1
|
Yuan P, Xu M, Mao C, Zheng H, Sun D. Dynamically Regulating Glucose Uptake to Reduce Overflow Metabolism with a Quorum-Sensing Circuit for the Efficient Synthesis of d-Pantothenic Acid in Bacillus subtilis. ACS Synth Biol 2023; 12:2983-2995. [PMID: 37664894 DOI: 10.1021/acssynbio.3c00315] [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: 09/05/2023]
Abstract
In response to a high concentration of glucose, Bacillus subtilis, a microbial chassis for producing many industrial metabolites, rapidly takes up glucose using the phosphotransferase system (PTS), leading to overflow metabolism, a common phenomenon observed in many bacteria. Although overflow metabolism affects cell growth and reduces the production of many metabolites, effective strategies that reduce overflow metabolism while maintaining normal cell growth remain to be developed. Here, we used a quorum sensing (QS)-mediated circuit to tune the glucose uptake rate and thereby relieve overflow metabolism in an engineered B. subtilis for producing d-pantothenic acid (DPA). A low-efficiency non-PTS system was used for glucose uptake at the early growth stages to avoid a rapid glycolytic flux, while an efficient PTS system, which was activated by a QS circuit, was automatically activated at the late growth stages after surpassing a threshold cell density. This strategy was successfully applied as a modular metabolic engineering process for the high production of DPA. By enhancing the translation levels of key enzymes (3-methyl-2-oxobutanoate hydroxymethytransferase, pantothenate synthetase, aspartate 1-decarboxylase proenzyme, 2-dehydropantoate 2-reductase, dihydroxy-acid dehydratase, and acetolactate synthase) with engineered 5'-untranslated regions (UTRs) of mRNAs, the metabolic flux was promoted in the direction of DPA production, elevating the yield of DPA to 5.11 g/L in shake flasks. Finally, the engineered B. subtilis produced 21.52 g/L of DPA in fed-batch fermentations. Our work not only revealed a new strategy for reducing overflow metabolism by adjusting the glucose uptake rate in combination with promoting the translation of key metabolic enzymes through engineering the 5'-UTR of mRNAs but also showed its power in promoting the bioproduction of DPA in B. subtilis, exhibiting promising application prospects.
Collapse
Affiliation(s)
- Panhong Yuan
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
| | - Mengtao Xu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
| | - Chengyao Mao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
| | - Han Zheng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
| | - Dongchang Sun
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
| |
Collapse
|
2
|
Du Y, Cheng F, Wang M, Xu C, Yu H. Indirect Pathway Metabolic Engineering Strategies for Enhanced Biosynthesis of Hyaluronic Acid in Engineered Corynebacterium glutamicum. Front Bioeng Biotechnol 2022; 9:768490. [PMID: 34988066 PMCID: PMC8721151 DOI: 10.3389/fbioe.2021.768490] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
Hyaluronic acid (HA) is composed of alternating d-glucuronic acid and N-acetyl-d-glucosamine, with excellent biocompatibility and water retention capacity. To achieve heterologous biosynthesis of HA, Corynebacterium glutamicum, a safe GRAS (generally recognized as safe) host, was utilized and metabolically engineered previously. In this work, to achieve further enhancement of HA yield, four strategies were proposed and performed separately first, i.e., (1) improvement of glucose uptake via iolR gene knockout, releasing the inhibition of transporter IolT1/IolT2 and glucokinases; (2) intensification of cardiolipin synthesis through overexpression of genes pgsA1/pgsA2/cls involved in cardiolipin synthesis; (3) duly expressed Vitreoscilla hemoglobin in genome, enhancing HA titer coupled with more ATP and improved NAD+/NADH (>7.5) ratio; and (4) identification of the importance of glutamine for HA synthesis through transcriptome analyses and then enhancement of the HA titer via its supplement. After that, we combined different strategies together to further increase the HA titer. As a result, one of the optimal recombinant strains, Cg-dR-CLS, yielded 32 g/L of HA at 60 h in a fed-batch culture, which was increased by 30% compared with that of the starting strain. This high value of HA titer will enable the industrial production of HA via the engineered C. glutamicum.
Collapse
Affiliation(s)
- Yan Du
- Key Laboratory for Industrial Biocatalysis of the Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Fangyu Cheng
- Key Laboratory for Industrial Biocatalysis of the Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Miaomiao Wang
- Key Laboratory for Industrial Biocatalysis of the Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Chunmeng Xu
- Key Laboratory for Industrial Biocatalysis of the Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Huimin Yu
- Key Laboratory for Industrial Biocatalysis of the Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China.,Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China
| |
Collapse
|
3
|
Taymaz-Nikerel H, Lara AR. Vitreoscilla Haemoglobin: A Tool to Reduce Overflow Metabolism. Microorganisms 2021; 10:microorganisms10010043. [PMID: 35056491 PMCID: PMC8779101 DOI: 10.3390/microorganisms10010043] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/18/2021] [Accepted: 12/20/2021] [Indexed: 11/26/2022] Open
Abstract
Overflow metabolism is a phenomenon extended in nature, ranging from microbial to cancer cells. Accumulation of overflow metabolites pose a challenge for large-scale bioprocesses. Yet, the causes of overflow metabolism are not fully clarified. In this work, the underlying mechanisms, reasons and consequences of overflow metabolism in different organisms have been summarized. The reported effect of aerobic expression of Vitreoscilla haemoglobin (VHb) in different organisms are revised. The use of VHb to reduce overflow metabolism is proposed and studied through flux balance analysis in E. coli at a fixed maximum substrate and oxygen uptake rates. Simulations showed that the presence of VHb increases the growth rate, while decreasing acetate production, in line with the experimental measurements. Therefore, aerobic VHb expression is considered a potential tool to reduce overflow metabolism in cells.
Collapse
Affiliation(s)
- Hilal Taymaz-Nikerel
- Department of Genetics and Bioengineering, Istanbul Bilgi University, İstanbul 34060, Turkey;
| | - Alvaro R. Lara
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Mexico City 05348, Mexico
- Correspondence:
| |
Collapse
|
4
|
Ziegler M, Zieringer J, Döring CL, Paul L, Schaal C, Takors R. Engineering of a robust Escherichia coli chassis and exploitation for large-scale production processes. Metab Eng 2021; 67:75-87. [PMID: 34098100 DOI: 10.1016/j.ymben.2021.05.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 05/30/2021] [Accepted: 05/31/2021] [Indexed: 11/28/2022]
Abstract
In large-scale bioprocesses microbes are exposed to heterogeneous substrate availability reducing the overall process performance. A series of deletion strains was constructed from E. coli MG1655 aiming for a robust phenotype in heterogeneous fermentations with transient starvation. Deletion targets were hand-picked based on a list of genes derived from previous large-scale simulation runs. Each gene deletion was conducted on the premise of strict neutrality towards growth parameters in glucose minimal medium. The final strain of the series, named E. coli RM214, was cultivated continuously in an STR-PFR (stirred tank reactor - plug flow reactor) scale-down reactor. The scale-down reactor system simulated repeated passages through a glucose starvation zone. When exposed to nutrient gradients, E. coli RM214 had a significantly lower maintenance coefficient than E. coli MG1655 (Δms = 0.038 gGlucose/gCDW/h, p < 0.05). In an exemplary protein production scenario E. coli RM214 remained significantly more productive than E. coli MG1655 reaching 44% higher eGFP yield after 28 h of STR-PFR cultivation. This study developed E. coli RM214 as a robust chassis strain and demonstrated the feasibility of engineering microbial hosts for large-scale applications.
Collapse
Affiliation(s)
- Martin Ziegler
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Julia Zieringer
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Clarissa-Laura Döring
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Liv Paul
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Christoph Schaal
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| | - Ralf Takors
- University of Stuttgart - Institute of Biochemical Engineering, Allmandring 31, 70569, Stuttgart, Germany.
| |
Collapse
|
5
|
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]
|
6
|
Lara AR, Galindo J, Jaén KE, Juárez M, Sigala JC. Physiological Response of Escherichia coli W3110 and BL21 to the Aerobic Expression of Vitreoscilla Hemoglobin. J Microbiol Biotechnol 2020; 30:1592-1596. [PMID: 32699196 PMCID: PMC9728183 DOI: 10.4014/jmb.2004.04030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/03/2020] [Accepted: 07/13/2020] [Indexed: 12/15/2022]
Abstract
The aerobic growth and metabolic performance of Escherichia coli strains BL21 and W3110 were studied when the Vitreoscilla hemoglobin (VHb) was constitutively expressed in the chromosome. When VHb was expressed, acetate production decreased in both strains and was nearly eliminated in BL21. Transcriptional levels of the glyoxylate shunt genes decreased in both strains when VHb was expressed. However, higher transcription of the α-ketoglutarate dehydrogenase genes were observed for W3110, while for BL21 transcription levels decreased. VHb expression reduced the transcription of the cytochrome bo3 genes only in BL21. These results are useful for better selecting a production host.
Collapse
Affiliation(s)
- Alvaro R. Lara
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe, CP 05348, Mexico City, Mexico,Corresponding author Phone: +52-55-58146500 Fax: +52-55-58146500 E-mail:
| | - Janet Galindo
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe, CP 05348, Mexico City, Mexico
| | - Karim E. Jaén
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe, CP 05348, Mexico City, Mexico
| | - Mariana Juárez
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe, CP 05348, Mexico City, Mexico
| | - Juan-Carlos Sigala
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe, CP 05348, Mexico City, Mexico
| |
Collapse
|
7
|
Zhao X, Zhou J, Du G, Chen J. Recent Advances in the Microbial Synthesis of Hemoglobin. Trends Biotechnol 2020; 39:286-297. [PMID: 32912649 DOI: 10.1016/j.tibtech.2020.08.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/27/2020] [Accepted: 08/11/2020] [Indexed: 01/08/2023]
Abstract
Hemoglobin is a cofactor-containing protein with heme that plays important roles in transporting and storing oxygen. Hemoglobins have been widely applied as acellular oxygen carriers, bioavailable iron-supplying agents, and food-grade coloring and flavoring agents. To meet increasing demands and overcome the drawbacks of chemical extraction, the biosynthesis of hemoglobin has become an attractive alternative. Several hemoglobins have recently been synthesized by various microorganisms through metabolic engineering and synthetic biology. In this review, we summarize the novel strategies that have been used to biosynthesize hemoglobin. These strategies can also serve as references for producing other heme-binding proteins.
Collapse
Affiliation(s)
- Xinrui Zhao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Science Center for Future Foods, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Science Center for Future Foods, Jiangnan University, Wuxi, Jiangsu 214122, China; National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
| | - Guocheng Du
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Science Center for Future Foods, Jiangnan University, Wuxi, Jiangsu 214122, China; Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Science Center for Future Foods, Jiangnan University, Wuxi, Jiangsu 214122, China; National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| |
Collapse
|
8
|
Oliveira GHDD, Schneider ALDS, Vo MT, Ramsay JA, Ramsay BA. Heterologous Expression of Vitreoscilla Hemoglobin in Pseudomonas putida KT2440 for the Production of mcl-PHA in Carbon-Limited Fermentations. Ind Biotechnol (New Rochelle N Y) 2020. [DOI: 10.1089/ind.2019.0023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
| | | | - Minh Tri Vo
- Chemical Engineering, Queen's University, Kingston, ON, Canada
| | | | | |
Collapse
|
9
|
Lara AR, Jaén KE, Folarin O, Keshavarz-Moore E, Büchs J. Effect of the oxygen transfer rate on oxygen-limited production of plasmid DNA by Escherichia coli. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.107303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
10
|
Han Q, Eiteman MA. Acetate formation during recombinant protein production in Escherichia coli K-12 with an elevated NAD(H) pool. Eng Life Sci 2019; 19:770-780. [PMID: 32624970 DOI: 10.1002/elsc.201900045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 08/15/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022] Open
Abstract
Acetate formation is a disadvantage in the use of Escherichia coli for recombinant protein production, and many studies have focused on optimizing fermentation processes or altering metabolism to eliminate acetate accumulation. In this study, E. coli MEC697 (MG1655 nadR nudC mazG) maintained a larger pool of NAD(H) compared to the wild-type control, and also accumulated lower concentrations of acetate when grown in batch culture on glucose. In steady-state cultures, the elevated total NAD(H) found in MEC697 delayed the threshold dilution rate for acetate formation to a growth rate of 0.27 h-1. Batch and fed-batch processes using MEC697 were examined for the production of β-galactosidase as a model recombinant protein. Fed-batch culture of MEC697/pTrc99A-lacZ compared to MG1655/pTrc99A-lacZ at a growth rate of 0.22 h-1 showed only a modest increase of protein formation. However, 1 L batch growth of MEC697/pTrc99A-lacZ resulted in 50% lower acetate formation compared to MG1655/pTrc99A-lacZ and a two-fold increase in recombinant protein production.
Collapse
Affiliation(s)
- Qi Han
- School of Chemical Materials and Biomedical Engineering University of Georgia Athens GA USA
| | - Mark A Eiteman
- School of Chemical Materials and Biomedical Engineering University of Georgia Athens GA USA
| |
Collapse
|
11
|
Lozano Terol G, Gallego-Jara J, Sola Martínez RA, Cánovas Díaz M, de Diego Puente T. Engineering protein production by rationally choosing a carbon and nitrogen source using E. coli BL21 acetate metabolism knockout strains. Microb Cell Fact 2019; 18:151. [PMID: 31484572 PMCID: PMC6724240 DOI: 10.1186/s12934-019-1202-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/29/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Escherichia coli (E. coli) is a bacteria that is widely employed in many industries for the production of high interest bio-products such as recombinant proteins. Nevertheless, the use of E. coli for recombinant protein production may entail some disadvantages such as acetate overflow. Acetate is accumulated under some culture conditions, involves a decrease in biomass and recombinant protein production, and its metabolism is related to protein lysine acetylation. Thereby, the carbon and nitrogen sources employed are relevant factors in cell host metabolism, and the study of the central metabolism of E. coli and its regulation is essential for optimizing the production of biomass and recombinant proteins. In this study, our aim was to find the most favourable conditions for carrying out recombinant protein production in E. coli BL21 using two different approaches, namely, manipulation of the culture media composition and the deletion of genes involved in acetate metabolism and Nε-lysine acetylation. RESULTS We evaluated protein overexpression in E. coli BL21 wt and five mutant strains involved in acetate metabolism (Δacs, ΔackA and Δpta) and lysine acetylation (ΔpatZ and ΔcobB) grown in minimal medium M9 (inorganic ammonium nitrogen source) and in complex TB7 medium (peptide-based nitrogen source) supplemented with glucose (PTS carbon source) or glycerol (non-PTS carbon source). We observed a dependence of recombinant protein production on acetate metabolism and the carbon and nitrogen source employed. The use of complex medium supplemented with glycerol as a carbon source entails an increase in protein production and an efficient use of resources, since is a sub-product of biodiesel synthesis. Furthermore, the deletion of the ackA gene results in a fivefold increase in protein production with respect to the wt strain and a reduction in acetate accumulation. CONCLUSION The results showed that the use of diverse carbon and nitrogen sources and acetate metabolism knockout strains can redirect E. coli carbon fluxes to different pathways and affect the final yield of the recombinant protein bioprocess. Thereby, we obtained a fivefold increase in protein production and an efficient use of the resources employing the most suitable strain and culture conditions.
Collapse
Affiliation(s)
- Gema Lozano Terol
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain
| | - Julia Gallego-Jara
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain.
| | - Rosa Alba Sola Martínez
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain
| | - Manuel Cánovas Díaz
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain
| | - Teresa de Diego Puente
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain.
| |
Collapse
|
12
|
Perez-Zabaleta M, Guevara-Martínez M, Gustavsson M, Quillaguamán J, Larsson G, van Maris AJA. Comparison of engineered Escherichia coli AF1000 and BL21 strains for (R)-3-hydroxybutyrate production in fed-batch cultivation. Appl Microbiol Biotechnol 2019; 103:5627-5639. [PMID: 31104101 PMCID: PMC6597613 DOI: 10.1007/s00253-019-09876-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 04/18/2019] [Accepted: 04/24/2019] [Indexed: 02/06/2023]
Abstract
Accumulation of acetate is a limiting factor in recombinant production of (R)-3-hydroxybutyrate (3HB) by Escherichia coli in high-cell-density processes. To alleviate this limitation, this study investigated two approaches: (i) deletion of phosphotransacetylase (pta), pyruvate oxidase (poxB), and/or the isocitrate lyase regulator (iclR), known to decrease acetate formation, on bioreactor cultivations designed to achieve high 3HB concentrations. (ii) Screening of different E. coli strain backgrounds (B, BL21, W, BW25113, MG1655, W3110, and AF1000) for their potential as low acetate-forming, 3HB-producing platforms. Deletion of pta and pta-poxB in the AF1000 strain background was to some extent successful in decreasing acetate formation, but also dramatically increased excretion of pyruvate and did not result in increased 3HB production in high-cell-density fed-batch cultivations. Screening of the different E. coli strains confirmed BL21 as a low acetate-forming background. Despite low 3HB titers in low-cell-density screening, 3HB-producing BL21 produced five times less acetic acid per mole of 3HB, which translated into a 2.3-fold increase in the final 3HB titer and a 3-fold higher volumetric 3HB productivity over 3HB-producing AF1000 strains in nitrogen-limited fed-batch cultivations. Consequently, the BL21 strain achieved the hitherto highest described volumetric productivity of 3HB (1.52 g L−1 h−1) and the highest 3HB concentration (16.3 g L−1) achieved by recombinant E. coli. Screening solely for 3HB titers in low-cell-density batch cultivations would not have identified the potential of this strain, reaffirming the importance of screening with the final production conditions in mind.
Collapse
Affiliation(s)
- Mariel Perez-Zabaleta
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
- Center of Biotechnology, Faculty of Science and Technology, Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Mónica Guevara-Martínez
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
- Center of Biotechnology, Faculty of Science and Technology, Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Martin Gustavsson
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
| | - Jorge Quillaguamán
- Center of Biotechnology, Faculty of Science and Technology, Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Gen Larsson
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
| | - Antonius J. A. van Maris
- School of Engineering Sciences in Chemistry, Biotechnology, and Health (CBH), Department of Industrial Biotechnology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
| |
Collapse
|
13
|
Jaén KE, Velazquez D, Delvigne F, Sigala JC, Lara AR. Engineering E. coli for improved microaerobic pDNA production. Bioprocess Biosyst Eng 2019; 42:1457-1466. [PMID: 31079222 DOI: 10.1007/s00449-019-02142-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 03/20/2019] [Accepted: 05/02/2019] [Indexed: 02/08/2023]
Abstract
Escherichia coli strains W3110 and BL21 were engineered for the production of plasmid DNA (pDNA) under aerobic and transitions to microaerobic conditions. The gene coding for recombinase A (recA) was deleted in both strains. In addition, the Vitreoscilla hemoglobin (VHb) gene (vgb) was chromosomally inserted and constitutively expressed in each E. coli recA mutant and wild type. The recA inactivation increased the supercoiled pDNA fraction (SCF) in both strains, while VHb expression improved the pDNA production in W3110, but not in BL21. Therefore, a codon-optimized version of vgb was inserted in strain BL21recA-, which, together with W3110recA-vgb+, was tested in cultures with shifts from aerobic to oxygen-limited regimes. VHb expression lowered the accumulation of fermentative by-products in both strains. VHb-expressing cells displayed higher oxidative activity as indicated by the Redox Sensor Green fluorescence, which was more intense in BL21 than in W3110. Furthermore, VHb expression did not change pDNA production in W3110, but decreased it in BL21. These results are useful for understanding the physiological effects of VHb expression in two industrially relevant E. coli strains, and for the selection of a host for pDNA production.
Collapse
Affiliation(s)
- Karim E Jaén
- Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe, 05348, Mexico City, Mexico
| | - Daniela Velazquez
- Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe, 05348, Mexico City, Mexico
| | - Frank Delvigne
- Gembloux Agro-Bio Tech, TERRA Research and Teaching Centre, Microbial Processes and Interactions (MiPI), University of Liege, Gembloux, Belgium
| | - Juan-Carlos Sigala
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe, 05348, Mexico City, Mexico
| | - Alvaro R Lara
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe, 05348, Mexico City, Mexico.
| |
Collapse
|
14
|
Design of a synthetic miniR1 plasmid and its production by engineered Escherichia coli. Bioprocess Biosyst Eng 2019; 42:1391-1397. [PMID: 31006041 DOI: 10.1007/s00449-019-02129-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/08/2019] [Indexed: 02/06/2023]
Abstract
A synthetic plasmid consisting of the minimal elements for replication control of the R1 replicon and kanamycin resistance marker, which was named pminiR1, was developed. pminiR1 production was tested at 30 °C under aerobic and microaerobic conditions in Escherichia coli W3110 recA- (W1). The plasmid DNA yields from biomass (YpDNA/X) were only 0.06 ± 0.02 and 0.22 ± 0.11 mg/g under aerobic and microaerobic conditions, respectively. As an option to increase YpDNA/X values, pminiR1 was introduced in an engineered E. coli strain expressing the Vitreoscilla hemoglobin inserted in chromosome (W12). The YpDNA/X values using strain W12 increased to 0.85 ± 0.05 and 1.53 ± 0.14 mg/g under aerobic and microaerobic conditions, respectively. pminiR1 production in both strains was compared with that of pUC57Kan at 37 °C under aerobic and microaerobic conditions. The YpDNA/X values for pminiR1 using strain W12 were 6.25 ± 0.16 and 9.27 ± 0.95 mg/g under aerobic and microaerobic conditions, respectively. Such yields were similar to those obtained for plasmid pUC57Kan using strain W12 (6.9 ± 0.64 and 10.85 ± 1.06 mg/g for aerobic and microaerobic cultures, respectively). Therefore, the synthetic minimal plasmid based on the R1 replicon is a valuable alternative to pUC plasmids for biotechnological applications.
Collapse
|
15
|
Liu X. Hydrolysing the soluble protein secreted by Escherichia coli in trans-4-hydroxy-L-proline fermentation increased dissolve oxygen to promote high-level trans-4-hydroxy-L-proline production. Bioengineered 2019; 10:52-58. [PMID: 30955438 PMCID: PMC6527073 DOI: 10.1080/21655979.2019.1600966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Trans-4-hydroxy-L-proline (Hyp) production by Escherichia coli (E. coli) in fermentation is a high-oxygen-demand process. E. coli secretes large amounts of soluble protein, especially in the anaphase of fermentation, which is an important factor leading to inadequate oxygen supply. And acetic acid that is the major by-product of Hyp production accumulates under low dissolved oxygen (DO). To increase DO and achieve high-level Hyp production, soluble protein was hydrolysed by adding protease in Hyp fermentation. The optimal protease, concentration, and addition time were trypsin, 0.2 g/L, and 18 h, respectively. With the addition of trypsin, the soluble protein in Hyp fermentation decreased by 43.5%. The DO could be maintained at 20–30% throughout fermentation. Hyp production and glucose conversion rate were 45.3 g/L and 18.1%, which were increases of 24.1% and 8.4%, respectively. The accumulation of acetic acid was decreased by 52.1%. The metabolic flux of Hyp was increased by 44.2% and the flux of acetate was decreased by 51.0%.
Collapse
Affiliation(s)
- Xiaocui Liu
- a School of Life Sciences of Shanxi Datong University , Datong Shanxi , China
| |
Collapse
|
16
|
Veeravalli K, Schindler T, Dong E, Yamada M, Hamilton R, Laird MW. Strain engineering to reduce acetate accumulation during microaerobic growth conditions inEscherichia coli. Biotechnol Prog 2017; 34:303-314. [DOI: 10.1002/btpr.2592] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/16/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Karthik Veeravalli
- Late Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Tony Schindler
- Late Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Emily Dong
- Early Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Masaki Yamada
- Late Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Ryan Hamilton
- Late Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| | - Michael W. Laird
- Early Stage Cell Culture, Genentech, Inc., 1 DNA Way; South San Francisco California 94080
| |
Collapse
|
17
|
Lara AR, Jaén KE, Sigala JC, Mühlmann M, Regestein L, Büchs J. Characterization of Endogenous and Reduced Promoters for Oxygen-Limited Processes Using Escherichia coli. ACS Synth Biol 2017; 6:344-356. [PMID: 27715021 DOI: 10.1021/acssynbio.6b00233] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Oxygen limitation can be used as a simple environmental inducer for the expression of target genes. However, there is scarce information on the characteristics of microaerobic promoters potentially useful for cell engineering and synthetic biology applications. Here, we characterized the Vitreoscilla hemoglobin promoter (Pvgb) and a set of microaerobic endogenous promoters in Escherichia coli. Oxygen-limited cultures at different maximum oxygen transfer rates were carried out. The FMN-binding fluorescent protein (FbFP), which is a nonoxygen dependent marker protein, was used as a reporter. Fluorescence and fluorescence emission rates under oxygen-limited conditions were the highest when FbFP was under transcriptional control of PadhE, Ppfl and Pvgb. The lengths of the E. coli endogenous promoters were shortened by 60%, maintaining their key regulatory elements. This resulted in improved promoter activity in most cases, particularly for PadhE, Ppfl and PnarK. Selected promoters were also evaluated using an engineered E. coli strain expressing Vitreoscilla hemoglobin (VHb). The presence of the VHb resulted in a better repression using these promoters under aerobic conditions, and increased the specific growth and fluorescence emission rates under oxygen-limited conditions. These results are useful for the selection of promoters for specific applications and for the design of modified artificial promoters.
Collapse
Affiliation(s)
- Alvaro R. Lara
- Departamento
de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa. Av. Vasco de Quiroga 4871, Santa
Fe, C.P. 05348, Mexico City, México
| | - Karim E. Jaén
- Departamento
de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa. Av. Vasco de Quiroga 4871, Santa
Fe, C.P. 05348, Mexico City, México
| | - Juan-Carlos Sigala
- Departamento
de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa. Av. Vasco de Quiroga 4871, Santa
Fe, C.P. 05348, Mexico City, México
| | - Martina Mühlmann
- RWTH Aachen University, AVT - Biochemical Engineering, Worringer Weg 1, 52074 Aachen, Germany
| | - Lars Regestein
- RWTH Aachen University, AVT - Biochemical Engineering, Worringer Weg 1, 52074 Aachen, Germany
| | - Jochen Büchs
- RWTH Aachen University, AVT - Biochemical Engineering, Worringer Weg 1, 52074 Aachen, Germany
| |
Collapse
|
18
|
Improved production of trans-4-hydroxy-l-proline by chromosomal integration of the Vitreoscilla hemoglobin gene into recombinant Escherichia coli with expression of proline-4-hydroxylase. J Biosci Bioeng 2017; 123:109-115. [DOI: 10.1016/j.jbiosc.2016.07.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 07/22/2016] [Accepted: 07/25/2016] [Indexed: 02/01/2023]
|
19
|
Juárez M, González-De la Rosa CH, Memún E, Sigala JC, Lara AR. Aerobic expression of Vitreoscilla hemoglobin improves the growth performance of CHO-K1 cells. Biotechnol J 2016; 12. [PMID: 27906496 DOI: 10.1002/biot.201600438] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 11/16/2016] [Accepted: 11/29/2016] [Indexed: 11/10/2022]
Abstract
Inefficient carbon metabolism is a relevant issue during the culture of mammalian cells for the production of biopharmaceuticals. Therefore, cell engineering strategies to improve the metabolic and growth performance of cell lines are needed. The expression of Vitreoscilla stercoraria hemoglobin (VHb) has been shown to significantly reduce overflow metabolism and improve the aerobic growth of bacteria. However, the effects of VHb on mammalian cells have been rarely studied. Here, the impact of VHb on growth and lactate accumulation during CHO-K1 cell culture was investigated. For this purpose, CHO-K1 cells were transfected with plasmids carrying the vgb or gfp gene to express VHb or green fluorescence protein (GFP), respectively. VHb expression increased the specific growth rate and biomass yields on glucose and glutamine by 60 %, and reduced the amount of lactate produced per cell by 40 %, compared to the GFP-expression controls. Immunofluorescence microscopy showed that VHb is distributed in the cytoplasm and organelles, which support the hypothesis that VHb could serve as an oxygen carrier, enhancing aerobic respiration. These results are useful for the development of better producing cell lines for industrial applications.
Collapse
Affiliation(s)
- Mariana Juárez
- Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolitana-Cuajimalpa, Ciudad de México, México
| | | | - Elisa Memún
- Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana-Cuajimalpa, Ciudad de México, México
| | - Juan-Carlos Sigala
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Ciudad de México, México
| | - Alvaro R Lara
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Ciudad de México, México
| |
Collapse
|
20
|
|
21
|
Li T, Guo YY, Qiao GQ, Chen GQ. Microbial Synthesis of 5-Aminolevulinic Acid and Its Coproduction with Polyhydroxybutyrate. ACS Synth Biol 2016; 5:1264-1274. [PMID: 27238205 DOI: 10.1021/acssynbio.6b00105] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
5-Aminolevulinic acid (ALA), an important cell metabolic intermediate useful for cancer treatments or plant growth regulator, was produced by recombinant Escherichia coli expressing the codon optimized mitochondrial 5-aminolevulinic acid synthase (EC: 2.3.1.37, hem1) from Saccharomyces cerevisiae controlled via the plasmid encoding T7 expression system with a T7 RNA polymerase. When a more efficient autoinduced expression approach free of IPTG was applied, the recombinant containing antibiotic-free stabilized plasmid was able to produce 3.6 g/L extracellular ALA in shake flask studies under optimized temperature. A recombinant E. coli expressing synthesis pathways of poly-3-hydroxybutyrate (PHB) and ALA resulted in coproduction of 43% PHB in the cell dry weights and 1.6 g/L extracellular ALA, leading to further reduction on ALA cost as two products were harvested both intracellularly and extracellularly. This was the first study on coproduction of extracellular ALA and intracellular PHB for improving bioprocessing efficiency. The cost of ALA production could be further reduced by employing a Halomonas spp. TD01 able to grow and produce ALA and PHB under continuous and unsterile conditions even though ALA had the highest titer of only 0.7 g/L at the present time.
Collapse
Affiliation(s)
- Tian Li
- Peking-Tsinghua
Center for Life Sciences, School of Life Science, Tsinghua University, Beijing 100084, China
| | - Ying-Ying Guo
- Peking-Tsinghua
Center for Life Sciences, School of Life Science, Tsinghua University, Beijing 100084, China
- Center
for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China
| | - Guan-Qing Qiao
- Peking-Tsinghua
Center for Life Sciences, School of Life Science, Tsinghua University, Beijing 100084, China
| | - Guo-Qiang Chen
- Peking-Tsinghua
Center for Life Sciences, School of Life Science, Tsinghua University, Beijing 100084, China
- Center
for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China
- MOE
Key Lab of Industrial Biocatalysis, Tsinghua University, Beijing 100081, China
| |
Collapse
|
22
|
Baert J, Delepierre A, Telek S, Fickers P, Toye D, Delamotte A, Lara AR, Jaén KE, Gosset G, Jensen PR, Delvigne F. Microbial population heterogeneity versus bioreactor heterogeneity: Evaluation of Redox Sensor Green as an exogenous metabolic biosensor. Eng Life Sci 2016. [DOI: 10.1002/elsc.201500149] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- Jonathan Baert
- Gembloux Agro-Bio Tech; Microbial Processes and Interactions (MiPI); University of Liège; Gembloux Belgium
| | - Anissa Delepierre
- Gembloux Agro-Bio Tech; Microbial Processes and Interactions (MiPI); University of Liège; Gembloux Belgium
| | - Samuel Telek
- Gembloux Agro-Bio Tech; Microbial Processes and Interactions (MiPI); University of Liège; Gembloux Belgium
| | - Patrick Fickers
- Gembloux Agro-Bio Tech; Microbial Processes and Interactions (MiPI); University of Liège; Gembloux Belgium
| | - Dominique Toye
- Department of Chemical Engineering-Product; Environment and Processes (PEPs); University of Liège; Liège Belgium
| | - Anne Delamotte
- Department of Chemical Engineering-Product; Environment and Processes (PEPs); University of Liège; Liège Belgium
| | - Alvaro R. Lara
- Departamento de Procesos y Tecnología; Universidad Autónoma Metropolitana-Cuajimalpa; Col. Santa Fe Cuajimalpa México D. F., Mexico
| | - Karim E. Jaén
- Departamento de Procesos y Tecnología; Universidad Autónoma Metropolitana-Cuajimalpa; Col. Santa Fe Cuajimalpa México D. F., Mexico
| | - Guillermo Gosset
- Instituto de Biotecnología; Universidad Nacional Autónoma de México; Cuernavaca Morelos México
| | - Peter R. Jensen
- National Food Institute; Technical University of Denmark (DTU); Lyngby Denmark
| | - Frank Delvigne
- Gembloux Agro-Bio Tech; Microbial Processes and Interactions (MiPI); University of Liège; Gembloux Belgium
| |
Collapse
|
23
|
Pablos TE, Olivares R, Sigala JC, Ramírez OT, Lara AR. Toward efficient microaerobic processes using engineeredEscherichia coliW3110 strains. Eng Life Sci 2016. [DOI: 10.1002/elsc.201500129] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Tania E. Pablos
- Doctorado en Ciencias Biológicas y de la Salud; Universidad Autónoma Metropolitana; México D.F. México
| | - Roberto Olivares
- Departamento de Procesos y Tecnología; Universidad Autónoma Metropolitana-Cuajimalpa; México D.F. México
| | - Juan Carlos Sigala
- Departamento de Procesos y Tecnología; Universidad Autónoma Metropolitana-Cuajimalpa; México D.F. México
| | - Octavio T. Ramírez
- Departamento de Medicina Molecular y Bioprocesos; Instituto de Biotecnología; Universidad Nacional Autónoma de México; Cuernavaca México
| | - Alvaro R. Lara
- Departamento de Procesos y Tecnología; Universidad Autónoma Metropolitana-Cuajimalpa; México D.F. México
| |
Collapse
|
24
|
Ye W, Zhang W, Chen Y, Li H, Li S, Pan Q, Tan G, Liu T. A new approach for improving epothilone B yield in Sorangium cellulosum by the introduction of vgb epoF genes. J Ind Microbiol Biotechnol 2016; 43:641-50. [PMID: 26803504 DOI: 10.1007/s10295-016-1735-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 01/07/2016] [Indexed: 10/22/2022]
Abstract
Epothilone B has drawn great attention due to its much stronger anticancer activity and weaker side effects compared with taxol. The relative low yield of epothilone B limited its application. In this study, we report the successful introduction of the vgb gene and the epoF gene into Sorangium cellulosum So ce M4 by electroporation for the first time, which was demonstrated by Southern blot analysis. Results of qRT-PCR, SDS-PAGE and western blot analysis confirmed the transcription and expression of the vgb and epoF genes. LC-MS results showed that the epothilones B, A yields were improved and epothilones D, C yields were decreased. The yields of epothilone B were improved by 57.9 ± 0.3, 62.7 ± 0.8 and 122.4 ± 0.7 % through the introduction of vgb gene, epoF gene and both genes into strain So ce M4, respectively. Our study provides a new approach for improving epothilone B yield in S. cellulosum.
Collapse
Affiliation(s)
- Wei Ye
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China
| | - Weimin Zhang
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China.
| | - Yuchan Chen
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China
| | - Haohua Li
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China
| | - Saini Li
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China
| | - Qingling Pan
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China
| | - Guohui Tan
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China
| | - Taomei Liu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China
| |
Collapse
|
25
|
Recombinant Escherichia coli strains with inducible Campylobacter jejuni single domain hemoglobin CHb expression exhibited improved cell growth in bioreactor culture. PLoS One 2015; 10:e0116503. [PMID: 25748170 PMCID: PMC4352031 DOI: 10.1371/journal.pone.0116503] [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: 09/24/2014] [Accepted: 12/10/2014] [Indexed: 11/19/2022] Open
Abstract
Maintaining an appropriate concentration of dissolved oxygen in aqueous solution is critical for efficient operation of a bioreactor, requiring sophisticated engineering design and a system of regulation to maximize oxygen transfer from the injected air bubbles to the cells. Bacterial hemoglobins are oxygen-binding proteins that transfer oxygen from the environment to metabolic processes and allow bacteria to grow even under microaerophilic conditions. To improve the oxygen utilization efficiency of cells and overcome the oxygen shortage in bioreactors, the gene coding for the Campylobacter jejuni single domain hemoglobin (CHb) gene was artificially synthesized and functionally expressed under the control of inducible expression promoters PT7 and Pvgh in Escherichia coli. The effects of the recombinants PT7-CHb and Pvgh-CHb on cell growth were evaluated in aerobic shake flasks, anaerobic capped bottles and a 5-L bioreactor, and a pronounced improvement in cell biomass was observed for CHb-expressing cells. To determine the growth curves, CHb gene expression, and CHb oxygen-binding capacity of specific recombinants with different promoters, we determined the time course of CHb gene expression in the two recombinants by semi-quantitative RT-PCR and CO differential spectrum assays. Based on the growth patterns of the two recombinants in the bioreactor, we proposed different recombinant types with optimal performance under specific culture conditions.
Collapse
|
26
|
Glassey J, Ottens M. Editorial: Industrial biotechnology - Technologies and methods for rapid process development. Biotechnol J 2014; 9:711-2. [DOI: 10.1002/biot.201400304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|