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Zhao ZM, Liu ZH, Zhang T, Meng R, Gong Z, Li Y, Hu J, Ragauskas AJ, Li BZ, Yuan YJ. Unleashing the capacity of Rhodococcus for converting lignin into lipids. Biotechnol Adv 2024; 70:108274. [PMID: 37913947 DOI: 10.1016/j.biotechadv.2023.108274] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/11/2023] [Accepted: 10/22/2023] [Indexed: 11/03/2023]
Abstract
Bioconversion of bioresources/wastes (e.g., lignin, chemical pulping byproducts) represents a promising approach for developing a bioeconomy to help address growing energy and materials demands. Rhodococcus, a promising microbial strain, utilizes numerous carbon sources to produce lipids, which are precursors for synthesizing biodiesel and aviation fuels. However, compared to chemical conversion, bioconversion involves living cells, which is a more complex system that needs further understanding and upgrading. Various wastes amenable to bioconversion are reviewed herein to highlight the potential of Rhodococci for producing lipid-derived bioproducts. In light of the abundant availability of these substrates, Rhodococcus' metabolic pathways converting them to lipids are analyzed from a "beginning-to-end" view. Based on an in-depth understanding of microbial metabolic routes, genetic modifications of Rhodococcus by employing emerging tools (e.g., multiplex genome editing, biosensors, and genome-scale metabolic models) are presented for promoting the bioconversion. Co-solvent enhanced lignocellulose fractionation (CELF) strategy facilitates the generation of a lignin-derived aromatic stream suitable for the Rhodococcus' utilization. Novel alkali sterilization (AS) and elimination of thermal sterilization (ETS) approaches can significantly enhance the bioaccessibility of lignin and its derived aromatics in aqueous fermentation media, which promotes lipid titer significantly. In order to achieve value-added utilization of lignin, biodiesel and aviation fuel synthesis from lignin and lipids are further discussed. The possible directions for unleashing the capacity of Rhodococcus through synergistically modifying microbial strains, substrates, and fermentation processes are proposed toward a sustainable biological lignin valorization.
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Affiliation(s)
- Zhi-Min Zhao
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, United States; Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Zhi-Hua Liu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Tongtong Zhang
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Rongqian Meng
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Zhiqun Gong
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Yibing Li
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Jing Hu
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Arthur J Ragauskas
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, United States; Joint Institute of Biological Science, Biosciences Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, United States; Department of Forestry, Wildlife, and Fisheries, Center for Renewable Carbon, University of Tennessee Institute of Agriculture, Knoxville, TN 37996, United States.
| | - Bing-Zhi Li
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Ying-Jin Yuan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
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2
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Qian J, Fan L, Yang J, Feng J, Gao N, Cheng G, Pu W, Zhou W, Cai T, Li S, Zheng P, Sun J, Wang D, Wang Y. Directed evolution of a neutrophilic and mesophilic methanol dehydrogenase based on high-throughput and accurate measurement of formaldehyde. Synth Syst Biotechnol 2023; 8:386-395. [PMID: 37342805 PMCID: PMC10277290 DOI: 10.1016/j.synbio.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/01/2023] [Accepted: 05/21/2023] [Indexed: 06/23/2023] Open
Abstract
Methanol is a promising one-carbon feedstock for biomanufacturing, which can be sustainably produced from carbon dioxide and natural gas. However, the efficiency of methanol bioconversion is limited by the poor catalytic properties of nicotinamide adenine dinucleotide (NAD+)-dependent methanol dehydrogenase (Mdh) that oxidizes methanol to formaldehyde. Herein, the neutrophilic and mesophilic NAD+-dependent Mdh from Bacillus stearothermophilus DSM 2334 (MdhBs) was subjected to directed evolution for enhancing the catalytic activity. The combination of formaldehyde biosensor and Nash assay allowed high-throughput and accurate measurement of formaldehyde and facilitated efficient selection of desired variants. MdhBs variants with up to 6.5-fold higher Kcat/KM value for methanol were screened from random mutation libraries. The T153 residue that is spatially proximal to the substrate binding pocket has significant influence on enzyme activity. The beneficial T153P mutation changes the interaction network of this residue and breaks the α-helix important for substrate binding into two short α-helices. Reconstructing the interaction network of T153 with surrounding residues may represent a promising strategy to further improve MdhBs, and this study provides an efficient strategy for directed evolution of Mdh.
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Affiliation(s)
- Jin Qian
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300222, China
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Liwen Fan
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Jinxing Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Jinhui Feng
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Ning Gao
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guimin Cheng
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300222, China
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Wei Pu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Wenjuan Zhou
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Tao Cai
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Shuang Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Ping Zheng
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jibin Sun
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Depei Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300222, China
| | - Yu Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300222, China
- Haihe Laboratory of Synthetic Biology, Tianjin, 300308, China
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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3
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Isolation and Characterization of Homologically Expressed Methanol Dehydrogenase from Methylorubrum extorquens AM1 for the Development of Bioelectrocatalytical Systems. Int J Mol Sci 2022; 23:ijms231810337. [PMID: 36142248 PMCID: PMC9499683 DOI: 10.3390/ijms231810337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/27/2022] [Accepted: 09/02/2022] [Indexed: 12/05/2022] Open
Abstract
(Ca2+)-dependent pyrroloquinolinequinone (PQQ)-dependent methanol dehydrogenase (MDH) (EC: 1.1.2.7) is one of the key enzymes of primary C1-compound metabolism in methylotrophy. PQQ-MDH is a promising catalyst for electrochemical biosensors and biofuel cells. However, the large-scale use of PQQ-MDH in bioelectrocatalysis is not possible due to the low yield of the native enzyme. Homologously overexpressed MDH was obtained from methylotrophic bacterium Methylorubrum extorquens AM1 by cloning the gene of only one subunit, mxaF. The His-tagged enzyme was easily purified by immobilized metal ion affinity chromatography (36% yield). A multimeric form (α6β6) of recombinant PQQ-MDH possessing enzymatic activity (0.54 U/mg) and high stability was demonstrated for the first time. pH-optimum of the purified protein was about 9–10; the enzyme was activated by ammonium ions. It had the highest affinity toward methanol (KM = 0.36 mM). The recombinant MDH was used for the fabrication of an amperometric biosensor. Its linear range for methanol concentrations was 0.002–0.1 mM, the detection limit was 0.7 µM. The properties of the invented biosensor are competitive to the analogs, meaning that this enzyme is a promising catalyst for industrial methanol biosensors. The developed simplified technology for PQQ-MDH production opens up new opportunities for the development of bioelectrocatalytic systems.
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Andon JS, Lee B, Wang T. Enzyme directed evolution using genetically encodable biosensors. Org Biomol Chem 2022; 20:5891-5906. [PMID: 35437559 DOI: 10.1039/d2ob00443g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Directed evolution has been remarkably successful in identifying enzyme variants with new or improved properties, such as altered substrate scope or novel reactivity. Genetically encodable biosensors (GEBs), which convert the concentration of a small molecule ligand into an easily detectable output signal, have seen increasing application to enzyme directed evolution in the last decade. GEBs enable the use of high-throughput methods to assess enzyme activity of very large libraries, which can accelerate the search for variants with desirable activity. Here, we review different classes of GEBs and their properties in the context of enzyme evolution, how GEBs have been integrated into directed evolution workflows, and recent examples of enzyme evolution efforts utilizing GEBs. Finally, we discuss the advantages, challenges, and opportunities for using GEBs in the directed evolution of enzymes.
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Affiliation(s)
- James S Andon
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - ByungUk Lee
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Tina Wang
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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5
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Lipskerov FA, Sheshukova EV, Komarova TV. Approaches to Formaldehyde Measurement: From Liquid Biological Samples to Cells and Organisms. Int J Mol Sci 2022; 23:6642. [PMID: 35743083 PMCID: PMC9224381 DOI: 10.3390/ijms23126642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/09/2022] [Accepted: 06/12/2022] [Indexed: 12/14/2022] Open
Abstract
Formaldehyde (FA) is the simplest aldehyde present both in the environment and in living organisms. FA is an extremely reactive compound capable of protein crosslinking and DNA damage. For a long time, FA was considered a "biochemical waste" and a by-product of normal cellular metabolism, but in recent decades the picture has changed. As a result, the need arose for novel instruments and approaches to monitor and measure not only environmental FA in water, cosmetics, and household products, but also in food, beverages and biological samples including cells and even organisms. Despite numerous protocols being developed for in vitro and in cellulo FA assessment, many of them have remained at the "proof-of-concept" stage. We analyze the suitability of different methods developed for non-biological objects, and present an overview of the recently developed approaches, including chemically-synthesized probes and genetically encoded FA-sensors for in cellulo and in vivo FA monitoring. We also discuss the prospects of classical methods such as chromatography and spectrophotometry, and how they have been adapted in response to the demand for precise, selective and highly sensitive evaluation of FA concentration fluctuations in biological samples. The main objectives of this review is to summarize data on the main approaches for FA content measurement in liquid biological samples, pointing out the advantages and disadvantages of each method; to report the progress in development of novel molecules suitable for application in living systems; and, finally, to discuss genetically encoded FA-sensors based on existing natural biological FA-responsive elements.
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Affiliation(s)
- Fedor A. Lipskerov
- Vavilov Institute of General Genetics Russian Academy of Sciences, 119991 Moscow, Russia; (F.A.L.); (E.V.S.)
- Chemistry Department, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Ekaterina V. Sheshukova
- Vavilov Institute of General Genetics Russian Academy of Sciences, 119991 Moscow, Russia; (F.A.L.); (E.V.S.)
| | - Tatiana V. Komarova
- Vavilov Institute of General Genetics Russian Academy of Sciences, 119991 Moscow, Russia; (F.A.L.); (E.V.S.)
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
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6
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Miller CA, Ho JML, Bennett MR. Strategies for Improving Small-Molecule Biosensors in Bacteria. BIOSENSORS 2022; 12:bios12020064. [PMID: 35200325 PMCID: PMC8869690 DOI: 10.3390/bios12020064] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 05/03/2023]
Abstract
In recent years, small-molecule biosensors have become increasingly important in synthetic biology and biochemistry, with numerous new applications continuing to be developed throughout the field. For many biosensors, however, their utility is hindered by poor functionality. Here, we review the known types of mechanisms of biosensors within bacterial cells, and the types of approaches for optimizing different biosensor functional parameters. Discussed approaches for improving biosensor functionality include methods of directly engineering biosensor genes, considerations for choosing genetic reporters, approaches for tuning gene expression, and strategies for incorporating additional genetic modules.
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Affiliation(s)
- Corwin A. Miller
- Department of Biosciences, Rice University MS-140, 6100 Main St., Houston, TX 77005, USA; (C.A.M.); (J.M.L.H.)
| | - Joanne M. L. Ho
- Department of Biosciences, Rice University MS-140, 6100 Main St., Houston, TX 77005, USA; (C.A.M.); (J.M.L.H.)
| | - Matthew R. Bennett
- Department of Biosciences, Rice University MS-140, 6100 Main St., Houston, TX 77005, USA; (C.A.M.); (J.M.L.H.)
- Department of Bioengineering, Rice University MS-140, 6100 Main St., Houston, TX 77005, USA
- Correspondence:
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7
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Methylotrophic bacterium-based molecular sensor for the detection of low concentrations of methanol. J Biosci Bioeng 2021; 132:247-252. [PMID: 34092492 DOI: 10.1016/j.jbiosc.2021.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/30/2021] [Accepted: 05/06/2021] [Indexed: 11/21/2022]
Abstract
Methylotrophic bacterium Methylorubrum extorquens is a promising microorganism for the production of value-added compounds from methanol. This study focused on the development of a single-cell level biosensor system that detects methanol by using the intrinsic regulatory machinery which responds to the presence of methanol in this bacterium. A green fluorescent protein (GFP) gene located downstream of the promoter region of the serine glyoxylate aminotransferase gene (Psga) or the methanol dehydrogenase subunit 1 precursor gene (PmxaF) was inserted into the chromosome of M. extorquens wild-type strain AM1. The expression of GFP upon methanol exposure was measured by spectrofluorometer and fluorescence-activated cell sorting (FACS). The strain harboring Psga-gfp emitted fluorescence only when methanol was supplied to the culture medium, while the other strain harboring PmxaF-gfp showed high basal fluorescence even in the absence of methanol. The fluorescence intensity of the Psga-gfp strain depended on a methanol concentration higher than 25 μM, and the sensitivity and dose-dependency of this strain were much higher than previous systems using Escherichia coli. The methanol-sensing properties of the engineered M. extorquens strain were comparable to those of a methylotrophic yeast-based biosensor, suggesting the usefulness of methylotrophic microorganisms as platforms for single-cell sensing of C1 compounds. The constructed methanol sensor strain, coupled with flow cytometry techniques, provides a high-throughput and highly sensitive screening method for the selection of functional methanol-producing enzymes.
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8
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Biosensor-Based Directed Evolution of Methanol Dehydrogenase from Lysinibacillus xylanilyticus. Int J Mol Sci 2021; 22:ijms22031471. [PMID: 33540582 PMCID: PMC7867188 DOI: 10.3390/ijms22031471] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 01/27/2021] [Accepted: 01/27/2021] [Indexed: 11/25/2022] Open
Abstract
Methanol dehydrogenase (Mdh), is a crucial enzyme for utilizing methane and methanol as carbon and energy sources in methylotrophy and synthetic methylotrophy. Engineering of Mdh, especially NAD-dependent Mdh, has thus been actively investigated to enhance methanol conversion. However, its poor catalytic activity and low methanol affinity limit its wider application. In this study, we applied a transcriptional factor-based biosensor for the direct evolution of Mdh from Lysinibacillus xylanilyticus (Lxmdh), which has a relatively high turnover rate and low KM value compared to other wild-type NAD-dependent Mdhs. A random mutant library of Lxmdh was constructed in Escherichia coli and was screened using formaldehyde-detectable biosensors by incubation with low methanol concentrations. Positive clones showing higher fluorescence were selected by fluorescence-activated cell sorting (FACS) system, and their catalytic activities toward methanol were evaluated. The successfully isolated mutants E396V, K318N, and K46E showed high activity, particularly at very low methanol concentrations. In kinetic analysis, mutant E396V, K318N, and K46E had superior methanol conversion efficiency, with 79-, 23-, and 3-fold improvements compared to the wild-type, respectively. These mutant enzymes could thus be useful for engineering synthetic methylotrophy and for enhancing methanol conversion to various useful products.
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9
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Woo SG, Kim SK, Oh BR, Lee SG, Lee DH. Genetically Encoded Biosensor-Based Screening for Directed Bacteriophage T4 Lysozyme Evolution. Int J Mol Sci 2020; 21:ijms21228668. [PMID: 33212940 PMCID: PMC7698408 DOI: 10.3390/ijms21228668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/05/2020] [Accepted: 11/16/2020] [Indexed: 11/16/2022] Open
Abstract
Lysozyme is widely used as a model protein in studies of structure–function relationships. Recently, lysozyme has gained attention for use in accelerating the degradation of secondary sludge, which mainly consists of bacteria. However, a high-throughput screening system for lysozyme engineering has not been reported. Here, we present a lysozyme screening system using a genetically encoded biosensor. We first cloned bacteriophage T4 lysozyme (T4L) into a plasmid under control of the araBAD promoter. The plasmid was expressed in Escherichia coli with no toxic effects on growth. Next, we observed that increased soluble T4L expression decreased the fluorescence produced by the genetic enzyme screening system. To investigate T4L evolution based on this finding, we generated a T4L random mutation library, which was screened using the genetic enzyme screening system. Finally, we identified two T4L variants showing 1.4-fold enhanced lytic activity compared to native T4L. To our knowledge, this is the first report describing the use of a genetically encoded biosensor to investigate bacteriophage T4L evolution. Our approach can be used to investigate the evolution of other lysozymes, which will expand the applications of lysozyme.
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Affiliation(s)
- Seung-Gyun Woo
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (S.-G.W.); (S.K.K.)
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon 34113, Korea
| | - Seong Keun Kim
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (S.-G.W.); (S.K.K.)
| | - Baek-Rock Oh
- Microbial Biotechnology Research Center, Jeonbuk Branch Institute, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup 56212, Korea;
| | - Seung-Goo Lee
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (S.-G.W.); (S.K.K.)
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon 34113, Korea
- Correspondence: (S.-G.L.); (D.-H.L.); Tel.: +82-42-860-4373 (S.-G.L.); +82-42-879-8225 (D.-H.L.)
| | - Dae-Hee Lee
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (S.-G.W.); (S.K.K.)
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon 34113, Korea
- Correspondence: (S.-G.L.); (D.-H.L.); Tel.: +82-42-860-4373 (S.-G.L.); +82-42-879-8225 (D.-H.L.)
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10
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Zhang Z, Wang Y, Zheng P, Sun J. Promoting Lignin Valorization by Coping with Toxic C1 Byproducts. Trends Biotechnol 2020; 39:331-335. [PMID: 33008644 DOI: 10.1016/j.tibtech.2020.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/06/2020] [Accepted: 09/08/2020] [Indexed: 11/16/2022]
Abstract
The toxic C1 compounds methanol and formaldehyde are generated during bioconversion of lignin into value-added chemicals. These toxins can be detoxified and assimilated by methylotrophs to synthesize useful metabolites and cell biomass. We discuss the promising future of constructing integrated biosystems to use toxic C1 byproducts and promote lignin valorization.
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Affiliation(s)
- Zhihui Zhang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Ping Zheng
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Jibin Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China; University of Chinese Academy of Sciences, Beijing 100049, China
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11
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Tan SI, Yu PJ, Ng IS. CRISPRi-mediated programming essential gene can as a Direct Enzymatic Performance Evaluation & Determination (DEPEND) system. Biotechnol Bioeng 2020; 117:2842-2851. [PMID: 32458463 DOI: 10.1002/bit.27443] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/18/2020] [Accepted: 05/24/2020] [Indexed: 12/16/2022]
Abstract
Harnessing enzyme expression for production of target chemicals is a critical and multifarious process, where screening of different genes by inspection of enzymatic activity plays an imperative role. Here, we conceived an idea to improve the time-consuming and labor-intensive process of enzyme screening. Controlling cell growth was achieved by the Cluster Regularly Interspaced Short Palindromic Repeat (CRISPRi) system with different single guide RNA targeting the essential gene can (CRISPRi::CA) that encodes a carbonic anhydrase for CO2 uptake. CRISPRi::CA comprises a whole-cell biosensor to monitor CO2 concentration, ranging from 1% to 5%. On the basis of CRISPRi::CA, an effective and simple Direct Enzymatic Performance Evaluation & Determination (DEPEND) system was developed by a single step of plasmid transformation for targeted enzymes. As a result, the activity of different carbonic anhydrases corresponded to the colony-forming units. Furthermore, the enzymatic performance of 5-aminolevulinic acid synthetase (ALAS), which converts glycine and succinate-CoA to release a molecule of CO2 , has also been distinguished, and the effect of the chaperone GroELS on ALAS enzyme folding was successfully identified in the DEPEND system. We provide a highly feasible, time-saving, and flexible technology for the screening and inspection of high-performance enzymes, which may accelerate protein engineering in the future.
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Affiliation(s)
- Shih-I Tan
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Peng-Jui Yu
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
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12
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Lee H, Baek JI, Kim SJ, Kwon KK, Rha E, Yeom SJ, Kim H, Lee DH, Kim DM, Lee SG. Sensitive and Rapid Phenotyping of Microbes With Soluble Methane Monooxygenase Using a Droplet-Based Assay. Front Bioeng Biotechnol 2020; 8:358. [PMID: 32391352 PMCID: PMC7193049 DOI: 10.3389/fbioe.2020.00358] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/31/2020] [Indexed: 12/22/2022] Open
Abstract
Methanotrophs with soluble methane monooxygenase (sMMO) show high potential for various ecological and biotechnological applications. Here, we developed a high throughput method to identify sMMO-producing microbes by integrating droplet microfluidics and a genetic circuit-based biosensor system. sMMO-producers and sensor cells were encapsulated in monodispersed droplets with benzene as the substrate and incubated for 5 h. The sensor cells were analyzed as the reporter for phenol-sensitive transcription activation of fluorescence. Various combinations of methanotrophs and biosensor cells were investigated to optimize the performance of our droplet-integrated transcriptional factor biosensor system. As a result, the conditions to ensure sMMO activity to convert the starting material, benzene, into phenol, were determined. The biosensor signals were sensitive and quantitative under optimal conditions, showing that phenol is metabolically stable within both cell species and accumulates in picoliter-sized droplets, and the biosensor cells are healthy enough to respond quantitatively to the phenol produced. These results show that our system would be useful for rapid evaluation of phenotypes of methanotrophs showing sMMO activity, while minimizing the necessity of time-consuming cultivation and enzyme preparation, which are required for conventional analysis of sMMO activity.
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Affiliation(s)
- Hyewon Lee
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Ji In Baek
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon, South Korea
| | - Su Jin Kim
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Kil Koang Kwon
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Eugene Rha
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Soo-Jin Yeom
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea
| | - Haseong Kim
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, South Korea
| | - Dae-Hee Lee
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, South Korea
| | - Dong-Myung Kim
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon, South Korea
| | - Seung-Goo Lee
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, South Korea
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