51
|
Zhai X, Ji L, Gao J, Zhou YJ. Characterizing methanol metabolism-related promoters for metabolic engineering of Ogataea polymorpha. Appl Microbiol Biotechnol 2021; 105:8761-8769. [PMID: 34748038 DOI: 10.1007/s00253-021-11665-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/22/2021] [Accepted: 10/25/2021] [Indexed: 01/24/2023]
Abstract
Promoters play an important role in regulating gene expression, and construction of microbial cell factories requires multiple promoters for balancing the metabolic pathways. However, there are only a limited number of characterized promoters for gene expression in the methylotrophic yeast Ogataea polymorpha, which hampers the extensive harnessing of this important yeast toward a cell factory. Here we characterized the promoters of methanol utilization pathway, precursor supply pathway, and reactive oxygen species (ROS) defense system, by using a green fluorescence protein variant (GFPUV) as a quantification signal. Finally, the characterized promoters were used for tuning a fatty alcohol biosynthetic pathway in O. polymorpha and realized fatty alcohol production from methanol. This promoter box should be helpful for gene expression and pathway optimization in the methylotrophic yeast O. polymorpha. KEY POINTS : • 22 promoters related to methanol metabolism were characterized in O. polymorpha. • Promoter truncation resulted shorter and compact promoters. • Promoters with various strengths were used for regulating a fatty alcohol biosynthesis from methanol.
Collapse
Affiliation(s)
- Xiaoxin Zhai
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian, 116023, People's Republic of China.,CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, People's Republic of China.,Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, People's Republic of China
| | - Lulu Ji
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian, 116023, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Jiaoqi Gao
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian, 116023, People's Republic of China.,CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, People's Republic of China.,Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, People's Republic of China
| | - Yongjin J Zhou
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian, 116023, People's Republic of China. .,CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, People's Republic of China. .,Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, People's Republic of China.
| |
Collapse
|
52
|
Tietze L, Lale R. Importance of the 5' regulatory region to bacterial synthetic biology applications. Microb Biotechnol 2021; 14:2291-2315. [PMID: 34171170 PMCID: PMC8601185 DOI: 10.1111/1751-7915.13868] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 01/02/2023] Open
Abstract
The field of synthetic biology is evolving at a fast pace. It is advancing beyond single-gene alterations in single hosts to the logical design of complex circuits and the development of integrated synthetic genomes. Recent breakthroughs in deep learning, which is increasingly used in de novo assembly of DNA components with predictable effects, are also aiding the discipline. Despite advances in computing, the field is still reliant on the availability of pre-characterized DNA parts, whether natural or synthetic, to regulate gene expression in bacteria and make valuable compounds. In this review, we discuss the different bacterial synthetic biology methodologies employed in the creation of 5' regulatory regions - promoters, untranslated regions and 5'-end of coding sequences. We summarize methodologies and discuss their significance for each of the functional DNA components, and highlight the key advances made in bacterial engineering by concentrating on their flaws and strengths. We end the review by outlining the issues that the discipline may face in the near future.
Collapse
Affiliation(s)
- Lisa Tietze
- PhotoSynLabDepartment of BiotechnologyFaculty of Natural SciencesNorwegian University of Science and TechnologyTrondheimN‐7491Norway
| | - Rahmi Lale
- PhotoSynLabDepartment of BiotechnologyFaculty of Natural SciencesNorwegian University of Science and TechnologyTrondheimN‐7491Norway
| |
Collapse
|
53
|
Intelligent host engineering for metabolic flux optimisation in biotechnology. Biochem J 2021; 478:3685-3721. [PMID: 34673920 PMCID: PMC8589332 DOI: 10.1042/bcj20210535] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 12/13/2022]
Abstract
Optimising the function of a protein of length N amino acids by directed evolution involves navigating a 'search space' of possible sequences of some 20N. Optimising the expression levels of P proteins that materially affect host performance, each of which might also take 20 (logarithmically spaced) values, implies a similar search space of 20P. In this combinatorial sense, then, the problems of directed protein evolution and of host engineering are broadly equivalent. In practice, however, they have different means for avoiding the inevitable difficulties of implementation. The spare capacity exhibited in metabolic networks implies that host engineering may admit substantial increases in flux to targets of interest. Thus, we rehearse the relevant issues for those wishing to understand and exploit those modern genome-wide host engineering tools and thinking that have been designed and developed to optimise fluxes towards desirable products in biotechnological processes, with a focus on microbial systems. The aim throughput is 'making such biology predictable'. Strategies have been aimed at both transcription and translation, especially for regulatory processes that can affect multiple targets. However, because there is a limit on how much protein a cell can produce, increasing kcat in selected targets may be a better strategy than increasing protein expression levels for optimal host engineering.
Collapse
|
54
|
Liu Y, Huang Y, Lu R, Xin F, Liu G. Synthetic biology applications of the yeast mating signal pathway. Trends Biotechnol 2021; 40:620-631. [PMID: 34666896 DOI: 10.1016/j.tibtech.2021.09.007] [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] [Received: 08/09/2021] [Revised: 09/17/2021] [Accepted: 09/17/2021] [Indexed: 12/18/2022]
Abstract
Cell fusion is a fundamental biological process that is involved in the development of most eukaryotic organisms. During the fusion process in Saccharomyces cerevisiae, cells respond to pheromones to trigger the MAPK (mitogen-activated protein kinase) cascade to initiate mating, followed by polarization, cell-wall remodeling, membrane fusion, and karyogamy. We highlight the applications of the yeast mating signal pathway in promoter engineering for tuning the expression of output genes, as well as in metabolic engineering for decoupling growth and metabolism, biosensors for sensitive detection and signal amplification, genetic circuits for programmable biological functionalities, and artificial consortia for cell-cell communication. Strategies such as exploiting rational engineering of modular circuits and optimizing the reproductive pathway to precisely maneuver physiological events have implications for scientific research and industrial development.
Collapse
Affiliation(s)
- Ying Liu
- College of Biological and Pharmaceutical Engineering, Nanjing Tech University, Jiangsu Province, China
| | - Yuxin Huang
- College of Biological and Pharmaceutical Engineering, Nanjing Tech University, Jiangsu Province, China
| | - Ran Lu
- College of Biological and Pharmaceutical Engineering, Nanjing Tech University, Jiangsu Province, China
| | - Fengxue Xin
- College of Biological and Pharmaceutical Engineering, Nanjing Tech University, Jiangsu Province, China
| | - Guannan Liu
- College of Biological and Pharmaceutical Engineering, Nanjing Tech University, Jiangsu Province, China; Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture, Nanjing Tech University, Jiangsu Province, China.
| |
Collapse
|
55
|
Cui DY, Ge JL, Song YM, Feng PP, Lin LC, Guo LY, Zhang CY. Regulating the ratio of higher alcohols to esters by simultaneously overexpressing ATF1 and deleting BAT2 in brewer's yeast Saccharomyces pastorianus. FOOD BIOSCI 2021. [DOI: 10.1016/j.fbio.2021.101231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
56
|
Wang GH, Cheng CY, Tsai TH, Chiang PK, Chung YC. Highly Sensitive Luminescent Bioassay Using Recombinant Escherichia coli Biosensor for Rapid Detection of Low Cr(VI) Concentration in Environmental Water. BIOSENSORS-BASEL 2021; 11:bios11100357. [PMID: 34677313 PMCID: PMC8534196 DOI: 10.3390/bios11100357] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/24/2021] [Accepted: 09/24/2021] [Indexed: 01/24/2023]
Abstract
In this study, we constructed a recombinant Escherichia coli strain with different promoters inserted between the chromate-sensing regulator chrB and the reporter gene luxAB to sense low hexavalent chromium (Cr(VI)) concentrations (<0.05 mg/L); subsequently, its biosensor characteristics (sensitivity, selectivity, and specificity) for measuring Cr(VI) in various water bodies were evaluated. The luminescence intensity of each biosensor depended on pH, temperature, detection time, coexisting carbon source, coexisting ion, Cr(VI) oxyanion form, Cr(VI) concentration, cell type, and type of medium. Recombinant lux-expressing E. coli with the T7 promoter (T7-lux-E. coli, limit of detection (LOD) = 0.0005 mg/L) had the highest luminescence intensity or was the most sensitive for Cr(VI) detection, followed by E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.001 mg/L) and that with the SP6 promoter (SP6-lux-E. coli, LOD = 0.005 mg/L). All biosensors could be used to determine whether the Cr(VI) standard was met in terms of water quality, even when using thawing frozen cells as biosensors after 90-day cryogenic storage. The SP6-lux-E. coli biosensor had the shortest detection time (0.5 h) and the highest adaptability to environmental interference. The T7-lux-E. coli biosensor—with the optimal LOD, a wide measurement range (0.0005–0.5 mg/L), and low deviation (−5.0–7.9%) in detecting Cr(VI) from industrial effluents, domestic effluents, and surface water—is an efficient Cr(VI) biosensor. This unprecedented study is to evaluate recombinant lux E. coli with dissimilar promoters for their possible practice in Cr(VI) measurement in water bodies, and the biosensor performance is clearly superior to that of past systems in terms of detection time, LOD, and detection deviation for real water samples.
Collapse
Affiliation(s)
- Guey-Horng Wang
- Research Center of Natural Cosmeceuticals Engineering, Xiamen Medical College, Xiamen 361008, China;
| | - Chiu-Yu Cheng
- Department of Biological Science and Technology, China University of Science and Technology, Taipei 115, Taiwan; (C.-Y.C.); (P.-K.C.)
| | - Teh-Hua Tsai
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 10608, Taiwan;
| | - Pin-Kuan Chiang
- Department of Biological Science and Technology, China University of Science and Technology, Taipei 115, Taiwan; (C.-Y.C.); (P.-K.C.)
| | - Ying-Chien Chung
- Department of Biological Science and Technology, China University of Science and Technology, Taipei 115, Taiwan; (C.-Y.C.); (P.-K.C.)
- Correspondence: ; Tel.: +886-22782-1862; Fax: +886-22786-5456
| |
Collapse
|
57
|
Optimization of protein trans-splicing in an inducible plasmid display system for high-throughput screening and selection of soluble proteins. Enzyme Microb Technol 2021; 153:109914. [PMID: 34670187 DOI: 10.1016/j.enzmictec.2021.109914] [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] [Received: 05/28/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 11/24/2022]
Abstract
Directed evolution is widely used to optimize protein folding and solubility in cells. Although the screening and selection of desired mutants is an essential step in directed evolution, it generally requires laborious optimization and/or specialized equipment. With a view toward designing a more practical procedure, we previously developed an inducible plasmid display system, in which the intein (auto-processing) and Oct-1 DNA-binding (DBD) domains were used as the protein trans-splicing domain and DNA-binding module, respectively. Specifically, the N-terminal (CfaN) and C-terminal (CfaC) domains of intein were fused to the C-terminal end of the His-tag and the N-terminal end of Oct-1 DBD to generate His6-CfaN and CfaC-Oct-1, respectively. For such a system to be viable, the efficiency of protein trans-splicing without the protein of interest (POI) should be maximized, such that the probability of occurrence is solely dependent on the solubility of the POI. To this end, we initially prevented the degradation of l-arabinose (the inducer of the PBAD promoter) by employing an Escherichia coli host strain deficient in the metabolism of l-arabinose. Given that a low expression of His6-CfaN, compared with that of CfaC-Oct-1, was found to be conducive to the generation to a soluble product of the protein trans-splicing event, we designed the expression of His6-CfaN and CfaC-Oct-1 to be inducible from the PBAD and PT7 promoters, respectively. The optimized system thus obtained enabled in vitro selection of the plasmid-protein complex with high yield. We believe that the inducible plasmid display system developed in this study would be applicable to high-throughput screening and/or selection of protein variants with enhanced solubility.
Collapse
|
58
|
Yang H, Qu J, Zou W, Shen W, Chen X. An overview and future prospects of recombinant protein production in Bacillus subtilis. Appl Microbiol Biotechnol 2021; 105:6607-6626. [PMID: 34468804 DOI: 10.1007/s00253-021-11533-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 08/12/2021] [Accepted: 08/15/2021] [Indexed: 12/27/2022]
Abstract
Bacillus subtilis is a well-characterized Gram-positive bacterium and a valuable host for recombinant protein production because of its efficient secretion ability, high yield, and non-toxicity. Here, we comprehensively review the recent studies on recombinant protein production in B. subtilis to update and supplement other previous reviews. We have focused on several aspects, including optimization of B. subtilis strains, enhancement and regulation of expression, improvement of secretion level, surface display of proteins, and fermentation optimization. Among them, optimization of B. subtilis strains mainly involves undirected chemical/physical mutagenesis and selection and genetic manipulation; enhancement and regulation of expression comprises autonomous plasmid and integrated expression, promoter regulation and engineering, and fine-tuning gene expression based on proteases and molecular chaperones; improvement of secretion level predominantly involves secretion pathway and signal peptide screening and optimization; surface display of proteins includes surface display of proteins on spores or vegetative cells; and fermentation optimization incorporates medium optimization, process condition optimization, and feeding strategy optimization. Furthermore, we propose some novel methods and future challenges for recombinant protein production in B. subtilis.Key points• A comprehensive review on recombinant protein production in Bacillus subtilis.• Novel techniques facilitate recombinant protein expression and secretion.• Surface display of proteins has significant potential for different applications.
Collapse
Affiliation(s)
- Haiquan Yang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
| | - Jinfeng Qu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Wei Zou
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin, 644000, Sichuan, China
| | - Wei Shen
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Xianzhong Chen
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
| |
Collapse
|
59
|
Metabolome and proteome analyses reveal transcriptional misregulation in glycolysis of engineered E. coli. Nat Commun 2021; 12:4929. [PMID: 34389727 PMCID: PMC8363753 DOI: 10.1038/s41467-021-25142-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 07/21/2021] [Indexed: 01/24/2023] Open
Abstract
Synthetic metabolic pathways are a burden for engineered bacteria, but the underlying mechanisms often remain elusive. Here we show that the misregulated activity of the transcription factor Cra is responsible for the growth burden of glycerol overproducing E. coli. Glycerol production decreases the concentration of fructose-1,6-bisphoshate (FBP), which then activates Cra resulting in the downregulation of glycolytic enzymes and upregulation of gluconeogenesis enzymes. Because cells grow on glucose, the improper activation of gluconeogenesis and the concomitant inhibition of glycolysis likely impairs growth at higher induction of the glycerol pathway. We solve this misregulation by engineering a Cra-binding site in the promoter controlling the expression of the rate limiting enzyme of the glycerol pathway to maintain FBP levels sufficiently high. We show the broad applicability of this approach by engineering Cra-dependent regulation into a set of constitutive and inducible promoters, and use one of them to overproduce carotenoids in E. coli. Synthetic pathways represent a metabolic burden on host cells. Here the authors engineer Cra-binding sites to prevent misregulation in glycerol and carotenoid overproducing E. coli strains.
Collapse
|
60
|
Cazier AP, Blazeck J. Advances in promoter engineering: novel applications and predefined transcriptional control. Biotechnol J 2021; 16:e2100239. [PMID: 34351706 DOI: 10.1002/biot.202100239] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/30/2021] [Accepted: 08/03/2021] [Indexed: 11/08/2022]
Abstract
Synthetic biology continues to progress by relying on more robust tools for transcriptional control, of which promoters are the most fundamental component. Numerous studies have sought to characterize promoter function, determine principles to guide their engineering, and create promoters with stronger expression or tailored inducible control. In this review, we will summarize promoter architecture and highlight recent advances in the field, focusing on the novel applications of inducible promoter design and engineering towards metabolic engineering and cellular therapeutic development. Additionally, we will highlight how the expansion of new, machine learning techniques for modeling and engineering promoter sequences are enabling more accurate prediction of promoter characteristics. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Andrew P Cazier
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst St. NW, Atlanta, Georgia, 30332, USA
| | - John Blazeck
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst St. NW, Atlanta, Georgia, 30332, USA
| |
Collapse
|
61
|
Dhakal D, Chen M, Luesch H, Ding Y. Heterologous production of cyanobacterial compounds. J Ind Microbiol Biotechnol 2021; 48:6119914. [PMID: 33928376 PMCID: PMC8210676 DOI: 10.1093/jimb/kuab003] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/17/2020] [Indexed: 12/29/2022]
Abstract
Cyanobacteria produce a plethora of compounds with unique chemical structures and diverse biological activities. Importantly, the increasing availability of cyanobacterial genome sequences and the rapid development of bioinformatics tools have unraveled the tremendous potential of cyanobacteria in producing new natural products. However, the discovery of these compounds based on cyanobacterial genomes has progressed slowly as the majority of their corresponding biosynthetic gene clusters (BGCs) are silent. In addition, cyanobacterial strains are often slow-growing, difficult for genetic engineering, or cannot be cultivated yet, limiting the use of host genetic engineering approaches for discovery. On the other hand, genetically tractable hosts such as Escherichia coli, Actinobacteria, and yeast have been developed for the heterologous expression of cyanobacterial BGCs. More recently, there have been increased interests in developing model cyanobacterial strains as heterologous production platforms. Herein, we present recent advances in the heterologous production of cyanobacterial compounds in both cyanobacterial and noncyanobacterial hosts. Emerging strategies for BGC assembly, host engineering, and optimization of BGC expression are included for fostering the broader applications of synthetic biology tools in the discovery of new cyanobacterial natural products.
Collapse
Affiliation(s)
- Dipesh Dhakal
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL 31610, USA
| | - Manyun Chen
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL 31610, USA
| | - Hendrik Luesch
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL 31610, USA
| | - Yousong Ding
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL 31610, USA
| |
Collapse
|
62
|
Adebami GE, Kuila A, Ajunwa OM, Fasiku SA, Asemoloye MD. Genetics and metabolic engineering of yeast strains for efficient ethanol production. J FOOD PROCESS ENG 2021. [DOI: 10.1111/jfpe.13798] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
| | - Arindam Kuila
- Department of Bioscience and Biotechnology Banasthali University Vanasthali India
| | - Obinna M. Ajunwa
- Department of Microbiology Modibbo Adama University of Technology Yola Nigeria
| | - Samuel A. Fasiku
- Department of Biological Sciences Ajayi Crowther University Oyo Nigeria
| | - Michael D. Asemoloye
- Department of Pharmaceutical Science and Technology Tianjin University Tianjin China
| |
Collapse
|
63
|
Sun W, Jiang B, Zhao D, Pu Z, Bao Y. Integration of metabolic pathway manipulation and promoter engineering for the fine-tuned biosynthesis of malic acid in Bacillus coagulans. Biotechnol Bioeng 2021; 118:2597-2608. [PMID: 33829485 DOI: 10.1002/bit.27780] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 11/08/2022]
Abstract
Bacillus coagulans, a thermophilic facultative anaerobe, is a favorable chassis strain for the biosynthesis of desired products. In this study, B. coagulans was converted into an efficient malic acid producer by metabolic engineering and promoter engineering. Promoter mapping revealed that the endogenous promoter Pldh was a tandem promoter. Accordingly, a promoter library was developed, covering a wide range of relative transcription efficiencies with small increments. A reductive tricarboxylic acid pathway was established in B. coagulans by introducing the genes encoding pyruvate carboxylase (pyc), malate dehydrogenase (mdh), and phosphoenolpyruvate carboxykinase (pckA). Five promoters of various strengths within the library were screened to fine-tune the expression of pyc to improve the biosynthesis of malic acid. In addition, genes involved in the competitive metabolic pathways were deleted to focus the substrate and energy flux toward malic acid. Dual-phase fed-batch fermentation was performed to increase the biomass of the strain, further improving the titer of malic acid to 25.5 g/L, with a conversion rate of 0.3 g/g glucose. Our study is a pioneer research using promoter engineering and genetically modified B. coagulans for the biosynthesis of malic acid, providing an effective approach for the industrialized production of desired products using B. coagulans.
Collapse
Affiliation(s)
- Wenhui Sun
- School of Bioengineering, Dalian University of Technology, Dalian, Liaoning, China
| | - Bo Jiang
- School of Bioengineering, Dalian University of Technology, Dalian, Liaoning, China
| | - Dongying Zhao
- School of Bioengineering, Dalian University of Technology, Dalian, Liaoning, China
| | - Zhongji Pu
- School of Bioengineering, Dalian University of Technology, Dalian, Liaoning, China
| | - Yongming Bao
- School of Bioengineering, Dalian University of Technology, Dalian, Liaoning, China.,School of Ocean Science and Technology, Dalian University of Technology, Panjin, Liaoning, China
| |
Collapse
|
64
|
Liang Y, Yu H. Genetic toolkits for engineering Rhodococcus species with versatile applications. Biotechnol Adv 2021; 49:107748. [PMID: 33823269 DOI: 10.1016/j.biotechadv.2021.107748] [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: 01/01/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 02/09/2023]
Abstract
Rhodococcus spp. are a group of non-model gram-positive bacteria with diverse catabolic activities and strong adaptive capabilities, which enable their wide application in whole-cell biocatalysis, environmental bioremediation, and lignocellulosic biomass conversion. Compared with model microorganisms, the engineering of Rhodococcus is challenging because of the lack of universal molecular tools, high genome GC content (61% ~ 71%), and low transformation and recombination efficiencies. Nevertheless, because of the high interest in Rhodococcus species for bioproduction, various genetic elements and engineering tools have been recently developed for Rhodococcus spp., including R. opacus, R. jostii, R. ruber, and R. erythropolis, leading to the expansion of the genetic toolkits for Rhodococcus engineering. In this article, we provide a comprehensive review of the important developed genetic elements for Rhodococcus, including shuttle vectors, promoters, antibiotic markers, ribosome binding sites, and reporter genes. In addition, we also summarize gene transfer techniques and strategies to improve transformation efficiency, as well as random and precise genome editing tools available for Rhodococcus, including transposition, homologous recombination, recombineering, and CRISPR/Cas9. We conclude by discussing future trends in Rhodococcus engineering. We expect that more synthetic and systems biology tools (such as multiplex genome editing, dynamic regulation, and genome-scale metabolic models) will be adapted and optimized for Rhodococcus.
Collapse
Affiliation(s)
- Youxiang Liang
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Key Laboratory of Industrial Biocatalysis (Tsinghua University), the Ministry of Education, Beijing 100084, China
| | - Huimin Yu
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Key Laboratory of Industrial Biocatalysis (Tsinghua University), the Ministry of Education, Beijing 100084, China; Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China.
| |
Collapse
|
65
|
Göttl VL, Schmitt I, Braun K, Peters-Wendisch P, Wendisch VF, Henke NA. CRISPRi-Library-Guided Target Identification for Engineering Carotenoid Production by Corynebacterium glutamicum. Microorganisms 2021; 9:670. [PMID: 33805131 PMCID: PMC8064071 DOI: 10.3390/microorganisms9040670] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/19/2021] [Accepted: 03/21/2021] [Indexed: 01/24/2023] Open
Abstract
Corynebacterium glutamicum is a prominent production host for various value-added compounds in white biotechnology. Gene repression by dCas9/clustered regularly interspaced short palindromic repeats (CRISPR) interference (CRISPRi) allows for the identification of target genes for metabolic engineering. In this study, a CRISPRi-based library for the repression of 74 genes of C. glutamicum was constructed. The chosen genes included genes encoding enzymes of glycolysis, the pentose phosphate pathway, and the tricarboxylic acid cycle, regulatory genes, as well as genes of the methylerythritol phosphate and carotenoid biosynthesis pathways. As expected, CRISPRi-mediated repression of the carotenogenesis repressor gene crtR resulted in increased pigmentation and cellular content of the native carotenoid pigment decaprenoxanthin. CRISPRi screening identified 14 genes that affected decaprenoxanthin biosynthesis when repressed. Carotenoid biosynthesis was significantly decreased upon CRISPRi-mediated repression of 11 of these genes, while repression of 3 genes was beneficial for decaprenoxanthin production. Largely, but not in all cases, deletion of selected genes identified in the CRISPRi screen confirmed the pigmentation phenotypes obtained by CRISPRi. Notably, deletion of pgi as well as of gapA improved decaprenoxanthin levels 43-fold and 9-fold, respectively. The scope of the designed library to identify metabolic engineering targets, transfer of gene repression to stable gene deletion, and limitations of the approach were discussed.
Collapse
Affiliation(s)
| | | | | | | | - Volker F. Wendisch
- Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, 33615 Bielefeld, Germany; (V.L.G.); (I.S.); (K.B.); (P.P.-W.); (N.A.H.)
| | | |
Collapse
|
66
|
Gilman J, Walls L, Bandiera L, Menolascina F. Statistical Design of Experiments for Synthetic Biology. ACS Synth Biol 2021; 10:1-18. [PMID: 33406821 DOI: 10.1021/acssynbio.0c00385] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The design and optimization of biological systems is an inherently complex undertaking that requires careful balancing of myriad synergistic and antagonistic variables. However, despite this complexity, much synthetic biology research is predicated on One Factor at A Time (OFAT) experimentation; the genetic and environmental variables affecting the activity of a system of interest are sequentially altered while all other variables are held constant. Beyond being time and resource intensive, OFAT experimentation crucially ignores the effect of interactions between factors. Given the ubiquity of interacting genetic and environmental factors in biology this failure to account for interaction effects in OFAT experimentation can result in the development of suboptimal systems. To address these limitations, an increasing number of studies have turned to Design of Experiments (DoE), a suite of methods that enable efficient, systematic exploration and exploitation of complex design spaces. This review provides an overview of DoE for synthetic biologists. Key concepts and commonly used experimental designs are introduced, and we discuss the advantages of DoE as compared to OFAT experimentation. We dissect the applicability of DoE in the context of synthetic biology and review studies which have successfully employed these methods, illustrating the potential of statistical experimental design to guide the design, characterization, and optimization of biological protocols, pathways, and processes.
Collapse
Affiliation(s)
- James Gilman
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH8 9YL, U.K
| | - Laura Walls
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH8 9YL, U.K
| | - Lucia Bandiera
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH8 9YL, U.K
| | - Filippo Menolascina
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH8 9YL, U.K
| |
Collapse
|
67
|
Varchenko OI, Kuchuk MV, Parii MF, Symonenko YV. Comparison of gfp Gene Expression Levels after Agrobacterium-Mediated Transient Transformation of Nicotiana rustica L. by Constructs with Different Promoter Sequences. CYTOL GENET+ 2021. [DOI: 10.3103/s0095452720060110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
68
|
Optimization of Cephalosporin C Acylase Expression in Escherichia coli by High-Throughput Screening a Constitutive Promoter Mutant library. Appl Biochem Biotechnol 2021; 193:1056-1071. [PMID: 33405008 DOI: 10.1007/s12010-020-03482-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/30/2020] [Indexed: 10/22/2022]
Abstract
Cephalosporin C acylase (CCA) is capable of catalyzing cephalosporin C (CPC) to produce 7-aminocephalosporanic acid (7-ACA), an intermediate of semi-synthetic cephalosporins. Inducible expression is usually used for CCA. To improve the efficiency of CCA expression without gene induction, three recombinant strains regulated by constitutive promoters BBa_J23105, PLtetO1, and tac were constructed, respectively. Among them, BBa_J23105 was the best promoter and its mutant libraries were established using saturation mutagenesis. In order to obtain the mutants with enhanced activity, a high-throughput screening method based on flow cytometric sorting techniques was developed by using green fluorescent protein (GFP) as the reporter gene. A series of mutants were screened at 28 °C, 200 rpm, and 24-h culture condition. The study of mutants showed that the enzyme activity, fluorescence intensity, and promoter transcriptional strength were positively correlated. The enzyme activity of the optimal mutant obtained by screening reached 12772 U/L, 3.47 times that of the original strain.
Collapse
|
69
|
Wang GH, Tsai TH, Kui CC, Cheng CY, Huang TL, Chung YC. Analysis of bioavailable toluene by using recombinant luminescent bacterial biosensors with different promoters. J Biol Eng 2021; 15:2. [PMID: 33407661 PMCID: PMC7789755 DOI: 10.1186/s13036-020-00254-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 12/29/2020] [Indexed: 01/24/2023] Open
Abstract
In this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol and lux genes as toluene biosensors and evaluated their sensitivity, selectivity, and specificity for measuring bioavailable toluene in groundwater and river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, and concentrations of toluene and coexisting organic compounds. Toluene induced the highest luminescence intensity in recombinant lux-expressing E. coli with the T7 promoter [T7-lux-E. coli, limit of detection (LOD) = 0.05 μM], followed by that in E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.2 μM) and SP6 promoter (SP6-lux-E. coli, LOD = 0.5 μM). Luminescence may have been synergistically or antagonistically affected by coexisting organic compounds other than toluene; nevertheless, low concentrations of benzoate and toluene analogs had no such effect. In reproducibility experiments, the biosensors had low relative standard deviation (4.3-5.8%). SP6-lux-E. coli demonstrated high adaptability to environmental interference. T7-lux-E. coli biosensor-with low LOD, wide measurement range (0.05-500 μM), and acceptable deviation (- 14.3 to 9.1%)-is an efficient toluene biosensor. This is the first study evaluating recombinant lux E. coli with different promoters for their potential application in toluene measurement in actual water bodies.
Collapse
Affiliation(s)
- Guey-Horng Wang
- Research Center of Natural Cosmeceuticals Engineering, Xiamen Medical College, Xiamen, 361008, China
| | - Teh-Hua Tsai
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan
| | - Chun-Chi Kui
- Department of Biological Science and Technology, China University of Science and Technology, Taipei, 11581, Taiwan
| | - Chiu-Yu Cheng
- Department of Biological Science and Technology, China University of Science and Technology, Taipei, 11581, Taiwan
| | - Tzu-Ling Huang
- Department of Biological Science and Technology, China University of Science and Technology, Taipei, 11581, Taiwan
| | - Ying-Chien Chung
- Department of Biological Science and Technology, China University of Science and Technology, Taipei, 11581, Taiwan.
| |
Collapse
|
70
|
Gilman J, Zulkower V, Menolascina F. Using a Design of Experiments Approach to Inform the Design of Hybrid Synthetic Yeast Promoters. Methods Mol Biol 2021; 2189:1-17. [PMID: 33180289 DOI: 10.1007/978-1-0716-0822-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Hybrid promoter engineering takes advantage of the modular nature of eukaryotic promoters by combining discrete promoter motifs to confer novel regulatory function. By combinatorially screening sequence libraries for trans-acting transcriptional operators, activators, repressors and core promoter sequences, it is possible to derive constitutive or inducible promoter collections covering a broad range of expression strengths. However, combinatorial approaches to promoter design can result in highly complex, multidimensional design spaces, which can be experimentally costly to thoroughly explore in vivo. Here, we describe an in silico pipeline for the design of hybrid promoter libraries that employs a Design of Experiments (DoE) approach to reduce experimental burden and efficiently explore the promoter fitness landscape. We also describe a software pipeline to ensure that the designed promoter sequences are compatible with the YTK assembly standard.
Collapse
Affiliation(s)
- James Gilman
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh, UK
| | - Valentin Zulkower
- Edinburgh Genome Foundry, The University of Edinburgh, Edinburgh, UK
| | - Filippo Menolascina
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh, UK.
| |
Collapse
|
71
|
Modeling SELEX for regulatory regions using Royal Road and Royal Staircase fitness functions. Biosystems 2020; 200:104312. [PMID: 33278501 DOI: 10.1016/j.biosystems.2020.104312] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/11/2020] [Accepted: 11/23/2020] [Indexed: 01/24/2023]
Abstract
The field of evolutionary algorithms (EAs) emerged in the area of computer science due to transfer of ideas from biology and developed independently for several decades, enriched with techniques from probability theory, complexity theory and optimization methods. In this paper, we consider some recent results form the EAs theory transferred back into biology. The well-known biotechnological procedure SELEX (Systematic Evolution of Ligands by EXponential enrichment) is viewed as an experimental implementation of an evolutionary algorithm. Theoretical bounds on EAs runtime are applied to model SELEX search for a regulatory region consisting of promoter and enhancer sequences. A comparison of theoretical bounds to the results of computational simulation indicates some cases where the theoretical bounds give favorable prediction, while simulation requires prohibitive computational resource.
Collapse
|
72
|
Guirimand G, Kulagina N, Papon N, Hasunuma T, Courdavault V. Innovative Tools and Strategies for Optimizing Yeast Cell Factories. Trends Biotechnol 2020; 39:488-504. [PMID: 33008642 DOI: 10.1016/j.tibtech.2020.08.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/24/2020] [Accepted: 08/27/2020] [Indexed: 12/13/2022]
Abstract
Metabolic engineering (ME) aims to develop efficient microbial cell factories that can produce a wide variety of valuable compounds, ideally at the highest yield and from various feedstocks. We summarize recent developments in ME methods for tailoring different yeast cell factories (YCFs). In particular, we highlight the most timely and cutting-edge molecular tools and strategies for biosynthetic pathway optimization (including genome-editing tools), combinatorial transcriptional and post-transcriptional engineering (cis/trans regulators), dynamic control of metabolic fluxes (e.g., rewiring of primary metabolism), and spatial reconfiguration of metabolic pathways. Finally, we discuss challenges and perspectives for adaptive laboratory evolution (ALE) of yeast to advance ME of microbial cell factories.
Collapse
Affiliation(s)
- Gregory Guirimand
- Graduate School of Sciences, Technology and Innovation, Kobe University, Kobe, Japan; Biomolécules et Biotechnologies Végétales (BBV), Équipe d'Accueil (EA) 2106, Université de Tours, Tours, France
| | - Natalja Kulagina
- Biomolécules et Biotechnologies Végétales (BBV), Équipe d'Accueil (EA) 2106, Université de Tours, Tours, France
| | - Nicolas Papon
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP), EA 3142, Université Angers and Université Brest, Structure Féderative de Recherche (SFR) 4208 Interactions Cellulaires et Applications Thérapeutiques (ICAT), Angers, France
| | - Tomohisa Hasunuma
- Graduate School of Sciences, Technology and Innovation, Kobe University, Kobe, Japan; Engineering Biology Research Center, Kobe University, Kobe, Japan.
| | - Vincent Courdavault
- Biomolécules et Biotechnologies Végétales (BBV), Équipe d'Accueil (EA) 2106, Université de Tours, Tours, France.
| |
Collapse
|
73
|
Su Y, Liu C, Fang H, Zhang D. Bacillus subtilis: a universal cell factory for industry, agriculture, biomaterials and medicine. Microb Cell Fact 2020; 19:173. [PMID: 32883293 PMCID: PMC7650271 DOI: 10.1186/s12934-020-01436-8] [Citation(s) in RCA: 149] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 08/27/2020] [Indexed: 12/18/2022] Open
Abstract
Due to its clear inherited backgrounds as well as simple and diverse genetic manipulation systems, Bacillus subtilis is the key Gram-positive model bacterium for studies on physiology and metabolism. Furthermore, due to its highly efficient protein secretion system and adaptable metabolism, it has been widely used as a cell factory for microbial production of chemicals, enzymes, and antimicrobial materials for industry, agriculture, and medicine. In this mini-review, we first summarize the basic genetic manipulation tools and expression systems for this bacterium, including traditional methods and novel engineering systems. Secondly, we briefly introduce its applications in the production of chemicals and enzymes, and summarize its advantages, mainly focusing on some noteworthy products and recent progress in the engineering of B. subtilis. Finally, this review also covers applications such as microbial additives and antimicrobials, as well as biofilm systems and spore formation. We hope to provide an overview for novice researchers in this area, offering them a better understanding of B. subtilis and its applications.
Collapse
Affiliation(s)
- Yuan Su
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Chuan Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Huan Fang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
74
|
Tang H, Wu Y, Deng J, Chen N, Zheng Z, Wei Y, Luo X, Keasling JD. Promoter Architecture and Promoter Engineering in Saccharomyces cerevisiae. Metabolites 2020; 10:metabo10080320. [PMID: 32781665 PMCID: PMC7466126 DOI: 10.3390/metabo10080320] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/30/2020] [Accepted: 08/04/2020] [Indexed: 12/23/2022] Open
Abstract
Promoters play an essential role in the regulation of gene expression for fine-tuning genetic circuits and metabolic pathways in Saccharomyces cerevisiae (S. cerevisiae). However, native promoters in S. cerevisiae have several limitations which hinder their applications in metabolic engineering. These limitations include an inadequate number of well-characterized promoters, poor dynamic range, and insufficient orthogonality to endogenous regulations. Therefore, it is necessary to perform promoter engineering to create synthetic promoters with better properties. Here, we review recent advances related to promoter architecture, promoter engineering and synthetic promoter applications in S. cerevisiae. We also provide a perspective of future directions in this field with an emphasis on the recent advances of machine learning based promoter designs.
Collapse
Affiliation(s)
- Hongting Tang
- Center for Synthetic Biochemistry, Shenzhen Institutes for Advanced Technologies, Chinese Academy of Sciences, Shenzhen 518055, China; (H.T.); (Y.W.); (J.D.); (N.C.); (Z.Z.)
| | - Yanling Wu
- Center for Synthetic Biochemistry, Shenzhen Institutes for Advanced Technologies, Chinese Academy of Sciences, Shenzhen 518055, China; (H.T.); (Y.W.); (J.D.); (N.C.); (Z.Z.)
| | - Jiliang Deng
- Center for Synthetic Biochemistry, Shenzhen Institutes for Advanced Technologies, Chinese Academy of Sciences, Shenzhen 518055, China; (H.T.); (Y.W.); (J.D.); (N.C.); (Z.Z.)
| | - Nanzhu Chen
- Center for Synthetic Biochemistry, Shenzhen Institutes for Advanced Technologies, Chinese Academy of Sciences, Shenzhen 518055, China; (H.T.); (Y.W.); (J.D.); (N.C.); (Z.Z.)
| | - Zhaohui Zheng
- Center for Synthetic Biochemistry, Shenzhen Institutes for Advanced Technologies, Chinese Academy of Sciences, Shenzhen 518055, China; (H.T.); (Y.W.); (J.D.); (N.C.); (Z.Z.)
| | - Yongjun Wei
- School of Pharmaceutical Sciences, Key Laboratory of Advanced Drug Preparation Technologies, Ministry of Education, Zhengzhou University, Zhengzhou 450001, China;
| | - Xiaozhou Luo
- Center for Synthetic Biochemistry, Shenzhen Institutes for Advanced Technologies, Chinese Academy of Sciences, Shenzhen 518055, China; (H.T.); (Y.W.); (J.D.); (N.C.); (Z.Z.)
- Correspondence: (X.L.); (J.D.K.)
| | - Jay D. Keasling
- Center for Synthetic Biochemistry, Shenzhen Institutes for Advanced Technologies, Chinese Academy of Sciences, Shenzhen 518055, China; (H.T.); (Y.W.); (J.D.); (N.C.); (Z.Z.)
- Joint BioEnergy Institute, Emeryville, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Chemical and Biomolecular Engineering & Department of Bioengineering, University of California, Berkeley, CA 94720, USA
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
- Correspondence: (X.L.); (J.D.K.)
| |
Collapse
|
75
|
Transcriptional control of gene expression in Pichia pastoris by manipulation of terminators. Appl Microbiol Biotechnol 2020; 104:7841-7851. [DOI: 10.1007/s00253-020-10785-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/03/2020] [Accepted: 07/13/2020] [Indexed: 12/11/2022]
|
76
|
Construction of a High-Expression System in Bacillus through Transcriptomic Profiling and Promoter Engineering. Microorganisms 2020; 8:microorganisms8071030. [PMID: 32664655 PMCID: PMC7409208 DOI: 10.3390/microorganisms8071030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/26/2020] [Accepted: 07/09/2020] [Indexed: 01/24/2023] Open
Abstract
Bacillus subtilis is an ideal host for secretion and expression of foreign proteins. The promoter is one of the most important elements to facilitate the high-level production of recombinant protein. To expand the repertoire of strong promoters for biotechnological applications in Bacillus species, 14 highly transcribed genes based on transcriptome profiling of B. pumilus BA06 were selected and evaluated for their promoter strength in B. subtilis. Consequently, a strong promoter P2069 was obtained, which could drive the genes encoding alkaline protease (aprE) and green fluorescent protein (GFP) to express more efficiency by an increase of 3.65-fold and 18.40-fold in comparison with the control promoter (PaprE), respectively. Further, promoter engineering was applied to P2069, leading to a mutation promoter (P2069M) that could increase GFP expression by 3.67-fold over the wild-type promoter (P2069). Moreover, the IPTG-inducible expression systems were constructed using the lac operon based on the strong promoters of P2069 and P2069M, which could work well both in B. subtilis and B. pumilus. In this study, highly efficient expression system for Bacillus was constructed based on transcriptome data and promoter engineering, which provide not only a new option for recombinant expression in B. subtilis, but also novel genetic tool for B. pumilus.
Collapse
|
77
|
Transcriptional regulatory proteins in central carbon metabolism of Pichia pastoris and Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2020; 104:7273-7311. [PMID: 32651601 DOI: 10.1007/s00253-020-10680-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/04/2020] [Accepted: 05/10/2020] [Indexed: 01/21/2023]
Abstract
System-wide interactions in living cells and discovery of the diverse roles of transcriptional regulatory proteins that are mediator proteins with catalytic domains and regulatory subunits and transcription factors in the cellular pathways have become crucial for understanding the cellular response to environmental conditions. This review provides information for future metabolic engineering strategies through analyses on the highly interconnected regulatory networks in Saccharomyces cerevisiae and Pichia pastoris and identifying their components. We discuss the current knowledge on the carbon catabolite repression (CCR) mechanism, interconnecting regulatory system of the central metabolic pathways that regulate cell metabolism based on nutrient availability in the industrial yeasts. The regulatory proteins and their functions in the CCR signalling pathways in both yeasts are presented and discussed. We highlight the importance of metabolic signalling networks by signifying ways on how effective engineering strategies can be designed for generating novel regulatory circuits, furthermore to activate pathways that reconfigure the network architecture. We summarize the evidence that engineering of multilayer regulation is needed for directed evolution of the cellular network by putting the transcriptional control into a new perspective for the regulation of central carbon metabolism of the industrial yeasts; furthermore, we suggest research directions that may help to enhance production of recombinant products in the widely used, creatively engineered, but relatively less studied P. pastoris through de novo metabolic engineering strategies based on the discovery of components of signalling pathways in CCR metabolism. KEY POINTS: • Transcriptional regulation and control is the key phenomenon in the cellular processes. • Designing de novo metabolic engineering strategies depends on the discovery of signalling pathways in CCR metabolism. • Crosstalk between pathways occurs through essential parts of transcriptional machinery connected to specific catalytic domains. • In S. cerevisiae, a major part of CCR metabolism is controlled through Snf1 kinase, Glc7 phosphatase, and Srb10 kinase. • In P. pastoris, signalling pathways in CCR metabolism have not yet been clearly known yet. • Cellular regulations on the transcription of promoters are controlled with carbon sources.
Collapse
|
78
|
Synthetic biology, systems biology, and metabolic engineering of Yarrowia lipolytica toward a sustainable biorefinery platform. J Ind Microbiol Biotechnol 2020; 47:845-862. [PMID: 32623653 DOI: 10.1007/s10295-020-02290-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 06/25/2020] [Indexed: 01/24/2023]
Abstract
Yarrowia lipolytica is an oleaginous yeast that has been substantially engineered for production of oleochemicals and drop-in transportation fuels. The unique acetyl-CoA/malonyl-CoA supply mode along with the versatile carbon-utilization pathways makes this yeast a superior host to upgrade low-value carbons into high-value secondary metabolites and fatty acid-based chemicals. The expanded synthetic biology toolkits enabled us to explore a large portfolio of specialized metabolism beyond fatty acids and lipid-based chemicals. In this review, we will summarize the recent advances in genetic, omics, and computational tool development that enables us to streamline the genetic or genomic modification for Y. lipolytica. We will also summarize various metabolic engineering strategies to harness the endogenous acetyl-CoA/malonyl-CoA/HMG-CoA pathway for production of complex oleochemicals, polyols, terpenes, polyketides, and commodity chemicals. We envision that Y. lipolytica will be an excellent microbial chassis to expand nature's biosynthetic capacity to produce plant secondary metabolites, industrially relevant oleochemicals, agrochemicals, commodity, and specialty chemicals and empower us to build a sustainable biorefinery platform that contributes to the prosperity of a bio-based economy in the future.
Collapse
|
79
|
Dhillon N, Shelansky R, Townshend B, Jain M, Boeger H, Endy D, Kamakaka R. Permutational analysis of Saccharomyces cerevisiae regulatory elements. Synth Biol (Oxf) 2020; 5:ysaa007. [PMID: 32775697 PMCID: PMC7402160 DOI: 10.1093/synbio/ysaa007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/12/2020] [Accepted: 05/29/2020] [Indexed: 01/24/2023] Open
Abstract
Gene expression in Saccharomyces cerevisiae is regulated at multiple levels. Genomic and epigenomic mapping of transcription factors and chromatin factors has led to the delineation of various modular regulatory elements—enhancers (upstream activating sequences), core promoters, 5′ untranslated regions (5′ UTRs) and transcription terminators/3′ untranslated regions (3′ UTRs). However, only a few of these elements have been tested in combinations with other elements and the functional interactions between the different modular regulatory elements remain under explored. We describe a simple and rapid approach to build a combinatorial library of regulatory elements and have used this library to study 26 different enhancers, core promoters, 5′ UTRs and transcription terminators/3′ UTRs to estimate the contribution of individual regulatory parts in gene expression. Our combinatorial analysis shows that while enhancers initiate gene expression, core promoters modulate the levels of enhancer-mediated expression and can positively or negatively affect expression from even the strongest enhancers. Principal component analysis (PCA) indicates that enhancer and promoter function can be explained by a single principal component while UTR function involves multiple functional components. The PCA also highlights outliers and suggest differences in mechanisms of regulation by individual elements. Our data also identify numerous regulatory cassettes composed of different individual regulatory elements that exhibit equivalent gene expression levels. These data thus provide a catalog of elements that could in future be used in the design of synthetic regulatory circuits.
Collapse
Affiliation(s)
- Namrita Dhillon
- Department of MCD Biology, University of California, Santa Cruz, CA, USA
| | - Robert Shelansky
- Department of MCD Biology, University of California, Santa Cruz, CA, USA
| | - Brent Townshend
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Miten Jain
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA, USA
| | - Hinrich Boeger
- Department of MCD Biology, University of California, Santa Cruz, CA, USA
| | - Drew Endy
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Rohinton Kamakaka
- Department of MCD Biology, University of California, Santa Cruz, CA, USA
| |
Collapse
|
80
|
Li N, Zeng W, Xu S, Zhou J. Toward fine-tuned metabolic networks in industrial microorganisms. Synth Syst Biotechnol 2020; 5:81-91. [PMID: 32542205 PMCID: PMC7283098 DOI: 10.1016/j.synbio.2020.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 03/30/2020] [Accepted: 05/06/2020] [Indexed: 12/11/2022] Open
Abstract
There are numerous microorganisms in nature capable of synthesizing diverse useful compounds; however, these natural microorganisms are generally inefficient in the production of target products on an industrial scale, relative to either chemical synthesis or extraction methods. To achieve industrial production of useful compounds, these natural microorganisms must undergo a certain degree of mutation or effective fine-tuning strategies. This review describes how to achieve an ideal metabolic fine-tuned process, including static control strategies and dynamic control strategies. The static control strategies mainly focus on various matabolic engineering strategies, including protein engineering, upregulation/downregulation, and combinatrorial control of these metabolic engineering strategies, to enhance the flexibility of their application in fine-tuned metabolic metworks. Then, we focus on the dynamic control strategies for fine-tuned metabolic metworks. The design principles derived would guide us to construct microbial cell factories for various useful compounds.
Collapse
Affiliation(s)
- Ning Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
| | - Weizhu Zeng
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
| | - Sha Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
| | - Jingwen Zhou
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
| |
Collapse
|
81
|
Xu D, Zhang L. Pathway Engineering for Phenethylamine Production in Escherichia coli. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:5917-5926. [PMID: 32367713 DOI: 10.1021/acs.jafc.0c01706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this study, the metabolic pathway of phenethylamine synthesis was reconstructed by chromosomal integration and overexpression of the Enterococcus faecium pdc gene encoding phenylalanine decarboxylase in Escherichia coli. The genes encoding 3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (aroG), shikimate kinase II (aroL), chorismate mutase/prephenate dehydratase (pheA), and tyrosine aminotransferase (tyrB) in the phenethylamine synthetic pathway were sequentially chromosomally overexpressed. The phosphotransferase system was replaced by deleting the ptsH-ptsI-crr genes and chromosomally overexpressing the genes encoding galactose permease (galP) and glucokinase (glk). In addition, the zwf gene encoding glucose-6-phosphate dehydrogenase in the pentose phosphate pathway was chromosomally overexpressed, generating the final engineered E. coli strain AUD9. The AUD9 strain produced 2.65 g L-1 phenethylamine with a yield of 0.27 g of phenethylamine g-1 glucose in batch fermentation; fed-batch fermentation of AUD9 produced 38.82 g L-1 phenethylamine with a productivity of 1.08 g L-1 h-1 phenethylamine, demonstrating its potential for industrial fermentative production of phenethylamine.
Collapse
Affiliation(s)
- Daqing Xu
- College of Life Sciences, Hebei Agricultural University, Baoding 071000, China
| | - Lirong Zhang
- College of Plant Protection, Hebei Agricultural University, Baoding 071000, China
| |
Collapse
|
82
|
Bhattarai K, Bastola R, Baral B. Antibiotic drug discovery: Challenges and perspectives in the light of emerging antibiotic resistance. ADVANCES IN GENETICS 2020; 105:229-292. [PMID: 32560788 DOI: 10.1016/bs.adgen.2019.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Amid a rising threat of antimicrobial resistance in a global scenario, our huge investments and high-throughput technologies injected for rejuvenating the key therapeutic scaffolds to suppress these rising superbugs has been diminishing severely. This has grasped world-wide attention, with increased consideration being given to the discovery of new chemical entities. Research has now proven that the relatively tiny and simpler microbes possess enhanced capability of generating novel and diverse chemical constituents with huge therapeutic leads. The usage of these beneficial organisms could help in producing new chemical scaffolds that govern the power to suppress the spread of obnoxious superbugs. Here in this review, we have explicitly focused on several appealing strategies employed for the generation of new chemical scaffolds. Also, efforts on providing novel insights on some of the unresolved questions in the production of metabolites, metabolic profiling and also the serendipity of getting "hit molecules" have been rigorously discussed. However, we are highly aware that biosynthetic pathway of different classes of secondary metabolites and their biosynthetic route is a vast topic, thus we have avoided discussion on this topic.
Collapse
Affiliation(s)
- Keshab Bhattarai
- University of Tübingen, Tübingen, Germany; Center for Natural and Applied Sciences (CENAS), Kathmandu, Nepal
| | - Rina Bastola
- Spinal Cord Injury Association-Nepal (SCIAN), Pokhara, Nepal
| | - Bikash Baral
- Spinal Cord Injury Association-Nepal (SCIAN), Pokhara, Nepal.
| |
Collapse
|
83
|
Jaishankar J, Srivastava P. Strong synthetic stationary phase promoter-based gene expression system for Escherichia coli. Plasmid 2020; 109:102491. [DOI: 10.1016/j.plasmid.2020.102491] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 01/25/2020] [Accepted: 01/28/2020] [Indexed: 01/24/2023]
|
84
|
Zhang J, Wang Z, Su T, Sun H, Zhu Y, Qi Q, Wang Q. Tuning the Binding Affinity of Heme-Responsive Biosensor for Precise and Dynamic Pathway Regulation. iScience 2020; 23:101067. [PMID: 32371371 PMCID: PMC7200772 DOI: 10.1016/j.isci.2020.101067] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 02/21/2020] [Accepted: 04/13/2020] [Indexed: 02/06/2023] Open
Abstract
Current challenge for dynamic pathway control in metabolic engineering is enabling the components of the artificial regulatory system to be tunable. Here, we designed and built a heme-responsive regulatory system containing a heme biosensor HrtR and CRISPRi to regulate chemicals production while maintaining the intracellular heme homeostasis. A series of engineered biosensors with varied sensitivity and threshold were obtained by semi-rational design with site saturated mutation of HrtR. The modified metabolite-binding affinity of HrtR was confirmed by heme titration and molecular dynamic simulation. Dynamic regulation pattern of the system was validated by the fluctuation of gene expression and intracellular heme concentration. The efficiency of this regulatory system was proved by improving the 5-aminolevulinic acid (ALA) production to 5.35g/L, the highest yield in batch fermentation of Escherichia coli. This system was also successfully used in improving porphobilinogen (PBG) and porphyrins biosynthesis and can be applied in many other biological processes. Designed and built a heme-responsive regulatory system employing HrtR and CRISPRi Turning the binding affinity of HrtR by site saturation mutations Optimizing the system to achieve dynamic regulation of target genes The system was applied to the ALA, PBG, and porphyrins production
Collapse
Affiliation(s)
- Jian Zhang
- State Key Laboratory of Microbial Technology, National Glycoengineering Research Center, Shandong University, Qingdao 266237, P. R. China
| | - Zhiguo Wang
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, P. R. China
| | - Tianyuan Su
- State Key Laboratory of Microbial Technology, National Glycoengineering Research Center, Shandong University, Qingdao 266237, P. R. China
| | - Huanhuan Sun
- State Key Laboratory of Microbial Technology, National Glycoengineering Research Center, Shandong University, Qingdao 266237, P. R. China
| | - Yuan Zhu
- State Key Laboratory of Microbial Technology, National Glycoengineering Research Center, Shandong University, Qingdao 266237, P. R. China
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, National Glycoengineering Research Center, Shandong University, Qingdao 266237, P. R. China; CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, P. R. China.
| | - Qian Wang
- State Key Laboratory of Microbial Technology, National Glycoengineering Research Center, Shandong University, Qingdao 266237, P. R. China.
| |
Collapse
|
85
|
Natural and engineered promoters for gene expression in Lactobacillus species. Appl Microbiol Biotechnol 2020; 104:3797-3805. [DOI: 10.1007/s00253-020-10426-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/20/2020] [Accepted: 02/03/2020] [Indexed: 01/24/2023]
|
86
|
Landberg J, Mundhada H, Nielsen AT. An autoinducible trp-T7 expression system for production of proteins and biochemicals in Escherichia coli. Biotechnol Bioeng 2020; 117:1513-1524. [PMID: 32022248 PMCID: PMC7186829 DOI: 10.1002/bit.27297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 01/11/2020] [Accepted: 02/03/2020] [Indexed: 12/19/2022]
Abstract
Inducible expression systems can be applied to control the expression of proteins or biochemical pathways in cell factories. However, several of the established systems require the addition of expensive inducers, making them unfeasible for large‐scale production. Here, we establish a genome integrated trp‐T7 expression system where tryptophan can be used to control the induction of a gene or a metabolic pathway. We show that the initiation of gene expression from low‐ and high‐copy vectors can be tuned by varying the initial concentration of tryptophan or yeast extract, and that expression is tightly regulated and homogenous when compared with the commonly used lac‐T7 system. Finally, we apply the trp‐T7 expression system for the production of l‐serine, where we reach titers of 26 g/L in fed‐batch fermentation.
Collapse
Affiliation(s)
- Jenny Landberg
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Hemanshu Mundhada
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark.,CysBio ApS, Hørsholm, Denmark
| | - Alex Toftgaard Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| |
Collapse
|
87
|
Halmschlag B, Putri SP, Fukusaki E, Blank LM. Identification of Key Metabolites in Poly-γ-Glutamic Acid Production by Tuning γ-PGA Synthetase Expression. Front Bioeng Biotechnol 2020; 8:38. [PMID: 32083073 PMCID: PMC7002566 DOI: 10.3389/fbioe.2020.00038] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 01/16/2020] [Indexed: 11/13/2022] Open
Abstract
Poly-γ-glutamic acid (γ-PGA) production is commonly achieved using glycerol, citrate, and L-glutamic acid as substrates. The constitutive expression of the γ-PGA synthetase enabled γ-PGA production with Bacillus subtilis from glucose only. The precursors for γ-PGA synthesis, D- and L-glutamate, are ubiquitous metabolites. Hence, the metabolic flux toward γ-PGA directly depends on the concentration and activity of the synthetase and thereby on its expression. To identify pathway bottlenecks and important metabolites that are highly correlated with γ-PGA production from glucose, we engineered B. subtilis strains with varying γ-PGA synthesis rates. To alter the rate of γ-PGA synthesis, the expression level was controlled by two approaches: (1) Using promoter variants from the constitutive promoter P veg and (2) Varying induction strength of the xylose inducible promoter P xyl . The variation in the metabolism caused by γ-PGA production was investigated using metabolome analysis. The xylose-induction strategy revealed that the γ-PGA production rate increased the total fluxes through metabolism indicating a driven by demand adaption of the metabolism. Metabolic bottlenecks during γ-PGA from glucose were identified by generation of a model that correlates γ-PGA production rate with intracellular metabolite levels. The generated model indicates the correlation of certain metabolites such as phosphoenolpyruvate with γ-PGA production. The identified metabolites are targets for strain improvement to achieve high level γ-PGA production from glucose.
Collapse
Affiliation(s)
- Birthe Halmschlag
- Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology-ABBt, RWTH Aachen University, Aachen, Germany
| | - Sastia P. Putri
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Lars M. Blank
- Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology-ABBt, RWTH Aachen University, Aachen, Germany
| |
Collapse
|
88
|
Ren J, Lee J, Na D. Recent advances in genetic engineering tools based on synthetic biology. J Microbiol 2020; 58:1-10. [PMID: 31898252 DOI: 10.1007/s12275-020-9334-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/19/2019] [Accepted: 11/05/2019] [Indexed: 12/26/2022]
Abstract
Genome-scale engineering is a crucial methodology to rationally regulate microbiological system operations, leading to expected biological behaviors or enhanced bioproduct yields. Over the past decade, innovative genome modification technologies have been developed for effectively regulating and manipulating genes at the genome level. Here, we discuss the current genome-scale engineering technologies used for microbial engineering. Recently developed strategies, such as clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9, multiplex automated genome engineering (MAGE), promoter engineering, CRISPR-based regulations, and synthetic small regulatory RNA (sRNA)-based knockdown, are considered as powerful tools for genome-scale engineering in microbiological systems. MAGE, which modifies specific nucleotides of the genome sequence, is utilized as a genome-editing tool. Contrastingly, synthetic sRNA, CRISPRi, and CRISPRa are mainly used to regulate gene expression without modifying the genome sequence. This review introduces the recent genome-scale editing and regulating technologies and their applications in metabolic engineering.
Collapse
Affiliation(s)
- Jun Ren
- School of Integrative Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Jingyu Lee
- School of Integrative Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Dokyun Na
- School of Integrative Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea.
| |
Collapse
|
89
|
Calles B, Goñi‐Moreno Á, de Lorenzo V. Digitalizing heterologous gene expression in Gram-negative bacteria with a portable ON/OFF module. Mol Syst Biol 2019; 15:e8777. [PMID: 31885200 PMCID: PMC6920698 DOI: 10.15252/msb.20188777] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 10/16/2019] [Accepted: 10/24/2019] [Indexed: 01/24/2023] Open
Abstract
While prokaryotic promoters controlled by signal-responding regulators typically display a range of input/output ratios when exposed to cognate inducers, virtually no naturally occurring cases are known to have an OFF state of zero transcription-as ideally needed for synthetic circuits. To overcome this problem, we have modelled and implemented a simple digitalizer module that completely suppresses the basal level of otherwise strong promoters in such a way that expression in the absence of induction is entirely impeded. The circuit involves the interplay of a translation-inhibitory sRNA with the translational coupling of the gene of interest to a repressor such as LacI. The digitalizer module was validated with the strong inducible promoters Pm (induced by XylS in the presence of benzoate) and PalkB (induced by AlkS/dicyclopropyl ketone) and shown to perform effectively in both Escherichia coli and the soil bacterium Pseudomonas putida. The distinct expression architecture allowed cloning and conditional expression of, e.g. colicin E3, one molecule of which per cell suffices to kill the host bacterium. Revertants that escaped ColE3 killing were not found in hosts devoid of insertion sequences, suggesting that mobile elements are a major source of circuit inactivation in vivo.
Collapse
Affiliation(s)
- Belén Calles
- Systems Biology ProgramCentro Nacional de Biotecnología‐CSICMadridSpain
| | - Ángel Goñi‐Moreno
- Systems Biology ProgramCentro Nacional de Biotecnología‐CSICMadridSpain
- Present address:
School of ComputingNewcastle UniversityNewcastle upon TyneUK
| | - Víctor de Lorenzo
- Systems Biology ProgramCentro Nacional de Biotecnología‐CSICMadridSpain
| |
Collapse
|
90
|
Wang Y, Shi Y, Hu L, Du G, Chen J, Kang Z. Engineering strong and stress-responsive promoters in Bacillus subtilis by interlocking sigma factor binding motifs. Synth Syst Biotechnol 2019; 4:197-203. [PMID: 31750410 PMCID: PMC6849360 DOI: 10.1016/j.synbio.2019.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/11/2019] [Accepted: 10/29/2019] [Indexed: 01/24/2023] Open
Abstract
Prokaryotic gene expression is largely regulated on transcriptional levels with the involvement of promoters, RNA polymerase and sigma factors. Developing new promoters to customize gene transcriptional regulation becomes increasingly demanded in synthetic biology and biotechnology. In this study, we designed synthetic promoters in the Gram-positive model bacterium Bacillus subtilis by interlocking the binding motifs of σA for house-keeping gene expression and that of two alternative sigma factors σH and σB which are involved in responding post-exponential growth and general stress, respectively. The developed promoters are recognized by multiple sigma factors and hence generate strong transcriptional strength when host cells grow under normal or stressed conditions. With green fluorescent protein as the reporter, a set of strong promoters were identified, in which the transcription activities of PHA-1, PHAB-4, PHAB-7 were 18.6, 4.1, 3.3 fold of that of the commonly used promoter P43, respectively. Moreover, some of the promoters such as PHA-1, PHAB-4, PHAB-7, PBA-2 displayed increased transcriptional activities in response to high salinity or low pH. The promoters developed in this study should enrich the biotechnological toolboxes of B. subtilis.
Collapse
Affiliation(s)
- Yang Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Yanan Shi
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Litao Hu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Guocheng Du
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jian Chen
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Zhen Kang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| |
Collapse
|
91
|
Identification and characterization of sequence signatures in the Bacillus subtilis promoter P ylb for tuning promoter strength. Biotechnol Lett 2019; 42:115-124. [PMID: 31691164 PMCID: PMC6940355 DOI: 10.1007/s10529-019-02749-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/18/2019] [Indexed: 01/24/2023]
Abstract
Objective To thoroughly characterize the Pylb promoter and identify the elements that affect the promoter activity. Result The sequences flanking the − 35 and − 10 box of the Pylb promoter were divided into six segments, and six random-scanning mutant promoter libraries fused to an enhanced green fluorescent protein EGFP were made and analyzed by flow cytometry. Our results showed that the four nucleotides flanking the − 35 box could mostly influence the promoter activity, and this influence was related to the GC content. The promoters mutated in these regions were successfully used for expressing the gene ophc2 encoding organophosphorus hydrolase (OPHC2) and the gene katA encoding catalase (KatA). Conclusion Our work identified and characterized the sequence signatures of the Pylb promoter that could tune the promoter strength, providing further information for the potential application of this promoter. Meanwhile, the sequence signatures have the potential to be used for tuning gene expression in enzyme production, metabolic engineering, and synthetic biology. Electronic supplementary material The online version of this article (10.1007/s10529-019-02749-4) contains supplementary material, which is available to authorized users.
Collapse
|
92
|
Decoene T, De Maeseneire SL, De Mey M. Modulating transcription through development of semi-synthetic yeast core promoters. PLoS One 2019; 14:e0224476. [PMID: 31689317 PMCID: PMC6830820 DOI: 10.1371/journal.pone.0224476] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 10/15/2019] [Indexed: 01/07/2023] Open
Abstract
Altering gene expression regulation by promoter engineering is a very effective way to fine-tune heterologous pathways in eukaryotic hosts. Typically, pathway building approaches in yeast still use a limited set of long, native promoters. With the today’s introduction of longer and more complex pathways, an expansion of this synthetic biology toolbox is necessary. In this study we elucidated the core promoter structure of the well-characterized yeast TEF1 promoter and determined the minimal length needed for sufficient protein expression. Furthermore, this minimal core promoter sequence was used for the creation of a promoter library covering different expression strengths. This resulted in a group of short, 69 bp promoters with an 8.0-fold expression range. One exemplar had a two and four times higher expression compared to the native CYC1 and ADH1 promoter, respectively. Additionally, as it was described that the protein expression range could be broadened by upstream activating sequences (UASs), we integrated earlier described single and multiple short, synthetic UASs in front of the strongest yeast core promoter. This approach resulted to further variation in protein expression and an overall promoter library spanning a 20-fold activity range and covering a length from 69 bp to maximally 129 bp. Furthermore, the robustness of this library was assessed on three alternative carbon sources besides glucose. As such, the suitability of short yeast core promoters for metabolic engineering applications on different media, either in an individual context or combined with UAS elements, was demonstrated.
Collapse
Affiliation(s)
- Thomas Decoene
- Centre for Synthetic Biology (CSB), Ghent University, Ghent, Belgium
| | - Sofie L. De Maeseneire
- Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Ghent University, Coupure links, Ghent, Belgium
| | - Marjan De Mey
- Centre for Synthetic Biology (CSB), Ghent University, Ghent, Belgium
- * E-mail:
| |
Collapse
|
93
|
Chen W, Chen R, Wang H, Li Y, Zhang Y, Li S. Tuning chromosomal gene expression in Escherichia coli by combining single-stranded oligonucleotides mediated recombination and kil counter selection system. J Biotechnol 2019; 307:63-68. [PMID: 31678458 DOI: 10.1016/j.jbiotec.2019.10.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 10/03/2019] [Accepted: 10/21/2019] [Indexed: 10/25/2022]
Abstract
Extensively modulating gene expression to achieve optimal flux is a critical step in metabolic engineering. Gene expression is usually modulated at the transcriptional level by controlling the strength of a promoter. However, this type of modulation is often hampered by its inability to fully sample the complete continuum of transcriptional control. In Escherichia coli, this limitation can be solved by constructing promoters with a wide range of strengths. In this study, a highly efficient method was developed to modulate a particular chromosomal gene of E. coli at a wide range of expression levels. This was achieved by combining highly efficient single-stranded oligonucleotide-mediated recombination and a stringent counter selection system kil. Using this strategy, a chromosomal library, with a range from 0.3% to 388% relative to the wild lac promoter, was easily obtained. The strength of our chromosomal promoter library was approximately 5-60 times wider in range than those of libraries reported before.
Collapse
Affiliation(s)
- Wei Chen
- Guangdong Province Key Laboratory for Biotechnology Drug Candidates, School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China.
| | - Ruyi Chen
- Guangdong Province Key Laboratory for Biotechnology Drug Candidates, School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Hui Wang
- School of Biological Medicine, Beijing City University, Beijing, 10084, China
| | - Yujuan Li
- Guangdong Province Key Laboratory for Biotechnology Drug Candidates, School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Yunyi Zhang
- Guangdong Province Key Laboratory for Biotechnology Drug Candidates, School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Shanhu Li
- Beijing Institute of Biotechnology, Beijing 100850, China.
| |
Collapse
|
94
|
Jin L, Nawab S, Xia M, Ma X, Huo Y. Context-dependency of synthetic minimal promoters in driving gene expression: a case study. Microb Biotechnol 2019; 12:1476-1486. [PMID: 31578818 PMCID: PMC6801132 DOI: 10.1111/1751-7915.13489] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 09/09/2019] [Indexed: 12/13/2022] Open
Abstract
Synthetic promoters are considered ideal candidates in driving robust gene expression. Most of the available synthetic promoters are minimal promoters, for which the upstream sequence of the 5' end of the core region is usually excluded. Although the upstream sequence has been shown to mediate transcription of natural promoters, its impact on synthetic promoters has not been widely studied. Here, a library of chromosomal DNA fragments is randomly fused with the 5' end of the J23119 synthetic promoter, and the transcriptional performance of the promoter is evaluated through β-galactosidase assay, fluorescence intensity and chemical biosynthesis. Results show that changes in the upstream sequence can induce significant variation in the promoter strength of up to 5.8-fold. The effect is independent of the length of the insertions and the number of potential transcription factor binding sites. Several DNA fragments that are able to enhance the transcription of both the natural and the synthetic promoters are identified. This study indicates that the synthetic minimal promoters are susceptible to the surrounding sequence context. Therefore, the upstream sequence should be treated as an indispensable component in the design and application of synthetic promoters, or as an independent genetic part for the fine-tuning of gene expression.
Collapse
Affiliation(s)
- Liyuan Jin
- Key Laboratory of Molecular Medicine and BiotherapySchool of Life ScienceBeijing Institute of Technology5 South Zhongguancun Street, Haidian DistrictBeijing100081China
| | - Said Nawab
- Key Laboratory of Molecular Medicine and BiotherapySchool of Life ScienceBeijing Institute of Technology5 South Zhongguancun Street, Haidian DistrictBeijing100081China
| | - Mengli Xia
- Key Laboratory of Molecular Medicine and BiotherapySchool of Life ScienceBeijing Institute of Technology5 South Zhongguancun Street, Haidian DistrictBeijing100081China
| | - Xiaoyan Ma
- Key Laboratory of Molecular Medicine and BiotherapySchool of Life ScienceBeijing Institute of Technology5 South Zhongguancun Street, Haidian DistrictBeijing100081China
| | - Yi‐Xin Huo
- Key Laboratory of Molecular Medicine and BiotherapySchool of Life ScienceBeijing Institute of Technology5 South Zhongguancun Street, Haidian DistrictBeijing100081China
- UCLA Institute for Technology Advancement (Suzhou)10 Yueliangwan Road, Suzhou Industrial ParkSuzhou215123China
| |
Collapse
|
95
|
Promoter engineering strategies for the overproduction of valuable metabolites in microbes. Appl Microbiol Biotechnol 2019; 103:8725-8736. [PMID: 31630238 DOI: 10.1007/s00253-019-10172-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/04/2019] [Accepted: 10/08/2019] [Indexed: 12/16/2022]
Abstract
Promoter engineering is an enabling technology in metabolic engineering and synthetic biology. As an indispensable part of synthetic biology, the promoter is a key factor in regulating genetic circuits and in coordinating multi-gene biosynthetic pathways. In this review, we summarized the recent progresses in promoter engineering in microbes. Specifically, the endogenous promoters are firstly discussed, followed by the statement of the influence of nucleotides exchange on the strength of promoters explored by site-selective mutagenesis. We then introduced the promoter libraries with a wide range of strength, which are constructed focusing on core promoter regions and upstream activating sequences by rational designs. Finally, the application of promoter libraries in the optimization of multi-gene metabolic pathways for high-yield production of metabolites was illustrated with a couple of recent examples.
Collapse
|
96
|
Qiang S, Su AP, Li Y, Chen Z, Hu CY, Meng YH. Elevated β-Carotene Synthesis by the Engineered Rhodobacter sphaeroides with Enhanced CrtY Expression. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:9560-9568. [PMID: 31368704 DOI: 10.1021/acs.jafc.9b02597] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
β-Carotene is a precursor of vitamin A and a dietary supplement for its antioxidant property. Producing β-carotene by microbial fermentation has attracted much attention owing to consumers' preference for the natural product. In this study, an engineered photosynthetic Rhodobacter sphaeroides producing β-carotene was constructed by the following strategies: (1) five promoters of different strengths were used to investigate the effect of the expression level of crtY on β-carotene content. It was found that PrrnB increased the β-carotene content by 109%. (2) blocking of the branched pentose phosphate pathway by zwf deletion, and (3) overexpressing dxs could restore the transcriptional levels of crtE and crtB. Finally, the engineered RS-C3 has the highest β-carotene content of 14.93 mg/g dry cell weight (DCW) among all of the reported photosynthetic bacteria and the β-carotene content reached 3.34 mg/g DCW under light conditions. Our results will be available for industrial use to supply a large quantity of natural β-carotene.
Collapse
Affiliation(s)
- Shan Qiang
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China
- Xi'an Healthful Biotechnology Co., Ltd. , HangTuo Road , Chang'an, Xi'an 710100 , P. R. China
| | - An Ping Su
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China
| | - Ying Li
- State Key Laboratory of Agrobiotechnology , China Agricultural University , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , P. R. China
| | - Zhi Chen
- State Key Laboratory of Agrobiotechnology , China Agricultural University , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , P. R. China
| | - Ching Yuan Hu
- Human Nutrition, Food, and Animal Science , University of Hawai'i at Manoa , 1955 East-West Road, AgSci. 415J , Honolulu , Hawaii 96822-2217 , United States
| | - Yong Hong Meng
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China
| |
Collapse
|
97
|
Xu D, Zhang L. Increasing Agmatine Production in Escherichia coli through Metabolic Engineering. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:7908-7915. [PMID: 31268314 DOI: 10.1021/acs.jafc.9b03038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this study, to obtain higher agmatine yields using the previously developed E. coli strain AUX4 (JM109 ΔspeC ΔspeF ΔspeB ΔargR), the genes encoding glutamate dehydrogenase (gdhA), glutamine synthetase (glnA), phosphoenolpyruvate carboxylase (ppc), aspartate aminotransferase (aspC), transhydrogenase (pntAB), and biosynthetic arginine decarboxylase (speA) were sequentially overexpressed by replacing their native promoters with the heterologous strong trp, core-trc, or 5Ptacs promoters to generate the plasmid-free E. coli strain AUX11. The fermentation results obtained using a 3-L bioreactor showed that AUX11 produced 2.93 g L-1 agmatine with the yield of 0.29 g agmatine g-1 glucose in the batch fermentation, and the fed-batch fermentation of AUX11 allowed the production of 40.43 g L-1 agmatine with the productivity of 1.26 g L-1 h-1 agmatine. The results showed that the engineered E. coli strain AUX11 can be used for the industrial fermentative production of agmatine.
Collapse
Affiliation(s)
- Daqing Xu
- College of Life Sciences , Hebei Agricultural University , Baoding 071000 , China
| | - Lirong Zhang
- College of Plant Protection , Hebei Agricultural University , Baoding 071000 , China
| |
Collapse
|
98
|
Zhou C, Ye B, Cheng S, Zhao L, Liu Y, Jiang J, Yan X. Promoter engineering enables overproduction of foreign proteins from a single copy expression cassette in Bacillus subtilis. Microb Cell Fact 2019; 18:111. [PMID: 31200722 PMCID: PMC6570832 DOI: 10.1186/s12934-019-1159-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 06/09/2019] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Bacillus subtilis is developed to be an attractive expression host to produce both secreted and cytoplasmic proteins owing to its prominent biological characteristics. Chromosomal integration is a stable expression strategy while the expression level is not ideal compared with plasmid expression. Thus, to meet the requirement of protein overexpression, promoter, as one of the key elements, is important. It is necessary to obtain an ideal promoter for overproduction of foreign proteins from a single copy expression cassette. RESULTS The activity of promoter Pylb was further enhanced by optimizing the - 35, - 10 core region and upstream sequence (UP) by substituting both sequences with consensus sequences. The final engineered promoter exhibited almost 26-fold in β-galactosidase (BgaB) activity and 195-fold in super-folded green fluorescent protein (sfGFP) intensity than that of WT. The two proteins account for 43% and 30% of intracellular proteins, respectively. The promoter was eventually tested by successful extracellular overproduction of Methyl Parathion Hydrolase (MPH) and Chlorothalonil hydrolytic dehalogenase (Chd) to a level of 0.3 g/L (144 U/mL) and 0.27 g/L (4.4 U/mL) on shake-flask culture condition. CONCLUSIONS A strong promoter was engineered for efficient chromosomally integrated expression of heterologous proteins.
Collapse
Affiliation(s)
- Chaoyang Zhou
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Bin Ye
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Shan Cheng
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Leizhen Zhao
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Yuanxin Liu
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Jiandong Jiang
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China
| | - Xin Yan
- Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural, Environment of Ministry of Agriculture, Nanjing Agricultural University, 6 Tongwei Road, Nanjing, 210095, Jiangsu, People's Republic of China.
| |
Collapse
|
99
|
Ahmed MS, Ikram S, Rasool A, Li C. Design and construction of short synthetic terminators for β-amyrin production in Saccharomyces cerevisiae. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
100
|
Han L, Cui W, Suo F, Miao S, Hao W, Chen Q, Guo J, Liu Z, Zhou L, Zhou Z. Development of a novel strategy for robust synthetic bacterial promoters based on a stepwise evolution targeting the spacer region of the core promoter in Bacillus subtilis. Microb Cell Fact 2019; 18:96. [PMID: 31142347 PMCID: PMC6540529 DOI: 10.1186/s12934-019-1148-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/22/2019] [Indexed: 01/06/2023] Open
Abstract
Background Promoter evolution by synthetic promoter library (SPL) is a powerful approach to development of functional synthetic promoters to synthetic biology. However, it requires much tedious and time-consuming screenings because of the plethora of different variants in SPL. Actually, a large proportion of mutants in the SPL are significantly lower in strength, which contributes only to fabrication of a promoter library with a continuum of strength. Thus, to effectively obtain the evolved synthetic promoter exhibiting higher strength, it is essential to develop novel strategies to construct mutant library targeting the pivotal region rather than the arbitrary region of the template promoter. In this study, a strategy termed stepwise evolution targeting the spacer of core promoter (SETarSCoP) was established in Bacillus subtilis to effectively evolve the strength of bacterial promoter. Results The native promoter, PsrfA, from B. subtilis, which exhibits higher strength than the strong promoter P43, was set as the parental template. According to the comparison of conservation of the spacer sequences between − 35 box and − 10 box among a set of strong and weak native promoter, it revealed that 7-bp sequence immediately upstream of the − 10 box featured in the regulation of promoter strength. Based on the conservative feature, two rounds of consecutive evolution were performed targeting the hot region of PsrfA. In the first round, a primary promoter mutation library (pPML) was constructed by mutagenesis targeting the 3-bp sequence immediately upstream of the − 10 box of the PsrfA. Subsequently, four evolved mutants from pPML were selected to construction of four secondary promoter mutation libraries (sPMLs) based on mutagenesis of the 4-bp sequence upstream of the first-round target. After the consecutive two-step evolution, the mutant PBH4 was identified and verified to be a highly evolved synthetic promoter. The strength of PBH4 was higher than PsrfA by approximately 3 times. Moreover, PBH4 also exhibited broad suitability for different cargo proteins, such as β-glucuronidase and nattokinase. The proof-of-principle test showed that SETarSCoP successfully evolved both constitutive and inducible promoters. Conclusion Comparing with the commonly used SPL strategy, SETarSCoP facilitates the evolution process to obtain strength-evolved synthetic bacterial promoter through fabrication and screening of small-scale mutation libraries. This strategy will be a promising method to evolve diverse bacterial promoters to expand the toolbox for synthetic biology. Electronic supplementary material The online version of this article (10.1186/s12934-019-1148-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Laichuang Han
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Wenjing Cui
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China.
| | - Feiya Suo
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Shengnan Miao
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Wenliang Hao
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Qiaoqing Chen
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Junling Guo
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Zhongmei Liu
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Li Zhou
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Zhemin Zhou
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, Wuxi, 214122, Jiangsu, China.
| |
Collapse
|