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Zhao L, Lu Y, Yang J, Fang Y, Zhu L, Ding Z, Wang C, Ma W, Hu X, Wang X. Expression regulation of multiple key genes to improve L-threonine in Escherichia coli. Microb Cell Fact 2020; 19:46. [PMID: 32093713 PMCID: PMC7041290 DOI: 10.1186/s12934-020-01312-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/18/2020] [Indexed: 11/28/2022] Open
Abstract
Background Escherichia coli is an important strain for l-threonine production. Genetic switch is a ubiquitous regulatory tool for gene expression in prokaryotic cells. To sense and regulate intracellular or extracellular chemicals, bacteria evolve a variety of transcription factors. The key enzymes required for l-threonine biosynthesis in E. coli are encoded by the thr operon. The thr operon could coordinate expression of these genes when l-threonine is in short supply in the cell. Results The thrL leader regulatory elements were applied to regulate the expression of genes iclR, arcA, cpxR, gadE, fadR and pykF, while the threonine-activating promoters PcysH, PcysJ and PcysD were applied to regulate the expression of gene aspC, resulting in the increase of l-threonine production in an l-threonine producing E. coli strain TWF001. Firstly, different parts of the regulator thrL were inserted in the iclR regulator region in TWF001, and the best resulting strain TWF063 produced 16.34 g l-threonine from 40 g glucose after 30 h cultivation. Secondly, the gene aspC following different threonine-activating promoters was inserted into the chromosome of TWF063, and the best resulting strain TWF066 produced 17.56 g l-threonine from 40 g glucose after 30 h cultivation. Thirdly, the effect of expression regulation of arcA, cpxR, gadE, pykF and fadR was individually investigated on l-threonine production in TWF001. Finally, using TWF066 as the starting strain, the expression of genes arcA, cpxR, gadE, pykF and fadR was regulated individually or in combination to obtain the best strain for l-threonine production. The resulting strain TWF083, in which the expression of seven genes (iclR, aspC, arcA, cpxR, gadE, pykF, fadR and aspC) was regulated, produced 18.76 g l-threonine from 30 g glucose, 26.50 g l-threonine from 40 g glucose, or 26.93 g l-threonine from 50 g glucose after 30 h cultivation. In 48 h fed-batch fermentation, TWF083 could produce 116.62 g/L l‐threonine with a yield of 0.486 g/g glucose and productivity of 2.43 g/L/h. Conclusion The genetic engineering through the expression regulation of key genes is a better strategy than simple deletion of these genes to improve l-threonine production in E. coli. This strategy has little effect on the intracellular metabolism in the early stage of the growth but could increase l-threonine biosynthesis in the late stage.
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Affiliation(s)
- Lei Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Ying Lu
- Nanjing Customs District P. R. China, Wuxi, 214122, China
| | - Jun Yang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Yu Fang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Lifei Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Zhixiang Ding
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Chenhui Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Wenjian Ma
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Xiaoqing Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, 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, 1800 Lihu Avenue, 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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In vivo biosensors: mechanisms, development, and applications. ACTA ACUST UNITED AC 2018; 45:491-516. [DOI: 10.1007/s10295-018-2004-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 12/30/2017] [Indexed: 01/09/2023]
Abstract
Abstract
In vivo biosensors can recognize and respond to specific cellular stimuli. In recent years, biosensors have been increasingly used in metabolic engineering and synthetic biology, because they can be implemented in synthetic circuits to control the expression of reporter genes in response to specific cellular stimuli, such as a certain metabolite or a change in pH. There are many types of natural sensing devices, which can be generally divided into two main categories: protein-based and nucleic acid-based. Both can be obtained either by directly mining from natural genetic components or by engineering the existing genetic components for novel specificity or improved characteristics. A wide range of new technologies have enabled rapid engineering and discovery of new biosensors, which are paving the way for a new era of biotechnological progress. Here, we review recent advances in the design, optimization, and applications of in vivo biosensors in the field of metabolic engineering and synthetic biology.
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Mahr R, von Boeselager RF, Wiechert J, Frunzke J. Screening of an Escherichia coli promoter library for a phenylalanine biosensor. Appl Microbiol Biotechnol 2016; 100:6739-6753. [PMID: 27170323 DOI: 10.1007/s00253-016-7575-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/14/2016] [Accepted: 04/21/2016] [Indexed: 02/06/2023]
Abstract
In recent years, the application of transcription factor-based biosensors for the engineering of microbial production strains opened up new opportunities for industrial biotechnology. However, the design of synthetic regulatory circuits depends on the selection of suitable transcription factor-promoter pairs to convert the concentration of effector molecules into a measureable output. Here, we present an efficient strategy to screen promoter libraries for appropriate parts for biosensor design. To this end, we pooled the strains of the Alon library containing about 2000 different Escherichia coli promoter-gfpmut2 fusions, and enriched galactose- and L-phenylalanine-responsive promoters by toggled rounds of positive and negative selection using fluorescence-activated cell sorting (FACS). For both effectors, responsive promoters were isolated and verified by cultivation in microtiter plates. The promoter of mtr, encoding an L-tryptophan-specific transporter, was identified as suitable part for the construction of an L-phenylalanine biosensor. In the following, we performed a comparative analysis of different biosensor constructs based on the mtr promoter. The obtained data revealed a strong influence of the biosensor architecture on the performance characteristics. For proof-of-principle, the mtr sensor was applied in a FACS high-throughput screening of an E. coli MG1655 mutant library for the isolation of L-phenylalanine producers. These results emphasize the developed screening approach as a convenient strategy for the identification of effector-responsive promoters for the design of novel biosensors.
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Affiliation(s)
- Regina Mahr
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany
| | | | - Johanna Wiechert
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Julia Frunzke
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany.
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Gu P, Su T, Qi Q. Novel technologies provide more engineering strategies for amino acid-producing microorganisms. Appl Microbiol Biotechnol 2016; 100:2097-105. [PMID: 26754821 DOI: 10.1007/s00253-015-7276-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/20/2015] [Accepted: 12/23/2015] [Indexed: 10/22/2022]
Abstract
Traditionally, amino acid-producing strains were obtained by random mutagenesis and subsequent selection. With the development of genetic and metabolic engineering techniques, various microorganisms with high amino acid production yields are now constructed by rational design of targeted biosynthetic pathways. Recently, novel technologies derived from systems and synthetic biology have emerged and open a new promising avenue towards the engineering of amino acid production microorganisms. In this review, these approaches, including rational engineering of rate-limiting enzymes, real-time sensing of end-products, pathway optimization on the chromosome, transcription factor-mediated strain improvement, and metabolic modeling and flux analysis, were summarized with regard to their application in microbial amino acid production.
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Affiliation(s)
- Pengfei Gu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, People's Republic of China
| | - Tianyuan Su
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, People's Republic of China
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, People's Republic of China.
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Ma CW, Zhou LB, Zeng AP. Engineering Biomolecular Switches for Dynamic Metabolic Control. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2016; 162:45-76. [DOI: 10.1007/10_2016_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Mahr R, Frunzke J. Transcription factor-based biosensors in biotechnology: current state and future prospects. Appl Microbiol Biotechnol 2015; 100:79-90. [PMID: 26521244 PMCID: PMC4700088 DOI: 10.1007/s00253-015-7090-3] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 10/08/2015] [Accepted: 10/13/2015] [Indexed: 01/01/2023]
Abstract
Living organisms have evolved a plethora of sensing systems for the intra- and extracellular detection of small molecules, ions or physical parameters. Several recent studies have demonstrated that these principles can be exploited to devise synthetic regulatory circuits for metabolic engineering strategies. In this context, transcription factors (TFs) controlling microbial physiology at the level of transcription play a major role in biosensor design, since they can be implemented in synthetic circuits controlling gene expression in dependency of, for example, small molecule production. Here, we review recent progress on the utilization of TF-based biosensors in microbial biotechnology highlighting different areas of application. Recent advances in metabolic engineering reveal TF-based sensors to be versatile tools for strain and enzyme development using high-throughput (HT) screening strategies and adaptive laboratory evolution, the optimization of heterologous pathways via the implementation of dynamic control circuits and for the monitoring of single-cell productivity in live cell imaging studies. These examples underline the immense potential of TF-based biosensor circuits but also identify limitations and room for further optimization.
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Affiliation(s)
- Regina Mahr
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Julia Frunzke
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.
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Yim SS, Choi JW, Lee RJ, Lee YJ, Lee SH, Kim SY, Jeong KJ. Development of a new platform for secretory production of recombinant proteins inCorynebacterium glutamicum. Biotechnol Bioeng 2015; 113:163-72. [DOI: 10.1002/bit.25692] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 05/23/2015] [Accepted: 06/22/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Sung Sun Yim
- Department of Chemical and Biomolecular Engineering; BK21 Plus program, KAIST, 291 Daehak-ro, Yuseong-gu; Daejeon 305-701 Republic of Korea
| | - Jae Woong Choi
- Department of Chemical and Biomolecular Engineering; BK21 Plus program, KAIST, 291 Daehak-ro, Yuseong-gu; Daejeon 305-701 Republic of Korea
| | - Roo Jin Lee
- Department of Chemical and Biomolecular Engineering; BK21 Plus program, KAIST, 291 Daehak-ro, Yuseong-gu; Daejeon 305-701 Republic of Korea
| | - Yong Jae Lee
- Department of Chemical and Biomolecular Engineering; BK21 Plus program, KAIST, 291 Daehak-ro, Yuseong-gu; Daejeon 305-701 Republic of Korea
| | - Se Hwa Lee
- Department of Chemical and Biomolecular Engineering; BK21 Plus program, KAIST, 291 Daehak-ro, Yuseong-gu; Daejeon 305-701 Republic of Korea
| | - So Young Kim
- Bio R&D Center; CJ CheilJedang, 92 Gayang-dong, Gangseo-gu; Seoul 175-724 Republic of Korea
| | - Ki Jun Jeong
- Department of Chemical and Biomolecular Engineering; BK21 Plus program, KAIST, 291 Daehak-ro, Yuseong-gu; Daejeon 305-701 Republic of Korea
- Institute for the BioCentury; KAIST, 291 Daehak-ro, Yuseong-gu; Daejeon 305-701 Republic of Korea
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Liu Y, Li Q, Zheng P, Zhang Z, Liu Y, Sun C, Cao G, Zhou W, Wang X, Zhang D, Zhang T, Sun J, Ma Y. Developing a high-throughput screening method for threonine overproduction based on an artificial promoter. Microb Cell Fact 2015; 14:121. [PMID: 26296345 PMCID: PMC4546291 DOI: 10.1186/s12934-015-0311-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/04/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND L-Threonine is an important amino acid for animal feed. Though the industrial fermentation technology of threonine achieved a very high level, there is still significant room to further improve the industrial strains. The biosensor-based high-throughput screening (HTS) technology has demonstrated its powerful applications. Unfortunately, for most of valuable fine chemicals such as threonine, a HTS system has not been established mainly due to the absence of a suitable biosensor. In this study, we developed a HTS method to gain high-yielding threonine-producing strains. RESULTS Novel threonine sensing promoters including cysJp and cysHp were discovered by proteomic analyses of Escherichia coli in response to extracellular threonine challenges. The HTS method was constructed using a device composed of the fused cysJp and cysHp as a promoter and a linked enhanced green fluorescent protein gene as a reporter. More than 400 strains were selected with fluorescence activated cell sorting technology from a library of 20 million mutants and tested within 1 week. Thirty-four mutants have higher productivities than the starting industrial producer. One mutant produced 17.95 % more threonine in a 5-L jar fermenter. CONCLUSIONS This method should play a functional role for continuous improvement of threonine industry. Additionally, the threonine sensor construction using promoters obtained by proteomics analyses is so convenient that it would be easily extended to develop HTS models for other biochemicals.
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Affiliation(s)
- Ya'nan Liu
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300222, People's Republic of China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Qinggang Li
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Ping Zheng
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Zhidan Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Yongfei Liu
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Cunmin Sun
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Guoqiang Cao
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Wenjuan Zhou
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Xiaowei Wang
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, 211800, People's Republic of China.
| | - Dawei Zhang
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Tongcun Zhang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300222, People's Republic of China.
| | - Jibin Sun
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Yanhe Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
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