1
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Zhang L, Wang J, Gu S, Liu X, Hou M, Zhang J, Yang G, Zhao D, Dong R, Gao H. Biosynthesis of D-1,2,4-butanetriol promoted by a glucose-xylose dual metabolic channel system in engineered Escherichia coli. N Biotechnol 2024; 83:26-35. [PMID: 38936658 DOI: 10.1016/j.nbt.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 05/29/2024] [Accepted: 06/14/2024] [Indexed: 06/29/2024]
Abstract
D-1,2,4-butanetriol (BT) is a widely used fine chemical that can be manufactured by engineered Escherichia coli expressing heterologous pathways and using xylose as a substrate. The current study developed a glucose-xylose dual metabolic channel system in an engineered E. coli and Combinatorially optimized it using multiple strategies to promote BT production. The carbon catabolite repression effects were alleviated by deleting the gene ptsG that encodes the major glucose transporter IICBGlc and mutating the gene crp that encodes the catabolite repressor protein, thereby allowing C-fluxes of both glucose and xylose into their respective metabolic channels separately and simultaneously, which increased BT production by 33% compared with that of the original MJ133K-1 strain. Then, the branch metabolic pathways of intermediates in the BT channel were investigated, the transaminase HisC, the ketoreductases DlD, OLD, and IlvC, and the aldolase MhpE and YfaU were identified as the enzymes for the branched metabolism of 2-keto-3-deoxy-xylonate, deletion of the gene hisC increased BT titer by 21.7%. Furthermore, the relationship between BT synthesis and the intracellular NADPH level was examined, and deletion of the gene pntAB that encodes a transhydrogenase resulted in an 18.1% increase in BT production. The combination of the above approaches to optimize the metabolic network increased BT production by 47.5%, resulting in 2.67 g/L BT in 24 deep-well plates. This study provides insights into the BT biosynthesis pathway and demonstrates effective strategies to increase BT production, which will promote the industrialization of the biosynthesis of BT.
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Affiliation(s)
- Lu Zhang
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Jinbao Wang
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Songhe Gu
- School of Life Science, Qufu Normal University, Qufu 273165, Shandong, China
| | - Xuedan Liu
- School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Miao Hou
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Jing Zhang
- School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Ge Yang
- School of Life Science, Qufu Normal University, Qufu 273165, Shandong, China
| | - Dongxu Zhao
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Runan Dong
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Haijun Gao
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China.
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2
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Kumar V, Agrawal D, Bommareddy RR, Islam MA, Jacob S, Balan V, Singh V, Thakur VK, Navani NK, Scrutton NS. Arabinose as an overlooked sugar for microbial bioproduction of chemical building blocks. Crit Rev Biotechnol 2024; 44:1103-1120. [PMID: 37932016 DOI: 10.1080/07388551.2023.2270702] [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: 05/18/2023] [Revised: 08/06/2023] [Accepted: 09/19/2023] [Indexed: 11/08/2023]
Abstract
The circular economy is anticipated to bring a disruptive transformation in manufacturing technologies. Robust and industrial scalable microbial strains that can simultaneously assimilate and valorize multiple carbon substrates are highly desirable, as waste bioresources contain substantial amounts of renewable and fermentable carbon, which is diverse. Lignocellulosic biomass (LCB) is identified as an inexhaustible and alternative resource to reduce global dependence on oil. Glucose, xylose, and arabinose are the major monomeric sugars in LCB. However, primary research has focused on the use of glucose. On the other hand, the valorization of pentose sugars, xylose, and arabinose, has been mainly overlooked, despite possible assimilation by vast microbial communities. The present review highlights the research efforts that have explicitly proven the suitability of arabinose as the starting feedstock for producing various chemical building blocks via biological routes. It begins by analyzing the availability of various arabinose-rich biorenewable sources that can serve as potential feedstocks for biorefineries. The subsequent section outlines the current understanding of arabinose metabolism, biochemical routes prevalent in prokaryotic and eukaryotic systems, and possible products that can be derived from this sugar. Further, currently, exemplar products from arabinose, including arabitol, 2,3-butanediol, 1,2,3-butanetriol, ethanol, lactic acid, and xylitol are discussed, which have been produced by native and non-native microbial strains using metabolic engineering and genome editing tools. The final section deals with the challenges and obstacles associated with arabinose-based production, followed by concluding remarks and prospects.
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Affiliation(s)
- Vinod Kumar
- School of Water, Energy and Environment, Cranfield University, Cranfield, UK
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Deepti Agrawal
- Biochemistry and Biotechnology Area, Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Dehradun, India
| | - Rajesh Reddy Bommareddy
- Department of Applied Sciences, Health and Life Sciences, Hub for Biotechnology in the Built Environment, Northumbria University, Newcastle upon Tyne, UK
| | - M Ahsanul Islam
- Department of Chemical Engineering, Loughborough University, Loughborough, UK
| | - Samuel Jacob
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, India
| | - Venkatesh Balan
- Department of Engineering Technology, Cullen College of Engineering, University of Houston, Sugar Land, TX, USA
| | - Vijai Singh
- Department of Biosciences, School of Sciences, Indrashil University, Rajpur, Mehsana, India
| | - Vijay Kumar Thakur
- Biorefining and Advanced Materials Research Center, Scotland's Rural College (SRUC), Edinburgh, UK
| | - Naveen Kumar Navani
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Nigel S Scrutton
- EPSRC/BBSRC Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, Manchester, UK
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3
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Ma X, Sun C, Xian M, Guo J, Zhang R. Progress in research on the biosynthesis of 1,2,4-butanetriol by engineered microbes. World J Microbiol Biotechnol 2024; 40:68. [PMID: 38200399 DOI: 10.1007/s11274-024-03885-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 01/05/2024] [Indexed: 01/12/2024]
Abstract
1,2,4-butanetriol (BT) is a polyol with unique chemical properties, which has a stereocenter and can be divided into D-BT (the S-enantiomer) and L-BT (the R-enantiomer). BT can be used for the synthesis of 1,2,4-butanetriol trinitrate, 3-hydroxytetrahydrofuran, polyurethane, and other chemicals. It is widely used in the military industry, medicine, tobacco, polymer. At present, the BT is mainly synthesized by chemical methods, which are accompanied by harsh reaction conditions, poor selectivity, many by-products, and environmental pollution. Therefore, BT biosynthesis methods with the advantages of mild reaction conditions and green sustainability have become a current research hotspot. In this paper, the research status of microbial synthesis of BT was summarized from the following three aspects: (1) the biosynthetic pathway establishment for BT from xylose; (2) metabolic engineering strategies employed for improving BT production from xylose; (3) other substrates for BT production. Finally, the challenges and prospects of biosynthetic BT were discussed for future methods to improve competitiveness for industrial production.
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Affiliation(s)
- Xiangyu Ma
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chao Sun
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
- Shandong Energy Institute, Qingdao, 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China
| | - Mo Xian
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
- Shandong Energy Institute, Qingdao, 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China
| | - Jing Guo
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
- Shandong Energy Institute, Qingdao, 266101, China.
- Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China.
| | - Rubing Zhang
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
- Shandong Energy Institute, Qingdao, 266101, China.
- Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China.
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4
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Wang J, Chen Q, Wang X, Chen K, Ouyang P. The Biosynthesis of D-1,2,4-Butanetriol From d-Arabinose With an Engineered Escherichia coli. Front Bioeng Biotechnol 2022; 10:844517. [PMID: 35402410 PMCID: PMC8989435 DOI: 10.3389/fbioe.2022.844517] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 02/11/2022] [Indexed: 12/03/2022] Open
Abstract
D-1,2,4-Butanetriol (BT) has attracted much attention for its various applications in energetic materials and the pharmaceutical industry. Here, a synthetic pathway for the biosynthesis of BT from d-arabinose was constructed and optimized in Escherichia coli. First, E. coli Trans1-T1 was selected for the synthesis of BT. Considering the different performance of the enzymes from different organisms when expressed in E. coli, the synthetic pathway was optimized. After screening two d-arabinose dehydrogenases (ARAs), two d-arabinonate dehydratases (ADs), four 2-keto acid decarboxylases (ADXs), and three aldehyde reductases (ALRs), ADG from Burkholderia sp., AraD from Sulfolobus solfataricus, KivD from Lactococcus lactis IFPL730, and AdhP from E. coli were selected for the bio-production of BT. After 48 h of catalysis, 0.88 g/L BT was produced by the recombinant strain BT5. Once the enzymes were selected for the pathway, metabolic engineering strategy was conducted for further improvement. The final strain BT5ΔyiaEΔycdWΔyagE produced 1.13 g/L BT after catalyzing for 48 h. Finally, the fermentation conditions and characteristics of BT5ΔyiaEΔycdWΔyagE were also evaluated, and then 2.24 g/L BT was obtained after 48 h of catalysis under the optimized conditions. Our work was the first report on the biosynthesis of BT from d-arabinose which provided a potential for the large-scale production of d-glucose-based BT.
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5
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Shi LL, Zheng Y, Tan BW, Li ZJ. Establishment of a carbon-efficient xylulose cleavage pathway in Escherichia coli to metabolize xylose. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2021.108331] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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6
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Lu KW, Wang CT, Chang H, Wang RS, Shen CR. Overcoming glutamate auxotrophy in Escherichia coli itaconate overproducer by the Weimberg pathway. Metab Eng Commun 2021; 13:e00190. [PMID: 34934621 DOI: 10.1016/j.mec.2021.e00190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/11/2021] [Accepted: 11/26/2021] [Indexed: 10/19/2022] Open
Abstract
Biosynthesis of itaconic acid occurs through decarboxylation of the TCA cycle intermediate cis-aconitate. Engineering of efficient itaconate producers often requires elimination of the highly active isocitrate dehydrogenase to conserve cis-aconitate, leading to 2-ketoglutarate auxotrophy in the producing strains. Supplementation of glutamate or complex protein hydrolysate then becomes necessary, often in large quantities, to support the high cell density desired during itaconate fermentation and adds to the production cost. Here, we present an alternative approach to overcome the glutamate auxotrophy in itaconate producers by synthetically introducing the Weimberg pathway from Burkholderia xenovorans for 2-ketoglutarate biosynthesis. Because of its independence from natural carbohydrate assimilation pathways in Escherichia coli, the Weimberg pathway is able to provide 2-ketoglutarate using xylose without compromising the carbon flux toward itaconate. With xylose concentration carefully tuned to minimize excess 2-ketoglutarate flux in the stationary phase, the final strain accumulated 20 g/L of itaconate in minimal medium from 18 g/L of xylose and 45 g/L of glycerol. Necessity of the recombinant Weimberg pathway for growth also allowed us to maintain multi-copy plasmids carrying in operon the itaconate-producing genes without addition of antibiotics. Use of the Weimberg pathway for growth restoration is applicable to other production systems with disrupted 2-ketoglutarate synthesis.
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Affiliation(s)
- Ken W Lu
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan
| | - Chris T Wang
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan
| | - Hengray Chang
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan
| | - Ryan S Wang
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan
| | - Claire R Shen
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan
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7
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Yin W, Cao Y, Jin M, Xian M, Liu W. Metabolic Engineering of E. coli for Xylose Production from Glucose as the Sole Carbon Source. ACS Synth Biol 2021; 10:2266-2275. [PMID: 34412469 DOI: 10.1021/acssynbio.1c00184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Xylose is the raw material for the synthesis of many important platform compounds. At present, xylose is commercially produced by chemical extraction. However, there are still some bottlenecks in the extraction of xylose, including complicated operation processes and the chemical substances introduced, leading to the high cost of xylose and of synthesizing the downstream compounds of xylose. The current market price of xylose is 8× that of glucose, so using low-cost glucose as the substrate to produce the downstream compounds of xylose can theoretically reduce the cost by 70%. Here, we designed a pathway for the biosynthesis of xylose from glucose in Escherichia coli. This biosynthetic pathway was achieved by overexpressing five genes, namely, zwf, pgl, gnd, rpe, and xylA, while replacing the native xylulose kinase gene xylB with araL from B. subtilis, which displays phosphatase activity toward d-xylulose 5-phosphate. The yield of xylose was increased to 3.3 g/L by optimizing the metabolic pathway. Furthermore, xylitol was successfully synthesized by introducing the xyl1 gene, which suggested that the biosynthetic pathway of xylose from glucose is universally applicable for the synthesis of xylose downstream compounds. This is the first study to synthesize xylose and its downstream compounds by using glucose as a substrate, which not only reduces the cost of raw materials, but also alleviates carbon catabolite repression (CCR), providing a new idea for the synthesis of downstream compounds of xylose.
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Affiliation(s)
- Wencheng Yin
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
| | - Yujin Cao
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
| | - Miaomiao Jin
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
| | - Mo Xian
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
| | - Wei Liu
- CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
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8
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Understanding D-xylonic acid accumulation: a cornerstone for better metabolic engineering approaches. Appl Microbiol Biotechnol 2021; 105:5309-5324. [PMID: 34215905 DOI: 10.1007/s00253-021-11410-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/08/2021] [Accepted: 06/10/2021] [Indexed: 01/02/2023]
Abstract
The xylose oxidative pathway (XOP) has been engineered in microorganisms for the production of a wide range of industrially relevant compounds. However, the performance of metabolically engineered XOP-utilizing microorganisms is typically hindered by D-xylonic acid accumulation. It acidifies the media and perturbs cell growth due to toxicity, thus curtailing enzymatic activity and target product formation. Fortunately, from the growing portfolio of genetic tools, several strategies that can be adapted for the generation of efficient microbial cell factories have been implemented to address D-xylonic acid accumulation. This review centers its discussion on the causes of D-xylonic acid accumulation and how to address it through different engineering and synthetic biology techniques with emphasis given on bacterial strains. In the first part of this review, the ability of certain microorganisms to produce and tolerate D-xylonic acid is also tackled as an important aspect in developing efficient microbial cell factories. Overall, this review could shed some insights and clarity to those working on XOP in bacteria and its engineering for the development of industrially applicable product-specialist strains. KEY POINTS: D-Xylonic acid accumulation is attributed to the overexpression of xylose dehydrogenase concomitant with basal or inefficient expression of enzymes involved in D-xylonic acid assimilation. Redox imbalance and insufficient cofactors contribute to D-xylonic acid accumulation. Overcoming D-xylonic acid accumulation can increase product formation among engineered strains. Engineering strategies involving enzyme engineering, evolutionary engineering, coutilization of different sugar substrates, and synergy of different pathways could potentially address D-xylonic acid accumulation.
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9
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Yoo JI, Sohn YJ, Son J, Jo SY, Pyo J, Park SK, Choi JI, Joo JC, Kim HT, Park SJ. Recent advances in the microbial production of C4 alcohols by metabolically engineered microorganisms. Biotechnol J 2021; 17:e2000451. [PMID: 33984183 DOI: 10.1002/biot.202000451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND The heavy global dependence on petroleum-based industries has led to serious environmental problems, including climate change and global warming. As a result, there have been calls for a paradigm shift towards the use of biorefineries, which employ natural and engineered microorganisms that can utilize various carbon sources from renewable resources as host strains for the carbon-neutral production of target products. PURPOSE AND SCOPE C4 alcohols are versatile chemicals that can be used directly as biofuels and bulk chemicals and in the production of value-added materials such as plastics, cosmetics, and pharmaceuticals. C4 alcohols can be effectively produced by microorganisms using DCEO biotechnology (tools to design, construct, evaluate, and optimize) and metabolic engineering strategies. SUMMARY OF NEW SYNTHESIS AND CONCLUSIONS In this review, we summarize the production strategies and various synthetic tools available for the production of C4 alcohols and discuss the potential development of microbial cell factories, including the optimization of fermentation processes, that offer cost competitiveness and potential industrial commercialization.
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Affiliation(s)
- Jee In Yoo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Yu Jung Sohn
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Jina Son
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Seo Young Jo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Jiwon Pyo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Su Kyeong Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Jong-Il Choi
- Department of Biotechnology and Engineering, Interdisciplinary Program of Bioenergy and Biomaterials, Chonnam National University, Gwangju, Republic of Korea
| | - Jeong Chan Joo
- Department of Biotechnology, The Catholic University of Korea, Bucheon, Gyenggi-do, Republic of Korea
| | - Hee Taek Kim
- Department of Food Science and Technology, College of Agriculture and Life Sciences, Chungnam National University, Daejeon, Republic of Korea
| | - Si Jae Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
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10
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Bañares AB, Nisola GM, Valdehuesa KNG, Lee WK, Chung WJ. Engineering of xylose metabolism in Escherichia coli for the production of valuable compounds. Crit Rev Biotechnol 2021; 41:649-668. [PMID: 33563072 DOI: 10.1080/07388551.2021.1873243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The lignocellulosic sugar d-xylose has recently gained prominence as an inexpensive alternative substrate for the production of value-added compounds using genetically modified organisms. Among the prokaryotes, Escherichia coli has become the de facto host for the development of engineered microbial cell factories. The favored status of E. coli resulted from a century of scientific explorations leading to a deep understanding of its systems. However, there are limited literature reviews that discuss engineered E. coli as a platform for the conversion of d-xylose to any target compounds. Additionally, available critical review articles tend to focus on products rather than the host itself. This review aims to provide relevant and current information about significant advances in the metabolic engineering of d-xylose metabolism in E. coli. This focusses on unconventional and synthetic d-xylose metabolic pathways as several review articles have already discussed the engineering of native d-xylose metabolism. This paper, in particular, is essential to those who are working on engineering of d-xylose metabolism using E. coli as the host.
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Affiliation(s)
- Angelo B Bañares
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| | - Grace M Nisola
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| | - Kris N G Valdehuesa
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| | - Won-Keun Lee
- Division of Bioscience and Bioinformatics, Myongji University, Yongin, Gyeonggi, South Korea
| | - Wook-Jin Chung
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
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11
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Yukawa T, Bamba T, Guirimand G, Matsuda M, Hasunuma T, Kondo A. Optimization of 1,2,4-butanetriol production from xylose in Saccharomyces cerevisiae by metabolic engineering of NADH/NADPH balance. Biotechnol Bioeng 2020; 118:175-185. [PMID: 32902873 DOI: 10.1002/bit.27560] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/09/2020] [Accepted: 08/27/2020] [Indexed: 01/02/2023]
Abstract
1,2,4-Butanetriol (BT) is used as a precursor for the synthesis of various pharmaceuticals and the energetic plasticizer 1,2,4-butanetriol trinitrate. In Saccharomyces cerevisiae, BT is biosynthesized from xylose via heterologous four enzymatic reactions catalyzed by xylose dehydrogenase, xylonate dehydratase, 2-ketoacid decarboxylase, and alcohol dehydrogenase. We here aimed to improve the BT yield in S. cerevisiae by genetic engineering. First, the amount of the key intermediate 2-keto-3-deoxy-xylonate as described previously was successfully reduced in 41% by multiple integrations of Lactococcus lactis 2-ketoacid decarboxylase gene kdcA into the yeast genome. Since the heterologous BT synthetic pathway is independent of yeast native metabolism, this manipulation has led to NADH/NADPH imbalance and deficiency during BT production. Overexpression of the NADH kinase POS5Δ17 lacking the mitochondrial targeting sequence to relieve NADH/NADPH imbalance resulted in the BT titer of 2.2 g/L (31% molar yield). Feeding low concentrations of glucose and xylose to support the supply of NADH resulted in BT titer of 6.6 g/L with (57% molar yield). Collectively, improving the NADH/NADPH ratio and supply from glucose are essential for the construction of a xylose pathway, such as the BT synthetic pathway, independent of native yeast metabolism.
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Affiliation(s)
- Takahiro Yukawa
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Takahiro Bamba
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Gregory Guirimand
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Biomolécules et Biotechnologies Végétales, EA 2106, Département of Agronomie, productions animale et végétale et agro-alimentaire, Université de Tours, Tours, France.,LE STUDIUM, Loire Valley Institute for Advanced Studies, Orléans, France
| | - Mami Matsuda
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Engineering Biology Research Center, Kobe University, Kobe, Japan
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Engineering Biology Research Center, Kobe University, Kobe, Japan
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Engineering Biology Research Center, Kobe University, Kobe, Japan.,Biomass Engineering Program, RIKEN, Yokohama, Kanagawa, Japan
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12
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Zhao Z, Xian M, Liu M, Zhao G. Biochemical routes for uptake and conversion of xylose by microorganisms. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:21. [PMID: 32021652 PMCID: PMC6995148 DOI: 10.1186/s13068-020-1662-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/21/2020] [Indexed: 05/23/2023]
Abstract
Xylose is a major component of lignocellulose and the second most abundant sugar present in nature. Efficient utilization of xylose is required for the development of economically viable processes to produce biofuels and chemicals from biomass. However, there are still some bottlenecks in the bioconversion of xylose, including the fact that some microorganisms cannot assimilate xylose naturally and that the uptake and metabolism of xylose are inhibited by glucose, which is usually present with xylose in lignocellulose hydrolysate. To overcome these issues, numerous efforts have been made to discover, characterize, and engineer the transporters and enzymes involved in xylose utilization to relieve glucose inhibition and to develop recombinant microorganisms to produce fuels and chemicals from xylose. Here we describe a recent advancement focusing on xylose-utilizing pathways, biosynthesis of chemicals from xylose, and engineering strategies used to improve the conversion efficiency of xylose.
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Affiliation(s)
- Zhe Zhao
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Mo Xian
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 China
| | - Min Liu
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 China
| | - Guang Zhao
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 China
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13
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Metabolic engineering of Escherichia coli for shikimate pathway derivative production from glucose-xylose co-substrate. Nat Commun 2020; 11:279. [PMID: 31937786 PMCID: PMC6959354 DOI: 10.1038/s41467-019-14024-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 12/13/2019] [Indexed: 11/08/2022] Open
Abstract
Glucose and xylose are the major components of lignocellulose. Effective utilization of both sugars can improve the efficiency of bioproduction. Here, we report a method termed parallel metabolic pathway engineering (PMPE) for producing shikimate pathway derivatives from glucose–xylose co-substrate. In this method, we seek to use glucose mainly for target chemical production, and xylose for supplying essential metabolites for cell growth. Glycolysis and the pentose phosphate pathway are completely separated from the tricarboxylic acid (TCA) cycle. To recover cell growth, we introduce a xylose catabolic pathway that directly flows into the TCA cycle. As a result, we can produce 4.09 g L−1cis,cis-muconic acid using the PMPE Escherichia coli strain with high yield (0.31 g g−1 of glucose) and produce l-tyrosine with 64% of the theoretical yield. The PMPE strategy can contribute to the development of clean processes for producing various valuable chemicals from lignocellulosic resources. In lignocellulose biomass, microbes prefer consuming glucose over xylose, which affects target compound production. Here, the authors achieve simultaneous utilization of glucose and xylose for target chemical production and cell growth, respectively, and realize high-level production of shikimate pathway derivatives.
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14
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Bañares AB, Valdehuesa KNG, Ramos KRM, Nisola GM, Lee WK, Chung WJ. Discovering a novel d-xylonate-responsive promoter: the PyjhI-driven genetic switch towards better 1,2,4-butanetriol production. Appl Microbiol Biotechnol 2019; 103:8063-8074. [DOI: 10.1007/s00253-019-10073-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 07/11/2019] [Accepted: 07/31/2019] [Indexed: 01/12/2023]
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15
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Li X, Chen Y, Nielsen J. Harnessing xylose pathways for biofuels production. Curr Opin Biotechnol 2019; 57:56-65. [PMID: 30785001 DOI: 10.1016/j.copbio.2019.01.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 01/04/2019] [Accepted: 01/15/2019] [Indexed: 01/02/2023]
Abstract
Energy security, environmental pollution, and economic development drive the development of alternatives to fossil fuels as an urgent global priority. Lignocellulosic biomass has the potential to contribute to meeting the demand for biofuel production via hydrolysis and fermentation of released sugars, such as glucose, xylose, and arabinose. Construction of robust cell factories requires introducing and rewiring of their metabolism to efficiently use all these sugars. Here, we review recent advances in re-constructing pathways for metabolism of pentoses, with special focus on xylose metabolism in the most widely used cell factories Saccharomyces cerevisiae and Escherichia coli. We also highlight engineering advanced biofuels-synthesis pathways and describes progress toward overcoming the challenges facing adoption of large-scale biofuel production.
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Affiliation(s)
- Xiaowei Li
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden
| | - Yun 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
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark; Wallenberg Center for Protein Research, Chalmers University of Technology, Gothenburg, Sweden.
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16
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High-yield production of D-1,2,4-butanetriol from lignocellulose-derived xylose by using a synthetic enzyme cascade in a cell-free system. J Biotechnol 2019; 292:76-83. [PMID: 30703470 DOI: 10.1016/j.jbiotec.2019.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 12/17/2018] [Accepted: 01/03/2019] [Indexed: 11/21/2022]
Abstract
Approaches using metabolic engineering to produce D-1, 2, 4-butanetriol (BT) from renewable biomass in microbial systems have achieved initial success. However, due to the lack of incomplete understanding of the complex branch pathway, the efficient fermentation system for BT production was difficult to develop. Here we reconstituted a cell-free system in vitro using purified enzymes to produce BT from d-xylose. The factors that influencing the efficiency of cell-free system, including enzyme concentration, reaction buffer, pH, temperature, metal ion additives and cofactors were first identified to define optimal reaction conditions and essential components for the cascade reaction. Meanwhile, a natural cofactor recycling system was found in cell-free system. Finally, we were able to convert 18 g/L xylose to 6.1 g/L BT within 40 h with a yield of 48.0%. The feasibility of cell-free system to produce BT in corncob hydrolysates was also determined.
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17
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Jing P, Cao X, Lu X, Zong H, Zhuge B. Modification of an engineered Escherichia coli by a combined strategy of deleting branch pathway, fine-tuning xylose isomerase expression, and substituting decarboxylase to improve 1,2,4-butanetriol production. J Biosci Bioeng 2018; 126:547-552. [DOI: 10.1016/j.jbiosc.2018.05.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 04/10/2018] [Accepted: 05/24/2018] [Indexed: 12/18/2022]
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18
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Valdehuesa KNG, Ramos KRM, Nisola GM, Bañares AB, Cabulong RB, Lee WK, Liu H, Chung WJ. Everyone loves an underdog: metabolic engineering of the xylose oxidative pathway in recombinant microorganisms. Appl Microbiol Biotechnol 2018; 102:7703-7716. [PMID: 30003296 DOI: 10.1007/s00253-018-9186-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 11/25/2022]
Abstract
The D-xylose oxidative pathway (XOP) has recently been employed in several recombinant microorganisms for growth or for the production of several valuable compounds. The XOP is initiated by D-xylose oxidation to D-xylonolactone, which is then hydrolyzed into D-xylonic acid. D-Xylonic acid is then dehydrated to form 2-keto-3-deoxy-D-xylonic acid, which may be further dehydrated then oxidized into α-ketoglutarate or undergo aldol cleavage to form pyruvate and glycolaldehyde. This review introduces a brief discussion about XOP and its discovery in bacteria and archaea, such as Caulobacter crescentus and Haloferax volcanii. Furthermore, the current advances in the metabolic engineering of recombinant strains employing the XOP are discussed. This includes utilization of XOP for the production of diols, triols, and short-chain organic acids in Escherichia coli, Saccharomyces cerevisiae, and Corynebacterium glutamicum. Improving the D-xylose uptake, growth yields, and product titer through several metabolic engineering techniques bring some of these recombinant strains close to industrial viability. However, more developments are still needed to optimize the XOP pathway in the host strains, particularly in the minimization of by-product formation.
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Affiliation(s)
- Kris Niño G Valdehuesa
- Department of Energy Science and Technology (DEST), Energy and Environment Fusion Technology Center (E2FTC), Myongji University, Myongji-ro 116, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Republic of Korea
| | - Kristine Rose M Ramos
- Department of Energy Science and Technology (DEST), Energy and Environment Fusion Technology Center (E2FTC), Myongji University, Myongji-ro 116, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Republic of Korea
| | - Grace M Nisola
- Department of Energy Science and Technology (DEST), Energy and Environment Fusion Technology Center (E2FTC), Myongji University, Myongji-ro 116, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Republic of Korea
| | - Angelo B Bañares
- Department of Energy Science and Technology (DEST), Energy and Environment Fusion Technology Center (E2FTC), Myongji University, Myongji-ro 116, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Republic of Korea
| | - Rhudith B Cabulong
- Department of Energy Science and Technology (DEST), Energy and Environment Fusion Technology Center (E2FTC), Myongji University, Myongji-ro 116, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Republic of Korea
| | - Won-Keun Lee
- Division of Bioscience and Bioinformatics, Myongji University, Myongji-ro 116, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Republic of Korea
| | - Huaiwei Liu
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, Qingdao, 266237, People's Republic of China.
| | - Wook-Jin Chung
- Department of Energy Science and Technology (DEST), Energy and Environment Fusion Technology Center (E2FTC), Myongji University, Myongji-ro 116, Cheoin-gu, Yongin, Gyeonggi-do, 17058, Republic of Korea.
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19
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Zhang Y, Dong R, Zhang M, Gao H. Native efflux pumps of Escherichia coli responsible for short and medium chain alcohol. Biochem Eng J 2018. [DOI: 10.1016/j.bej.2018.02.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Wang X, Xu N, Hu S, Yang J, Gao Q, Xu S, Chen K, Ouyang P. d-1,2,4-Butanetriol production from renewable biomass with optimization of synthetic pathway in engineered Escherichia coli. BIORESOURCE TECHNOLOGY 2018; 250:406-412. [PMID: 29195152 DOI: 10.1016/j.biortech.2017.11.062] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 06/07/2023]
Abstract
Bio-based production of d-1,2,4-butanetriol (BT) from renewable substrates is increasingly attracting attention. Here, the BT biosynthetic pathway was constructed and optimized in Escherichia coli to produce BT from pure d-xylose or corncob hydrolysates. First, E. coli BL21(DE3) was identified as a more proper host for BT production through host screening. Then, BT pathway was systematically optimized with gene homolog screening strategy, mainly targeting three key steps from xylonic acid to BT catalyzed by d-xylonate dehydratase (XD), 2-keto acid decarboxylase (KDC) and aldehyde reductase (ALR). After screening six ALRs, four KDCs and four XDs, AdhP from E. coli, KdcA from Lactococcus lactis and XylD from Caulobacter crescentus were identified more efficiently for BT production. The co-expression of these enzymes in recombinant strain BL21-14 led to BT production of 5.1 g/L under the optimized cultivation conditions. Finally, BT production from corncob hydrolysates was achieved with a titer of 3.4 g/L.
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Affiliation(s)
- Xin Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
| | - Nana Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
| | - Shewei Hu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
| | - Jianming Yang
- Xian Modern Chemistry Research Institute, Xian 710065, China
| | - Qian Gao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
| | - Sheng Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
| | - Kequan Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China.
| | - Pingkai Ouyang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
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21
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Engineering Escherichia coli for glycolic acid production from D-xylose through the Dahms pathway and glyoxylate bypass. Appl Microbiol Biotechnol 2018; 102:2179-2189. [DOI: 10.1007/s00253-018-8744-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 12/20/2017] [Accepted: 12/26/2017] [Indexed: 11/25/2022]
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22
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Gao H, Gao Y, Dong R. Enhanced biosynthesis of 3,4-dihydroxybutyric acid by engineered Escherichia coli in a dual-substrate system. BIORESOURCE TECHNOLOGY 2017; 245:794-800. [PMID: 28926911 DOI: 10.1016/j.biortech.2017.09.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 09/03/2017] [Accepted: 09/04/2017] [Indexed: 06/07/2023]
Abstract
3,4-Dihydroxybutyric acid (3,4-DHBA), a versatile platform four carbon (C4) chemical, can be used as a precursor in the production of many commercially important chemicals. Here, a dual-substrate biosynthesis system was developed for 3,4-DHBA production via a synthetic pathway established in an engineered Escherichia coli, and using xylose as a synthetic substrate and glucose as a cell growth substrate. The deletion of genes xylA, yjhH and yagE and others encoding for alcohol dehydrogenases in E. coli is essential for the production of 3,4-DHBA. Blocking competing pathway by removing the gene yiaE encoding for a 2-keto-3-deoxy-D-xylonate reductase also facilitated carbon flow towards the synthesis of 3,4-DHBA. Furthermore, regulation the availability of NAD+ resulted in further improved 3,4-DHBA production. The combinational optimization of the biosynthesis system led to a production of 0.38g/L 3,4-DHBA. This study provides an alternative 3,4-DHBA biosynthesis approach with the possibility of utilizing hydrolysates of lignocellulosic biomass as substrates.
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Affiliation(s)
- Haijun Gao
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China.
| | - Yu Gao
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Runan Dong
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
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23
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Salusjärvi L, Toivari M, Vehkomäki ML, Koivistoinen O, Mojzita D, Niemelä K, Penttilä M, Ruohonen L. Production of ethylene glycol or glycolic acid from D-xylose in Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2017; 101:8151-8163. [PMID: 29038973 DOI: 10.1007/s00253-017-8547-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 09/05/2017] [Accepted: 09/17/2017] [Indexed: 11/26/2022]
Abstract
The important platform chemicals ethylene glycol and glycolic acid were produced via the oxidative D-xylose pathway in the yeast Saccharomyces cerevisiae. The expression of genes encoding D-xylose dehydrogenase (XylB) and D-xylonate dehydratase (XylD) from Caulobacter crescentus and YagE or YjhH aldolase and aldehyde dehydrogenase AldA from Escherichia coli enabled glycolic acid production from D-xylose up to 150 mg/L. In strains expressing only xylB and xylD, 29 mg/L 2-keto-3-deoxyxylonic acid [(S)-4,5-dihydroxy-2-oxopentanoic acid] (2K3DXA) was produced and D-xylonic acid accumulated to ca. 9 g/L. A significant amount of D-xylonic acid (ca. 14%) was converted to 3-deoxypentonic acid (3DPA), and also, 3,4-dihydroxybutyric acid was formed. 2K3DXA was further converted to glycolaldehyde when genes encoding by either YagE or YjhH aldolase from E. coli were expressed. Reduction of glycolaldehyde to ethylene glycol by an endogenous aldo-keto reductase activity resulted further in accumulation of ethylene glycol of 14 mg/L. The possibility of simultaneous production of lactic and glycolic acids was evaluated by expression of gene encoding lactate dehydrogenase ldhL from Lactobacillus helveticus together with aldA. Interestingly, this increased the accumulation of glycolic acid to 1 g/L. The D-xylonate dehydratase activity in yeast was notably low, possibly due to inefficient Fe-S cluster synthesis in the yeast cytosol, and leading to D-xylonic acid accumulation. The dehydratase activity was significantly improved by targeting its expression to mitochondria or by altering the Fe-S cluster metabolism of the cells with FRA2 deletion.
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Affiliation(s)
- Laura Salusjärvi
- VTT Technical Research Centre of Finland Ltd., Solutions for Natural Resources and Environment, Tietotie 2, P.O. Box 1000, FI-02044 VTT, Espoo, Finland.
| | - Mervi Toivari
- VTT Technical Research Centre of Finland Ltd., Solutions for Natural Resources and Environment, Tietotie 2, P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Maija-Leena Vehkomäki
- VTT Technical Research Centre of Finland Ltd., Solutions for Natural Resources and Environment, Tietotie 2, P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Outi Koivistoinen
- VTT Technical Research Centre of Finland Ltd., Solutions for Natural Resources and Environment, Tietotie 2, P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Dominik Mojzita
- VTT Technical Research Centre of Finland Ltd., Solutions for Natural Resources and Environment, Tietotie 2, P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Klaus Niemelä
- VTT Technical Research Centre of Finland Ltd., Solutions for Natural Resources and Environment, Tietotie 2, P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Merja Penttilä
- VTT Technical Research Centre of Finland Ltd., Solutions for Natural Resources and Environment, Tietotie 2, P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Laura Ruohonen
- VTT Technical Research Centre of Finland Ltd., Solutions for Natural Resources and Environment, Tietotie 2, P.O. Box 1000, FI-02044 VTT, Espoo, Finland
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