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Zeng M, Wu H, Han Z, Du Z, Yu X, Luo W. Metabolic Engineering of Escherichia coli for Production of 2,5-Dimethylpyrazine. J Agric Food Chem 2024; 72:4267-4276. [PMID: 38369722 DOI: 10.1021/acs.jafc.3c08481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
2,5-Dimethylpyrazine (2,5-DMP) is a high-value-added alkylpyrazine compound with important applications in both the food and pharmaceutical fields. In response to the increasing consumer preference for natural products over chemically synthesized ones, efforts have been made to develop efficient microbial cell factories for the production of 2,5-DMP. However, the previously reported recombinant strains have exhibited low yields and relied on expensive antibiotics and inducers. In this study, we employed metabolic engineering strategies to develop an Escherichia coli strain capable of producing 2,5-DMP at high levels without the need for inducers or antibiotics. Initially, the biosynthesis pathway of 2,5-DMP was constructed that realized 2,5-DMP production from glucose. Subsequently, efforts focused on enhancing 2,5-DMP production by improving the availability of the cofactor NAD+ and precursor l-threonine. Additionally, the supply and conversion of l-threonine were balanced by optimizing the copy number of the key gene tdh on the chromosome and by modifying the l-threonine transport system. The final engineering strain D19 produced 3.1 g/L of 2,5-DMP, which is the highest titer for fermentative production of 2,5-DMP using glucose as the carbon source up to date. The strategies used in this study lay a good foundation for the production of 2,5-DMP on a large scale.
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Affiliation(s)
- Mingxi Zeng
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Hui Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200231, China
| | - Zhenlin Han
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Zhiyan Du
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Xiaobin Yu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wei Luo
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
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Qin N, Zhu F, Liu Y, Liu D, Chen Z. Metabolic Engineering of Escherichia coli for De Novo Production of 1,2-Butanediol. ACS Synth Biol 2024; 13:351-357. [PMID: 38110368 DOI: 10.1021/acssynbio.3c00606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
1,2-Butanediol (1,2-BDO) is an important platform chemical widely utilized in the synthesis of polyester polyols, plasticizers, cosmetics, and pharmaceuticals. However, no natural metabolic pathway for its biosynthesis has been identified, and biological production of 1,2-BDO from renewable bioresources has not been reported so far. In this study, we designed and experimentally verified a feasible non-natural synthesis pathway for the de novo production of 1,2-BDO from renewable carbohydrates for the first time. This pathway extends the l-threonine synthesis pathway by introducing two artificial metabolic modules to sequentially convert l-threonine into 2-hydroxybutyric acid and 1,2-BDO. Following key enzyme screening and enhancement of l-threonine synthesis module in the chassis microorganism, the best engineered Escherichia coli strain was able to produce 0.15 g/L 1,2-BDO using glucose as the sole carbon source. This work lays the foundation for the bioproduction of 1,2-BDO from renewable resources.
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Affiliation(s)
- Nan Qin
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Fanghuan Zhu
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yanyan Liu
- School of Physiology, Pharmacology & Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Dehua Liu
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
- Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China
| | - Zhen Chen
- Key Laboratory of Industrial Biocatalysis (Ministry of Education), Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
- Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China
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3
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Nie M, Wang J, Zhang K. Engineering a Novel Acetyl-CoA Pathway for Efficient Biosynthesis of Acetyl-CoA-Derived Compounds. ACS Synth Biol 2024; 13:358-369. [PMID: 38151239 DOI: 10.1021/acssynbio.3c00613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Acetyl-CoA is an essential central metabolite in living organisms and a key precursor for various value-added products as well. However, the intracellular availability of acetyl-CoA limits the efficient production of these target products due to complex and strict regulation. Here, we proposed a new acetyl-CoA pathway, relying on two enzymes, threonine aldolase and acetaldehyde dehydrogenase (acetylating), which can convert one l-threonine into one acetyl-CoA, one glycine, and generate one NADH, without carbon loss. Introducing the acetyl-CoA pathway could increase the intracellular concentration of acetyl-CoA by 8.6-fold compared with the wild-type strain. To develop a cost-competitive and genetically stable acetyl-CoA platform strain, the new acetyl-CoA pathway, driven by the constitutive strong promoter, was integrated into the chromosome of Escherichia coli. We demonstrated the practical application of this new acetyl-CoA pathway by high titer production of β-alanine, mevalonate, and N-acetylglucosamine. At the same time, this pathway achieved a high-yield production of glycine, a value-added commodity chemical for the synthesis of glyphosate and thiamphenicol. This work shows the potential of this new acetyl-CoA pathway for the industrial production of acetyl-CoA-derived compounds.
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Affiliation(s)
- Mengzhen Nie
- Zhejiang University, Hangzhou, Zhejiang 310027, China
- Center of Synthetic Biology and Integrated Bioengineering, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China
| | - Jingyu Wang
- Center of Synthetic Biology and Integrated Bioengineering, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China
| | - Kechun Zhang
- Center of Synthetic Biology and Integrated Bioengineering, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China
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Sun W, Shi S, Chen J, Zhao W, Chen T, Li G, Zhang K, Yu B, Liu D, Chen Y, Ying H, Ouyang P. Blue Light Signaling Regulates Escherichia coli W1688 Biofilm Formation and l-Threonine Production. Microbiol Spectr 2022; 10:e0246022. [PMID: 36165805 DOI: 10.1128/spectrum.02460-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Escherichia coli biofilm may form naturally on biotic and abiotic surfaces; this represents a promising approach for efficient biochemical production in industrial fermentation. Recently, industrial exploitation of the advantages of optogenetics, such as simple operation, high spatiotemporal control, and programmability, for regulation of biofilm formation has garnered considerable attention. In this study, we used the blue light signaling-induced optogenetic system Magnet in an E. coli biofilm-based immobilized fermentation system to produce l-threonine in sufficient quantity. Blue light signaling significantly affected the phenotype of E. coli W1688. A series of biofilm-related experiments confirmed the inhibitory effect of blue light signaling on E. coli W1688 biofilm. Subsequently, a strain lacking a blue light-sensing protein (YcgF) was constructed via genetic engineering, which substantially reduced the inhibitory effect of blue light signaling on biofilm. A high-efficiency biofilm-forming system, Magnet, was constructed, which enhanced bacterial aggregation and biofilm formation. Furthermore, l-threonine production was increased from 10.12 to 16.57 g/L during immobilized fermentation, and the fermentation period was shortened by 6 h. IMPORTANCE We confirmed the mechanism underlying the inhibitory effects of blue light signaling on E. coli biofilm formation and constructed a strain lacking a blue light-sensing protein; this mitigated the aforementioned effects of blue light signaling and ensured normal fermentation performance. Furthermore, this study elucidated that the blue light signaling-induced optogenetic system Magnet effectively regulates E. coli biofilm formation and contributes to l-threonine production. This study not only enriches the mechanism of blue light signaling to regulate E. coli biofilm formation but also provides a theoretical basis and feasibility reference for the application of optogenetics technology in biofilm-based immobilized fermentation systems.
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Mu Q, Shi Y, Li R, Ma C, Tao Y, Yu B. Production of Propionate by a Sequential Fermentation-Biotransformation Process via l-Threonine. J Agric Food Chem 2021; 69:13895-13903. [PMID: 34757739 DOI: 10.1021/acs.jafc.1c05248] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Bio-based propionate is widely welcome in the food additive industry. The current anaerobic process by Propionibacteria endures low titers and a long fermentation time. In this study, a new route for propionate production from l-threonine was designed. 2-Ketobutyrate, deaminated from l-threonine, is cleaved into propionaldehyde and CO2 and then be oxidized into propionic acid, which is neutralized by ammonia released from the first deamination step. This CoA-independent pathway with only CO2 as a byproduct boosts propionate production from l-threonine with high productivity and purity. The key enzyme for 2-ketobutyrate decarboxylation was selected, and its expression was optimized. The engineered Pseudomonas putida strain, harboring 2-ketoisovalerate decarboxylase from Lactococcus lactis could produce 580 mM (43 g/L) pure propionic acid from 600 mM l-threonine in 24 h in the batch biotransformation process. Furthermore, a high titer of 62 g/L propionic acid with a productivity of 1.07 g/L/h and a molar yield of >0.98 was achieved in the fed-batch pattern. Finally, an efficient sequential fermentation-biotransformation process was demonstrated to produce propionate directly from the fermentation broth containing l-threonine, which further reduces the costs since no l-threonine purification step is required.
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Affiliation(s)
- Qingxuan Mu
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ya'nan Shi
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rongshan Li
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Chao Ma
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yong Tao
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bo Yu
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
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Qiao J, Tan X, Ren H, Wu Z, Hu X, Wang X. Construction of an Escherichia coli Strain Lacking Fimbriae by Deleting 64 Genes and Its Application for Efficient Production of Poly(3-Hydroxybutyrate) and l-Threonine. Appl Environ Microbiol 2021; 87:e0038121. [PMID: 33863704 PMCID: PMC8174762 DOI: 10.1128/aem.00381-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 04/03/2021] [Indexed: 12/28/2022] Open
Abstract
Escherichia coli contains 12 chaperone-usher operons for biosynthesis and assembly of various fimbriae. In this study, each of the 12 operons was deleted in E. coli MG1655, and the resulting 12 deletion mutants all grew better than the wild type, especially in the nutrient-deficient M9 medium. When the plasmid pBHR68 containing the key genes for polyhydroxyalkanoate production was introduced into these 12 mutants, each mutant synthesized more polyhydroxyalkanoate than the wild-type control. These results indicate that the fimbria removal in E. coli benefits cell growth and polyhydroxyalkanoate production. Therefore, all 12 chaperone-usher operons, including 64 genes, were deleted in MG1655, resulting in the fimbria-lacking strain WQM026. WQM026 grew better than MG1655, and no fimbria structures were observed on the surface of WQM026 cells. Transcriptomic analysis showed that in WQM026 cells, the genes related to glucose consumption, glycolysis, flagellar synthesis, and biosynthetic pathways of some key amino acids were upregulated, while the tricarboxylic acid cycle-related genes were downregulated. When pBHR68 was introduced into WQM026, huge amounts of poly-3-hydroxybutyrate were produced; when the plasmid pFW01-thrA*BC-rhtC, containing the key genes for l-threonine biosynthesis and transport, was transferred into WQM026, more l-threonine was synthesized than with the control. These results suggest that this fimbria-lacking E. coli WQM026 is a good host for efficient production of polyhydroxyalkanoate and l-threonine and has the potential to be developed into a valuable chassis microorganism. IMPORTANCE In this study, we investigated the interaction between the biosynthesis and assembly of fimbriae and intracellular metabolic networks in E. coli. We found that eliminating fimbriae could effectively improve the production of polyhydroxyalkanoate and l-threonine in E. coli MG1655. These results contribute to understanding the necessity of fimbriae and the advantages of fimbria removal for industrial microorganisms. The knowledge gathered from this study may be applied to the development of superior chassis microorganisms.
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Affiliation(s)
- Jun Qiao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province, China
| | - Xin Tan
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province, China
| | - Hongyu Ren
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province, China
| | - Zheng Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province, China
| | - Xiaoqing Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu Province, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu Province, China
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Qiao J, Tan X, Huang D, Li H, Wang Z, Ren H, Hu X, Wang X. Construction and Application of an Escherichia coli Strain Lacking 62 Genes Responsible for the Biosynthesis of Enterobacterial Common Antigen and Flagella. J Agric Food Chem 2021; 69:4153-4163. [PMID: 33787256 DOI: 10.1021/acs.jafc.1c00453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The biosynthesis of the enterobacterial common antigen and flagella in Escherichia coli consumes lots of substrates and energy. In this study, 12 genes responsible for the biosynthesis of the enterobacterial common antigen were deleted in E. coli MG1655, resulting in WQM021. WQM021 grew better than MG1655 in both rich LB medium and minimum M9 medium. Compared with MG1655, WQM021 showed higher membrane permeability and higher production efficiency for recombinant proteins, polyhydroxyalkanoate, and l-threonine. Transcriptome analysis revealed that genes relevant to glucose consumption, glycolysis, and flagellar synthesis were significantly upregulated in WQM021. Therefore, 50 genes responsible for flagellar biosynthesis were further deleted in WQM021, resulting in WQM022. WQM022 grew better and could synthesize more polyhydroxyalkanoate and l-threonine than WQM021. The results demonstrate that the productivity of E. coli can be efficiently improved when the enterobacterial common antigen and flagella are eliminated. This strategy has guiding significance in the optimization of other industrial products and microorganisms.
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Affiliation(s)
- Jun Qiao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xin Tan
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Danyang Huang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Hedan Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zhen Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Hongyu Ren
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xiaoqing Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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Koo B, Lee J, Nyachoti CM. Diet complexity and l-threonine supplementation: effects on nutrient digestibility, nitrogen and energy balance, and body composition in nursery pigs. J Anim Sci 2020; 98:skaa124. [PMID: 32307532 PMCID: PMC7216776 DOI: 10.1093/jas/skaa124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 04/16/2020] [Indexed: 01/13/2023] Open
Abstract
This study was conducted to investigate the effects of dietary complexity and l-Thr supplementation on energy and nutrient utilization in nursery pigs. Thirty-two nursery pigs (7.23 ± 0.48 kg) were randomly assigned to a 2 × 2 factorial treatment arrangement based on diet complexity (complex vs. simple) with different levels of l-Thr supplementation. The complex diet contained animal protein sources (e.g., fish meal and plasma) and a dairy product (e.g., dried whey) to mimic a conventional nursery diet. The simple diet was formulated with corn, wheat, and soybean meal. Both diets were supplemented with l-Thr to contain either 100% or 115% (SUP Thr) of the estimated standardized ileal digestible Thr requirement for 9 kg body weight pigs (NRC, 2012). The pigs were individually housed in metabolism crates and fed an experimental diet ad libitum for a 7-d adaptation period and 5 d of total but separate urine and fecal collection. On day 14, all pigs were euthanized to determine body composition. The diet complexity, l-Thr supplementation, and their interactions were considered main effects. Pigs fed the complex diet tended to exhibit greater (P < 0.10) apparent total tract digestibility (ATTD) of ash and urinary energy output than those fed the simple diet. The complex diet had greater (P < 0.05) digestible energy and net energy contents than the simple diet. Furthermore, the complex diet-fed pigs had lower (P < 0.05) plasma urea nitrogen concentration on day 14 than simple diet-fed pigs. The SUP Thr decreased (P < 0.05) ATTD of acid detergent fiber but trended (P < 0.10) toward a decrease in urinary nitrogen (N) output and an increase in N retention and body N mass. In conclusion, the simple diet for nursery pigs had lower digestible and net energy contents than a complex diet. The SUP Thr can improve N utilization and body protein deposition, irrespective of diet complexity.
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Affiliation(s)
- Bonjin Koo
- Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada
| | - Jinyoung Lee
- Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada
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Liu J, Li H, Xiong H, Xie X, Chen N, Zhao G, Caiyin Q, Zhu H, Qiao J. Two-stage carbon distribution and cofactor generation for improving l-threonine production of Escherichia coli. Biotechnol Bioeng 2018; 116:110-120. [PMID: 30252940 DOI: 10.1002/bit.26844] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 09/09/2018] [Accepted: 09/21/2018] [Indexed: 12/14/2022]
Abstract
L-Threonine, a kind of essential amino acid, has numerous applications in food, pharmaceutical, and aquaculture industries. Fermentative l-threonine production from glucose has been achieved in Escherichia coli. However, there are still several limiting factors hindering further improvement of l-threonine productivity, such as the conflict between cell growth and production, byproduct accumulation, and insufficient availability of cofactors (adenosine triphosphate, NADH, and NADPH). Here, a metabolic modification strategy of two-stage carbon distribution and cofactor generation was proposed to address the above challenges in E. coli THRD, an l-threonine producing strain. The glycolytic fluxes towards tricarboxylic acid cycle were increased in growth stage through heterologous expression of pyruvate carboxylase, phosphoenolpyruvate carboxykinase, and citrate synthase, leading to improved glucose utilization and growth performance. In the production stage, the carbon flux was redirected into l-threonine synthetic pathway via a synthetic genetic circuit. Meanwhile, to sustain the transaminase reaction for l-threonine production, we developed an l-glutamate and NADPH generation system through overexpression of glutamate dehydrogenase, formate dehydrogenase, and pyridine nucleotide transhydrogenase. This strategy not only exhibited 2.02- and 1.21-fold increase in l-threonine production in shake flask and bioreactor fermentation, respectively, but had potential to be applied in the production of many other desired oxaloacetate derivatives, especially those involving cofactor reactions.
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Affiliation(s)
- Jiaheng Liu
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University, Tianjin, China
| | - Huiling Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University, Tianjin, China
| | - Hui Xiong
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University, Tianjin, China
| | - Xixian Xie
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
| | - Ning Chen
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
| | - Guangrong Zhao
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University, Tianjin, China
| | - Qinggele Caiyin
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Hongji Zhu
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Jianjun Qiao
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University, Tianjin, China
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Tian X, Li L, Han J, Zhen X, Liu S. Stereoselectively synthesis and structural confirmation of dehydrodipeptides with dehydrobutyrine. Springerplus 2016; 5:400. [PMID: 27047726 PMCID: PMC4816936 DOI: 10.1186/s40064-016-2005-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/15/2016] [Indexed: 11/16/2022]
Abstract
Most of polypeptides containing α,β-dehydroamino acids have important biological activity, so exploration of synthetic method has practical significance. In this paper, dipeptides were prepared from l-threonine by protecting of c-terminal allyl acetate, and condensing reaction with a series of N-Boc amino acid. Then, treatment of dipeptides obtained with DMAP, (Boc)2O and tetramethylguanidine in the acetonitrile occured β-elimination reaction to yield stereoselectively dehydrodipeptides. Structures of dehydrodipeptides were confirmed by 1H NMR, 13C NMR and MS. Analysis of 1H NMR, 2D NMR and crystal structure showed that the dehydrodipeptides were Z-configuration.Dehydrodipeptides were prepared from l-threonine. Their structures were confirmed by 1H NMR, 13C NMR and MS ![]()
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Affiliation(s)
- Xia Tian
- College of Sciences, Hebei University of Science and Technology, Shijiazhuang, 050018 People's Republic of China
| | - Linna Li
- College of Sciences, Hebei University of Science and Technology, Shijiazhuang, 050018 People's Republic of China
| | - Jianrong Han
- College of Sciences, Hebei University of Science and Technology, Shijiazhuang, 050018 People's Republic of China
| | - Xiaoli Zhen
- College of Sciences, Hebei University of Science and Technology, Shijiazhuang, 050018 People's Republic of China
| | - Shouxin Liu
- State Key Laboratory Breeding Base-Hebei Province Key Laboratory of Molecular Chemistry for Drug, Hebei University of Science and Technology, Shijiazhuang, 050018 People's Republic of China
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