1
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Feng B, Hu W, Duan Y, Li Z. A flexible 'plug and play' bicistronic construct and its application in the screening of protein expression system in Escherichia coli. J Microbiol Methods 2024; 221:106928. [PMID: 38583783 DOI: 10.1016/j.mimet.2024.106928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/09/2024]
Abstract
The bicistronic expression system that utilizes fluorescent reporters has been demonstrated to be a straightforward method for detecting recombinant protein expression levels, particularly when compared to polyacrylamide gel electrophoresis and immunoblot analysis, which are tedious and labor-intensive. However, existing bicistronic reporter systems are less capable of quantitative measurement due to the lag in reporter expression and its negative impact on target protein. In this work, a plug and play bicistronic construct using mCherry as reporter was applied in the screening of optimal replicon and promoter for Sortase expression in Escherichia coli (E. coli). The bicistronic construct allowed the reporter gene and target open reading frame (ORF) to be co-transcribed under the same promoter, resulting in a highly positive quantitative correlation between the expression titer of Sortase and the fluorescent intensity (R2 > 0.97). With the correlation model, the titer of target protein can be quantified by noninvasively measuring the fluorescent intensity. On top of this, the expression of reporter has no significant effect on the yield of target protein, thus favoring a plug and play design for removing reporter gene to generate a plain plasmid for industrial use.
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Affiliation(s)
- Binbin Feng
- Microbial and Viral Platform, WuXi Biologics (Hangzhou FTZ) Co., Ltd, #9, 388 of No.16 street, Baiyang Avenue, Hangzhou Free Trade Zone, Hangzhou, Zhejiang Province, China
| | - Weiwei Hu
- Microbial and Viral Platform, WuXi Biologics (Hangzhou FTZ) Co., Ltd, #9, 388 of No.16 street, Baiyang Avenue, Hangzhou Free Trade Zone, Hangzhou, Zhejiang Province, China
| | - Yingyi Duan
- Microbial and Viral Platform, WuXi Biologics (Hangzhou FTZ) Co., Ltd, #9, 388 of No.16 street, Baiyang Avenue, Hangzhou Free Trade Zone, Hangzhou, Zhejiang Province, China.
| | - Zhaopeng Li
- Microbial and Viral Platform, WuXi Biologics (Hangzhou FTZ) Co., Ltd, #9, 388 of No.16 street, Baiyang Avenue, Hangzhou Free Trade Zone, Hangzhou, Zhejiang Province, China.
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2
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Lin J, Wang X, Liu T, Teng Y, Cui W. Diffusion-Based Generative Network for de Novo Synthetic Promoter Design. ACS Synth Biol 2024; 13:1513-1522. [PMID: 38613497 DOI: 10.1021/acssynbio.4c00041] [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: 04/15/2024]
Abstract
Computer-aided promoter design is a major development trend in synthetic promoter engineering. Various deep learning models have been used to evaluate or screen synthetic promoters, but there have been few works on de novo promoter design. To explore the potential ability of generative models in promoter design, we established a diffusion-based generative model for promoter design in Escherichia coli. The model was completely driven by sequence data and could study the essential characteristics of natural promoters, thus generating synthetic promoters similar to natural promoters in structure and component. We also improved the calculation method of FID indicator, using a convolution layer to extract the feature matrix of the promoter sequence instead. As a result, we got an FID equal to 1.37, which meant synthetic promoters have a distribution similar to that of natural ones. Our work provides a fresh approach to de novo promoter design, indicating that a completely data-driven generative model is feasible for promoter design.
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Affiliation(s)
- Jianfeng Lin
- School of Automation Science and Engineering, South China University of Technology, Guangzhou 510641, China
| | - Xin Wang
- School of Automation Science and Engineering, South China University of Technology, Guangzhou 510641, China
| | - Tuoyu Liu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yue Teng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Wei Cui
- School of Automation Science and Engineering, South China University of Technology, Guangzhou 510641, China
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3
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Chaisupa P, Wright RC. State-of-the-art in engineering small molecule biosensors and their applications in metabolic engineering. SLAS Technol 2024; 29:100113. [PMID: 37918525 DOI: 10.1016/j.slast.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/18/2023] [Accepted: 10/25/2023] [Indexed: 11/04/2023]
Abstract
Genetically encoded biosensors are crucial for enhancing our understanding of how molecules regulate biological systems. Small molecule biosensors, in particular, help us understand the interaction between chemicals and biological processes. They also accelerate metabolic engineering by increasing screening throughput and eliminating the need for sample preparation through traditional chemical analysis. Additionally, they offer significantly higher spatial and temporal resolution in cellular analyte measurements. In this review, we discuss recent progress in in vivo biosensors and control systems-biosensor-based controllers-for metabolic engineering. We also specifically explore protein-based biosensors that utilize less commonly exploited signaling mechanisms, such as protein stability and induced degradation, compared to more prevalent transcription factor and allosteric regulation mechanism. We propose that these lesser-used mechanisms will be significant for engineering eukaryotic systems and slower-growing prokaryotic systems where protein turnover may facilitate more rapid and reliable measurement and regulation of the current cellular state. Lastly, we emphasize the utilization of cutting-edge and state-of-the-art techniques in the development of protein-based biosensors, achieved through rational design, directed evolution, and collaborative approaches.
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Affiliation(s)
- Patarasuda Chaisupa
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA 24061, United States
| | - R Clay Wright
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA 24061, United States; Translational Plant Sciences Center (TPSC), Virginia Tech, Blacksburg, VA 24061, United States.
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4
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Eskandari A, Nezhad NG, Leow TC, Rahman MBA, Oslan SN. Essential factors, advanced strategies, challenges, and approaches involved for efficient expression of recombinant proteins in Escherichia coli. Arch Microbiol 2024; 206:152. [PMID: 38472371 DOI: 10.1007/s00203-024-03871-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 12/31/2023] [Accepted: 01/25/2024] [Indexed: 03/14/2024]
Abstract
Producing recombinant proteins is a major accomplishment of biotechnology in the past century. Heterologous hosts, either eukaryotic or prokaryotic, are used for the production of these proteins. The utilization of microbial host systems continues to dominate as the most efficient and affordable method for biotherapeutics and food industry productions. Hence, it is crucial to analyze the limitations and advantages of microbial hosts to enhance the efficient production of recombinant proteins on a large scale. E. coli is widely used as a host for the production of recombinant proteins. Researchers have identified certain obstacles with this host, and given the growing demand for recombinant protein production, there is an immediate requirement to enhance this host. The following review discusses the elements contributing to the manifestation of recombinant protein. Subsequently, it sheds light on innovative approaches aimed at improving the expression of recombinant protein. Lastly, it delves into the obstacles and optimization methods associated with translation, mentioning both cis-optimization and trans-optimization, producing soluble recombinant protein, and engineering the metal ion transportation. In this context, a comprehensive description of the distinct features will be provided, and this knowledge could potentially enhance the expression of recombinant proteins in E. coli.
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Affiliation(s)
- Azadeh Eskandari
- Enzyme and Microbial Technology Research Centre, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
- Department of Biochemistry, FacultyofBiotechnologyand BiomolecularSciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Nima Ghahremani Nezhad
- Enzyme and Microbial Technology Research Centre, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Thean Chor Leow
- Enzyme and Microbial Technology Research Centre, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
- Enzyme Technology and X-Ray Crystallography Laboratory, VacBio 5, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | | | - Siti Nurbaya Oslan
- Enzyme and Microbial Technology Research Centre, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
- Department of Biochemistry, FacultyofBiotechnologyand BiomolecularSciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
- Enzyme Technology and X-Ray Crystallography Laboratory, VacBio 5, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
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5
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Deal C, De Wannemaeker L, De Mey M. Towards a rational approach to promoter engineering: understanding the complexity of transcription initiation in prokaryotes. FEMS Microbiol Rev 2024; 48:fuae004. [PMID: 38383636 PMCID: PMC10911233 DOI: 10.1093/femsre/fuae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 01/29/2024] [Accepted: 02/20/2024] [Indexed: 02/23/2024] Open
Abstract
Promoter sequences are important genetic control elements. Through their interaction with RNA polymerase they determine transcription strength and specificity, thereby regulating the first step in gene expression. Consequently, they can be targeted as elements to control predictability and tuneability of a genetic circuit, which is essential in applications such as the development of robust microbial cell factories. This review considers the promoter elements implicated in the three stages of transcription initiation, detailing the complex interplay of sequence-specific interactions that are involved, and highlighting that DNA sequence features beyond the core promoter elements work in a combinatorial manner to determine transcriptional strength. In particular, we emphasize that, aside from promoter recognition, transcription initiation is also defined by the kinetics of open complex formation and promoter escape, which are also known to be highly sequence specific. Significantly, we focus on how insights into these interactions can be manipulated to lay the foundation for a more rational approach to promoter engineering.
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Affiliation(s)
- Cara Deal
- Centre for Synthetic Biology, Ghent University. Coupure Links 653, BE-9000 Ghent, Belgium
| | - Lien De Wannemaeker
- Centre for Synthetic Biology, Ghent University. Coupure Links 653, BE-9000 Ghent, Belgium
| | - Marjan De Mey
- Centre for Synthetic Biology, Ghent University. Coupure Links 653, BE-9000 Ghent, Belgium
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6
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Sarkhel R, Priyadarsini S, Mahawar M. Nutrient limitation and oxidative stress induce the promoter of acetate operon in Salmonella Typhimurium. Arch Microbiol 2024; 206:126. [PMID: 38411730 DOI: 10.1007/s00203-024-03863-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/28/2024]
Abstract
Glyoxylate shunt is an important pathway for microorganisms to survive under multiple stresses. One of its enzymes, malate synthase (encoded by aceB gene), has been widely speculated for its contribution to both the pathogenesis and virulence of various microorganisms. We have previously demonstrated that malate synthase (MS) is required for the growth of Salmonella Typhimurium (S. Typhimurium) under carbon starvation and survival under oxidative stress conditions. The aceB gene is encoded by the acetate operon in S. Typhimurium. We attempted to study the activity of acetate promoter under both the starvation and oxidative stress conditions in a heterologous system. The lac promoter of the pUC19 plasmid was substituted with the putative promoter sequence of the acetate operon of S. Typhimurium upstream to the lacZ gene and transformed the vector construct into E. coli NEBα cells. The transformed cells were subjected to the stress conditions mentioned above. We observed a fourfold increase in the β-galactosidase activity in these cells resulting from the upregulation of the lacZ gene in the stationary phase of cell growth (nutrient deprived) as compared to the mid-log phase. Following exposure of stationary phase cells to hypochlorite-induced oxidative stress, we further observed a 1.6-fold increase in β galactosidase activity. These data suggest the induction of promoter activity of the acetate operon under carbon starvation and oxidative stress conditions. Thus, these observations corroborate our previous findings regarding the upregulation of aceB expression under stressful environments.
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Affiliation(s)
- Ratanti Sarkhel
- ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Swagatika Priyadarsini
- ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India.
- Indian Council of Agricultural Research- National Research Centre on Camel, Bikaner, Rajasthan, India.
| | - Manish Mahawar
- ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India.
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7
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Andreani V, South EJ, Dunlop MJ. Generating information-dense promoter sequences with optimal string packing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.01.565124. [PMID: 37961203 PMCID: PMC10635063 DOI: 10.1101/2023.11.01.565124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Dense arrangements of binding sites within nucleotide sequences can collectively influence downstream transcription rates or initiate biomolecular interactions. For example, natural promoter regions can harbor many overlapping transcription factor binding sites that influence the rate of transcription initiation. Despite the prevalence of overlapping binding sites in nature, rapid design of nucleotide sequences with many overlapping sites remains a challenge. Here, we show that this is an NP-hard problem, coined here as the nucleotide String Packing Problem (SPP). We then introduce a computational technique that efficiently assembles sets of DNA-protein binding sites into dense, contiguous stretches of double-stranded DNA. For the efficient design of nucleotide sequences spanning hundreds of base pairs, we reduce the SPP to an Orienteering Problem with integer distances, and then leverage modern integer linear programming solvers. Our method optimally packs libraries of 20-100 binding sites into dense nucleotide arrays of 50-300 base pairs in 0.05-10 seconds. Unlike approximation algorithms or meta-heuristics, our approach finds provably optimal solutions. We demonstrate how our method can generate large sets of diverse sequences suitable for library generation, where the frequency of binding site usage across the returned sequences can be controlled by modulating the objective function. As an example, we then show how adding additional constraints, like the inclusion of sequence elements with fixed positions, allows for the design of bacterial promoters. The nucleotide string packing approach we present can accelerate the design of sequences with complex DNA-protein interactions. When used in combination with synthesis and high-throughput screening, this design strategy could help interrogate how complex binding site arrangements impact either gene expression or biomolecular mechanisms in varied cellular contexts. Author Summary The way protein binding sites are arranged on DNA can control the regulation and transcription of downstream genes. Areas with a high concentration of binding sites can enable complex interplay between transcription factors, a feature that is exploited by natural promoters. However, designing synthetic promoters that contain dense arrangements of binding sites is a challenge. The task involves overlapping many binding sites, each typically about 10 nucleotides long, within a constrained sequence area, which becomes increasingly difficult as sequence length decreases, and binding site variety increases. We introduce an approach to design nucleotide sequences with optimally packed protein binding sites, which we call the nucleotide String Packing Problem (SPP). We show that the SPP can be solved efficiently using integer linear programming to identify the densest arrangements of binding sites for a specified sequence length. We show how adding additional constraints, like the inclusion of sequence elements with fixed positions, allows for the design of bacterial promoters. The presented approach enables the rapid design and study of nucleotide sequences with complex, dense binding site architectures.
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8
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Zeng M, Sarker B, Howitz N, Shah I, Andrews LB. Synthetic Homoserine Lactone Sensors for Gram-Positive Bacillus subtilis Using LuxR-Type Regulators. ACS Synth Biol 2024; 13:282-299. [PMID: 38079538 PMCID: PMC10805106 DOI: 10.1021/acssynbio.3c00504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/11/2023] [Accepted: 10/18/2023] [Indexed: 01/23/2024]
Abstract
A universal biochemical signal for bacterial cell-cell communication could facilitate programming dynamic responses in diverse bacterial consortia. However, the classical quorum sensing paradigm is that Gram-negative and Gram-positive bacteria generally communicate via homoserine lactones (HSLs) or oligopeptide molecular signals, respectively, to elicit population responses. Here, we create synthetic HSL sensors for Gram-positive Bacillus subtilis 168 using allosteric LuxR-type regulators (RpaR, LuxR, RhlR, and CinR) and synthetic promoters. Promoters were combinatorially designed from different sequence elements (-35, -16, -10, and transcriptional start regions). We quantified the effects of these combinatorial promoters on sensor activity and determined how regulator expression affects its activation, achieving up to 293-fold activation. Using the statistical design of experiments, we identified significant effects of promoter regions and pairwise interactions on sensor activity, which helped to understand the sequence-function relationships for synthetic promoter design. We present the first known set of functional HSL sensors (≥20-fold dynamic range) in B. subtilis for four different HSL chemical signals: p-coumaroyl-HSL, 3-oxohexanoyl-HSL, n-butyryl-HSL, and n-(3-hydroxytetradecanoyl)-HSL. This set of synthetic HSL sensors for a Gram-positive bacterium can pave the way for designable interspecies communication within microbial consortia.
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Affiliation(s)
- Min Zeng
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Biprodev Sarker
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Nathaniel Howitz
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Ishita Shah
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Lauren B. Andrews
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
- Molecular
and Cellular Biology Graduate Program, University
of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
- Biotechnology
Training Program, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
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9
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Blanch‐Asensio M, Dey S, Tadimarri VS, Sankaran S. Expanding the genetic programmability of Lactiplantibacillus plantarum. Microb Biotechnol 2024; 17:e14335. [PMID: 37638848 PMCID: PMC10832526 DOI: 10.1111/1751-7915.14335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/05/2023] [Accepted: 08/14/2023] [Indexed: 08/29/2023] Open
Abstract
Lactobacilli are ubiquitous in nature and symbiotically provide health benefits for countless organisms including humans, animals and plants. They are vital for the fermented food industry and are being extensively explored for healthcare applications. For all these reasons, there is considerable interest in enhancing and controlling their capabilities through the engineering of genetic modules and circuits. One of the most robust and reliable microbial chassis for these synthetic biology applications is the widely used Lactiplantibacillus plantarum species. However, the genetic toolkit needed to advance its applicability remains poorly equipped. This mini-review highlights the genetic parts that have been discovered to achieve food-grade recombinant protein production and speculates on lessons learned from these studies for L. plantarum engineering. Furthermore, strategies to identify, create and optimize genetic parts for real-time regulation of gene expression and enhancement of biosafety are also suggested.
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Affiliation(s)
- Marc Blanch‐Asensio
- Bioprogrammable Materials, INM—Leibniz Institute for New MaterialsSaarbrückenGermany
| | - Sourik Dey
- Bioprogrammable Materials, INM—Leibniz Institute for New MaterialsSaarbrückenGermany
| | - Varun Sai Tadimarri
- Bioprogrammable Materials, INM—Leibniz Institute for New MaterialsSaarbrückenGermany
| | - Shrikrishnan Sankaran
- Bioprogrammable Materials, INM—Leibniz Institute for New MaterialsSaarbrückenGermany
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10
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Flores-Villegas M, Rebnegger C, Kowarz V, Prielhofer R, Mattanovich D, Gasser B. Systematic sequence engineering enhances the induction strength of the glucose-regulated GTH1 promoter of Komagataella phaffii. Nucleic Acids Res 2023; 51:11358-11374. [PMID: 37791854 PMCID: PMC10639056 DOI: 10.1093/nar/gkad752] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 08/16/2023] [Accepted: 09/07/2023] [Indexed: 10/05/2023] Open
Abstract
The promoter of the high-affinity glucose transporter Gth1 (PGTH1) is tightly repressed on glucose and glycerol surplus, and strongly induced in glucose-limitation, thus enabling regulated methanol-free production processes in the yeast production host Komagataella phaffii. To further improve this promoter, an intertwined approach of nucleotide diversification through random and rational engineering was pursued. Random mutagenesis and fluorescence activated cell sorting of PGTH1 yielded five variants with enhanced induction strength. Reverse engineering of individual point mutations found in the improved variants identified two single point mutations with synergistic action. Sequential deletions revealed the key promoter segments for induction and repression properties, respectively. Combination of the single point mutations and the amplification of key promoter segments led to a library of novel promoter variants with up to 3-fold higher activity. Unexpectedly, the effect of gaining or losing a certain transcription factor binding site (TFBS) was highly dependent on its context within the promoter. Finally, the applicability of the novel promoter variants for biotechnological production was proven for the secretion of different recombinant model proteins in fed batch cultivation, where they clearly outperformed their ancestors. In addition to advancing the toolbox for recombinant protein production and metabolic engineering of K. phaffii, we discovered single nucleotide positions and correspondingly affected TFBS that distinguish between glycerol- and glucose-mediated repression of the native promoter.
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Affiliation(s)
- Mirelle Flores-Villegas
- CD-Laboratory for Growth-decoupled Protein Production in Yeast at Department of Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
- University of Natural Resources and Life Sciences Vienna (BOKU), Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, Muthgasse 18, 1190 Vienna, Austria
| | - Corinna Rebnegger
- CD-Laboratory for Growth-decoupled Protein Production in Yeast at Department of Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
- University of Natural Resources and Life Sciences Vienna (BOKU), Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, Muthgasse 18, 1190 Vienna, Austria
- ACIB GmbH, Muthgasse 11, 1190 Vienna, Austria
| | - Viktoria Kowarz
- CD-Laboratory for Growth-decoupled Protein Production in Yeast at Department of Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
- University of Natural Resources and Life Sciences Vienna (BOKU), Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, Muthgasse 18, 1190 Vienna, Austria
| | - Roland Prielhofer
- University of Natural Resources and Life Sciences Vienna (BOKU), Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, Muthgasse 18, 1190 Vienna, Austria
| | - Diethard Mattanovich
- CD-Laboratory for Growth-decoupled Protein Production in Yeast at Department of Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
- University of Natural Resources and Life Sciences Vienna (BOKU), Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, Muthgasse 18, 1190 Vienna, Austria
- ACIB GmbH, Muthgasse 11, 1190 Vienna, Austria
| | - Brigitte Gasser
- CD-Laboratory for Growth-decoupled Protein Production in Yeast at Department of Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
- University of Natural Resources and Life Sciences Vienna (BOKU), Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, Muthgasse 18, 1190 Vienna, Austria
- ACIB GmbH, Muthgasse 11, 1190 Vienna, Austria
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11
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Myburgh MW, Schwerdtfeger KS, Cripwell RA, van Zyl WH, Viljoen-Bloom M. Promoters and introns as key drivers for enhanced gene expression in Saccharomyces cerevisiae. ADVANCES IN APPLIED MICROBIOLOGY 2023; 124:1-29. [PMID: 37597945 DOI: 10.1016/bs.aambs.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/21/2023]
Abstract
The transcription of genes in the yeast Saccharomyces cerevisiae is governed by multiple layers of regulatory elements and proteins, cooperating to ensure optimum expression of the final protein product based on the cellular requirements. Promoters have always been regarded as the most important determinant of gene transcription, but introns also play a key role in the expression of intron-encoding genes. Some introns can enhance transcription when introduced either promoter-proximal or embedded in the open reading frame of genes. However, the outcome is seldom predictable, with some introns increasing or decreasing transcription depending on the promoter and reporter gene employed. This chapter provides an overview of the general structure and function of promoters and introns and how they may cooperate during transcription to allow intron-mediated enhancement of gene expression. Since S. cerevisiae is a suitable host for recombinant protein production on a commercial level, stronger and more controllable promoters are in high demand. Enhanced gene expression can be achieved via promoter engineering, which may include introns that increase the efficacy of recombinant expression cassettes. Different models for the role of introns in transcription are briefly discussed to show how these intervening sequences can actively interact with the transcription machinery. Furthermore, recent examples of improved protein production via the introduction of promoter-proximal introns are highlighted to showcase the potential value of intron-mediated enhancement of gene expression.
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Affiliation(s)
| | | | - Rosemary Anne Cripwell
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, South Africa
| | - Willem Heber van Zyl
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, South Africa
| | - Marinda Viljoen-Bloom
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, South Africa.
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12
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Huttanus HM, Triola EKH, Velasquez-Guzman JC, Shin SM, Granja-Travez RS, Singh A, Dale T, Jha RK. Targeted mutagenesis and high-throughput screening of diversified gene and promoter libraries for isolating gain-of-function mutations. Front Bioeng Biotechnol 2023; 11:1202388. [PMID: 37545889 PMCID: PMC10400447 DOI: 10.3389/fbioe.2023.1202388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 06/25/2023] [Indexed: 08/08/2023] Open
Abstract
Targeted mutagenesis of a promoter or gene is essential for attaining new functions in microbial and protein engineering efforts. In the burgeoning field of synthetic biology, heterologous genes are expressed in new host organisms. Similarly, natural or designed proteins are mutagenized at targeted positions and screened for gain-of-function mutations. Here, we describe methods to attain complete randomization or controlled mutations in promoters or genes. Combinatorial libraries of one hundred thousands to tens of millions of variants can be created using commercially synthesized oligonucleotides, simply by performing two rounds of polymerase chain reactions. With a suitably engineered reporter in a whole cell, these libraries can be screened rapidly by performing fluorescence-activated cell sorting (FACS). Within a few rounds of positive and negative sorting based on the response from the reporter, the library can rapidly converge to a few optimal or extremely rare variants with desired phenotypes. Library construction, transformation and sequence verification takes 6-9 days and requires only basic molecular biology lab experience. Screening the library by FACS takes 3-5 days and requires training for the specific cytometer used. Further steps after sorting, including colony picking, sequencing, verification, and characterization of individual clones may take longer, depending on number of clones and required experiments.
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Affiliation(s)
- Herbert M. Huttanus
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
- Agile BioFoundry, Emeryville, CA, United States
| | - Ellin-Kristina H. Triola
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
- Agile BioFoundry, Emeryville, CA, United States
| | - Jeanette C. Velasquez-Guzman
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
- Agile BioFoundry, Emeryville, CA, United States
| | - Sang-Min Shin
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
- BOTTLE Consortium, Golden, CO, United States
| | - Rommel S. Granja-Travez
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
- BOTTLE Consortium, Golden, CO, United States
| | - Anmoldeep Singh
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Taraka Dale
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
- Agile BioFoundry, Emeryville, CA, United States
- BOTTLE Consortium, Golden, CO, United States
| | - Ramesh K. Jha
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
- Agile BioFoundry, Emeryville, CA, United States
- BOTTLE Consortium, Golden, CO, United States
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13
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Yang J, Yue HR, Pan LY, Feng JX, Zhao S, Suwannarangsee S, Chempreda V, Liu CG, Zhao XQ. Fungal strain improvement for efficient cellulase production and lignocellulosic biorefinery: Current status and future prospects. BIORESOURCE TECHNOLOGY 2023:129449. [PMID: 37406833 DOI: 10.1016/j.biortech.2023.129449] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/29/2023] [Accepted: 07/01/2023] [Indexed: 07/07/2023]
Abstract
Lignocellulosic biomass (LCB) has been recognized as a valuable carbon source for the sustainable production of biofuels and value-added biochemicals. Crude enzymes produced by fungal cell factories benefit economic LCB degradation. However, high enzyme production cost remains a great challenge. Filamentous fungi have been widely used to produce cellulolytic enzymes. Metabolic engineering of fungi contributes to efficient cellulase production for LCB biorefinery. Here the latest progress in utilizing fungal cell factories for cellulase production was summarized, including developing genome engineering tools to improve the efficiency of fungal cell factories, manipulating promoters, and modulating transcription factors. Multi-omics analysis of fungi contributes to identifying novel genetic elements for enhancing cellulase production. Furthermore, the importance of translation regulation of cellulase production are emphasized. Efficient development of fungal cell factories based on integrative strain engineering would benefit the overall bioconversion efficacy of LCB for sustainable bioproduction.
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Affiliation(s)
- Jie Yang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hou-Ru Yue
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Li-Ya Pan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Jia-Xun Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Shuai Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Surisa Suwannarangsee
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Khlong Luang, Pathumthani 12120, Thailand
| | - Verawat Chempreda
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Khlong Luang, Pathumthani 12120, Thailand
| | - Chen-Guang Liu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
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14
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Ni X, Liu Z, Guo J, Zhang G. Development of Terminator-Promoter Bifunctional Elements for Application in Saccharomyces cerevisiae Pathway Engineering. Int J Mol Sci 2023; 24:9870. [PMID: 37373018 DOI: 10.3390/ijms24129870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 05/31/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
The construction of a genetic circuit requires the substitution and redesign of different promoters and terminators. The assembly efficiency of exogenous pathways will also decrease significantly when the number of regulatory elements and genes is increased. We speculated that a novel bifunctional element with promoter and terminator functions could be created via the fusion of a termination signal with a promoter sequence. In this study, the elements from a Saccharomyces cerevisiae promoter and terminator were employed to design a synthetic bifunctional element. The promoter strength of the synthetic element is apparently regulated through a spacer sequence and an upstream activating sequence (UAS) with a ~5-fold increase, and the terminator strength could be finely regulated by the efficiency element, with a ~5-fold increase. Furthermore, the use of a TATA box-like sequence resulted in the adequate execution of both functions of the TATA box and the efficiency element. By regulating the TATA box-like sequence, UAS, and spacer sequence, the strengths of the promoter-like and terminator-like bifunctional elements were optimally fine-tuned with ~8-fold and ~7-fold increases, respectively. The application of bifunctional elements in the lycopene biosynthetic pathway showed an improved pathway assembly efficiency and higher lycopene yield. The designed bifunctional elements effectively simplified pathway construction and can serve as a useful toolbox for yeast synthetic biology.
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Affiliation(s)
- Xiaoxia Ni
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China
| | - Zhengyang Liu
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China
| | - Jintang Guo
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China
| | - Genlin Zhang
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China
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15
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Xiao C, Xue S, Pan Y, Liu X, Huang M. Overexpression of genes by stress-responsive promoters increases protein secretion in Saccharomyces cerevisiae. World J Microbiol Biotechnol 2023; 39:203. [PMID: 37209206 DOI: 10.1007/s11274-023-03646-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 05/10/2023] [Indexed: 05/22/2023]
Abstract
Recombinant proteins produced by cell factories are now widely used in various fields. Many efforts have been made to improve the secretion capacity of cell factories to meet the increasing demand for recombinant proteins. Recombinant protein production usually causes cell stress in the endoplasmic reticulum (ER). The overexpression of key genes possibly removes limitations in protein secretion. However, inappropriate gene expression may have negative effects. There is a need for dynamic control of genes adapted to cellular status. In this study, we constructed and characterized synthetic promoters that were inducible under ER stress conditions in Saccharomyces cerevisiae. The unfolded protein response element UPRE2, responding to stress with a wide dynamic range, was assembled with various promoter core regions, resulting in UPR-responsive promoters. Synthetic responsive promoters regulated gene expression by responding to stress level, which reflected the cellular status. The engineered strain using synthetic responsive promoters P4UPRE2 - TDH3 and P4UPRE2 - TEF1 for co-expression of ERO1 and SLY1 had 95% higher α-amylase production compared with the strain using the native promoters PTDH3 and PTEF1. This work showed that UPR-responsive promoters were useful in the metabolic engineering of yeast strains for tuning genes to support efficient protein production.
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Affiliation(s)
- Chufan Xiao
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China
| | - Songlyu Xue
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China
| | - Yuyang Pan
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China
| | - Xiufang Liu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China
| | - Mingtao Huang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510641, China.
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16
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Pouresmaeil M, Azizi-Dargahlou S. Factors involved in heterologous expression of proteins in E. coli host. Arch Microbiol 2023; 205:212. [PMID: 37120438 PMCID: PMC10148705 DOI: 10.1007/s00203-023-03541-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/26/2023] [Accepted: 04/05/2023] [Indexed: 05/01/2023]
Abstract
The production of recombinant proteins is one of the most significant achievements of biotechnology in the last century. These proteins are produced in the eukaryotic or prokaryotic heterologous hosts. By increasing the omics data especially related to different heterologous hosts as well as the presence of new amenable genetic engineering tools, we can artificially engineer heterologous hosts to produce recombinant proteins in sufficient quantities. Numerous recombinant proteins have been produced and applied in various industries, and the global recombinant proteins market size is expected to be cast to reach USD 2.4 billion by 2027. Therefore, identifying the weakness and strengths of heterologous hosts is critical to optimize the large-scale biosynthesis of recombinant proteins. E. coli is one of the popular hosts to produce recombinant proteins. Scientists reported some bottlenecks in this host, and due to the increasing demand for the production of recombinant proteins, there is an urgent need to improve this host. In this review, we first provide general information about the E. coli host and compare it with other hosts. In the next step, we describe the factors involved in the expression of the recombinant proteins in E. coli. Successful expression of recombinant proteins in E. coli requires a complete elucidation of these factors. Here, the characteristics of each factor will be fully described, and this information can help to improve the heterologous expression of recombinant proteins in E. coli.
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Affiliation(s)
- Mahin Pouresmaeil
- Agricultural Biotechnology, Department of Biotechnology, Azarbaijan Shahid Madani University, Tabriz, Iran
| | - Shahnam Azizi-Dargahlou
- Agricultural Biotechnology, Department of Biotechnology, Azarbaijan Shahid Madani University, Tabriz, Iran.
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17
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Wichmann J, Behrendt G, Boecker S, Klamt S. Characterizing and utilizing oxygen-dependent promoters for efficient dynamic metabolic engineering. Metab Eng 2023; 77:199-207. [PMID: 37054967 DOI: 10.1016/j.ymben.2023.04.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/03/2023] [Accepted: 04/10/2023] [Indexed: 04/15/2023]
Abstract
Promoters adjust cellular gene expression in response to internal or external signals and are key elements for implementing dynamic metabolic engineering concepts in fermentation processes. One useful signal is the dissolved oxygen content of the culture medium, since production phases often proceed in anaerobic conditions. Although several oxygen-dependent promoters have been described, a comprehensive and comparative study is missing. The goal of this work is to systematically test and characterize 15 promoter candidates that have been previously reported to be induced upon oxygen depletion in Escherichia coli. For this purpose, we developed a microtiter plate-level screening using an algal oxygen-independent flavin-based fluorescent protein and additionally employed flow cytometry analysis for verification. Various expression levels and dynamic ranges could be observed, and six promoters (nar-strong, nar-medium, nar-weak, nirB-m, yfiD-m, and fnrF8) appear particularly suited for dynamic metabolic engineering applications. We demonstrate applicability of these candidates for dynamic induction of enforced ATP wasting, a metabolic engineering approach to increase productivity of microbial strains that requires a narrow level of ATPase expression for optimal function. The selected candidates exhibited sufficient tightness under aerobic conditions while, under complete anaerobiosis, driving expression of the cytosolic F1-subunit of the ATPase from E. coli to levels that resulted in unprecedented specific glucose uptake rates. We finally utilized the nirB-m promoter to demonstrate the optimization of a two-stage lactate production process by dynamically enforcing ATP wasting, which is automatically turned on in the anaerobic (growth-arrested) production phase to boost the volumetric productivity. Our results are valuable for implementing metabolic control and bioprocess design concepts that use oxygen as signal for regulation and induction.
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Affiliation(s)
- Julian Wichmann
- Analysis and Redesign of Biological Networks, Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstr. 1, 39106, Magdeburg, Germany
| | - Gerrich Behrendt
- Analysis and Redesign of Biological Networks, Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstr. 1, 39106, Magdeburg, Germany
| | - Simon Boecker
- Analysis and Redesign of Biological Networks, Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstr. 1, 39106, Magdeburg, Germany
| | - Steffen Klamt
- Analysis and Redesign of Biological Networks, Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstr. 1, 39106, Magdeburg, Germany.
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18
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Sun S, Peng K, Sun S, Wang M, Shao Y, Li L, Xiang J, Sedjoah RCAA, Xin Z. Engineering Modular and Highly Sensitive Cell-Based Biosensors for Aromatic Contaminant Monitoring and High-Throughput Enzyme Screening. ACS Synth Biol 2023; 12:877-891. [PMID: 36821745 DOI: 10.1021/acssynbio.3c00036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Although a variety of whole-cell-based biosensors have been developed for different applications in recent years, most cannot meet practical requirements due to insufficient sensing performance. Here, we constructed two sets of modular genetic circuits by serial and parallel modes capable of significantly amplifying the input/output signal in Escherichia coli. The biosensors are engineered using σ54-dependent phenol-responsive regulator DmpR as a sensor and enhanced green fluorescent protein as a reporter. Cells harboring serial and parallel genetic circuits displayed nearly 9- and 16-fold higher sensitivity than the general circuit. The genetic circuits enabled rapid detection of six phenolic contaminants in 12 h and showed the low limit of detection of 2.5 and 2.2 ppb for benzopyrene (BaP) and tetracycline (Tet), with a broad detection range of 0.01-1 and 0.005-5 μM, respectively. Furthermore, the positive rate was as high as 73% when the biosensor was applied to screen intracellular enzymes with ester-hydrolysis activity from soil metagenomic libraries using phenyl acetate as a phenolic substrate. Several novel enzymes were isolated, identified, and biochemically characterized, including serine peptidases and alkaline phosphatase family protein/metalloenzyme. Consequently, this study provides a new signal amplification method for cell-based biosensors that can be widely applied to environmental contaminant assessment and screening of intracellular enzymes.
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Affiliation(s)
- Shengwei Sun
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Kailin Peng
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Sen Sun
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Mengxi Wang
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yuting Shao
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Longxiang Li
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Jiahui Xiang
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Rita-Cindy Aye-Ayire Sedjoah
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Zhihong Xin
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
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19
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Kim GB, Choi SY, Cho IJ, Ahn DH, Lee SY. Metabolic engineering for sustainability and health. Trends Biotechnol 2023; 41:425-451. [PMID: 36635195 DOI: 10.1016/j.tibtech.2022.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/17/2022] [Accepted: 12/21/2022] [Indexed: 01/12/2023]
Abstract
Bio-based production of chemicals and materials has attracted much attention due to the urgent need to establish sustainability and enhance human health. Metabolic engineering (ME) allows purposeful modification of cellular metabolic, regulatory, and signaling networks to achieve enhanced production of desired chemicals and degradation of environmentally harmful chemicals. ME has significantly progressed over the past 30 years through further integration of the strategies of synthetic biology, systems biology, evolutionary engineering, and data science aided by artificial intelligence. Here we review the field of ME from its emergence to the current state-of-the-art, highlighting its contribution to sustainable production of chemicals, health, and the environment through representative examples. Future challenges of ME and perspectives are also discussed.
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Affiliation(s)
- Gi Bae Kim
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 four), Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - So Young Choi
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 four), Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - In Jin Cho
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 four), Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; BioProcess Engineering Research Center and BioInformatics Research Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Da-Hee Ahn
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 four), Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Sang Yup Lee
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 four), Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; BioProcess Engineering Research Center and BioInformatics Research Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
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20
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CRISPR/Cas9-Mediated Multi-Locus Promoter Engineering in ery Cluster to Improve Erythromycin Production in Saccharopolyspora erythraea. Microorganisms 2023; 11:microorganisms11030623. [PMID: 36985197 PMCID: PMC10059589 DOI: 10.3390/microorganisms11030623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/10/2023] [Accepted: 02/22/2023] [Indexed: 03/05/2023] Open
Abstract
Erythromycins are a group of macrolide antibiotics produced by Saccharopolyspora erythraea. Erythromycin biosynthesis, which is a long pathway composed of a series of biochemical reactions, is precisely controlled by the type I polyketide synthases and accessary tailoring enzymes encoded by ery cluster. In the previous work, we have characterized that six genes representing extremely low transcription levels, SACE_0716-SACE_0720 and SACE_0731, played important roles in limiting erythromycin biosynthesis in the wild-type strain S. erythraea NRRL 23338. In this study, to relieve the potential bottlenecks of erythromycin biosynthesis, we fine-tuned the expression of each key limiting ery gene by CRISPR/Cas9-mediated multi-locus promoter engineering. The native promoters were replaced with different heterologous ones of various strengths, generating ten engineered strains, whose erythromycin productions were 2.8- to 6.0-fold improved compared with that of the wild-type strain. Additionally, the optimal expression pattern of multiple rate-limiting genes and preferred engineering strategies of each locus for maximizing erythromycin yield were also summarized. Collectively, our work lays a foundation for the overall engineering of ery cluster to further improve erythromycin production. The experience of balancing multiple rate-limiting factors within a cluster is also promising to be applied in other actinomycetes to efficiently produce value-added natural products.
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21
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Liu X, Zhang P, Zhao Q, Huang AC. Making small molecules in plants: A chassis for synthetic biology-based production of plant natural products. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:417-443. [PMID: 35852486 DOI: 10.1111/jipb.13330] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
Plant natural products have been extensively exploited in food, medicine, flavor, cosmetic, renewable fuel, and other industrial sectors. Synthetic biology has recently emerged as a promising means for the cost-effective and sustainable production of natural products. Compared with engineering microbes for the production of plant natural products, the potential of plants as chassis for producing these compounds is underestimated, largely due to challenges encountered in engineering plants. Knowledge in plant engineering is instrumental for enabling the effective and efficient production of valuable phytochemicals in plants, and also paves the way for a more sustainable future agriculture. In this manuscript, we briefly recap the biosynthesis of plant natural products, focusing primarily on industrially important terpenoids, alkaloids, and phenylpropanoids. We further summarize the plant hosts and strategies that have been used to engineer the production of natural products. The challenges and opportunities of using plant synthetic biology to achieve rapid and scalable production of high-value plant natural products are also discussed.
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Affiliation(s)
- Xinyu Liu
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Department of Biology, School of Life Sciences, SUSTech-PKU Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Peijun Zhang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Department of Biology, School of Life Sciences, SUSTech-PKU Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Qiao Zhao
- Shenzhen Institutes of Advanced Technology (SIAT), the Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ancheng C Huang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Department of Biology, School of Life Sciences, SUSTech-PKU Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
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22
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Accuracy and data efficiency in deep learning models of protein expression. Nat Commun 2022; 13:7755. [PMID: 36517468 PMCID: PMC9751117 DOI: 10.1038/s41467-022-34902-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 11/10/2022] [Indexed: 12/23/2022] Open
Abstract
Synthetic biology often involves engineering microbial strains to express high-value proteins. Thanks to progress in rapid DNA synthesis and sequencing, deep learning has emerged as a promising approach to build sequence-to-expression models for strain optimization. But such models need large and costly training data that create steep entry barriers for many laboratories. Here we study the relation between accuracy and data efficiency in an atlas of machine learning models trained on datasets of varied size and sequence diversity. We show that deep learning can achieve good prediction accuracy with much smaller datasets than previously thought. We demonstrate that controlled sequence diversity leads to substantial gains in data efficiency and employed Explainable AI to show that convolutional neural networks can finely discriminate between input DNA sequences. Our results provide guidelines for designing genotype-phenotype screens that balance cost and quality of training data, thus helping promote the wider adoption of deep learning in the biotechnology sector.
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23
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Huang X, Song Q, Guo S, Fei Q. Transcription regulation strategies in methylotrophs: progress and challenges. BIORESOUR BIOPROCESS 2022; 9:126. [PMID: 38647763 PMCID: PMC10992012 DOI: 10.1186/s40643-022-00614-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/22/2022] [Indexed: 12/14/2022] Open
Abstract
As a promising industrial microorganism, methylotroph is capable of using methane or methanol as the sole carbon source natively, which has been utilized in the biosynthesis of various bioproducts. However, the relatively low efficiency of carbon conversion has become a limiting factor throughout the development of methanotrophic cell factories due to the unclear genetic background. To better highlight their advantages in methane or methanol-based biomanufacturing, some metabolic engineering strategies, including upstream transcription regulation projects, are being popularized in methylotrophs. In this review, several strategies of transcription regulations applied in methylotrophs are summarized and their applications are discussed and prospected.
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Affiliation(s)
- Xiaohan Huang
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Qiaoqiao Song
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Shuqi Guo
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Qiang Fei
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
- Shaanxi Key Laboratory of Energy Chemical Process Intensification, Xi'an Jiaotong University, Xi'an, 710049, China.
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24
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Plasmids for Controlled and Tunable High-Level Expression in E. coli. Appl Environ Microbiol 2022; 88:e0093922. [PMID: 36342148 PMCID: PMC9680613 DOI: 10.1128/aem.00939-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Genetic systems for protein overexpression are required tools in microbiological and biochemical research. Ideally, these systems include standardized genetic parts with predictable behavior, enabling the construction of stable expression systems in the host organism.
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25
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Characterization of the endogenous promoters in Yarrowia lipolytica for the biomanufacturing applications. Process Biochem 2022. [DOI: 10.1016/j.procbio.2022.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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26
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Hussein MK, Papež M, Dhiman H, Baumann M, Galosy S, Borth N. In silico design of CMV promoter binding oligonucleotides and their impact on inhibition of gene expression in Chinese hamster ovary cells. J Biotechnol 2022; 359:185-193. [DOI: 10.1016/j.jbiotec.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 10/31/2022]
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27
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Development of a Glycerol-Inducible Expression System for High-Yield Heterologous Protein Production in Bacillus subtilis. Microbiol Spectr 2022; 10:e0132222. [PMID: 36036634 PMCID: PMC9604022 DOI: 10.1128/spectrum.01322-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The development of efficient, low-cost, and robust expression systems is important for the mass production of proteins and natural products in large amounts using cell factories. Glycerol is an ideal carbon source for large-scale fermentation due to its low cost and favorable maintenance of the fermentation process. Here, we used the antiterminator protein GlpP and its target promoter PglpD to construct a highly efficient glycerol-inducible expression system (GIES) in Bacillus subtilis. This system was able to express heterologous genes in an autoinducible manner based on the sequential utilization of glucose and glycerol under the regulation of carbon catabolite repression. In such a system, the concentration of glycerol regulated the strength of gene expression, and the concentration of glucose affected both the timing of induction and the strength of gene expression. By enhancing GlpP, the GIES was further strengthened for high-level intracellular expression of aspartase and secretory expression of nattokinase. High yields of nattokinase in a 5-L fermenter through batch and fed-batch fermentation demonstrated the potential to apply the GIES for large-scale enzyme production. Through the evolution of the -10 box of PglpD, mutants with gradient activities were obtained. In addition, hybrid glycerol-inducible promoters were successfully constructed by combining the constitutive promoters and the 5' untranslated region of PglpD. Collectively, this study developed a GIES to obtain high-value products from inexpensive glycerol. More importantly, the great potential of the pair of inherent terminator and antiterminator protein as a portable biological tool for various purposes in synthetic biology is proposed. IMPORTANCE In this study, a GIES was constructed in B. subtilis by employing the antiterminator protein GlpP and the GlpP-regulated promoter PglpD. Based on the sequential utilization of glucose and glycerol by B. subtilis, the GIES was able to express genes in an autoinducible manner. The amounts and ratio of glucose and glycerol can regulate the gene induction timing and expression strength. The GIES was further applied for high yields of nattokinase, and its robustness in production scale-up was confirmed in a 5-L fermenter. The high-level expression of heterologous proteins demonstrated the huge application potential of the GIES. Furthermore, mutants of PglpD with gradient activities and hybrid glycerol-inducible promoters were obtained through the evolution of the -10 box of PglpD and the combination of the constitutive promoters and the 5' untranslated region of PglpD, respectively. These results demonstrated the use of the antiterminator protein as a regulator for various purposes in synthetic biology.
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Zhu Q, Liu Q, Yao C, Zhang Y, Cai M. Yeast transcriptional device libraries enable precise synthesis of value-added chemicals from methanol. Nucleic Acids Res 2022; 50:10187-10199. [PMID: 36095129 PMCID: PMC9508829 DOI: 10.1093/nar/gkac765] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 08/08/2022] [Accepted: 08/25/2022] [Indexed: 11/16/2022] Open
Abstract
Natural methylotrophs are attractive methanol utilization hosts, but lack flexible expression tools. In this study, we developed yeast transcriptional device libraries for precise synthesis of value-added chemicals from methanol. We synthesized transcriptional devices by fusing bacterial DNA-binding proteins (DBPs) with yeast transactivation domains, and linking bacterial binding sequences (BSs) with the yeast core promoter. Three DBP–BS pairs showed good activity when working with transactivation domains and the core promoter of PAOX1 in the methylotrophic yeast, Pichia pastoris. Fine-tuning of the tandem BSs, spacers and differentiated input promoters further enabled a constitutive transcriptional device library (cTRDL) composed of 126 transcriptional devices with an expression strength of 16–520% and an inducible TRDL (iTRDL) composed of 162 methanol-inducible transcriptional devices with an expression strength of 30–500%, compared with PAOX1. Selected devices from iTRDL were adapted to the dihydromonacolin L biosynthetic pathway by orthogonal experimental design, reaching 5.5-fold the production from the PAOX1-driven pathway. The full factorial design of the selected devices from the cTRDL was adapted to the downstream pathway of dihydromonacolin L to monacolin J. Monacolin J production from methanol reached 3.0-fold the production from the PAOX1-driven pathway. Our engineered toolsets ensured multilevel pathway control of chemical synthesis in methylotrophic yeasts.
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Affiliation(s)
- Qiaoyun Zhu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Qi Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Chaoying Yao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.,Shanghai Collaborative Innovation Center for Biomanufacturing, 130 Meilong Road, Shanghai 200237, China
| | - Menghao Cai
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.,Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
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Controlling gene expression with deep generative design of regulatory DNA. Nat Commun 2022; 13:5099. [PMID: 36042233 PMCID: PMC9427793 DOI: 10.1038/s41467-022-32818-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 08/18/2022] [Indexed: 11/25/2022] Open
Abstract
Design of de novo synthetic regulatory DNA is a promising avenue to control gene expression in biotechnology and medicine. Using mutagenesis typically requires screening sizable random DNA libraries, which limits the designs to span merely a short section of the promoter and restricts their control of gene expression. Here, we prototype a deep learning strategy based on generative adversarial networks (GAN) by learning directly from genomic and transcriptomic data. Our ExpressionGAN can traverse the entire regulatory sequence-expression landscape in a gene-specific manner, generating regulatory DNA with prespecified target mRNA levels spanning the whole gene regulatory structure including coding and adjacent non-coding regions. Despite high sequence divergence from natural DNA, in vivo measurements show that 57% of the highly-expressed synthetic sequences surpass the expression levels of highly-expressed natural controls. This demonstrates the applicability and relevance of deep generative design to expand our knowledge and control of gene expression regulation in any desired organism, condition or tissue. Design of de novo synthetic regulatory DNA is a promising avenue to control gene expression in biotechnology and medicine. Here the authors present EspressionGAN, a generative adversarial network that uses genomic and transcriptomic data to generate regulatory sequences.
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Xiao H, Liu X, Feng Y, Zheng L, Zhao M, Huang M. Secretion of collagenases by Saccharomyces cerevisiae for collagen degradation. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:89. [PMID: 36031598 PMCID: PMC9420286 DOI: 10.1186/s13068-022-02186-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 08/13/2022] [Indexed: 11/22/2022]
Abstract
Background The production and processing of animal-based products generates many collagen-rich by-products, which have received attention both for exploitation to increase their added value and to reduce their negative environmental impact. The collagen-rich by-products can be hydrolyzed by collagenases for further utilization. Therefore, collagenases are of benefit for efficient collagen materials processing. An alternative and safe way to produce secreted collagenases is needed. Results Two collagenases from Hathewaya histolytica, ColG and ColH, were successfully secreted by the yeast Saccharomyces cerevisiae. Compared with the native signal peptide of collagenase, the α-factor leader is more efficient in guiding collagenase secretion. Collagenase secretion was significantly increased in YPD medium by supplementing with calcium and zinc ions. Recombinant collagenase titers reached 68 U/mL and 55 U/mL for ColG and ColH, respectively. Collagenase expression imposed metabolic perturbations on yeast cells; substrate consumption, metabolites production and intracellular cofactor levels changed in engineered strains. Both recombinant collagenases from yeast could hydrolyze soluble and insoluble collagen materials. Recombinant ColG and ColH showed a synergistic effect on efficient collagen digestion. Conclusions Sufficient calcium and zinc ions are essential for active collagenase production by yeast. Collagenase secretion was increased by optimization of expression cassettes. Collagenase expression imposed metabolic burden and cofactor perturbations on yeast cells, which could be improved through metabolic engineering. Our work provides a useful way to produce collagenases for collagen resource utilization. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02186-y.
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Ma K, Deng L, Wu H, Fan J. Towards green biomanufacturing of high-value recombinant proteins using promising cell factory: Chlamydomonas reinhardtii chloroplast. BIORESOUR BIOPROCESS 2022; 9:83. [PMID: 38647750 PMCID: PMC10992328 DOI: 10.1186/s40643-022-00568-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/29/2022] [Indexed: 11/10/2022] Open
Abstract
Microalgae are cosmopolitan organisms in nature with short life cycles, playing a tremendous role in reducing the pressure of industrial carbon emissions. Besides, microalgae have the unique advantages of being photoautotrophic and harboring both prokaryotic and eukaryotic expression systems, becoming a popular host for recombinant proteins. Currently, numerous advanced molecular tools related to microalgal transgenesis have been explored and established, especially for the model species Chlamydomonas reinhardtii (C. reinhardtii hereafter). The development of genetic tools and the emergence of new strategies further increase the feasibility of developing C. reinhardtii chloroplasts as green factories, and the strong genetic operability of C. reinhardtii endows it with enormous potential as a synthetic biology platform. At present, C. reinhardtii chloroplasts could successfully produce plenty of recombinant proteins, including antigens, antibodies, antimicrobial peptides, protein hormones and enzymes. However, additional techniques and toolkits for chloroplasts need to be developed to achieve efficient and markerless editing of plastid genomes. Mining novel genetic elements and selectable markers will be more intensively studied in the future, and more factors affecting protein expression are urged to be explored. This review focuses on the latest technological progress of selectable markers for Chlamydomonas chloroplast genetic engineering and the factors that affect the efficiency of chloroplast protein expression. Furthermore, urgent challenges and prospects for future development are pointed out.
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Affiliation(s)
- Ke Ma
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Lei Deng
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Haizhen Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
- Department of Applied Biology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
| | - Jianhua Fan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
- Department of Applied Biology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
- School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, People's Republic of China.
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Yang H, Wang H, Wang F, Zhang K, Qu J, Guan J, Shen W, Cao Y, Xia Y, Chen X. Efficient extracellular production of recombinant proteins in E. coli via enhancing expression of dacA on the genome. J Ind Microbiol Biotechnol 2022; 49:6596876. [PMID: 35648451 PMCID: PMC9338883 DOI: 10.1093/jimb/kuac016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/21/2022] [Indexed: 11/14/2022]
Abstract
D, D-carboxypeptidase DacA plays an important role in the synthesis and stabilization of Escherichia coli cell wall peptidoglycan. The production level of extracellular recombinant proteins in E. coli can be enhanced by high D, D-carboxypeptidase activity. Construction of expression systems under optimal promoters is one of the main strategies to realize high protein production in E. coli. In this study, the promoter PdacA-3 from DacA on the genome of E. coli BL21 (DE3) was verified to be efficient for recombinant green fluorescent protein using the plasmid mutant pET28a-PdacA with PdacA-3. Meanwhile, the promoter PdacA-3 was engineered to increase the production level of proteins via inserting one or two Shine–Dalgarno (SD) sequences between the promoter PdacA-3 and the target genes. The expression level of dacA on the genome was increased by the improved transcription of the engineered promoters (especially after inserting one additional SD sequence). The engineered promoters increased cell membrane permeabilities to significantly enhance the secretion production of extracellular recombinant proteins in E. coli. Among them, the extracellular recombinant amylase activities in E. coli BL21::1SD-pET28a-amyK and E. coli BL21::2SD-pET28a-amyK were increased by 2.0- and 1.6-fold that of the control (E. coli BL21-pET28a-amyK), respectively. Promoter engineering also affected the morphology and growth of the E. coli mutants. It was indicated that the engineered promoters enhanced the expression of dacA on the genome to disturb the synthesis and structural stability of cell wall peptidoglycans.
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Affiliation(s)
- Haiquan Yang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Haokun Wang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Fuxiang Wang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Kunjie Zhang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jinfeng Qu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jianmin Guan
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Wei Shen
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yu Cao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yuanyuan Xia
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xianzhong Chen
- Correspondence should be addressed to: Xianzhong Chen at
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Zhang X, Cheng Z, Fan G, Yao W, Li W, Chen S, Jiang T. Functional analysis of PagNAC045 transcription factor that improves salt and ABA tolerance in transgenic tobacco. BMC PLANT BIOLOGY 2022; 22:261. [PMID: 35610568 PMCID: PMC9131654 DOI: 10.1186/s12870-022-03623-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/26/2022] [Indexed: 05/16/2023]
Abstract
BACKGROUND Salt stress causes inhibition of plant growth and development, and always leads to an increasing threat to plant agriculture. Transcription factors regulate the expression of various genes for stress response and adaptation. It's crucial to reveal the regulatory mechanisms of transcription factors in the response to salt stress. RESULTS A salt-inducible NAC transcription factor gene PagNAC045 was isolated from Populus alba×P. glandulosa. The PagNAC045 had a high sequence similarity with NAC045 (Potri.007G099400.1) in P. trichocarpa, and they both contained the same conserved motifs 1 and 2, which constitute the highly conserved NAM domain at the N-terminus. Protein-protein interaction (PPI) prediction showed that PagNAC045 potentially interacts with many proteins involved in plant hormone signaling, DNA-binding and transcriptional regulation. The results of subcellular localization and transient expression in tobacco leaves confirmed the nuclear localization of PagNAC045. Yeast two-hybrid revealed that PagNAC045 protein exhibits transcriptional activation property and the activation domain located in its C-terminus. In addition, the 1063 bp promoter of PagNAC045 was able to drive GUS gene expression in the leaves and roots. In poplar leaves and roots, PagNAC045 expression increased significantly by salt and ABA treatments. Tobacco seedlings overexpressing PagNAC045 exhibited enhanced tolerance to NaCl and ABA compared to the wild-type (WT). Yeast one-hybrid assay demonstrated that a bHLH104-like transcription factor can bind to the promoter sequence of PagNAC045. CONCLUSION The PagNAC045 functions as positive regulator in plant responses to NaCl and ABA-mediated stresses.
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Affiliation(s)
- Xuemei Zhang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 51 Hexing Road, Harbin, 150040, China
- Department of Biology, Genetics Institute, University of Florida (UF), Gainesville, FL, 32611, USA
| | - Zihan Cheng
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 51 Hexing Road, Harbin, 150040, China
| | - Gaofeng Fan
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 51 Hexing Road, Harbin, 150040, China
| | - Wenjing Yao
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 51 Hexing Road, Harbin, 150040, China
- Co-Innovation Center for Sustainable Forestry in Southern China/Bamboo Research Institute, Nanjing Forestry University, 159 Longpan Road, Nanjing, 210037, China
| | - Wei Li
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 51 Hexing Road, Harbin, 150040, China
| | - Sixue Chen
- Department of Biology, Genetics Institute, University of Florida (UF), Gainesville, FL, 32611, USA.
- Plant Molecular and Cellular Biology Program, UF, Gainesville, FL, 32610, USA.
- Proteomics and Mass Spectrometry, Interdisciplinary Center for Biotechnology Research, UF, Gainesville, FL, 32610, USA.
| | - Tingbo Jiang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 51 Hexing Road, Harbin, 150040, China.
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Li S, Ma L, Fu W, Su R, Zhao Y, Deng Y. Programmable Synthetic Upstream Activating Sequence Library for Fine-Tuning Gene Expression Levels in Saccharomyces cerevisiae. ACS Synth Biol 2022; 11:1228-1239. [PMID: 35195994 DOI: 10.1021/acssynbio.1c00511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A wide dynamic range of promoters is necessary for fine-tuning transcription levels. However, weak intensity and narrow dynamic range limit transcriptional regulation via constitutive promoters. The upstream activation sequence (UAS) located upstream of the core promoter is a crucial region that could obviously enhance promoter strength. Herein, we created a random mutagenesis library consisting of 330 different variants based on the UAS of the TDH3 promoter with an ∼37-fold dynamic range by error-prone polymerase chain reaction (PCR) and obtained strong intensity mutant UAS, which was ∼12-fold greater than the wild-type UASTDH3. Analysis of the mutant library revealed 15 strength-enhancing sites and their corresponding bases of the UASTDH3 regions, which provided the impetus for a synthetic library. The resulting 32 768 mutant UAS library was constructed by permutation and combination of the bases of the 15 enhancing sites. To characterize the library, a strength prediction model was built by correlating DNA structural features and UAS strength, which provided a model between UAS sequence and intensity. Following characterization, the UAS library was applied to precisely regulate gene expression in the production of β-carotene, proving that the UAS library would be a useful tool for gene tuning in metabolic engineering. In summary, we designed, constructed, and characterized a UAS library that facilitated precise tuning of transcription levels of target proteins.
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Affiliation(s)
- Shiyun Li
- National Engineering Laboratory for Cereal Fermentation Technology (NELCF), Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Lizhou Ma
- National Engineering Laboratory for Cereal Fermentation Technology (NELCF), Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Wenxuan Fu
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Ruifang Su
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Yunying Zhao
- National Engineering Laboratory for Cereal Fermentation Technology (NELCF), Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Yu Deng
- National Engineering Laboratory for Cereal Fermentation Technology (NELCF), Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
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Sun ML, Shi TQ, Lin L, Ledesma-Amaro R, Ji XJ. Advancing Yarrowia lipolytica as a superior biomanufacturing platform by tuning gene expression using promoter engineering. BIORESOURCE TECHNOLOGY 2022; 347:126717. [PMID: 35031438 DOI: 10.1016/j.biortech.2022.126717] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/08/2022] [Accepted: 01/10/2022] [Indexed: 06/14/2023]
Abstract
Yarrowia lipolytica is recognized as an excellent non-conventional yeast in the field of biomanufacturing, where it is used as a host to produce oleochemicals, terpenes, organic acids, polyols and recombinant proteins. Consequently, metabolic engineering of this yeast is becoming increasingly popular to advance it as a superior biomanufacturing platform, of which promoters are the most basic elements for tuning gene expression. Endogenous promoters of Yarrowia lipolytica were reviewed, which are the basis for promoter engineering. The engineering strategies, such as hybrid promoter engineering, intron enhancement promoter engineering, and transcription factor-based inducible promoter engineering are described. Additionally, the applications of Yarrowia lipolytica promoter engineering to rationally reconstruct biosynthetic gene clusters and improve the genome-editing efficiency of the CRISPR-Cas systems were reviewed. Finally, research needs and future directions for promoter engineering are also discussed in this review.
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Affiliation(s)
- Mei-Li Sun
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - Tian-Qiong Shi
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing 210046, People's Republic of China
| | - Lu Lin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - Rodrigo Ledesma-Amaro
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, United Kingdom
| | - Xiao-Jun Ji
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China.
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Liu Q, Song L, Peng Q, Zhu Q, Shi X, Xu M, Wang Q, Zhang Y, Cai M. A programmable high-expression yeast platform responsive to user-defined signals. SCIENCE ADVANCES 2022; 8:eabl5166. [PMID: 35148182 PMCID: PMC8836803 DOI: 10.1126/sciadv.abl5166] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Rapidly growing yeasts with appropriate posttranslational modifications are favored hosts for protein production in the biopharmaceutical industry. However, limited production capacity and intricate transcription regulation restrict their application and adaptability. Here, we describe a programmable high-expression yeast platform, SynPic-X, which responds to defined signals and is broadly applicable. We demonstrated that a synthetic improved transcriptional signal amplification device (iTSAD) with a bacterial-yeast transactivator and bacterial-yeast promoter markedly increased expression capacity in Pichia pastoris. CRISPR activation and interference devices were designed to strictly regulate iTSAD in response to defined signals. Engineered switches were then constructed to exemplify the response of SynPic-X to exogenous signals. Expression of α-amylase by SynPic-R, a specific SynPic-X, in a bioreactor proved a methanol-free high-production process of recombinant protein. Our SynPic-X platform provides opportunities for protein production in customizable yeast hosts with high expression and regulatory flexibility.
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Affiliation(s)
- Qi Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Lili Song
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Qiangqiang Peng
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Qiaoyun Zhu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Xiaona Shi
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Mingqiang Xu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
- Shanghai Collaborative Innovation Center for Biomanufacturing, 130 Meilong Road, Shanghai 200237, China
| | - Menghao Cai
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
- Corresponding author.
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Ai G, Liu J, Fu X, Li T, Zhu H, Zhai Y, Xia C, Pan W, Li J, Jing M, Shen D, Xia A, Dou D. Making Use of Plant uORFs to Control Transgene Translation in Response to Pathogen Attack. BIODESIGN RESEARCH 2022; 2022:9820540. [PMID: 37850142 PMCID: PMC10521741 DOI: 10.34133/2022/9820540] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/06/2022] [Indexed: 10/19/2023] Open
Abstract
Reducing crop loss to diseases is urgently needed to meet increasing food production challenges caused by the expanding world population and the negative impact of climate change on crop productivity. Disease-resistant crops can be created by expressing endogenous or exogenous genes of interest through transgenic technology. Nevertheless, enhanced resistance by overexpressing resistance-produced genes often results in adverse developmental affects. Upstream open reading frames (uORFs) are translational control elements located in the 5' untranslated region (UTR) of eukaryotic mRNAs and may repress the translation of downstream genes. To investigate the function of three uORFs from the 5' -UTR of ACCELERATED CELL 11 (uORFsACD11), we develop a fluorescent reporter system and find uORFsACD11 function in repressing downstream gene translation. Individual or simultaneous mutations of the three uORFsACD11 lead to repression of downstream translation efficiency at different levels. Importantly, uORFsACD11-mediated translational inhibition is impaired upon recognition of pathogen attack of plant leaves. When coupled with the PATHOGENESIS-RELATED GENE 1 (PR1) promoter, the uORFsACD11 cassettes can upregulate accumulation of Arabidopsis thaliana LECTIN RECEPTOR KINASE-VI.2 (AtLecRK-VI.2) during pathogen attack and enhance plant resistance to Phytophthora capsici. These findings indicate that the uORFsACD11 cassettes can be a useful toolkit that enables a high level of protein expression during pathogen attack, while for ensuring lower levels of protein expression at normal conditions.
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Affiliation(s)
- Gan Ai
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Jin Liu
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaowei Fu
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Tianli Li
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Hai Zhu
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Ying Zhai
- Department of Plant Pathology, Washington State University, Pullman, WA 99164, USA
| | - Chuyan Xia
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Weiye Pan
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Jialu Li
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Maofeng Jing
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Danyu Shen
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Ai Xia
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Daolong Dou
- College of Plant Protection, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
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38
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Trivedi VD, Mohan K, Chappell TC, Mays ZJS, Nair NU. Cheating the Cheater: Suppressing False-Positive Enrichment during Biosensor-Guided Biocatalyst Engineering. ACS Synth Biol 2022; 11:420-429. [PMID: 34914365 DOI: 10.1021/acssynbio.1c00506] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Transcription factor (TF)-based biosensors are very desirable reagents for high-throughput enzyme and strain engineering campaigns. Despite their potential, they are often difficult to deploy effectively as the small molecules being detected can leak out of high-producer cells, into low-producer cells, and activate the biosensor therein. This crosstalk leads to the overrepresentation of false-positive/cheater cells in the enriched population. While the host cell can be engineered to minimize crosstalk (e.g., by deleting responsible transporters), this is not easily applicable to all molecules of interest, particularly those that can diffuse passively. One such biosensor recently reported for trans-cinnamic acid (tCA) suffers from crosstalk when used for phenylalanine ammonia-lyase (PAL) enzyme engineering by directed evolution. We report that desensitizing the biosensor (i.e., increasing the limit of detection) suppresses cheater population enrichment. Furthermore, we show that, if we couple the biosensor-based screen with an orthogonal prescreen that eliminates a large fraction of true negatives, we can successfully reduce the cheater population during the fluorescence-activated cell sorting. Using the approach developed here, we were successfully able to isolate PAL variants with ∼70% higher kcat after a single sort. These mutants have tremendous potential in phenylketonuria (PKU) treatment and flavonoid production.
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Affiliation(s)
- Vikas D. Trivedi
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Karishma Mohan
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Todd C. Chappell
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Zachary J. S. Mays
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Nikhil U. Nair
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
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39
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Verma BK, Mannan AA, Zhang F, Oyarzún DA. Trade-Offs in Biosensor Optimization for Dynamic Pathway Engineering. ACS Synth Biol 2022; 11:228-240. [PMID: 34968029 DOI: 10.1021/acssynbio.1c00391] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent progress in synthetic biology allows the construction of dynamic control circuits for metabolic engineering. This technology promises to overcome many challenges encountered in traditional pathway engineering, thanks to its ability to self-regulate gene expression in response to bioreactor perturbations. The central components in these control circuits are metabolite biosensors that read out pathway signals and actuate enzyme expression. However, the construction of metabolite biosensors is a major bottleneck for strain design, and a key challenge is to understand the relation between biosensor dose-response curves and pathway performance. Here we employ multiobjective optimization to quantify performance trade-offs that arise in the design of metabolite biosensors. Our approach reveals strategies for tuning dose-response curves along an optimal trade-off between production flux and the cost of an increased expression burden on the host. We explore properties of control architectures built in the literature and identify their advantages and caveats in terms of performance and robustness to growth conditions and leaky promoters. We demonstrate the optimality of a control circuit for glucaric acid production in Escherichia coli, which has been shown to increase the titer by 2.5-fold as compared to static designs. Our results lay the groundwork for the automated design of control circuits for pathway engineering, with applications in the food, energy, and pharmaceutical sectors.
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Affiliation(s)
- Babita K. Verma
- School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Ahmad A. Mannan
- Warwick Integrative Synthetic Biology Centre, School of Engineering, University of Warwick, Coventry CV4 7AL, U.K
| | - Fuzhong Zhang
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Diego A. Oyarzún
- School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, U.K
- School of Informatics, The University of Edinburgh, Edinburgh EH8 9AB, U.K
- The Alan Turing Institute, London, NW1 2DB, U.K
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40
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Zhao M, Yuan Z, Wu L, Zhou S, Deng Y. Precise Prediction of Promoter Strength Based on a De Novo Synthetic Promoter Library Coupled with Machine Learning. ACS Synth Biol 2022; 11:92-102. [PMID: 34927418 DOI: 10.1021/acssynbio.1c00117] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Promoters are one of the most critical regulatory elements controlling metabolic pathways. However, the fast and accurate prediction of promoter strength remains challenging, leading to time- and labor-consuming promoter construction and characterization processes. This dilemma is caused by the lack of a big promoter library that has gradient strengths, broad dynamic ranges, and clear sequence profiles that can be used to train an artificial intelligence model of promoter strength prediction. To overcome this challenge, we constructed and characterized a mutant library of Trc promoters (Ptrc) using 83 rounds of mutation-construction-screening-characterization engineering cycles. After excluding invalid mutation sites, we established a synthetic promoter library that consisted of 3665 different variants, displaying an intensity range of more than two orders of magnitude. The strongest variant was ∼69-fold stronger than the original Ptrc and 1.52-fold stronger than a 1 mM isopropyl-β-d-thiogalactoside-driven PT7 promoter, with an ∼454-fold difference between the strongest and weakest expression levels. Using this synthetic promoter library, different machine learning models were built and optimized to explore the relationships between promoter sequences and transcriptional strength. Finally, our XgBoost model exhibited optimal performance, and we utilized this approach to precisely predict the strength of artificially designed promoter sequences (R2 = 0.88, mean absolute error = 0.15, and Pearson correlation coefficient = 0.94). Our work provides a powerful platform that enables the predictable tuning of promoters to achieve optimal transcriptional strength.
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Affiliation(s)
- Mei Zhao
- National Engineering Laboratory for Cereal Fermentation Technology (NELCF), Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China
| | - Zhenqi Yuan
- School of Artificial Intelligence and Computer Science, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Longtao Wu
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
| | - Shenghu Zhou
- National Engineering Laboratory for Cereal Fermentation Technology (NELCF), Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Yu Deng
- National Engineering Laboratory for Cereal Fermentation Technology (NELCF), Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
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41
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Yan C, Yu W, Zhai X, Yao L, Guo X, Gao J, Zhou YJ. Characterizing and engineering promoters for metabolic engineering of Ogataea polymorpha. Synth Syst Biotechnol 2022; 7:498-505. [PMID: 34977394 PMCID: PMC8685918 DOI: 10.1016/j.synbio.2021.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 12/18/2022] Open
Abstract
Bio-manufacturing via microbial cell factory requires large promoter library for fine-tuned metabolic engineering. Ogataea polymorpha, one of the methylotrophic yeasts, possesses advantages in broad substrate spectrum, thermal-tolerance, and capacity to achieve high-density fermentation. However, a limited number of available promoters hinders the engineering of O. polymorpha for bio-productions. Here, we systematically characterized native promoters in O. polymorpha by both GFP fluorescence and fatty alcohol biosynthesis. Ten constitutive promoters (PPDH, PPYK, PFBA, PPGM, PGLK, PTRI, PGPI, PADH1, PTEF1 and PGCW14) were obtained with the activity range of 13%–130% of the common promoter PGAP (the promoter of glyceraldehyde-3-phosphate dehydrogenase), among which PPDH and PGCW14 were further verified by biosynthesis of fatty alcohol. Furthermore, the inducible promoters, including ethanol-induced PICL1, rhamnose-induced PLRA3 and PLRA4, and a bidirectional promoter (PMal-PPer) that is strongly induced by sucrose, further expanded the promoter toolbox in O. polymorpha. Finally, a series of hybrid promoters were constructed via engineering upstream activation sequence (UAS), which increased the activity of native promoter PLRA3 by 4.7–10.4 times without obvious leakage expression. Therefore, this study provided a group of constitutive, inducible, and hybrid promoters for metabolic engineering of O. polymorpha, and also a feasible strategy for rationally regulating the promoter strength.
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Affiliation(s)
- Chunxiao Yan
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China.,Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, PR China
| | - Wei Yu
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, PR China.,Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, PR China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaoxin Zhai
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, PR China.,Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, PR China
| | - Lun Yao
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, PR China.,Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, PR China
| | - Xiaoyu Guo
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, PR China
| | - Jiaoqi Gao
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, PR China.,CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, PR China.,Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, PR China
| | - Yongjin J Zhou
- Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, PR China.,CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, PR China.,Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, PR China
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Abstract
The availability of exceptionally strong and tightly regulated promoters is a key feature of Komagataella phaffii (syn. Pichia pastoris), a widely applied yeast expression system for heterologous protein production. Most commonly, the methanol-inducible promoter of the alcohol oxidase 1 gene (PAOX1) and the constitutive promoter of the glyceraldehyde 3 phosphate dehydrogenase gene (PGAP) have been used. Recently, also promising novel constitutive (PGCW14), regulated (PGTH1, PCAT1), and bidirectional promoters (histone promoters and synthetic hybrid variants) have been reported.As natural promoters showed so far limited tunability of expression levels and regulatory profiles, various promoter engineering efforts have been undertaken for P. pastoris . PAOX1, PDAS2, PGAP, and PGCW14 have been engineered by systematic deletion studies or random mutagenesis of upstream regulatory sequences. New engineering strategies have focused on PAOX1 core promoter modifications by random or rational approaches and transcriptional regulatory circuits to render PAOX1 independent of methanol induction. These promoter engineering efforts in P. pastoris have resulted in improved, sequence-diversified synthetic promoter variants allowing coordinated fine-tuning of gene expression for a multitude of biotechnological applications.
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Affiliation(s)
- Thomas Vogl
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University Graz, Graz, Austria.
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43
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Rafique N, Bashir S, Khan MZ, Hayat I, Orts W, Wong DWS. Metabolic engineering of Bacillus subtilis with an endopolygalacturonase gene isolated from Pectobacterium. carotovorum; a plant pathogenic bacterial strain. PLoS One 2021; 16:e0256562. [PMID: 34936645 PMCID: PMC8694468 DOI: 10.1371/journal.pone.0256562] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 11/20/2021] [Indexed: 12/02/2022] Open
Abstract
Pectinolytic enzymes or pectinases are synthesized naturally by numerous microbes and plants. These enzymes degrade various kinds of pectin which exist as the major component of the cell wall in plants. A pectinase gene encoding endo-polygalacturonase (endo-PGase) enzyme was isolated from Pectobacterium carotovorum a plant pathogenic strain of bacteria and successfully cloned into a secretion vector pHT43 having σA-dependent promoter for heterologous expression in Bacillus subtilis (WB800N).The desired PCR product was 1209bp which encoded an open reading frame of 402 amino acids. Recombinant proteins showed an estimated molecular weight of 48 kDa confirmed by sodium dodecyl sulphate–polyacrylamide-gel electrophoresis. Transformed B. subtilis competent cells harbouring the engineered pHT43 vector with the foreign endo-PGase gene were cultured in 2X-yeast extract tryptone medium and subsequently screened for enzyme activity at various temperatures and pH ranges. Optimal activity of recombinant endo-PGase was found at 40°C and pH 5.0. To assay the catalytic effect of metal ions, the recombinant enzyme was incubated with 1 mM concentration of various metal ions. Potassium chloride increased the enzyme activity while EDTA, Zn++ and Ca++, strongly inhibited the activity. The chromatographic analysis of enzymatic hydrolysates of polygalacturonic acid (PGA) and pectin substrates using HPLC and TLC revealed tri and tetra-galacturonates as the end products of recombinant endo-PGase hydrolysis. Conclusively, endo-PGase gene from the plant pathogenic strain was successfully expressed in Bacillus subtilis for the first time using pHT43 expression vector and could be assessed for enzyme production using a very simple medium with IPTG induction. These findings proposed that the Bacillus expression system might be safer to escape endotoxins for commercial enzyme production as compared to yeast and fungi. Additionally, the hydrolysis products generated by the recombinant endo-PGase activity offer their useful applications in food and beverage industry for quality products.
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Affiliation(s)
- Nagina Rafique
- Department of Food Science and Technology, Faculty of Agriculture, University of the Poonch, Rawalakot, Azad Jammu and Kashmir, Pakistan
- Bioproducts Research Unit, Western Regional Research Centre, United States Department of Agriculture, Albany, California, United States of America
| | - Saiqa Bashir
- Department of Food Science and Technology, Faculty of Agriculture, University of the Poonch, Rawalakot, Azad Jammu and Kashmir, Pakistan
| | - Muhammad Zubair Khan
- Department of Plant Breeding and Molecular Genetics, Faculty of Agriculture, University of Poonch Rawalakot, Azad Jammu and Kashmir, Pakistan
- * E-mail:
| | - Imran Hayat
- Department of Food Science and Technology, Faculty of Agriculture, University of the Poonch, Rawalakot, Azad Jammu and Kashmir, Pakistan
| | - Willium Orts
- Bioproducts Research Unit, Western Regional Research Centre, United States Department of Agriculture, Albany, California, United States of America
| | - Dominic W. S. Wong
- Bioproducts Research Unit, Western Regional Research Centre, United States Department of Agriculture, Albany, California, United States of America
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44
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Wang ZK, Gong JS, Qin J, Li H, Lu ZM, Shi JS, Xu ZH. Improving the Intensity of Integrated Expression for Microbial Production. ACS Synth Biol 2021; 10:2796-2807. [PMID: 34738786 DOI: 10.1021/acssynbio.1c00334] [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] [Indexed: 01/24/2023]
Abstract
Chromosomal integration of exogenous genes is preferred for industrially related fermentation, as plasmid-mediated fermentation leads to extra metabolic burden and genetic instability. Moreover, with the development and advancement of genome engineering and gene editing technologies, inserting genes into chromosomes has become more convenient; integration expression is extensively utilized in microorganisms for industrial bioproduction and expected to become the trend of recombinant protein expression. However, in actual research and application, it is important to enhance the expression of heterologous genes at the host genome level. Herein, we summarized the basic principles and characteristics of genomic integration; furthermore, we highlighted strategies to improve the expression of chromosomal integration of genes and pathways in host strains from three aspects, including chassis cell optimization, regulation of expression elements in gene expression cassettes, optimization of gene dose level and integration sites on chromosomes. Moreover, we reviewed and summarized the relevant studies on the application of integrated expression in the exploration of gene function and the various types of industrial microorganism production. Consequently, this review would serve as a reference for the better application of integrated expression.
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Affiliation(s)
- Zi-Kai Wang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, PR China
- National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, PR China
| | - Jin-Song Gong
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, PR China
| | - Jiufu Qin
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, PR China
| | - Hui Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, PR China
| | - Zhen-Ming Lu
- National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China
| | - Jin-Song Shi
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, PR China
| | - Zheng-Hong Xu
- National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, PR China
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45
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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: 3] [Impact Index Per Article: 1.0] [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.
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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.
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46
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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.
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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
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47
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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.
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48
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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.
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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.
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49
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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]
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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.
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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
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