sampling can estimate the probability distribution of each flux, or a flux configuration can be singled out by further minimizing the sum of fluxes according to the assumption that cellular metabolism favors states where enzyme-related costs are economized. However, flux sampling is susceptible to artifacts introduced by thermodynamically infeasible cycles and is it not clear if the economy of fluxes assumption (EFA) is universally valid. Here, we formulated a constraint-based approach, MaxEnt, based on the principle of maximum entropy, which in this context states that if more than one flux configuration is consistent with a set of experimentally measured fluxes, then the one with the minimum amount of unwarranted assumptions corresponds to the best estimation of the non-observed fluxes. We compared MaxEnt predictions to Escherichia coli and Saccharomyces cerevisiae publicly available flux data. We found that the mean square error (MSE) between experimental and predicted fluxes by MaxEnt and EFA-based methods are three orders of magnitude lower than the median of 1,350,000 MSE values obtained using flux sampling. However, only MaxEnt and flux sampling correctly predicted flux through E. coli’s glyoxylate cycle, whereas EFA-based methods, in general, predict no flux cycles. We also tested MaxEnt predictions at increasing levels of overflow metabolism. We found that MaxEnt accuracy is not affected by overflow metabolism levels, whereas the EFA-based methods show a decreasing performance. These results suggest that MaxEnt is less sensitive than flux sampling to artifacts introduced by thermodynamically infeasible cycles and that its predictions are less susceptible to overfitting than EFA-based methods.
Collapse
Affiliation(s)
- Marcelo Rivas-Astroza
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
- * E-mail:
| | - Raúl Conejeros
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| |
Collapse
|
19
|
Zhang J, Petersen SD, Radivojevic T, Ramirez A, Pérez-Manríquez A, Abeliuk E, Sánchez BJ, Costello Z, Chen Y, Fero MJ, Martin HG, Nielsen J, Keasling JD, Jensen MK. Combining mechanistic and machine learning models for predictive engineering and optimization of tryptophan metabolism. Nat Commun 2020; 11:4880. [PMID: 32978375 PMCID: PMC7519671 DOI: 10.1038/s41467-020-17910-1] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 07/27/2020] [Indexed: 12/23/2022] Open
Abstract
Through advanced mechanistic modeling and the generation of large high-quality datasets, machine learning is becoming an integral part of understanding and engineering living systems. Here we show that mechanistic and machine learning models can be combined to enable accurate genotype-to-phenotype predictions. We use a genome-scale model to pinpoint engineering targets, efficient library construction of metabolic pathway designs, and high-throughput biosensor-enabled screening for training diverse machine learning algorithms. From a single data-generation cycle, this enables successful forward engineering of complex aromatic amino acid metabolism in yeast, with the best machine learning-guided design recommendations improving tryptophan titer and productivity by up to 74 and 43%, respectively, compared to the best designs used for algorithm training. Thus, this study highlights the power of combining mechanistic and machine learning models to effectively direct metabolic engineering efforts.
Collapse
Affiliation(s)
- Jie Zhang
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs., Lyngby, Denmark
| | - Søren D Petersen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs., Lyngby, Denmark
| | - Tijana Radivojevic
- Joint BioEnergy Institute, Emeryville, CA, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- DOE Agile BioFoundry, Emeryville, CA, USA
| | | | | | | | - Benjamín J Sánchez
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs., Lyngby, Denmark
| | - Zak Costello
- Joint BioEnergy Institute, Emeryville, CA, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- DOE Agile BioFoundry, Emeryville, CA, USA
| | - Yu Chen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden
| | | | - Hector Garcia Martin
- Joint BioEnergy Institute, Emeryville, CA, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- DOE Agile BioFoundry, Emeryville, CA, USA
- BCAM, Basque Center for Applied Mathematics, Bilbao, Spain
| | - Jens Nielsen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs., Lyngby, Denmark
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- BioInnovation Institute, Ole Maaløes Vej 3, DK-2200, Copenhagen N, Denmark
| | - Jay D Keasling
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs., Lyngby, Denmark
- Joint BioEnergy Institute, Emeryville, CA, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Chemical and Biomolecular Engineering & Department of Bioengineering, University of California, Berkeley, CA, USA
- Center for Synthetic Biochemistry, Institute for Synthetic Biology, Shenzhen Institutes of Advanced Technologies, Shenzhen, China
| | - Michael K Jensen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs., Lyngby, Denmark.
| |
Collapse
|
20
|
Jia S, Hong H, Yang Q, Liu X, Zhuang S, Li Y, Liu J, Luo Y. TMT-based proteomic analysis of the fish-borne spoiler Pseudomonas psychrophila subjected to chitosan oligosaccharides in fish juice system. Food Microbiol 2020; 90:103494. [DOI: 10.1016/j.fm.2020.103494] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/04/2020] [Accepted: 03/17/2020] [Indexed: 01/16/2023]
|
21
|
de Arroyo Garcia L, Jones PR. In silico co-factor balance estimation using constraint-based modelling informs metabolic engineering in Escherichia coli. PLoS Comput Biol 2020; 16:e1008125. [PMID: 32776925 PMCID: PMC7440669 DOI: 10.1371/journal.pcbi.1008125] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 08/20/2020] [Accepted: 07/06/2020] [Indexed: 02/06/2023] Open
Abstract
In the growing field of metabolic engineering, where cells are treated as ‘factories’ that synthesize industrial compounds, it is essential to consider the ability of the cells’ native metabolism to accommodate the demands of synthetic pathways, as these pathways will alter the homeostasis of cellular energy and electron metabolism. From the breakdown of substrate, microorganisms activate and reduce key co-factors such as ATP and NAD(P)H, which subsequently need to be hydrolysed and oxidized, respectively, in order to restore cellular balance. A balanced supply and consumption of such co-factors, here termed co-factor balance, will influence biotechnological performance. To aid the strain selection and design process, we used stoichiometric modelling (FBA, pFBA, FVA and MOMA) and the Escherichia coli (E.coli) core stoichiometric model to investigate the network-wide effect of butanol and butanol precursor production pathways differing in energy and electron demand on product yield. An FBA-based co-factor balance assessment (CBA) algorithm was developed to track and categorise how ATP and NAD(P)H pools are affected in the presence of a new pathway. CBA was compared to the balance calculations proposed by Dugar et al. (Nature Biotechnol. 29 (12), 1074–1078). Predicted solutions were compromised by excessively underdetermined systems, displaying greater flexibility in the range of reaction fluxes than experimentally measured by 13C-metabolic flux analysis (MFA) and the appearance of unrealistic futile co-factor cycles. With the assumption that futile cycles are tightly regulated in reality, the FBA models were manually constrained in a step-wise manner. Solutions with minimal futile cycling diverted surplus energy and electrons towards biomass formation. As an alternative, the use of loopless FBA or constraining the models with measured flux ranges were tried but did not prevent futile co-factor cycles. The results highlight the need to account for co-factor imbalance and confirm that better-balanced pathways with minimal diversion of surplus towards biomass formation present the highest theoretical yield. The analysis also suggests that ATP and NAD(P)H balancing cannot be assessed in isolation from each other, or even from the balance of additional co-factors such as AMP and ADP. We conclude that, through revealing the source of co-factor imbalance CBA can facilitate pathway and host selection when designing new biocatalysts for implementation by metabolic engineering. The chemicals industry is a major contributor to greenhouse gas emissions and desperately requires more sustainable alternatives. Genetically engineered microorganisms can be used as ‘bio-factories’ to manufacture chemicals, replacing those currently sourced from fossil fuels or unsustainable tropical plant agriculture. However, due to the complexity of biology, the features that render one bio-factory design more efficient than others are difficult to identify. Computational modelling of such designs can enable the selection of optimally performing designs, but it remains challenging as biology is complex and not fully understood. Microorganisms require energy for their own growth and maintenance, but also to convert molecules into desired target products. The supply and consumption of such energy is through co-factors, and the balance of such co-factors influences the performance of the engineered bio-factories. This study developed a computer-aided approach for quantification of the co-factor balance of bio-factories. Using the chemical n-butanol as a case study, our study explores the impact of variant bio-factory designs with differing co-factor balance on the potential efficiency of biomanufacturing. We provide insights into the relative balance of different designs and provide a computational framework to select the best-performing designs.
Collapse
Affiliation(s)
| | - Patrik R. Jones
- Department of Life Sciences, Imperial College London, London, United Kingdom
- * E-mail:
| |
Collapse
|
22
|
Chromosome Engineering To Generate Plasmid-Free Phenylalanine- and Tyrosine-Overproducing Escherichia coli Strains That Can Be Applied in the Generation of Aromatic-Compound-Producing Bacteria. Appl Environ Microbiol 2020; 86:AEM.00525-20. [PMID: 32414798 DOI: 10.1128/aem.00525-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/11/2020] [Indexed: 12/25/2022] Open
Abstract
Many phenylalanine- and tyrosine-producing strains have used plasmid-based overexpression of pathway genes. The resulting strains achieved high titers and yields of phenylalanine and tyrosine. Chromosomally engineered, plasmid-free producers have shown lower titers and yields than plasmid-based strains, but the former are advantageous in terms of cultivation cost and public health/environmental risk. Therefore, we engineered here the Escherichia coli chromosome to create superior phenylalanine- and tyrosine-overproducing strains that did not depend on plasmid-based expression. Integration into the E. coli chromosome of two central metabolic pathway genes (ppsA and tktA) and eight shikimate pathway genes (aroA, aroB, aroC, aroD, aroE, aroGfbr , aroL, and pheAfbr ), controlled by the T7lac promoter, resulted in excellent titers and yields of phenylalanine; the superscript "fbr" indicates that the enzyme encoded by the gene was feedback resistant. The generated strain could be changed to be a superior tyrosine-producing strain by replacing pheAfbr with tyrAfbr A rational approach revealed that integration of seven genes (ppsA, tktA, aroA, aroB, aroC, aroGfbr , and pheAfbr ) was necessary as the minimum gene set for high-yield phenylalanine production in E. coli MG1655 (tyrR, adhE, ldhA, pykF, pflDC, and ascF deletant). The phenylalanine- and tyrosine-producing strains were further applied to generate phenyllactic acid-, 4-hydroxyphenyllactic acid-, tyramine-, and tyrosol-producing strains; yield of these aromatic compounds increased proportionally to the increase in phenylalanine and tyrosine yields.IMPORTANCE Plasmid-free strains for aromatic compound production are desired in the aspect of industrial application. However, the yields of phenylalanine and tyrosine have been considerably lower in plasmid-free strains than in plasmid-based strains. The significance of this research is that we succeeded in generating superior plasmid-free phenylalanine- and tyrosine-producing strains by engineering the E. coli chromosome, which was comparable to that in plasmid-based strains. The generated strains have a potential to generate superior strains for the production of aromatic compounds. Actually, we demonstrated that four kinds of aromatic compounds could be produced from glucose with high yields (e.g., 0.28 g tyrosol/g glucose).
Collapse
|
23
|
Identification of new arylamine N-acetyltransferases and enhancing 2-acetamidophenol production in Pseudomonas chlororaphis HT66. Microb Cell Fact 2020; 19:105. [PMID: 32430011 PMCID: PMC7236291 DOI: 10.1186/s12934-020-01364-7] [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: 11/24/2019] [Accepted: 05/12/2020] [Indexed: 01/03/2023] Open
Abstract
Background 2-Acetamidophenol (AAP) is an aromatic compound with the potential for antifungal, anti-inflammatory, antitumor, anti-platelet, and anti-arthritic activities. Due to the biosynthesis of AAP is not yet fully understood, AAP is mainly produced by chemical synthesis. Currently, metabolic engineering of natural microbial pathway to produce valuable aromatic compound has remarkable advantages and exhibits attractive potential. Thus, it is of paramount importance to develop a dominant strain to produce AAP by elucidating the AAP biosynthesis pathway. Result In this study, the active aromatic compound AAP was first purified and identified in gene phzB disruption strain HT66ΔphzB, which was derived from Pseudomonas chlororaphis HT66. The titer of AAP in the strain HT66ΔphzB was 236.89 mg/L. Then, the genes involved in AAP biosynthesis were determined. Through the deletion of genes phzF, Nat and trpE, AAP was confirmed to have the same biosynthesis route as phenazine-1-carboxylic (PCA). Moreover, a new arylamine N-acetyltransferases (NATs) was identified and proved to be the key enzyme required for generating AAP by in vitro assay. P. chlororaphis P3, a chemical mutagenesis mutant strain of HT66, has been demonstrated to have a robust ability to produce antimicrobial phenazines. Therefore, genetic engineering, precursor addition, and culture optimization strategies were used to enhance AAP production in P. chlororaphis P3. The inactivation of phzB in P3 increased AAP production by 92.4%. Disrupting the phenazine negative regulatory genes lon and rsmE and blocking the competitive pathway gene pykA in P3 increased AAP production 2.08-fold, which also confirmed that AAP has the same biosynthesis route as PCA. Furthermore, adding 2-amidophenol to the KB medium increased AAP production by 64.6%, which suggested that 2-amidophenol is the precursor of AAP. Finally, by adding 5 mM 2-amidophenol and 2 mM Fe3+ to the KB medium, the production of AAP reached 1209.58 mg/L in the engineered strain P3ΔphzBΔlonΔpykAΔrsmE using a shaking-flask culture. This is the highest microbial-based AAP production achieved to date. Conclusion In conclusion, this study clarified the biosynthesis process of AAP in Pseudomonas and provided a promising host for industrial-scale biosynthesis of AAP from renewable resources. ![]()
Collapse
|
24
|
Rang J, He H, Yuan S, Tang J, Liu Z, Xia Z, Khan TA, Hu S, Yu Z, Hu Y, Sun Y, Huang W, Ding X, Xia L. Deciphering the Metabolic Pathway Difference Between Saccharopolyspora pogona and Saccharopolyspora spinosa by Comparative Proteomics and Metabonomics. Front Microbiol 2020; 11:396. [PMID: 32256469 PMCID: PMC7093602 DOI: 10.3389/fmicb.2020.00396] [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: 01/10/2020] [Accepted: 02/26/2020] [Indexed: 12/12/2022] Open
Abstract
Butenyl-spinosyn, a secondary metabolite produced by Saccharopolyspora pogona, exhibits strong insecticidal activity than spinosyn. However, the low synthesis capacity and unknown metabolic characteristics of butenyl-spinosyn in wild-type S. pogona limit its broad application and metabolic engineering. Here, we showed that S. pogona exhibited increased glucose consumption ability and growth rate compared with S. spinosa, but the production of butenyl-spinosyn was much lower than that of spinosyn. To further elucidate the metabolic mechanism of these different phenotypes, we performed a comparative proteomic and metabolomic study on S. pogona and S. spinosa to identify the change in the abundance levels of proteins and metabolites. We found that the abundance of most proteins and metabolites associated with glucose transport, fatty acid metabolism, tricarboxylic acid cycle, amino acid metabolism, energy metabolism, purine and pyrimidine metabolism, and target product biosynthesis in S. pogona was higher than that in S. spinosa. However, the overall abundance of proteins involved in butenyl-spinosyn biosynthesis was much lower than that of the high-abundance protein chaperonin GroEL, such as the enzymes related to rhamnose synthesis. We speculated that these protein and metabolite abundance changes may be directly responsible for the above phenotypic changes in S. pogona and S. spinosa, especially affecting butenyl-spinosyn biosynthesis. Further studies revealed that the over-expression of the rhamnose synthetic genes and methionine adenosyltransferase gene could effectively improve the production of butenyl-spinosyn by 2.69- and 3.03-fold, respectively, confirming the reliability of this conjecture. This work presents the first comparative proteomics and metabolomics study of S. pogona and S. spinosa, providing new insights into the novel links of phenotypic change and metabolic difference between two strains. The result will be valuable in designing strategies to promote the biosynthesis of butenyl-spinosyn by metabolic engineering.
Collapse
Affiliation(s)
- Jie Rang
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Haocheng He
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Shuangqin Yuan
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Jianli Tang
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Zhudong Liu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Ziyuan Xia
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Tahir Ali Khan
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Shengbiao Hu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Ziquan Yu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Yibo Hu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Yunjun Sun
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Weitao Huang
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Xuezhi Ding
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Liqiu Xia
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| |
Collapse
|
25
|
Jung HM, Im DK, Lim JH, Jung GY, Oh MK. Metabolic perturbations in mutants of glucose transporters and their applications in metabolite production in Escherichia coli. Microb Cell Fact 2019; 18:170. [PMID: 31601271 PMCID: PMC6786474 DOI: 10.1186/s12934-019-1224-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 09/29/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Most microorganisms have evolved to maximize growth rate, with rapid consumption of carbon sources from the surroundings. However, fast growing phenotypes usually feature secretion of organic compounds. For example, E. coli mainly produced acetate in fast growing condition such as glucose rich and aerobic condition, which is troublesome for metabolic engineering because acetate causes acidification of surroundings, growth inhibition and decline of production yield. The overflow metabolism can be alleviated by reducing glucose uptake rate. RESULTS As glucose transporters or their subunits were knocked out in E. coli, the growth and glucose uptake rates decreased and biomass yield was improved. Alteration of intracellular metabolism caused by the mutations was investigated with transcriptome analysis and 13C metabolic flux analysis (13C MFA). Various transcriptional and metabolic perturbations were identified in the sugar transporter mutants. Transcription of genes related to glycolysis, chemotaxis, and flagella synthesis was downregulated, and that of gluconeogenesis, Krebs cycle, alternative transporters, quorum sensing, and stress induced proteins was upregulated in the sugar transporter mutants. The specific production yields of value-added compounds (enhanced green fluorescent protein, γ-aminobutyrate, lycopene) were improved significantly in the sugar transporter mutants. CONCLUSIONS The elimination of sugar transporter resulted in alteration of global gene expression and redirection of carbon flux distribution, which was purposed to increase energy yield and recycle carbon sources. When the pathways for several valuable compounds were introduced to mutant strains, specific yield of them were highly improved. These results showed that controlling the sugar uptake rate is a good strategy for ameliorating metabolite production.
Collapse
Affiliation(s)
- Hwi-Min Jung
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841 South Korea
| | - Dae-Kyun Im
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841 South Korea
| | - Jae Hyung Lim
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673 South Korea
| | - Gyoo Yeol Jung
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673 South Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673 South Korea
| | - Min-Kyu Oh
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841 South Korea
| |
Collapse
|
26
|
Choi SS, Seo SY, Park SO, Lee HN, Song JS, Kim JY, Park JH, Kim S, Lee SJ, Chun GT, Kim ES. Cell Factory Design and Culture Process Optimization for Dehydroshikimate Biosynthesis in Escherichia coli. Front Bioeng Biotechnol 2019; 7:241. [PMID: 31649923 PMCID: PMC6795058 DOI: 10.3389/fbioe.2019.00241] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 09/11/2019] [Indexed: 11/13/2022] Open
Abstract
3-Dehydroshikimate (DHS) is a useful starting metabolite for the biosynthesis of muconic acid (MA) and shikimic acid (SA), which are precursors of various valuable polymers and drugs. Although DHS biosynthesis has been previously reported in several bacteria, the engineered strains were far from satisfactory, due to their low DHS titers. Here, we created an engineered Escherichia coli cell factory to produce a high titer of DHS as well as an efficient system for the conversion DHS into MA. First, the genes showing negative effects on DHS accumulation in E. coli, such as tyrR (tyrosine dependent transcriptional regulator), ptsG (glucose specific sugar: phosphoenolpyruvate phosphotransferase), and pykA (pyruvate kinase 2), were disrupted. In addition, the genes involved in DHS biosynthesis, such as aroB (DHQ synthase), aroD (DHQ dehydratase), ppsA (phosphoenolpyruvate synthase), galP (D-galactose transporter), aroG (DAHP synthase), and aroF (DAHP synthase), were overexpressed to increase the glucose uptake and flux of intermediates. The redesigned DHS-overproducing E. coli strain grown in an optimized medium produced ~117 g/L DHS in 7-L fed-batch fermentation, which is the highest level of DHS production demonstrated in E. coli. To accomplish the DHS-to-MA conversion, which is originally absent in E. coli, a codon-optimized heterologous gene cassette containing asbF, aroY, and catA was expressed as a single operon under a strong promoter in a DHS-overproducing E. coli strain. This redesigned E. coli grown in an optimized medium produced about 64.5 g/L MA in 7-L fed-batch fermentation, suggesting that the rational cell factory design of DHS and MA biosynthesis could be a feasible way to complement petrochemical-based chemical processes.
Collapse
Affiliation(s)
- Si-Sun Choi
- Department of Biological Engineering, Inha University, Incheon, South Korea
| | - Seung-Yeul Seo
- STR Biotech Co., Ltd., Chuncheon-si, South Korea.,Department of Molecular Bio-Science, Kangwon National University, Chuncheon-si, South Korea
| | - Sun-Ok Park
- STR Biotech Co., Ltd., Chuncheon-si, South Korea
| | - Han-Na Lee
- Department of Biological Engineering, Inha University, Incheon, South Korea.,STR Biotech Co., Ltd., Chuncheon-si, South Korea
| | - Ji-Soo Song
- Department of Biological Engineering, Inha University, Incheon, South Korea
| | - Ji-Yeon Kim
- Department of Biological Engineering, Inha University, Incheon, South Korea
| | - Ji-Hoon Park
- Department of Biological Engineering, Inha University, Incheon, South Korea
| | - Sangyong Kim
- Green Chemistry and Materials Group, Korea Institute of Industrial Technology, Cheonan-si, South Korea.,Green Process and System Engineering Major, Korea University of Science and Technology (UST), Daejeon, South Korea
| | | | - Gie-Taek Chun
- Department of Molecular Bio-Science, Kangwon National University, Chuncheon-si, South Korea
| | - Eung-Soo Kim
- Department of Biological Engineering, Inha University, Incheon, South Korea
| |
Collapse
|
27
|
Sousa J, Westhoff P, Methling K, Lalk M. The Absence of Pyruvate Kinase Affects Glucose-Dependent Carbon Catabolite Repression in Bacillus subtilis. Metabolites 2019; 9:metabo9100216. [PMID: 31590319 PMCID: PMC6835821 DOI: 10.3390/metabo9100216] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 12/30/2022] Open
Abstract
Pyruvate is a key intermediate of diverse metabolic pathways of central carbon metabolism. In addition to being the end product of glycolysis, pyruvate is an essential carbon distribution point to oxidative metabolism, amino acid and fatty acid syntheses, and overflow metabolite production. Hence, a tight regulation of pyruvate kinase (Pyk) activity is of great importance. This study aimed to analyze targeted metabolites from several pathways and possible changes in Bacillus subtilis lacking Pyk. Wild type and Δpyk cells were cultivated in chemically defined medium with glucose and pyruvate as carbon sources, and the extracted metabolites were analyzed by 1H-NMR, GC-MS, HPLC-MS, and LC-MS/MS. The results showed that the perturbation created in the pyruvate node drove an adaptation to new conditions by altering the nutritional compounds’ consumption. In Δpyk, pyruvate, which is subject to glucose-dependent carbon catabolite repression, did not comply with the hierarchy in carbon source utilization. Other metabolic alterations were observed such as the higher secretion of the overflow metabolites acetoin and 2,3-butanediol by Δpyk. Our results help to elucidate the regulatory transport of glucose and pyruvate in B. subtilis and possible metabolic reroute to alternative pathways in the absence of Pyk.
Collapse
Affiliation(s)
- Joana Sousa
- Institute of Biochemistry, University of Greifswald, 17487 Greifswald, Germany.
- Innovayt S/A, Av. João Paulo II 30, 4715-213 Braga, Portugal.
| | - Philipp Westhoff
- Institute of Biochemistry, University of Greifswald, 17487 Greifswald, Germany.
- Institute of Plant Biochemistry, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, Düsseldorf, Germany.
| | - Karen Methling
- Institute of Biochemistry, University of Greifswald, 17487 Greifswald, Germany.
| | - Michael Lalk
- Institute of Biochemistry, University of Greifswald, 17487 Greifswald, Germany.
| |
Collapse
|
28
|
Zhu L, Fang Y, Ding Z, Zhang S, Wang X. Developing an l-threonine-producing strain from wild-type Escherichia coli by modifying the glucose uptake, glyoxylate shunt, and l-threonine biosynthetic pathway. Biotechnol Appl Biochem 2019; 66:962-976. [PMID: 31486127 DOI: 10.1002/bab.1813] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/03/2019] [Indexed: 12/20/2022]
Abstract
Wild-type Escherichia coli MG1655 usually does not accumulate l-threonine. In this study, the effects of 13 genes related to the glucose uptake, glycolysis, TCA cycle, l-threonine biosynthesis, or their regulation on l-threonine accumulation in E. coli MG1655 were investigated. Sixteen E. coli mutant strains were constructed by chromosomal deletion or overexpression of one or more genes of rsd, ptsG, ptsH, ptsI, crr, galP, glk, iclR, and gltA; the plasmid pFW01-thrA*BC-rhtC harboring the key genes for l-threonine biosynthesis and secretion was introduced into these mutants. The analyses on cell growth, glucose consumption, and l-threonine production of these recombinant strains showed that most of these strains could accumulate l-threonine, and the highest yield was obtained in WMZ016/pFW01-thrA*BC-rhtC. WMZ016 was derived from MG1655 by deleting crr and iclR and enhancing the expression of gltA. WMZ016/pFW01-thrA*BC-rhtC could produce 17.98 g/L l-threonine with a yield of 0.346 g/g glucose, whereas the control strain MG1655/pFW01-thrA*BC-rhtC could only produce 0.68 g/L l-threonine. In addition, WMZ016/pFW01-thrA*BC-rhtC could tolerate the high concentration of glucose and produced no detectable by-products; therefore, it should be an ideal platform strain for further development. The results indicate that manipulating the glucose uptake and TCA cycle could efficiently increase l-threonine production in E. coli.
Collapse
Affiliation(s)
- Lifei Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yu Fang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zhixiang Ding
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Shuyan Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China
| |
Collapse
|
29
|
Liu X, Niu H, Li Q, Gu P. Metabolic engineering for the production of l-phenylalanine in Escherichia coli. 3 Biotech 2019; 9:85. [PMID: 30800596 DOI: 10.1007/s13205-019-1619-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 02/08/2019] [Indexed: 10/27/2022] Open
Abstract
As one of the three proteinogenic aromatic amino acids, l-phenylalanine is widely applied in the food, chemical and pharmaceutical industries, especially in production of the low-calorie sweetener aspartame. Microbial production of l-phenylalanine has become attractive as it possesses the advantages of environmental friendliness, low cost, and feedstock renewability. With the progress of metabolic engineering, systems biology and synthetic biology, production of l-phenylalanine from glucose in Escherichia coli with relatively high titer has been achieved by improving the intracellular levels of precursors, alleviating transcriptional repression and feedback inhibition of key enzymes, increasing the export of l-phenylalanine, engineering of global regulators, and overexpression of rate-limiting enzymes. In this review, successful metabolic engineering strategies for increasing l-phenylalanine accumulation from glucose in E. coli are described. In addition, perspectives for further improvement of production of l-phenylalanine are discussed.
Collapse
|
30
|
Metabolic engineering for improving l-tryptophan production in Escherichia coli. ACTA ACUST UNITED AC 2019; 46:55-65. [DOI: 10.1007/s10295-018-2106-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 11/03/2018] [Indexed: 11/26/2022]
Abstract
Abstract
l-Tryptophan is an important aromatic amino acid that is used widely in the food, chemical, and pharmaceutical industries. Compared with the traditional synthetic methods, production of l-tryptophan by microbes is environmentally friendly and has low production costs, and feed stocks are renewable. With the development of metabolic engineering, highly efficient production of l-tryptophan in Escherichia coli has been achieved by eliminating negative regulation factors, improving the intracellular level of precursors, engineering of transport systems and overexpression of rate-limiting enzymes. However, challenges remain for l-tryptophan biosynthesis to be cost-competitive. In this review, successful and applicable strategies derived from metabolic engineering for increasing l-tryptophan accumulation in E. coli are summarized. In addition, perspectives for further efficient production of l-tryptophan are discussed.
Collapse
|
31
|
Candeias NR, Assoah B, Simeonov SP. Production and Synthetic Modifications of Shikimic Acid. Chem Rev 2018; 118:10458-10550. [PMID: 30350584 DOI: 10.1021/acs.chemrev.8b00350] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Shikimic acid is a natural product of industrial importance utilized as a precursor of the antiviral Tamiflu. It is nowadays produced in multihundred ton amounts from the extraction of star anise ( Illicium verum) or by fermentation processes. Apart from the production of Tamiflu, shikimic acid has gathered particular notoriety as its useful carbon backbone and inherent chirality provide extensive use as a versatile chiral precursor in organic synthesis. This review provides an overview of the main synthetic and microbial methods for production of shikimic acid and highlights selected methods for isolation from available plant sources. Furthermore, we have attempted to demonstrate the synthetic utility of shikimic acid by covering the most important synthetic modifications and related applications, namely, synthesis of Tamiflu and derivatives, synthetic manipulations of the main functional groups, and its use as biorenewable material and in total synthesis. Given its rich chemistry and availability, shikimic acid is undoubtedly a promising platform molecule for further exploration. Therefore, in the end, we outline some challenges and promising future directions.
Collapse
Affiliation(s)
- Nuno R Candeias
- Laboratory of Chemistry and Bioengineering , Tampere University of Technology , Korkeakoulunkatu 8 , 33101 Tampere , Finland
| | - Benedicta Assoah
- Laboratory of Chemistry and Bioengineering , Tampere University of Technology , Korkeakoulunkatu 8 , 33101 Tampere , Finland
| | - Svilen P Simeonov
- Laboratory Organic Synthesis and Stereochemistry, Institute of Organic Chemistry with Centre of Phytochemistry , Bulgarian Academy of Sciences , Acad. G. Bontchev str. Bl. 9 , 1113 Sofia , Bulgaria
| |
Collapse
|
32
|
Zakaria MA, Mohd Yusoff MZ, Zakaria MR, Hassan MA, Wood TK, Maeda T. Pseudogene product YqiG is important for pflB expression and biohydrogen production in Escherichia coli BW25113. 3 Biotech 2018; 8:435. [PMID: 30306004 DOI: 10.1007/s13205-018-1461-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 09/24/2018] [Indexed: 01/08/2023] Open
Abstract
Pseudogenes in the Escherichia coli genome are assumed to be non-functional. In this study, Keio collection BW25113∆yqiG and YqiG-producing strain (BW25113/pCA24N-YqiG) were used to evaluate the importance of pseudogene yqiG in hydrogen metabolism. Our results show pseudogene protein YqiG was identified as an essential protein in the production of biohydrogen from glucose. The mutant yqiG decreased biohydrogen production from 37 µmol mg-1 protein to 6 µmol mg-1 protein compared to the wild-type strain, and glucose consumption was reduced by 80%. Through transcriptional analysis, we found that the yqiG mutation represses pflB transcription tenfold; pflB encodes pyruvate-formate lyase, one of the key enzymes in the anaerobic metabolism of E. coli. Moreover, production of YqiG stimulated glycolysis and increased biohydrogen productivity 1.5-fold compared to that of the wild-type strain. Thus, YqiG is important for the central glycolysis reaction and is able to influence hydrogen metabolism activity in E. coli.
Collapse
Affiliation(s)
- Muhammad Azman Zakaria
- 1Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Mohd Zulkhairi Mohd Yusoff
- 1Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- 2Laboratory of Biopolymer and Derivatives, Institute of Tropical Forestry and Forest Products, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Mohd Rafein Zakaria
- 1Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- 2Laboratory of Biopolymer and Derivatives, Institute of Tropical Forestry and Forest Products, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Mohd Ali Hassan
- 1Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Thomas K Wood
- 3Department of Chemical Engineering and Biochemistry and Molecular Biology, Pennsylvania State University, 161 Fenske Laboratory, University Park, PA 16802 USA
| | - Toshinari Maeda
- 4Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0196 Japan
| |
Collapse
|
33
|
Rational design and analysis of an Escherichia coli strain for high-efficiency tryptophan production. ACTA ACUST UNITED AC 2018; 45:357-367. [DOI: 10.1007/s10295-018-2020-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 02/04/2018] [Indexed: 01/24/2023]
Abstract
Abstract
l-tryptophan (l-trp) is a precursor of various bioactive components and has great pharmaceutical interest. However, due to the requirement of several precursors and complex regulation of the pathways involved, the development of an efficient l-trp production strain is challenging. In this study, Escherichia coli (E. coli) strain KW001 was designed to overexpress the l-trp operator sequences (trpEDCBA) and 3-deoxy-D-arabinoheptulosonate-7-phosphate synthase (aroGfbr). To further improve the production of l-trp, pyruvate kinase (pykF) and the phosphotransferase system HPr (ptsH) were deleted after inactivation of repression (trpR) and attenuation (attenuator) to produce strain KW006. To overcome the relatively slow growth and to increase the transport rate of glucose, strain KW018 was generated by combinatorial regulation of glucokinase (galP) and galactose permease (glk) expression. To reduce the production of acetic acid, strain KW023 was created by repressive regulation of phosphate acetyltransferase (pta) expression. In conclusion, strain KW023 efficiently produced 39.7 g/L of l-trp with a conversion rate of 16.7% and a productivity of 1.6 g/L/h in a 5 L fed-batch fermentation system.
Collapse
|
34
|
Liu Y, Xu Y, Ding D, Wen J, Zhu B, Zhang D. Genetic engineering of Escherichia coli to improve L-phenylalanine production. BMC Biotechnol 2018; 18:5. [PMID: 29382315 PMCID: PMC5791370 DOI: 10.1186/s12896-018-0418-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 01/18/2018] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND L-phenylalanine (L-Phe) is an essential amino acid for mammals and applications expand into human health and nutritional products. In this study, a system level engineering was conducted to enhance L-Phe biosynthesis in Escherichia coli. RESULTS We inactivated the PTS system and recruited glucose uptake via combinatorial modulation of galP and glk to increase PEP supply in the Xllp01 strain. In addition, the HTH domain of the transcription factor TyrR was engineered to decrease the repression on the transcriptional levels of L-Phe pathway enzymes. Finally, proteomics analysis demonstrated the third step of the SHIK pathway (catalyzed via AroD) as the rate-limiting step for L-Phe production. After optimization of the aroD promoter strength, the titer of L-Phe increased by 13.3%. Analysis of the transcriptional level of genes involved in the central metabolic pathways and L-Phe biosynthesis via RT-PCR showed that the recombinant L-Phe producer exhibited a great capability in the glucose utilization and precursor (PEP and E4P) generation. Via systems level engineering, the L-Phe titer of Xllp21 strain reached 72.9 g/L in a 5 L fermenter under the non-optimized fermentation conditions, which was 1.62-times that of the original strain Xllp01. CONCLUSION The metabolic engineering strategy reported here can be broadly employed for developing genetically defined organisms for the efficient production of other aromatic amino acids and derived compounds.
Collapse
Affiliation(s)
- Yongfei Liu
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China
| | - Yiran Xu
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.,Department of Biological Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China
| | - Dongqin Ding
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China
| | - Jianping Wen
- Department of Biological Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China
| | - Beiwei Zhu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, 116034, People's Republic of China
| | - Dawei Zhang
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, 116034, People's Republic of China.
| |
Collapse
|
35
|
Novel technologies combined with traditional metabolic engineering strategies facilitate the construction of shikimate-producing Escherichia coli. Microb Cell Fact 2017; 16:167. [PMID: 28962609 PMCID: PMC5622527 DOI: 10.1186/s12934-017-0773-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/14/2017] [Indexed: 11/10/2022] Open
Abstract
Shikimate is an important intermediate in the aromatic amino acid pathway, which can be used as a promising building block for the synthesis of biological compounds, such as neuraminidase inhibitor Oseltamivir (Tamiflu®). Compared with traditional methods, microbial production of shikimate has the advantages of environmental friendliness, low cost, feed stock renewability, and product selectivity and diversity, thus receiving more and more attentions. The development of metabolic engineering allows for high-efficiency production of shikimate of Escherichia coli by improving the intracellular level of precursors, blocking downstream pathway, releasing negative regulation factors, and overexpressing rate-limiting enzymes. In addition, novel technologies derived from systems and synthetic biology have opened a new avenue towards construction of shikimate-producing strains. This review summarized successful and applicable strategies derived from traditional metabolic engineering and novel technologies for increasing accumulation of shikimate in E. coli.
Collapse
|
36
|
Jaén KE, Sigala JC, Olivares-Hernández R, Niehaus K, Lara AR. Heterogeneous oxygen availability affects the titer and topology but not the fidelity of plasmid DNA produced by Escherichia coli. BMC Biotechnol 2017; 17:60. [PMID: 28676110 PMCID: PMC5496438 DOI: 10.1186/s12896-017-0378-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 06/22/2017] [Indexed: 12/13/2022] Open
Abstract
Background Dissolved oxygen tension (DOT) is hardly constant and homogenously distributed in a bioreactor, which can have a negative impact in the metabolism and product synthesis. However, the effects of DOT on plasmid DNA (pDNA) production and quality have not been thoroughly investigated. In the present study, the effects of aerobic (DOT ≥30% air sat.), microaerobic (constant DOT = 3% air sat.) and oscillatory DOT (from 0 to 100% air sat.) conditions on pDNA production, quality and host performance were characterized. Results Microaerobic conditions had little effect on pDNA production, supercoiled fraction and sequence fidelity. By contrast, oscillatory DOT caused a 22% decrease in pDNA production compared with aerobic cultures. Although in aerobic cultures the pDNA supercoiled fraction was 98%, it decreased to 80% under heterogeneous DOT conditions. The different oxygen availabilities had no effect on the fidelity of the produced pDNA. The estimated metabolic fluxes indicated substantial differences at the level of the pentose phosphate pathway and TCA cycle under different conditions. Cyclic changes in fermentative pathway fluxes, as well as fast shifts in the fluxes through cytochromes, were also estimated. Model-based genetic modifications that can potentially improve the process performance are suggested. Conclusions DOT heterogeneities strongly affected cell performance, pDNA production and topology. This should be considered when operating or scaling-up a bioreactor with deficient mixing. Constant microaerobic conditions affected the bacterial metabolism but not the amount or quality of pDNA. Therefore, pDNA production in microaerobic cultures may be an alternative for bioreactor operation at higher oxygen transfer rates. Electronic supplementary material The online version of this article (doi:10.1186/s12896-017-0378-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Karim E Jaén
- Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolita-Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe, 05348, Mexico City, Mexico
| | - Juan-Carlos Sigala
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe, 05348, Mexico City, Mexico
| | - Roberto Olivares-Hernández
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe, 05348, Mexico City, Mexico
| | - Karsten Niehaus
- Abteilung für Proteom- und Metabolomforschung, Fakultät für Biologie & CeBiTec, Universität Bielefeld, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Alvaro R Lara
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe, 05348, Mexico City, Mexico.
| |
Collapse
|
37
|
Reexamination of the Physiological Role of PykA in Escherichia coli Revealed that It Negatively Regulates the Intracellular ATP Levels under Anaerobic Conditions. Appl Environ Microbiol 2017; 83:AEM.00316-17. [PMID: 28363967 DOI: 10.1128/aem.00316-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 03/24/2017] [Indexed: 11/20/2022] Open
Abstract
Pyruvate kinase is one of the three rate-limiting glycolytic enzymes that catalyze the last step of glycolysis, conversion of phosphoenolpyruvate (PEP) into pyruvate, which is associated with ATP generation. Two isozymes of pyruvate kinase, PykF and PykA, are identified in Escherichia coli PykF is considered important, whereas PykA has a less-defined role. Prior studies inactivated the pykA gene to increase the level of its substrate, PEP, and thereby increased the yield of end products derived from PEP. We were surprised when we found a pykA::Tn5 mutant in a screen for increased yield of an end product derived from pyruvate (n-butanol), suggesting that the role of PykA needs to be reexamined. We show that the pykA mutant exhibited elevated intracellular ATP levels, biomass concentrations, glucose consumption, and n-butanol production. We also discovered that the pykA mutant expresses higher levels of a presumed pyruvate transporter, YhjX, permitting the mutant to recapture and metabolize excreted pyruvate. Furthermore, we demonstrated that the nucleotide diphosphate kinase activity of PykA leads to negative regulation of the intracellular ATP levels. Taking the data together, we propose that inactivation of pykA can be considered a general strategy to enhance the production of pyruvate-derived metabolites under anaerobic conditions.IMPORTANCE This study showed that knocking out pykA significantly increased the intracellular ATP level and thus significantly increased the levels of glucose consumption, biomass formation, and pyruvate-derived product formation under anaerobic conditions. pykA was considered to be encoding a dispensable pyruvate kinase; here we show that pykA negatively regulates the anaerobic glycolysis rate through regulating the energy distribution. Thus, knocking out pykA can be used as a general strategy to increase the level of pyruvate-derived fermentative products.
Collapse
|
38
|
Rodriguez A, Martínez JA, Millard P, Gosset G, Portais JC, Létisse F, Bolivar F. Plasmid-encoded biosynthetic genes alleviate metabolic disadvantages while increasing glucose conversion to shikimate in an engineeredEscherichia colistrain. Biotechnol Bioeng 2017; 114:1319-1330. [DOI: 10.1002/bit.26264] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 01/17/2017] [Accepted: 02/08/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Alberto Rodriguez
- Instituto de Biotecnología; Universidad Nacional Autónoma de México (UNAM); Cuernavaca Morelos Mexico
| | - Juan A. Martínez
- Instituto de Biotecnología; Universidad Nacional Autónoma de México (UNAM); Cuernavaca Morelos Mexico
| | - Pierre Millard
- LISBP, Université de Toulouse, CNRS, INRA; INSA; Toulouse France
| | - Guillermo Gosset
- Instituto de Biotecnología; Universidad Nacional Autónoma de México (UNAM); Cuernavaca Morelos Mexico
| | | | - Fabien Létisse
- LISBP, Université de Toulouse, CNRS, INRA; INSA; Toulouse France
| | - Francisco Bolivar
- Instituto de Biotecnología; Universidad Nacional Autónoma de México (UNAM); Cuernavaca Morelos Mexico
| |
Collapse
|
39
|
Long CP, Au J, Sandoval NR, Gebreselassie NA, Antoniewicz MR. Enzyme I facilitates reverse flux from pyruvate to phosphoenolpyruvate in Escherichia coli. Nat Commun 2017; 8:14316. [PMID: 28128209 PMCID: PMC5290146 DOI: 10.1038/ncomms14316] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 12/16/2016] [Indexed: 01/29/2023] Open
Abstract
The bacterial phosphoenolpyruvate-carbohydrate phosphotransferase system (PTS) consists of cascading phosphotransferases that couple the simultaneous import and phosphorylation of a variety of sugars to the glycolytic conversion of phosphoenolpyruvate (PEP) to pyruvate. As the primary route of glucose uptake in E. coli, the PTS plays a key role in regulating central carbon metabolism and carbon catabolite repression, and is a frequent target of metabolic engineering interventions. Here we show that Enzyme I, the terminal phosphotransferase responsible for the conversion of PEP to pyruvate, is responsible for a significant in vivo flux in the reverse direction (pyruvate to PEP) during both gluconeogenic and glycolytic growth. We use 13C alanine tracers to quantify this back-flux in single and double knockouts of genes relating to PEP synthetase and PTS components. Our findings are relevant to metabolic engineering design and add to our understanding of gene-reaction connectivity in E. coli.
Collapse
Affiliation(s)
- Christopher P. Long
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
| | - Jennifer Au
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
| | - Nicholas R. Sandoval
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
| | - Nikodimos A. Gebreselassie
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
| | - Maciek R. Antoniewicz
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, Newark Delaware 19716, USA
| |
Collapse
|
40
|
Liu K, Hu H, Wang W, Zhang X. Genetic engineering of Pseudomonas chlororaphis GP72 for the enhanced production of 2-Hydroxyphenazine. Microb Cell Fact 2016; 15:131. [PMID: 27470070 PMCID: PMC4965901 DOI: 10.1186/s12934-016-0529-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 07/21/2016] [Indexed: 12/01/2022] Open
Abstract
Background The biocontrol strain Pseudomonas chlororaphis GP72 isolated from the green pepper rhizosphere synthesizes three antifungal phenazine compounds, 2-Hydroxyphenazine (2-OH-PHZ), 2-hydroxy-phenazine-1-carboxylic acid (2-OH-PCA) and phenazine-1-carboxylic acid (PCA). PCA has been a commercialized antifungal pesticide registered as “Shenqinmycin” in China since 2011. It is found that 2-OH-PHZ shows stronger fungistatic and bacteriostatic activity to some pathogens than PCA. 2-OH-PHZ could be developed as a potential antifungal pesticide. But the yield of 2-OH-PHZ generally is quite low, such as P. chlororaphis GP72, the production of 2-OH-PHZ by the wide-type strain is only 4.5 mg/L, it is necessary to enhance the yield of 2-OH-PHZ for its application in agriculture. Results Different strategies were used to improve the yield of 2-OH-PHZ: knocking out the negative regulatory genes, enhancing the shikimate pathway, deleting the competing pathways of 2-OH-PHZ synthesis based on chorismate, and improving the activity of PhzO which catalyzes the conversion of PCA to 2-OH-PHZ, although the last two strategies did not give us satisfactory results. In this study, four negative regulatory genes (pykF, rpeA, rsmE and lon) were firstly knocked out of the strain GP72 genome stepwise. The yield of 2-OH-PHZ improved more than 60 folds and increased from 4.5 to about 300 mg/L. Then six key genes (ppsA, tktA, phzC, aroB, aroD and aroE) selected from the gluconeogenesis, pentose phosphate and shikimate pathways which used to enhance the shikimate pathway were overexpressed to improve the production of 2-OH-PHZ. At last a genetically engineered strain that increased the 2-OH-PHZ production by 99-fold to 450.4 mg/L was obtained. Conclusions The 2-OH-PHZ production of P. chlororaphis GP72 was greatly improved through disruption of four negative regulatory genes and overexpression of six key genes, and it is shown that P. chlororaphis GP72 could be modified as a potential cell factory to produce 2-OH-PHZ and other phenazine biopesticides by genetic and metabolic engineering. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0529-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kaiquan Liu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hongbo Hu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Wei Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xuehong Zhang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| |
Collapse
|
41
|
Gu P, Su T, Wang Q, Liang Q, Qi Q. Tunable switch mediated shikimate biosynthesis in an engineered non-auxotrophic Escherichia coli. Sci Rep 2016; 6:29745. [PMID: 27406890 PMCID: PMC4942831 DOI: 10.1038/srep29745] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 06/23/2016] [Indexed: 12/28/2022] Open
Abstract
Shikimate is a key intermediate in the synthesis of neuraminidase inhibitors. Compared with traditional methods, microbial production of shikimate has the advantages of environmental friendliness, low cost, feed stock renewability, and product selectivity and diversity. Despite these advantages, shikimate kinase I and II respectively encoded by aroK and aroL are inactivated in most shikimate microbial producers, thus requiring the addition of aromatic compounds during the fermentation process. To overcome this problem, we constructed a non-auxotrophic, shikimate-synthesising strain of Escherichia coli. By inactivation of repressor proteins, blocking of competitive pathways and overexpression of key enzymes, we increased the shikimate production of wild-type E. coli BW25113 to 1.73 g/L. We then designed a tunable switch that can conditionally decrease gene expression and substituted it for the original aroK promoters. Expression of aroK in the resulting P-9 strain was maintained at a high level during the growth phase and then reduced at a suitable time by addition of an optimal concentration of inducer. In 5-L fed-batch fermentation, strain P-9 produced 13.15 g/L shikimate without the addition of any aromatic compounds. The tunable switch developed in this study is an efficient tool for regulating indispensable genes involved in critical metabolic pathways.
Collapse
Affiliation(s)
- Pengfei Gu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Tianyuan Su
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Qian Wang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Quanfeng Liang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| |
Collapse
|
42
|
Metabolic engineering of Escherichia coli for the production of cinnamaldehyde. Microb Cell Fact 2016; 15:16. [PMID: 26785776 PMCID: PMC4719340 DOI: 10.1186/s12934-016-0415-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/07/2016] [Indexed: 11/16/2022] Open
Abstract
Background Plant parasitic nematodes are harmful to agricultural crops and plants, and may cause severe yield losses. Cinnamaldehyde, a volatile, yellow liquid commonly used as a flavoring or food additive, is increasingly becoming a popular natural nematicide because of its high nematicidal activity and, there is a high demand for the development of a biological platform to produce cinnamaldehyde. Results We engineered Escherichia coli as an eco-friendly biological platform for the production of cinnamaldehyde. In E. coli, cinnamaldehyde can be synthesized from intracellular l-phenylalanine, which requires the activities of three enzymes: phenylalanine-ammonia lyase (PAL), 4-coumarate:CoA ligase (4CL), and cinnamoyl-CoA reductase (CCR). For the efficient production of cinnamaldehyde in E. coli, we first examined the activities of enzymes from different sources and a gene expression system for the selected enzymes was constructed. Next, the metabolic pathway for l-phenylalanine biosynthesis was engineered to increase the intracellular pool of l-phenylalanine, which is a main precursor of cinnamaldehyde. Finally, we tried to produce cinnamaldehyde with the engineered E. coli. According to this result, cinnamaldehyde production as high as 75 mg/L could be achieved, which was about 35-fold higher compared with that in the parental E. coli W3110 harboring a plasmid for cinnamaldehyde biosynthesis. We also confirmed that cinnamaldehyde produced by our engineered E. coli had a nematicidal activity similar to the activity of commercial cinnamaldehyde by nematicidal assays against Bursaphelenchus xylophilus. Conclusion As a potential natural pesticide, cinnamaldehyde was successfully produced in E. coli by construction of the biosynthesis pathway and, its production titer was also significantly increased by engineering the metabolic pathway of l-phenylalanine. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0415-9) contains supplementary material, which is available to authorized users.
Collapse
|
43
|
Liu X, Lin J, Hu H, Zhou B, Zhu B. Site-specific integration and constitutive expression of key genes into Escherichia coli chromosome increases shikimic acid yields. Enzyme Microb Technol 2016; 82:96-104. [DOI: 10.1016/j.enzmictec.2015.08.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 08/30/2015] [Accepted: 08/31/2015] [Indexed: 01/05/2023]
|
44
|
Li KT, Peng WF, Xia W, Huang L, Cheng X. Metabolic differences of industrial acarbose-producing Actinoplanes sp. A56 under various osmolality levels. World J Microbiol Biotechnol 2015; 32:3. [PMID: 26712618 DOI: 10.1007/s11274-015-1976-1] [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: 08/17/2015] [Accepted: 10/14/2015] [Indexed: 11/26/2022]
Abstract
Many investigations have revealed that a certain concentration of osmolality was indispensable for efficient acarbose production, but little information was available on the response mechanism of acarbose-producing strains to osmotic stress. By using the gas chromatography-mass spectrometry (GC-MS) analysis coupled with the enzyme activity determination of central carbon metabolism, the present work investigated the metabolic characteristics of industrial acarbose-producing Actinoplanes sp. A56 under various osmolality levels. Relatively high osmolality (450-500 mOsm/kg) appeared to favor efficient acarbose production by Actinoplanes sp. A56, although it inhibited cell growth. Further GC-MS analysis showed that fatty acids were the uppermost differential intracellular metabolites under various osmolality levels, and the relatively high osmolality resulted in increases in levels of fatty acids.
Collapse
Affiliation(s)
- Kun-tai Li
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Wei-fu Peng
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Wei Xia
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Lin Huang
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Xin Cheng
- Nanchang Key Laboratory of Applied Fermentation Technology, Jiangxi Agricultural University, Nanchang, 330045, China.
| |
Collapse
|
45
|
Bobrovskyy M, Vanderpool CK. Diverse mechanisms of post-transcriptional repression by the small RNA regulator of glucose-phosphate stress. Mol Microbiol 2015; 99:254-73. [PMID: 26411266 DOI: 10.1111/mmi.13230] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2015] [Indexed: 01/17/2023]
Abstract
The Escherichia coli small RNA SgrS controls a metabolic stress response that occurs upon accumulation of certain glycolytic intermediates. SgrS base pairs with and represses translation of ptsG and manXYZ mRNAs, which encode sugar transporters, and activates translation of yigL mRNA, encoding a sugar phosphatase. This study defines four new genes as direct targets of E. coli SgrS. These new targets, asd, adiY, folE and purR, encode transcription factors or enzymes of diverse metabolic pathways, including aspartate semialdehyde dehydrogenase, arginine decarboxylase gene activator, GTP cyclohydrolase I and a repressor of purine biosynthesis, respectively. SgrS represses translation of each of the four target mRNAs via distinct mechanisms. SgrS binding sites overlapping the Shine-Dalgarno sequences of adiY and folE mRNAs suggest that SgrS pairing with these targets directly occludes ribosome binding and prevents translation initiation. SgrS binding within the purR coding sequence recruits the RNA chaperone Hfq to directly repress purR translation. Two separate SgrS binding sites were found on asd mRNA, and both are required for full translational repression. Ectopic overexpression of asd, adiY and folE is specifically detrimental to cells experiencing glucose-phosphate stress, suggesting that SgrS-dependent repression of the metabolic functions encoded by these targets promotes recovery from glucose-phosphate stress.
Collapse
Affiliation(s)
- Maksym Bobrovskyy
- Department of Microbiology, University of Illinois at Urbana-Champaign, 601 S. Goodwin Ave., Urbana, IL, 61801, USA
| | - Carin K Vanderpool
- Department of Microbiology, University of Illinois at Urbana-Champaign, 601 S. Goodwin Ave., Urbana, IL, 61801, USA
| |
Collapse
|
46
|
Increasing succinic acid production using the PTS-independent glucose transport system in a Corynebacterium glutamicum PTS-defective mutant. ACTA ACUST UNITED AC 2015; 42:1073-82. [DOI: 10.1007/s10295-015-1630-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/28/2015] [Indexed: 12/29/2022]
Abstract
Abstract
Succinic acid synthesized from glucose shows potential as a bio-based platform chemical. However, the need for a high glucose concentration, and the accompanying low yields, limit its industrial applications. Despite efficient glucose uptake by the phosphotransferase system (PTS), 1 mol of phosphoenolpyruvate is required for each mole of internalized glucose. Therefore, a PTS-defective Corynebacterium glutamicum mutant was constructed to increase phosphoenolpyruvate availability for succinic acid synthesis, resulting in a lower glucose utilization rate and slower growth. The transcriptional regulator iolR was also deleted to enable the PTS-defective mutant to utilize glucose via iolT-mediated glucose transport. Deletion of iolR and overexpression of iolT1 and ppgk (polyphosphate glucokinase) in the PTS-deficient C. glutamicum strain completely restored glucose utilization, increasing production by 11.6 % and yield by 32.4 % compared with the control. This study revealed for the first time that iolR represses the expression of the two glucokinase genes (glk and ppgk).
Collapse
|
47
|
Martins L, Pedro A, Oppolzer D, Sousa F, Queiroz J, Passarinha L. Enhanced biosynthesis of plasmid DNA from Escherichia coli VH33 using Box–Behnken design associated to aromatic amino acids pathway. Biochem Eng J 2015. [DOI: 10.1016/j.bej.2015.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
48
|
Zhang B, Jiang CY, Liu YM, Liu C, Liu SJ. Engineering of a hybrid route to enhance shikimic acid production in Corynebacterium glutamicum. Biotechnol Lett 2015; 37:1861-8. [DOI: 10.1007/s10529-015-1852-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/01/2015] [Indexed: 11/28/2022]
|
49
|
Becker J, Wittmann C. Advanced Biotechnology: Metabolically Engineered Cells for the Bio-Based Production of Chemicals and Fuels, Materials, and Health-Care Products. Angew Chem Int Ed Engl 2015; 54:3328-50. [DOI: 10.1002/anie.201409033] [Citation(s) in RCA: 223] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Indexed: 12/16/2022]
|
50
|
Biotechnologie von Morgen: metabolisch optimierte Zellen für die bio-basierte Produktion von Chemikalien und Treibstoffen, Materialien und Gesundheitsprodukten. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201409033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|