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Alba Burbano D, Cardiff RAL, Tickman BI, Kiattisewee C, Maranas CJ, Zalatan JG, Carothers JM. Engineering activatable promoters for scalable and multi-input CRISPRa/i circuits. Proc Natl Acad Sci U S A 2023; 120:e2220358120. [PMID: 37463216 PMCID: PMC10374173 DOI: 10.1073/pnas.2220358120] [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: 11/30/2022] [Accepted: 06/13/2023] [Indexed: 07/20/2023] Open
Abstract
Dynamic, multi-input gene regulatory networks (GRNs) are ubiquitous in nature. Multilayer CRISPR-based genetic circuits hold great promise for building GRNs akin to those found in naturally occurring biological systems. We develop an approach for creating high-performing activatable promoters that can be assembled into deep, wide, and multi-input CRISPR-activation and -interference (CRISPRa/i) GRNs. By integrating sequence-based design and in vivo screening, we engineer activatable promoters that achieve up to 1,000-fold dynamic range in an Escherichia coli-based cell-free system. These components enable CRISPRa GRNs that are six layers deep and four branches wide. We show the generalizability of the promoter engineering workflow by improving the dynamic range of the light-dependent EL222 optogenetic system from 6-fold to 34-fold. Additionally, high dynamic range promoters enable CRISPRa systems mediated by small molecules and protein-protein interactions. We apply these tools to build input-responsive CRISPRa/i GRNs, including feedback loops, logic gates, multilayer cascades, and dynamic pulse modulators. Our work provides a generalizable approach for the design of high dynamic range activatable promoters and enables classes of gene regulatory functions in cell-free systems.
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Affiliation(s)
- Diego Alba Burbano
- Department of Chemical Engineering, University of Washington, Seattle, WA98195
- Center for Synthetic Biology, University of Washington, Seattle, WA98195
| | - Ryan A. L. Cardiff
- Center for Synthetic Biology, University of Washington, Seattle, WA98195
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA98195
| | - Benjamin I. Tickman
- Center for Synthetic Biology, University of Washington, Seattle, WA98195
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA98195
| | - Cholpisit Kiattisewee
- Center for Synthetic Biology, University of Washington, Seattle, WA98195
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA98195
| | - Cassandra J. Maranas
- Center for Synthetic Biology, University of Washington, Seattle, WA98195
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA98195
| | - Jesse G. Zalatan
- Center for Synthetic Biology, University of Washington, Seattle, WA98195
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA98195
- Department of Chemistry, University of Washington, Seattle, WA98195
| | - James M. Carothers
- Department of Chemical Engineering, University of Washington, Seattle, WA98195
- Center for Synthetic Biology, University of Washington, Seattle, WA98195
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA98195
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2
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Plasmid-Based Gene Expression Systems for Lactic Acid Bacteria: A Review. Microorganisms 2022; 10:microorganisms10061132. [PMID: 35744650 PMCID: PMC9229153 DOI: 10.3390/microorganisms10061132] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/27/2022] [Accepted: 05/28/2022] [Indexed: 01/27/2023] Open
Abstract
Lactic acid bacteria (LAB) play a very vital role in food production, preservation, and as probiotic agents. Some of these species can colonize and survive longer in the gastrointestinal tract (GIT), where their presence is crucially helpful to promote human health. LAB has also been used as a safe and efficient incubator to produce proteins of interest. With the advent of genetic engineering, recombinant LAB have been effectively employed as vectors for delivering therapeutic molecules to mucosal tissues of the oral, nasal, and vaginal tracks and for shuttling therapeutics for diabetes, cancer, viral infections, and several gastrointestinal infections. The most important tool needed to develop genetically engineered LABs to produce proteins of interest is a plasmid-based gene expression system. To date, a handful of constitutive and inducible vectors for LAB have been developed, but their limited availability, host specificity, instability, and low carrying capacity have narrowed their spectrum of applications. The current review discusses the plasmid-based vectors that have been developed so far for LAB; their functionality, potency, and constraints; and further highlights the need for a new, more stable, and effective gene expression platform for LAB.
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3
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Woodley JM. Ensuring the Sustainability of Biocatalysis. CHEMSUSCHEM 2022; 15:e202102683. [PMID: 35084801 DOI: 10.1002/cssc.202102683] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Biocatalysis offers many attractive features for the synthetic chemist. In many cases, the high selectivity and ability to tailor specific enzyme features via protein engineering already make it the catalyst of choice. From the perspective of sustainability, several features such as catalysis under mild conditions and use of a renewable and biodegradable catalyst also look attractive. Nevertheless, to be sustainable at a larger scale it will be essential to develop processes operating at far higher concentrations of product, and which make better use of the enzyme via improved stability. In this Concept, it is argued that a particular emphasis on these specific metrics is of particular importance for the future implementation of biocatalysis in industry, at a level that fulfills its true potential.
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Affiliation(s)
- John M Woodley
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
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4
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Abstract
Biofuel consists of non-fossil fuel derived from the organic biomass of renewable resources, including plants, animals, microorganisms, and waste. Energy derived from biofuel is known as bioenergy. The reserve of fossil fuels is now limited and continuing to decrease, while at the same time demand for energy is increasing. In order to overcome this scarcity, it is vital for human beings to transfer their dependency on fossil fuels to alternative types of fuel, including biofuels, which are effective methods of fulfilling present and future demands. The current review therefore focusses on second-generation lignocellulosic biofuels obtained from non-edible plant biomass (i.e., cellulose, lignin, hemi-celluloses, non-food material) in a more sustainable manner. The conversion of lignocellulosic feedstock is an important step during biofuel production. It is, however, important to note that, as a result of various technical restrictions, biofuel production is not presently cost efficient, thus leading to the need for improvement in the methods employed. There remain a number of challenges for the process of biofuel production, including cost effectiveness and the limitations of various technologies employed. This leads to a vital need for ongoing and enhanced research and development, to ensure market level availability of lignocellulosic biofuel.
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5
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Hu L, Guo S, Wang B, Fu R, Fan D, Jiang M, Fei Q, Gonzalez R. Bio-valorization of C1 gaseous substrates into bioalcohols: Potentials and challenges in reducing carbon emissions. Biotechnol Adv 2022; 59:107954. [DOI: 10.1016/j.biotechadv.2022.107954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 03/29/2022] [Accepted: 04/04/2022] [Indexed: 11/02/2022]
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6
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Liang J, Zhang H, Tan YL, Zhao H, Ang EL. Directed Evolution of Replication-Competent Double-Stranded DNA Bacteriophage toward New Host Specificity. ACS Synth Biol 2022; 11:634-643. [PMID: 35090114 DOI: 10.1021/acssynbio.1c00319] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In the fight against antimicrobial resistance, bacteriophages are a promising alternative to antibiotics. However, due to their narrow spectra, phage therapy requires the careful matching between the host and bacteriophage to be effective. Despite our best efforts, nature remains as the only source of novel phage specificity. Directed evolution can potentially open an avenue for engineering phage specificity and improving qualities of phages that are not strongly selected for in their natural environments but are important for therapeutic applications. In this work, we present a strategy that generates large libraries of replication-competent phage variants directly from synthetic DNA fragments, with no restriction on their host specificity. Using the T7 bacteriophage as a proof-of-concept, we created a large library of tail fiber mutants with at least 107 unique variants. From this library, we identified mutants that have broadened specificity as evidenced by their novel lytic activity against Yersinia enterocolitica, a strain that the wild-type T7 was unable to lyse. Using the same concept, mutants with improved lytic efficiency and characteristics, such as lytic condition tolerance and resistance suppression, were also identified. However, the observed limitations in altering host specificity by tail fiber mutagenesis suggest that other bottlenecks could be of equal or even greater importance.
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Affiliation(s)
- Jing Liang
- Strain Engineering, Singapore Institute of Food and Biotechnology Innovation, Singapore 138669, Singapore
| | - Huibin Zhang
- Metabolic Engineering Research Laboratory (MERL), Agency for Science, Technology, and Research (A*STAR), Singapore 138669, Singapore
| | - Yee Ling Tan
- Strain Engineering, Singapore Institute of Food and Biotechnology Innovation, Singapore 138669, Singapore
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Ee Lui Ang
- Strain Engineering, Singapore Institute of Food and Biotechnology Innovation, Singapore 138669, Singapore
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7
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Ogawa Y, Katsuyama Y, Ohnishi Y. Engineering of the Ligand Specificity of Transcriptional Regulator XylS by Deep Mutational Scanning. ACS Synth Biol 2022; 11:473-485. [PMID: 34964613 DOI: 10.1021/acssynbio.1c00564] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Deep mutational scanning is a method for protein engineering. Here, we applied it to alter the ligand specificity of the transcriptional regulator XylS from Pseudomonas putida to recognize p-toluic acid instead of the native ligand m-toluic acid. For this purpose, we used an antibiotic resistance gene-based dual screening system, which was constructed for the directed evolution of XylS toward the above-mentioned ligand specificity. We constructed a xylS mutant library in which each codon for the amino acid residue of the putative ligand-binding domain (residues 1-213, except 7th residue) was randomized to generate all possible single amino acid-substituted XylS variants and introduced it into Escherichia coli harboring the selection plasmid for the screening system. The cells were cultured in the presence of appropriate antibiotics and m-toluic acid or p-toluic acid, and the frequency of each mutation present in the library was examined using a next-generation sequencer before and after cultivation. Heatmaps showing the enrichment score of each XylS variant were obtained. By searching for a p-toluic-acid-specific heatmap pattern, we focused on G71 and H77. Analysis of the ligand specificities of G71- or H77-substituted XylS variants revealed that several G71-substituted XylS variants responded specifically to p-toluic acid. Thus, the 71st residue was found to be an unprecedented residue that is important for switching ligand specificity. Our study demonstrated the usefulness of deep mutational scanning in engineering the ligand specificity of a transcriptional regulator without structural information. We also discussed the advantages and disadvantages of deep mutational scanning compared with directed evolution.
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Affiliation(s)
- Yuki Ogawa
- Department of Biotechnology, The Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yohei Katsuyama
- Department of Biotechnology, The Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yasuo Ohnishi
- Department of Biotechnology, The Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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8
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de Lorenzo V. 15 years of microbial biotechnology: the time has come to think big-and act soon. Microb Biotechnol 2022; 15:240-246. [PMID: 34932877 PMCID: PMC8719810 DOI: 10.1111/1751-7915.13993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 11/25/2022] Open
Abstract
Our epoch is largely characterized by the growing realization and concern about the reality of climate change and environmental deterioration, the surge of global pandemics, the unacceptable inequalities between developed and underdeveloped countries and their unavoidable translation into messy immigration, overpopulation and food crises. While all of these issues have a fundamentally political core, they are not altogether removed from the fact that Earth is primarily a microbial planet and microorganisms are the key agents that make the biosphere (including ourselves) function as it does. It thus makes sense that we bring the microbial world-that is the environmental microbiome-to the necessary multi-tiered conversation (hopefully followed by action) on how to avoid future threats and how to make our globe a habitable common house. Beyond discussion on governance, such a dialogue has technical and scientific aspects that only frontline microbial biotechnology can help to tackle. Fortunately, the field has witnessed the onset of new conceptual and material tools that were missing when the journal started.
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9
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Cao Y, Tian R, Lv X, Li J, Liu L, Du G, Chen J, Liu Y. Inducible Population Quality Control of Engineered Bacillus subtilis for Improved N-Acetylneuraminic Acid Biosynthesis. ACS Synth Biol 2021; 10:2197-2209. [PMID: 34404207 DOI: 10.1021/acssynbio.1c00086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Biosynthesis by microorganisms using renewable feedstocks is an important approach for realizing sustainable chemical manufacturing. However, cell-to-cell variation in biosynthesis capability during fermentation restricts the robustness and efficiency of bioproduction, hampering the industrialization of biosynthesis. Herein, we developed an inducible population quality control system (iPopQC) for dynamically modulating the producing and nonproducing subpopulations of engineered Bacillus subtilis, which was constructed via inducible promoter- and metabolite-responsive biosensor-based genetic circuit for regulating essential genes. Moreover, iPopQC achieved a 1.97-fold increase in N-acetylneuraminic acid (NeuAc) titer by enriching producing cell subpopulation during cultivation, representing 52% higher than that of previous PopQC. Strains with double-output iPopQC cocoupling the expression of double essential genes with NeuAc production improved production robustness further, retaining NeuAc production throughout 96 h of fermentation, upon which the strains cocoupling one essential gene expression with NeuAc production abolished the production ability.
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Affiliation(s)
- Yanting Cao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Rongzhen Tian
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Xueqin Lv
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Jian Chen
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
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10
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Zhang X, Luo W, Yao Y, Luo X, Han C, Zhong Y, Zhang B, Li D, Han L, Huang S, Greisen P, Shang Y. Enhanced chemoselectivity of a plant cytochrome P450 through protein engineering of surface and catalytic residues. ABIOTECH 2021; 2:215-225. [PMID: 36303887 PMCID: PMC9590459 DOI: 10.1007/s42994-021-00056-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/07/2021] [Indexed: 10/31/2022]
Abstract
Cytochrome P450s (P450s) are the most versatile catalysts utilized by plants to produce structurally and functionally diverse metabolites. Given the high degree of gene redundancy and challenge to functionally characterize plant P450s, protein engineering is used as a complementary strategy to study the mechanisms of P450-mediated reactions, or to alter their functions. We previously proposed an approach of engineering plant P450s based on combining high-accuracy homology models generated by Rosetta combined with data-driven design using evolutionary information of these enzymes. With this strategy, we repurposed a multi-functional P450 (CYP87D20) into a monooxygenase after redesigning its active site. Since most plant P450s are membrane-anchored proteins that are adapted to the micro-environments of plant cells, expressing them in heterologous hosts usually results in problems of expression or activity. Here, we applied computational design to tackle these issues by simultaneous optimization of the protein surface and active site. After screening 17 variants, effective substitutions of surface residues were observed to improve both expression and activity of CYP87D20. In addition, the identified substitutions were additive and by combining them a highly efficient C11 hydroxylase of cucurbitadienol was created to participate in the mogrol biosynthesis. This study shows the importance of considering the interplay between surface and active site residues for P450 engineering. Our integrated strategy also opens an avenue to create more tailoring enzymes with desired functions for the metabolic engineering of high-valued compounds like mogrol, the precursor of natural sweetener mogrosides. Supplementary Information The online version contains supplementary material available at 10.1007/s42994-021-00056-z.
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Affiliation(s)
- Xiaopeng Zhang
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518116 China
| | - Wei Luo
- Yunnan Key Laboratory of Potato Biology, The CAAS-YNNU-YINMORE Joint Academy of Potato Sciences, Yunnan Normal University, Kunming, 650500 China
| | - Yinying Yao
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518116 China.,National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 China
| | - Xuming Luo
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518116 China
| | - Chao Han
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Yang Zhong
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518116 China.,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of Ministry of Agriculture, Sino-Dutch Joint Lab of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Bo Zhang
- Yunnan Key Laboratory of Potato Biology, The CAAS-YNNU-YINMORE Joint Academy of Potato Sciences, Yunnan Normal University, Kunming, 650500 China
| | - Dawei Li
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518116 China
| | - Lida Han
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Sanwen Huang
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518116 China
| | - Per Greisen
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518116 China.,Novo Nordisk Research Center Seattle Inc, Seattle, WA 98109 USA
| | - Yi Shang
- Yunnan Key Laboratory of Potato Biology, The CAAS-YNNU-YINMORE Joint Academy of Potato Sciences, Yunnan Normal University, Kunming, 650500 China
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11
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Pagar AD, Patil MD, Flood DT, Yoo TH, Dawson PE, Yun H. Recent Advances in Biocatalysis with Chemical Modification and Expanded Amino Acid Alphabet. Chem Rev 2021; 121:6173-6245. [PMID: 33886302 DOI: 10.1021/acs.chemrev.0c01201] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The two main strategies for enzyme engineering, directed evolution and rational design, have found widespread applications in improving the intrinsic activities of proteins. Although numerous advances have been achieved using these ground-breaking methods, the limited chemical diversity of the biopolymers, restricted to the 20 canonical amino acids, hampers creation of novel enzymes that Nature has never made thus far. To address this, much research has been devoted to expanding the protein sequence space via chemical modifications and/or incorporation of noncanonical amino acids (ncAAs). This review provides a balanced discussion and critical evaluation of the applications, recent advances, and technical breakthroughs in biocatalysis for three approaches: (i) chemical modification of cAAs, (ii) incorporation of ncAAs, and (iii) chemical modification of incorporated ncAAs. Furthermore, the applications of these approaches and the result on the functional properties and mechanistic study of the enzymes are extensively reviewed. We also discuss the design of artificial enzymes and directed evolution strategies for enzymes with ncAAs incorporated. Finally, we discuss the current challenges and future perspectives for biocatalysis using the expanded amino acid alphabet.
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Affiliation(s)
- Amol D Pagar
- Department of Systems Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
| | - Mahesh D Patil
- Department of Systems Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
| | - Dillon T Flood
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Tae Hyeon Yoo
- Department of Molecular Science and Technology, Ajou University, 206 World cup-ro, Yeongtong-gu, Suwon 16499, Korea
| | - Philip E Dawson
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Hyungdon Yun
- Department of Systems Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
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12
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LaPanse AJ, Krishnan A, Posewitz MC. Adaptive Laboratory Evolution for algal strain improvement: methodologies and applications. ALGAL RES 2021. [DOI: 10.1016/j.algal.2020.102122] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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13
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Li N, Zeng W, Xu S, Zhou J. Toward fine-tuned metabolic networks in industrial microorganisms. Synth Syst Biotechnol 2020; 5:81-91. [PMID: 32542205 PMCID: PMC7283098 DOI: 10.1016/j.synbio.2020.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 03/30/2020] [Accepted: 05/06/2020] [Indexed: 12/11/2022] Open
Abstract
There are numerous microorganisms in nature capable of synthesizing diverse useful compounds; however, these natural microorganisms are generally inefficient in the production of target products on an industrial scale, relative to either chemical synthesis or extraction methods. To achieve industrial production of useful compounds, these natural microorganisms must undergo a certain degree of mutation or effective fine-tuning strategies. This review describes how to achieve an ideal metabolic fine-tuned process, including static control strategies and dynamic control strategies. The static control strategies mainly focus on various matabolic engineering strategies, including protein engineering, upregulation/downregulation, and combinatrorial control of these metabolic engineering strategies, to enhance the flexibility of their application in fine-tuned metabolic metworks. Then, we focus on the dynamic control strategies for fine-tuned metabolic metworks. The design principles derived would guide us to construct microbial cell factories for various useful compounds.
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Affiliation(s)
- Ning Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
| | - Weizhu Zeng
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
| | - Sha Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
| | - Jingwen Zhou
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.,Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
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14
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Nagappan S, Tsai PC, Devendran S, Alagarsamy V, Ponnusamy VK. Enhancement of biofuel production by microalgae using cement flue gas as substrate. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:17571-17586. [PMID: 31512119 DOI: 10.1007/s11356-019-06425-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
The cement industry generates a substantial amount of gaseous pollutants that cannot be treated efficiently and economically using standard techniques. Microalgae, a promising bioremediation and biodegradation agent used as feedstock for biofuel production, can be used for the biotreatment of cement flue gas. In specific, components of cement flue gas such as carbon dioxide, nitrogen, and sulfur oxides are shown to serve as nutrients for microalgae. Microalgae also have the capacity to sequestrate heavy metals present in cement kiln dust, adding further benefits. This work provides an extensive overview of multiple approaches taken in the inclusion of microalgae biofuel production in the cement sector. In addition, factors influencing the production of microalgal biomass are also described in such an integrated plant. In addition, process limitations such as the adverse impact of flue gas on medium pH, exhaust gas toxicity, and efficient delivery of carbon dioxide to media are also discussed. Finally, the article concludes by proposing the future potential for incorporating the microalgae biofuel plant into the cement sector.
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Affiliation(s)
- Senthil Nagappan
- Department of Biotechnology, Sri Venkateswara College of Engineering (Autonomous - Affiliated to Anna University), Sriperumbudur, Tamil Nadu, 602 117, India
| | - Pei-Chien Tsai
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, No. 100, Shiquan 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan
| | - Saravanan Devendran
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Vardhini Alagarsamy
- Department of Biotechnology, Sri Venkateswara College of Engineering (Autonomous - Affiliated to Anna University), Sriperumbudur, Tamil Nadu, 602 117, India
| | - Vinoth Kumar Ponnusamy
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, No. 100, Shiquan 1st Road, Sanmin District, Kaohsiung City, 807, Taiwan.
- Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung City, 807, Taiwan.
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Planson AG, Sauveplane V, Dervyn E, Jules M. Bacterial growth physiology and RNA metabolism. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194502. [PMID: 32044462 DOI: 10.1016/j.bbagrm.2020.194502] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/17/2020] [Accepted: 02/06/2020] [Indexed: 12/31/2022]
Abstract
Bacteria are sophisticated systems with high capacity and flexibility to adapt to various environmental conditions. Each prokaryote however possesses a defined metabolic network, which sets its overall metabolic capacity, and therefore the maximal growth rate that can be reached. To achieve optimal growth, bacteria adopt various molecular strategies to optimally adjust gene expression and optimize resource allocation according to the nutrient availability. The resulting physiological changes are often accompanied by changes in the growth rate, and by global regulation of gene expression. The growth-rate-dependent variation of the abundances in the cellular machineries, together with condition-specific regulatory mechanisms, affect RNA metabolism and fate and pose a challenge for rational gene expression reengineering of synthetic circuits. This article is part of a Special Issue entitled: RNA and gene control in bacteria, edited by Dr. M. Guillier and F. Repoila.
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Affiliation(s)
- Anne-Gaëlle Planson
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France.
| | - Vincent Sauveplane
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France.
| | - Etienne Dervyn
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France.
| | - Matthieu Jules
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France.
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16
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Shang Y, Huang S. Engineering Plant Cytochrome P450s for Enhanced Synthesis of Natural Products: Past Achievements and Future Perspectives. PLANT COMMUNICATIONS 2020; 1:100012. [PMID: 33404545 PMCID: PMC7747987 DOI: 10.1016/j.xplc.2019.100012] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Cytochrome P450s (P450s) are the most versatile catalysts and are widely used by plants to synthesize a vast array of structurally diverse specialized metabolites that not only play essential ecological roles but also constitute a valuable resource for the development of new drugs. To accelerate the metabolic engineering of these high-value metabolites, it is imperative to identify and characterize pathway P450s, and to further improve their activities through protein engineering. In this review, we focus on P450 engineering and summarize the major strategies for enhancing the stability and activity of P450s and successful cases of P450 engineering. Studies in which the functions of P450s were altered to create de novo metabolic pathways or novel compounds are discussed as well. We also overview emerging tools, specifically DNA synthesis, machine learning, and de novo protein design, as well as the evolutionary patterns of P450s unveiled from a massive number of DNA sequences that could be integrated to accelerate the engineering of these enzymes. These approaches would greatly aid in the exploitation of plant-specialized metabolites or derivatives for various uses including medical applications.
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Affiliation(s)
- Yi Shang
- Key Laboratory for Potato Biology of Yunnan Province, The CAAS-YNNU-YINMORE Joint Academy of Potato Science, Yunnan Normal University, Kunming, China
| | - Sanwen Huang
- Lingnan Guangdong Laboratory of Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
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17
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Ko YS, Kim JW, Lee JA, Han T, Kim GB, Park JE, Lee SY. Tools and strategies of systems metabolic engineering for the development of microbial cell factories for chemical production. Chem Soc Rev 2020; 49:4615-4636. [DOI: 10.1039/d0cs00155d] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This tutorial review covers tools, strategies, and procedures of systems metabolic engineering facilitating the development of microbial cell factories efficiently producing chemicals and materials.
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Affiliation(s)
- Yoo-Sung Ko
- Metabolic and Biomolecular Engineering National Research Laboratory
- Systems Metabolic Engineering and Systems Healthcare (SMESH) Cross-Generation Collaborative Laboratory
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program)
- Institute for the BioCentury
- Korea Advanced Institute of Science and Technology (KAIST)
| | - Je Woong Kim
- Metabolic and Biomolecular Engineering National Research Laboratory
- Systems Metabolic Engineering and Systems Healthcare (SMESH) Cross-Generation Collaborative Laboratory
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program)
- Institute for the BioCentury
- Korea Advanced Institute of Science and Technology (KAIST)
| | - Jong An Lee
- Metabolic and Biomolecular Engineering National Research Laboratory
- Systems Metabolic Engineering and Systems Healthcare (SMESH) Cross-Generation Collaborative Laboratory
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program)
- Institute for the BioCentury
- Korea Advanced Institute of Science and Technology (KAIST)
| | - Taehee Han
- Metabolic and Biomolecular Engineering National Research Laboratory
- Systems Metabolic Engineering and Systems Healthcare (SMESH) Cross-Generation Collaborative Laboratory
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program)
- Institute for the BioCentury
- Korea Advanced Institute of Science and Technology (KAIST)
| | - Gi Bae Kim
- Metabolic and Biomolecular Engineering National Research Laboratory
- Systems Metabolic Engineering and Systems Healthcare (SMESH) Cross-Generation Collaborative Laboratory
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program)
- Institute for the BioCentury
- Korea Advanced Institute of Science and Technology (KAIST)
| | - Jeong Eum Park
- Metabolic and Biomolecular Engineering National Research Laboratory
- Systems Metabolic Engineering and Systems Healthcare (SMESH) Cross-Generation Collaborative Laboratory
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program)
- Institute for the BioCentury
- Korea Advanced Institute of Science and Technology (KAIST)
| | - Sang Yup Lee
- Metabolic and Biomolecular Engineering National Research Laboratory
- Systems Metabolic Engineering and Systems Healthcare (SMESH) Cross-Generation Collaborative Laboratory
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program)
- Institute for the BioCentury
- Korea Advanced Institute of Science and Technology (KAIST)
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18
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Ogawa Y, Katsuyama Y, Ueno K, Ohnishi Y. Switching the Ligand Specificity of the Biosensor XylS from meta to para-Toluic Acid through Directed Evolution Exploiting a Dual Selection System. ACS Synth Biol 2019; 8:2679-2689. [PMID: 31689072 DOI: 10.1021/acssynbio.9b00237] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Pseudomonas putida transcriptional activator XylS induces transcription from the Pm promoter in the presence of several benzoic acid effectors, with m-toluic acid being the most effective and p-toluic acid being much less effective. To alter the effector specificity of XylS, we developed a dual selection system in Escherichia coli, which consists of (i) an artificial operon of an ampicillin resistance gene and tetR under Pm promoter control and (ii) a chloramphenicol resistance gene under tetR promoter control. This system enabled both positive selection to concentrate XylS mutants recognizing a desired ligand and negative selection to exclude undesired XylS mutants such as those recognizing undesired ligands and those that are active without effectors. Application of a random mutagenesis library of xylS to directed evolution that exploited this selection system yielded two XylS mutants that recognize p-toluic acid more effectively. Analysis of each missense mutation indicated three amino acid residues (N7, T74, and I205) important for p-toluic acid recognition. Then, a codon-randomized xylS library at these three residues was similarly screened, resulting in three XylS mutants with increased p-toluic acid-recognition specificity. Analysis of each amino acid substitution revealed that T74P attributes to both m-toluic acid sensitivity loss and subtle p-toluic acid sensitivity acquisition, and that N7R increases the overall ligand-sensitivity. Finally, the combination of these two mutations generated a desirable XylS mutant, which has a high p-toluic acid sensitivity and scarcely responds to m-toluic acid. These results demonstrate the effectiveness of the dual selection system in the directed evolution of biosensors.
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Affiliation(s)
- Yuki Ogawa
- Department of Biotechnology, The Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yohei Katsuyama
- Department of Biotechnology, The Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kento Ueno
- Department of Biotechnology, The Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yasuo Ohnishi
- Department of Biotechnology, The Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
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Szymanski E, Scher E. Models for DNA Design Tools: The Trouble with Metaphors Is That They Don't Go Away. ACS Synth Biol 2019; 8:2635-2641. [PMID: 31580653 DOI: 10.1021/acssynbio.9b00302] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Synthetic biology relies heavily on DNA design tools to enable manipulation of DNA in silico. Existing tools, however, are falling short of enabling aspirations for the field that emphasize efficient, automated design pipelines. We review existing DNA design tools, identify underlying similarities in how they model correlations between DNA structure and function, and suggest that iterating the existing model is unlikely to overcome limitations in matching software applications to design aspirations. The current model is predicated on metaphors conceptualizing DNA as linear text, accounting for relatively little of the known complexity of DNA function. New models that can account for more of that complexity and thus enable more ambitious DNA design goals are likely to call for new underlying metaphors-a need that may be addressed by rethinking DNA in terms of human rather than computer languages.
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Affiliation(s)
- Erika Szymanski
- Colorado State University, Department of English, Fort Collins, Colorado 80523, United States
| | - Emily Scher
- Informatics Forum, School of Informatics, University of Edinburgh, Edinburgh EH8 9AB, United Kingdom
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20
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Gionfriddo M, De Gara L, Loreto F. Directed Evolution of Plant Processes: Towards a Green (r)Evolution? TRENDS IN PLANT SCIENCE 2019; 24:999-1007. [PMID: 31604600 DOI: 10.1016/j.tplants.2019.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/11/2019] [Accepted: 08/13/2019] [Indexed: 05/13/2023]
Abstract
Directed evolution (DE) is a powerful approach for generating proteins with new chemical and physical properties. It mimics the principles of Darwinian evolution by imposing selective pressure on a large population of molecules harboring random genetic variation in DNA, such that sequences with specific desirable properties are generated and selected. We propose that combining DE and genome-editing (DE-GE) technologies represents a powerful tool to discover and integrate new traits into plants for agronomic and biotechnological gain. DE-GE has the potential to deliver a new green (r)evolution research platform that can provide novel solutions to major trait delivery aspirations for sustainable agriculture, climate-resilient crops, and improved food security and nutritional quality.
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Affiliation(s)
- Matteo Gionfriddo
- Unit of Food Science and Human Nutrition, Campus Bio-Medico, University of Rome, Via Álvaro del Portillo 21, 00128 Rome, Italy; Department of Biology, Agriculture, and Food Sciences, National Research Council of Italy (CNR-DISBA), Piazzale Aldo Moro 7, 00185 Rome, Italy
| | - Laura De Gara
- Unit of Food Science and Human Nutrition, Campus Bio-Medico, University of Rome, Via Álvaro del Portillo 21, 00128 Rome, Italy.
| | - Francesco Loreto
- Department of Biology, Agriculture, and Food Sciences, National Research Council of Italy (CNR-DISBA), Piazzale Aldo Moro 7, 00185 Rome, Italy; Department of Biology, University Federico II, Via Cinthia, 80126 Naples, Italy.
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21
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Droplet Microfluidics-Enabled High-Throughput Screening for Protein Engineering. MICROMACHINES 2019; 10:mi10110734. [PMID: 31671786 PMCID: PMC6915371 DOI: 10.3390/mi10110734] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 10/22/2019] [Accepted: 10/26/2019] [Indexed: 12/19/2022]
Abstract
Protein engineering—the process of developing useful or valuable proteins—has successfully created a wide range of proteins tailored to specific agricultural, industrial, and biomedical applications. Protein engineering may rely on rational techniques informed by structural models, phylogenic information, or computational methods or it may rely upon random techniques such as chemical mutation, DNA shuffling, error prone polymerase chain reaction (PCR), etc. The increasing capabilities of rational protein design coupled to the rapid production of large variant libraries have seriously challenged the capacity of traditional screening and selection techniques. Similarly, random approaches based on directed evolution, which relies on the Darwinian principles of mutation and selection to steer proteins toward desired traits, also requires the screening of very large libraries of mutants to be truly effective. For either rational or random approaches, the highest possible screening throughput facilitates efficient protein engineering strategies. In the last decade, high-throughput screening (HTS) for protein engineering has been leveraging the emerging technologies of droplet microfluidics. Droplet microfluidics, featuring controlled formation and manipulation of nano- to femtoliter droplets of one fluid phase in another, has presented a new paradigm for screening, providing increased throughput, reduced reagent volume, and scalability. We review here the recent droplet microfluidics-based HTS systems developed for protein engineering, particularly directed evolution. The current review can also serve as a tutorial guide for protein engineers and molecular biologists who need a droplet microfluidics-based HTS system for their specific applications but may not have prior knowledge about microfluidics. In the end, several challenges and opportunities are identified to motivate the continued innovation of microfluidics with implications for protein engineering.
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Martínez LM, Martinez A, Gosset G. Production of Melanins With Recombinant Microorganisms. Front Bioeng Biotechnol 2019; 7:285. [PMID: 31709247 PMCID: PMC6821874 DOI: 10.3389/fbioe.2019.00285] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 10/07/2019] [Indexed: 11/16/2022] Open
Abstract
The melanins constitute a diverse group of natural products found in most organisms, having functions related to protection against chemical and physical stresses. These products originate from the enzyme-catalyzed oxidation of phenolic and indolic substrates that polymerize to yield melanins, which include eumelanin, pheomelanin, pyomelanin, and the allomelanins. The enzymes involved in melanin formation belong mainly to the tyrosinase and laccase protein families. The melanins are polymeric materials having applications in the pharmaceutical, cosmetic, optical, and electronic industries. The biotechnological production of these polymers is an attractive alternative to obtaining them by extraction from plant or animal material, where they are present at low concentrations. Several species of microorganisms have been identified as having a natural melanogenic capacity. The development and optimization of culture conditions with these organisms has resulted in processes for generating melanins. These processes are based on the conversion of melanin precursors present in the culture medium to the corresponding polymers. With the application of genetic engineering techniques, it has become possible to overexpress genes encoding enzymes involved in melanin formation, mostly tyrosinases, leading to an improvement in the productivity of melanogenic organisms, as well as allowing the generation of novel recombinant microbial strains that can produce diverse types of melanins. Furthermore, the metabolic engineering of microbial hosts by modifying pathways related to the supply of melanogenic precursors has resulted in strains with the capacity of performing the total synthesis of melanins from simple carbon sources in the scale of grams. In this review, the latest advances toward the generation of recombinant melanin production strains and production processes are summarized and discussed.
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Affiliation(s)
- Luz María Martínez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Alfredo Martinez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Guillermo Gosset
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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Yi L, Peng Q, Liu D, Zhou L, Tang C, Zhou Y, Chai L. Enhanced degradation of perfluorooctanoic acid by a genome shuffling-modified Pseudomonas parafulva YAB-1. ENVIRONMENTAL TECHNOLOGY 2019; 40:3153-3161. [PMID: 29671379 DOI: 10.1080/09593330.2018.1466918] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 04/07/2018] [Indexed: 06/08/2023]
Abstract
Perfluorooctanoic acid (PFOA) as an emerging persistent organic pollutant is hard to be degraded by conventional methods because of its stable physical and chemical properties. Microbial transformation is an attractive remediation approach to prevent and clean up PFOA contamination. To date, several strains of wild microbes have been reported to have limited capacity to degrade PFOA, selection of superior strains degrading PFOA become urgently necessary. Here, we report the application of genome shuffling to improve the PFOA-degrading bacterium Pseudomonas Parafulva YAB-1. The initial mutant populations of strain YAB1 were generated by nitrosoguanidine and ultraviolet irradiation mutagenesis respectively, resulting in mutants YM-9 and YM-19 with slightly improved PFOA-degrading ability. YM-9 and YM-19 were used as the starting strains for three rounds of recursive protoplast fusion. The positive mutants were screened on inorganic salt medium plates containing different concentrations of PFOA and selected based on their PFOA degradability in shake-flask fermentation test. The best performing recombinant F3-52 was isolated after three rounds of genome shuffling. In batch fermentation, the PFOA degradation rate of mutant F3-52 was up to 58.6%, which was 1.8-fold higher than that of the parent strain YAB1, and 1.6-fold higher than the initial mutants YM-9 and YM-19. Pass-generation test indicated that the heredity character of F3-52 was stable. The results demonstrated that genome shuffling was an efficient method for improving PFOA degradation of Pseudomonas Parafulva YAB1. The bred mutant F3-52 with 58.6% PFOA-degrading rate could be used for the environmental control of PFOA pollutant.
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Affiliation(s)
- Langbo Yi
- School of Metallurgy and Environment, Central South University , Changsha , People's Republic of China
- College of Biology and Environmental Sciences, Jishou University , Jishou , People's Republic of China
| | - Qingzhong Peng
- College of Biology and Environmental Sciences, Jishou University , Jishou , People's Republic of China
| | - Deming Liu
- Analysis and Test Center, Hunan Agricultural University , Changsha , People's Republic of China
| | - Lulu Zhou
- College of Biology and Environmental Sciences, Jishou University , Jishou , People's Republic of China
| | - Chongjian Tang
- School of Metallurgy and Environment, Central South University , Changsha , People's Republic of China
| | - Yaoyu Zhou
- College of Resources and Environment, Hunan Agricultural University , Changsha , People's Republic of China
| | - Liyuan Chai
- School of Metallurgy and Environment, Central South University , Changsha , People's Republic of China
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24
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Synthetic microbial consortia for biosynthesis and biodegradation: promises and challenges. J Ind Microbiol Biotechnol 2019; 46:1343-1358. [PMID: 31278525 DOI: 10.1007/s10295-019-02211-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/01/2019] [Indexed: 02/07/2023]
Abstract
Functional differentiation and metabolite exchange enable microbial consortia to perform complex metabolic tasks and efficiently cycle the nutrients. Inspired by the cooperative relationships in environmental microbial consortia, synthetic microbial consortia have great promise for studying the microbial interactions in nature and more importantly for various engineering applications. However, challenges coexist with promises, and the potential of consortium-based technologies is far from being fully harnessed. Thorough understanding of the underlying molecular mechanisms of microbial interactions is greatly needed for the rational design and optimization of defined consortia. These knowledge gaps could be potentially filled with the assistance of the ongoing revolution in systems biology and synthetic biology tools. As current fundamental and technical obstacles down the road being removed, we would expect new avenues with synthetic microbial consortia playing important roles in biological and environmental engineering processes such as bioproduction of desired chemicals and fuels, as well as biodegradation of persistent contaminants.
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Sarkar K, Mukhopadhyay S, Bonnerjee D, Srivastava R, Bagh S. A frame-shifted gene, which rescued its function by non-natural start codons and its application in constructing synthetic gene circuits. J Biol Eng 2019; 13:20. [PMID: 30867677 PMCID: PMC6397469 DOI: 10.1186/s13036-019-0151-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 02/20/2019] [Indexed: 12/22/2022] Open
Abstract
Background Frame-shifted genes results in non-functional peptides. Because of this complete loss of function, frame-shifted genes have never been used in constructing synthetic gene circuits. Results Here we report that the function of gene circuits is rescued by a frame-shifted gene, which functions by translating from a non-natural start codon. We report a single nucleotide deletion mutation that developed in the λ-repressor cI within a synthetic genetic NOT gate in Escherichia coli during growth and through this mutation, a non-functional synthetic gene circuit became functional. This mutation resulted in a frame-shifted cI, which showed effective functionality among genetic NOT-gates in Escherichia coli with high regulatory ranges (> 300) and Hill coefficient (> 6.5). The cI worked over a large range of relative copy numbers between the frame-shifted gene and its target promoter. These properties make this frame-shifted gene an excellent candidate for building synthetic gene circuits. We hypothesized a new operating mechanism and showed evidence that frame-shifted cI was translated from non-natural start codon. We have engineered and tested a series of NOT gates made from a library of cI genes, each of which starts from a different codon within the first several amino acids of the frame-shifted cI. It is found that one form with start codon ACA, starting from the 3rd codon had similar repression behavior as the whole frame-shifted gene. We demonstrated synthetic genetic NAND and NOR logic-gates with frame-shifted cI. This is the first report of synthetic-gene-circuits made from a frame-shifted gene. Conclusions This study inspires a new view on frame-shifted gene and may serve as a novel way of building and optimizing synthetic-gene-circuits. This work may also have significance in the understanding of non-directed evolution of synthetic genetic circuits. Electronic supplementary material The online version of this article (10.1186/s13036-019-0151-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kathakali Sarkar
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Homi Bhabha National Institute, Block A/F, Sector-I, Bidhannagar, Kolkata, 700064 India
| | - Sayak Mukhopadhyay
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Homi Bhabha National Institute, Block A/F, Sector-I, Bidhannagar, Kolkata, 700064 India
| | - Deepro Bonnerjee
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Homi Bhabha National Institute, Block A/F, Sector-I, Bidhannagar, Kolkata, 700064 India
| | - Rajkamal Srivastava
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Homi Bhabha National Institute, Block A/F, Sector-I, Bidhannagar, Kolkata, 700064 India
| | - Sangram Bagh
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Homi Bhabha National Institute, Block A/F, Sector-I, Bidhannagar, Kolkata, 700064 India
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26
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Nora LC, Westmann CA, Martins‐Santana L, Alves LDF, Monteiro LMO, Guazzaroni M, Silva‐Rocha R. The art of vector engineering: towards the construction of next-generation genetic tools. Microb Biotechnol 2019; 12:125-147. [PMID: 30259693 PMCID: PMC6302727 DOI: 10.1111/1751-7915.13318] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 08/29/2018] [Accepted: 08/31/2018] [Indexed: 12/20/2022] Open
Abstract
When recombinant DNA technology was developed more than 40 years ago, no one could have imagined the impact it would have on both society and the scientific community. In the field of genetic engineering, the most important tool developed was the plasmid vector. This technology has been continuously expanding and undergoing adaptations. Here, we provide a detailed view following the evolution of vectors built throughout the years destined to study microorganisms and their peculiarities, including those whose genomes can only be revealed through metagenomics. We remark how synthetic biology became a turning point in designing these genetic tools to create meaningful innovations. We have placed special focus on the tools for engineering bacteria and fungi (both yeast and filamentous fungi) and those available to construct metagenomic libraries. Based on this overview, future goals would include the development of modular vectors bearing standardized parts and orthogonally designed circuits, a task not fully addressed thus far. Finally, we present some challenges that should be overcome to enable the next generation of vector design and ways to address it.
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Affiliation(s)
- Luísa Czamanski Nora
- Ribeirão Preto Medical SchoolUniversity of São PauloRibeirão Preto, São Paulo14049‐900Brazil
| | - Cauã Antunes Westmann
- Ribeirão Preto Medical SchoolUniversity of São PauloRibeirão Preto, São Paulo14049‐900Brazil
| | | | - Luana de Fátima Alves
- Ribeirão Preto Medical SchoolUniversity of São PauloRibeirão Preto, São Paulo14049‐900Brazil
- School of Philosophy, Science and Letters of Ribeirão PretoUniversity of São PauloRibeirão Preto, São Paulo14049‐900Brazil
| | | | - María‐Eugenia Guazzaroni
- School of Philosophy, Science and Letters of Ribeirão PretoUniversity of São PauloRibeirão Preto, São Paulo14049‐900Brazil
| | - Rafael Silva‐Rocha
- Ribeirão Preto Medical SchoolUniversity of São PauloRibeirão Preto, São Paulo14049‐900Brazil
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Selectable marker recycling in the nonconventional yeast Xanthophyllomyces dendrorhous by transient expression of Cre on a genetically unstable vector. Appl Microbiol Biotechnol 2018; 103:963-971. [DOI: 10.1007/s00253-018-9496-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 10/29/2018] [Accepted: 10/29/2018] [Indexed: 10/27/2022]
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28
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Advances and prospects of Bacillus subtilis cellular factories: From rational design to industrial applications. Metab Eng 2018; 50:109-121. [DOI: 10.1016/j.ymben.2018.05.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 05/02/2018] [Accepted: 05/10/2018] [Indexed: 01/29/2023]
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29
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Abstract
The yeast Kluyveromyces marxianus grows at high temperatures and on a wide range of carbon sources, making it a promising host for industrial biotechnology to produce renewable chemicals from plant biomass feedstocks. However, major genetic engineering limitations have kept this yeast from replacing the commonly used yeast Saccharomyces cerevisiae in industrial applications. Here, we describe genetic tools for genome editing and breeding K. marxianus strains, which we use to create a new thermotolerant strain with promising fatty acid production. These results open the door to using K. marxianus as a versatile synthetic biology platform organism for industrial applications. Throughout history, the yeast Saccharomyces cerevisiae has played a central role in human society due to its use in food production and more recently as a major industrial and model microorganism, because of the many genetic and genomic tools available to probe its biology. However, S. cerevisiae has proven difficult to engineer to expand the carbon sources it can utilize, the products it can make, and the harsh conditions it can tolerate in industrial applications. Other yeasts that could solve many of these problems remain difficult to manipulate genetically. Here, we engineered the thermotolerant yeast Kluyveromyces marxianus to create a new synthetic biology platform. Using CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats with Cas9)-mediated genome editing, we show that wild isolates of K. marxianus can be made heterothallic for sexual crossing. By breeding two of these mating-type engineered K. marxianus strains, we combined three complex traits—thermotolerance, lipid production, and facile transformation with exogenous DNA—into a single host. The ability to cross K. marxianus strains with relative ease, together with CRISPR-Cas9 genome editing, should enable engineering of K. marxianus isolates with promising lipid production at temperatures far exceeding those of other fungi under development for industrial applications. These results establish K. marxianus as a synthetic biology platform comparable to S. cerevisiae, with naturally more robust traits that hold potential for the industrial production of renewable chemicals.
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Sadler JC, Currin A, Kell DB. Ultra-high throughput functional enrichment of large monoamine oxidase (MAO-N) libraries by fluorescence activated cell sorting. Analyst 2018; 143:4747-4755. [PMID: 30199078 PMCID: PMC6156879 DOI: 10.1039/c8an00851e] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/17/2018] [Indexed: 12/16/2022]
Abstract
Directed evolution enables the improvement and optimisation of enzymes for particular applications and is a valuable tool for biotechnology and synthetic biology. However, studies are often limited in their scope by the inability to screen very large numbers of variants to identify improved enzymes. One class of enzyme for which a universal, operationally simple ultra-high throughput (>106 variants per day) assay is not available is flavin adenine dinucleotide (FAD) dependent oxidases. The current high throughput assay involves a visual, colourimetric, colony-based screen, however this is not suitable for very large libraries and does not enable quantification of the relative fitness of variants. To address this, we describe an optimised method for the sensitive detection of oxidase activity within single Escherichia coli (E. coli) cells, using the monoamine oxidase from Aspergillus niger, MAO-N, as a model system. In contrast to other methods for the screening of oxidase activity in vivo, this method does not require cell surface expression, emulsion formation or the addition of an extracellular peroxidase. Furthermore, we show that fluorescence activated cell sorting (FACS) of large libraries derived from MAO-N under the assay conditions can enrich the library in functional variants at much higher rates than via the colony-based method. We demonstrate its use for directed evolution by identifying a new mutant of MAO-N with improved activity towards a novel secondary amine substrate. This work demonstrates, for the first time, an ultra-high throughput screening methodology widely applicable for the directed evolution of FAD dependent oxidases in E. coli.
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Affiliation(s)
- Joanna C. Sadler
- School of Chemistry
, The University of Manchester
,
131 Princess St
, Manchester M1 7DN
, UK
- The Manchester Institute of Biotechnology
, The University of Manchester
,
131 Princess St
, Manchester M1 7DN
, UK
- Centre for the Synthetic Biology of Fine and Speciality Chemicals (SYNBIOCHEM)
, The University of Manchester
,
131 Princess St
, Manchester M1 7DN
, UK
.
;
;
; http://dbkgroup.org/@dbkell
| | - Andrew Currin
- School of Chemistry
, The University of Manchester
,
131 Princess St
, Manchester M1 7DN
, UK
- The Manchester Institute of Biotechnology
, The University of Manchester
,
131 Princess St
, Manchester M1 7DN
, UK
- Centre for the Synthetic Biology of Fine and Speciality Chemicals (SYNBIOCHEM)
, The University of Manchester
,
131 Princess St
, Manchester M1 7DN
, UK
.
;
;
; http://dbkgroup.org/@dbkell
| | - Douglas B. Kell
- School of Chemistry
, The University of Manchester
,
131 Princess St
, Manchester M1 7DN
, UK
- The Manchester Institute of Biotechnology
, The University of Manchester
,
131 Princess St
, Manchester M1 7DN
, UK
- Centre for the Synthetic Biology of Fine and Speciality Chemicals (SYNBIOCHEM)
, The University of Manchester
,
131 Princess St
, Manchester M1 7DN
, UK
.
;
;
; http://dbkgroup.org/@dbkell
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Dangi AK, Sharma B, Hill RT, Shukla P. Bioremediation through microbes: systems biology and metabolic engineering approach. Crit Rev Biotechnol 2018; 39:79-98. [DOI: 10.1080/07388551.2018.1500997] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Arun Kumar Dangi
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
| | - Babita Sharma
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
| | - Russell T. Hill
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD, USA
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
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32
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Kang MK, Tullman-Ercek D. Engineering expression and function of membrane proteins. Methods 2018; 147:66-72. [DOI: 10.1016/j.ymeth.2018.04.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 04/03/2018] [Accepted: 04/16/2018] [Indexed: 01/18/2023] Open
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Designing with living systems in the synthetic yeast project. Nat Commun 2018; 9:2950. [PMID: 30054478 PMCID: PMC6063962 DOI: 10.1038/s41467-018-05332-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/28/2018] [Indexed: 11/08/2022] Open
Abstract
Synthetic biology is challenged by the complexity and the unpredictability of living systems. While one response to this complexity involves simplifying cells to create more fully specified systems, another approach utilizes directed evolution, releasing some control and using unpredictable change to achieve design goals. Here we discuss SCRaMbLE, employed in the synthetic yeast project, as an example of synthetic biology design through working with living systems. SCRaMbLE is a designed tool without being a design tool, harnessing the activities of the yeast rather than relying entirely on scientists’ deliberate choices. We suggest that directed evolution at the level of the whole organism allows scientists and microorganisms to “collaborate” to achieve design goals, suggesting new directions for synthetic biology. Synthetic biology often views the organism as a chassis into which a circuit can be inserted. Here the authors explore the idea of the organism as a core aspect of design, aiding researchers in navigating the genetic space opened up by SCRaMbLE.
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Schwentner A, Feith A, Münch E, Busche T, Rückert C, Kalinowski J, Takors R, Blombach B. Metabolic engineering to guide evolution – Creating a novel mode for L-valine production with Corynebacterium glutamicum. Metab Eng 2018. [DOI: 10.1016/j.ymben.2018.02.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Sachsenhauser V, Bardwell JC. Directed evolution to improve protein folding in vivo. Curr Opin Struct Biol 2018; 48:117-123. [PMID: 29278775 PMCID: PMC5880552 DOI: 10.1016/j.sbi.2017.12.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/13/2017] [Indexed: 02/06/2023]
Abstract
Recently, several innovative approaches have been developed that allow one to directly screen or select for improved protein folding in the cellular context. These methods have the potential of not just leading to a better understanding of the in vivo folding process, they may also allow for improved production of proteins of biotechnological interest.
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Affiliation(s)
- Veronika Sachsenhauser
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University, Ann Arbor, MI 48109, USA
| | - James Ca Bardwell
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University, Ann Arbor, MI 48109, USA; Howard Hughes Medical Institute, University of Michigan, 830 N. University, Ann Arbor, MI 48109, USA.
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Duarte JM, Barbier I, Schaerli Y. Bacterial Microcolonies in Gel Beads for High-Throughput Screening of Libraries in Synthetic Biology. ACS Synth Biol 2017; 6:1988-1995. [PMID: 28803463 DOI: 10.1021/acssynbio.7b00111] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Synthetic biologists increasingly rely on directed evolution to optimize engineered biological systems. Applying an appropriate screening or selection method for identifying the potentially rare library members with the desired properties is a crucial step for success in these experiments. Special challenges include substantial cell-to-cell variability and the requirement to check multiple states (e.g., being ON or OFF depending on the input). Here, we present a high-throughput screening method that addresses these challenges. First, we encapsulate single bacteria into microfluidic agarose gel beads. After incubation, they harbor monoclonal bacterial microcolonies (e.g., expressing a synthetic construct) and can be sorted according their fluorescence by fluorescence activated cell sorting (FACS). We determine enrichment rates and demonstrate that we can measure the average fluorescent signals of microcolonies containing phenotypically heterogeneous cells, obviating the problem of cell-to-cell variability. Finally, we apply this method to sort a pBAD promoter library at ON and OFF states.
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Affiliation(s)
- José M. Duarte
- Department
of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Içvara Barbier
- Department
of Fundamental Microbiology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Yolanda Schaerli
- Department
of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
- Department
of Fundamental Microbiology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
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Arora AK, Douglas AE. Hype or opportunity? Using microbial symbionts in novel strategies for insect pest control. JOURNAL OF INSECT PHYSIOLOGY 2017; 103:10-17. [PMID: 28974456 DOI: 10.1016/j.jinsphys.2017.09.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/28/2017] [Accepted: 09/29/2017] [Indexed: 06/07/2023]
Abstract
All insects, including pest species, are colonized by microorganisms, variously located in the gut and within insect tissues. Manipulation of these microbial partners can reduce the pest status of insects, either by modifying insect traits (e.g. altering the host range or tolerance of abiotic conditions, reducing insect competence to vector disease agents) or by reducing fitness. Strategies utilizing heterologous microorganisms (i.e. derived from different insect species) and genetically-modified microbial symbionts are under development, particularly in relation to insect vectors of human disease agents. There is also the potential to target microorganisms absolutely required by the insect, resulting in insect mortality or suppression of insect growth or fecundity. This latter approach is particularly valuable for insect pests that depend on nutrients from symbiotic microorganisms to supplement their nutritionally-inadequate diet, e.g. insects feeding through the life cycle on vertebrate blood (cimicid bugs, anopluran lice, tsetse flies), plant sap (whiteflies, aphids, psyllids, planthoppers, leafhoppers/sharpshooters) and sound wood (various xylophagous beetles and some termites). Further research will facilitate implementation of these novel insect pest control strategies, particularly to ensure specificity of control agents to the pest insect without dissemination of bio-active compounds, novel microorganisms or their genes into the wider environment.
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Affiliation(s)
- Arinder K Arora
- Department of Entomology, Cornell University, Ithaca, NY 14853, USA
| | - Angela E Douglas
- Department of Entomology, Cornell University, Ithaca, NY 14853, USA; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
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Yang P, Wang J, Pang Q, Zhang F, Wang J, Wang Q, Qi Q. Pathway optimization and key enzyme evolution of N-acetylneuraminate biosynthesis using an in vivo aptazyme-based biosensor. Metab Eng 2017; 43:21-28. [PMID: 28780284 DOI: 10.1016/j.ymben.2017.08.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Revised: 07/18/2017] [Accepted: 08/01/2017] [Indexed: 10/19/2022]
Abstract
N-acetylneuraminate (NeuAc) biosynthesis has drawn much attention owing to its wide applications in many aspects. Previously, we engineered for the first time an artificial NeuAc biosynthetic pathway in Escherichia coli using glucose as sole substrate. However, rigorous requirements for the flux and cofactor balance make subsequent strain improvement rather difficult. In this study, an in vivo NeuAc biosensor was designed and applied for genetic screening the mutant library of NeuAc producer. Its NeuAc responsive manner was demonstrated using sfgfp as a reporter and a Ni2+-based selection system was developed to couple the cell growth with in vivo NeuAc concentration. Employing this selection system, the NeuAc biosynthesis pathway was optimized and the key enzyme NeuAc synthase was evolved, which improved the titer by 34% and 23%, respectively. The final strain produced up to 8.31g/L NeuAc in minimal medium using glucose as sole carbon source. This work demonstrated the effectiveness of NeuAc biosensor in genetic screening and great potential in metabolic engineering of other organisms.
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Affiliation(s)
- Peng Yang
- State Key Laboratory of Microbial Technology, National Glycoengineering Center, Shandong University, Jinan 250100, People's Republic of China
| | - Jing Wang
- State Key Laboratory of Microbial Technology, National Glycoengineering Center, Shandong University, Jinan 250100, People's Republic of China
| | - Qingxiao Pang
- State Key Laboratory of Microbial Technology, National Glycoengineering Center, Shandong University, Jinan 250100, People's Republic of China
| | - Fengyu Zhang
- State Key Laboratory of Microbial Technology, National Glycoengineering Center, Shandong University, Jinan 250100, People's Republic of China
| | - Junshu Wang
- State Key Laboratory of Microbial Technology, National Glycoengineering Center, Shandong University, Jinan 250100, People's Republic of China
| | - Qian Wang
- State Key Laboratory of Microbial Technology, National Glycoengineering Center, Shandong University, Jinan 250100, People's Republic of China.
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, National Glycoengineering Center, Shandong University, Jinan 250100, People's Republic of China.
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40
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Systems metabolic engineering strategies for the production of amino acids. Synth Syst Biotechnol 2017; 2:87-96. [PMID: 29062965 PMCID: PMC5637227 DOI: 10.1016/j.synbio.2017.07.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/16/2017] [Accepted: 07/18/2017] [Indexed: 12/31/2022] Open
Abstract
Systems metabolic engineering is a multidisciplinary area that integrates systems biology, synthetic biology and evolutionary engineering. It is an efficient approach for strain improvement and process optimization, and has been successfully applied in the microbial production of various chemicals including amino acids. In this review, systems metabolic engineering strategies including pathway-focused approaches, systems biology-based approaches, evolutionary approaches and their applications in two major amino acid producing microorganisms: Corynebacterium glutamicum and Escherichia coli, are summarized.
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41
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Zheng X, Xing XH, Zhang C. Targeted mutagenesis: A sniper-like diversity generator in microbial engineering. Synth Syst Biotechnol 2017; 2:75-86. [PMID: 29062964 PMCID: PMC5636951 DOI: 10.1016/j.synbio.2017.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 06/30/2017] [Accepted: 07/03/2017] [Indexed: 12/26/2022] Open
Abstract
Mutations, serving as the raw materials of evolution, have been extensively utilized to increase the chances of engineering molecules or microbes with tailor-made functions. Global and targeted mutagenesis are two main methods of obtaining various mutations, distinguished by the range of action they can cover. While the former one stresses the mining of novel genetic loci within the whole genomic background, targeted mutagenesis performs in a more straightforward manner, bringing evolutionary escape and error catastrophe under control. In this review, we classify the existing techniques of targeted mutagenesis into two categories in terms of whether the diversity is generated in vitro or in vivo, and briefly introduce the mechanisms and applications of them separately. The inherent connections and development trends of the two classes are also discussed to provide an insight into the next generation evolution research.
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Key Words
- 3′-LTR, 3’-long terminal repeat
- 5-FOA, 5-fluoro-orotic acid
- CRISPR/Cas9, clustered regularly interspaced short palindromic repeats and associated protein 9
- DNA Pol III, DNA polymerase III
- DNA PolI, DNA polymerase I
- DSB, double strand break
- Evolution
- FLASH, fast ligation-based automatable solid-phase high-throughput
- HDR, homology-directed repair
- HIV, human immunodeficiency virus
- ICE, in vivo continuous evolution
- LIC, ligation-independent cloning
- MAGE, multiplex automated genome engineering
- MMEJ, microhomology-mediated end-joining
- Mutations
- NHEJ, error-prone non-homologous end-joining
- ORF, open reading frame
- PAM, protospacer-adjacent motif
- RVD, repeat variable di-residue
- Synthetic biology
- TALE, transcription activator-like effector
- TALEN, transcription activator-like effector nuclease
- TP, terminal protein
- TP-DNAP, TP-DNA polymerase fusion
- TaGTEAM, targeting glycosylase to embedded arrays for mutagenesis
- Targeted mutagenesis
- YOGE, yeast oligo-mediated genome engineering
- ZF, zinc-finger protein
- ZFN, zinc-finger nuclease
- dCas9, catalytically dead Cas9
- dNTP, deoxy-ribonucleoside triphosphate
- dsDNA, double-stranded DNA
- error-prone PCR, error-prone polymerase chain reaction
- non-GMO, non-genetically modified organism
- pre-crRNA, pre-CRISPR RNA
- sctetR, single chain tetR
- sgRNA, single-guide RNA
- ssDNA, single-stranded DNA
- tracrRNA, trans-encoded RNA
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Affiliation(s)
| | | | - Chong Zhang
- Key Laboratory for Industrial Biocatalysis, Ministry of Education, Institute of Biochemical Engineering, Department of Chemical Engineering, Center for Synthetic & Systems Biology, Tsinghua University, Beijing 100084, China
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Brown R, Lengeling A, Wang B. Phage engineering: how advances in molecular biology and synthetic biology are being utilized to enhance the therapeutic potential of bacteriophages. QUANTITATIVE BIOLOGY 2017. [DOI: 10.1007/s40484-017-0094-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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43
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Kachlicki P, Piasecka A, Stobiecki M, Marczak Ł. Structural Characterization of Flavonoid Glycoconjugates and Their Derivatives with Mass Spectrometric Techniques. Molecules 2016; 21:E1494. [PMID: 27834838 PMCID: PMC6273528 DOI: 10.3390/molecules21111494] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 10/30/2016] [Accepted: 10/31/2016] [Indexed: 12/05/2022] Open
Abstract
Mass spectrometry is currently one of the most versatile and sensitive instrumental methods applied to structural characterization of plant secondary metabolite mixtures isolated from biological material including flavonoid glycoconjugates. Resolution of the applied mass spectrometers plays an important role in structural studies of mixtures of the target compounds isolated from biological material. High-resolution analyzers allow obtaining information about elemental composition of the analyzed compounds. Application of various mass spectrometric techniques, including different systems of ionization, analysis of both positive and negative ions of flavonoids, fragmentation of the protonated/deprotonated molecules and in some cases addition of metal ions to the studied compounds before ionization and fragmentation, may improve structural characterization of natural products. In our review we present different strategies allowing structural characterization of positional isomers and isobaric compounds existing in class of flavonoid glycoconjugates and their derivatives, which are synthetized in plants and are important components of the human food and drugs as well as animal feed.
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Affiliation(s)
- Piotr Kachlicki
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland.
| | - Anna Piasecka
- Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland.
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland.
| | - Maciej Stobiecki
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland.
| | - Łukasz Marczak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland.
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