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Zhang B, Guo P, Sun X, Shang Y, Luo Y, Wu H. Enhancement of lactate fraction in poly(lactate-co-3-hydroxybutyrate) biosynthesized by metabolically engineered E. coli. BIORESOUR BIOPROCESS 2024; 11:88. [PMID: 39297980 PMCID: PMC11413402 DOI: 10.1186/s40643-024-00803-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2024] [Accepted: 09/05/2024] [Indexed: 09/21/2024] Open
Abstract
Poly(lactate-co-3-hydroxybutyrate) [P(LA-co-3HB)] is a high-molecular-weight biomaterial with excellent biocompatibility and biodegradability. In this study, the properties of P(LA-co-3HB) were examined and found to be affected by its lactate fraction. The efficiency of lactyl-CoA biosynthesis from intracellular lactate significantly affected the microbial synthesis of P(LA-co-3HB). Two CoA transferases from Anaerotignum lactatifermentans and Bacillota bacterium were selected for use in copolymer biosynthesis from 11 candidates. We found that cotAl enhanced the lactate fraction by 31.56% compared to that of the frequently used modified form of propionyl-CoA transferase from Anaerotignum propionicum. In addition, utilizing xylose as a favorable carbon source and blocking the lactate degradation pathway further enhanced the lactate fraction to 30.42 mol% and 52.84 mol%, respectively. Furthermore, when a 5 L bioreactor was used for fermentation utilizing xylose as a carbon source, the engineered strain produced 60.60 wt% P(46.40 mol% LA-co-3HB), which was similar to the results of our flask experiments. Our results indicate that the application of new CoA transferases has great potential for the biosynthesis of other lactate-based copolymers.
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Affiliation(s)
- Binghao Zhang
- State Key Laboratory of Bioreactor Engineering, Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Pengye Guo
- State Key Laboratory of Bioreactor Engineering, Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Xinye Sun
- State Key Laboratory of Bioreactor Engineering, Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Yanzhe Shang
- MOE Key Laboratory of Bio-Intelligent Manufacturing, School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Yuanchan Luo
- State Key Laboratory of Bioreactor Engineering, Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Hui Wu
- State Key Laboratory of Bioreactor Engineering, Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
- MOE Key Laboratory of Bio-Intelligent Manufacturing, School of Bioengineering, Dalian University of Technology, Dalian, China.
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai, 200237, China.
- Key Laboratory of Bio-based Material Engineering of China, National Light Industry Council, 130 Meilong Road, Shanghai, 200237, China.
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Koh S, Endo R, Kahar P, Mori Y, Ogino C, Tanaka S, Tanaka S, Imai Y, Taguchi S. Complete sequence randomness of lactate-based copolymers (LAHBs) with varied lactate monomer fractions employing a series of propionyl-CoA transferases. Int J Biol Macromol 2024; 274:133055. [PMID: 38866271 DOI: 10.1016/j.ijbiomac.2024.133055] [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: 03/04/2024] [Revised: 05/31/2024] [Accepted: 06/07/2024] [Indexed: 06/14/2024]
Abstract
Previously, we biosynthesized an evolved version of a bio-based polylactide (PLA) on microbial platforms using our engineered lactate-polymerizing enzyme (LPE). This lactate (LA)-based copolyester, LAHB, has advantages over PLA, including improved flexibility and biodegradability, and its properties can be regulated through the LA fraction. To expand the LA-incorporation capacity and improve polymer properties, in the state of in vivo LAHB production, propionyl-CoA transferases (PCTs) that exhibited enhanced production of LA-CoA than the conventional PCTs were selected. Here, the present study has demonstrated that the LA fraction of LAHB could be altered using various PCTs. Enhanced PCT performance was achieved by balancing polymer production and cell growth. Both events are governed by the use of acetyl-CoA, a commonly shared key metabolite. This could be attributed to the different reactivities of individual PCTs towards acetyl-CoA, which serves both as a CoA donor and a leading compound in the TCA cycle. Interestingly, we found complete sequence randomness in the LAHB copolymers, independent of the LA fraction. The mechanism of LA fraction-independent sequence randomness is discussed. This new PCT-based strategy synergistically combines with the evolution of LPE to advance the LAHB project, and enables us to perform advanced applications other than LAHB production utilizing CoA-linked substrates.
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Affiliation(s)
- Sangho Koh
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Ryota Endo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Prihardi Kahar
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Yutaro Mori
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Chiaki Ogino
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Shinji Tanaka
- Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
| | - Shinji Tanaka
- Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
| | - Yusuke Imai
- Multi-Material Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 4-205, Sakurazaka, Moriyama-ku, Nagoya, Aichi 463-8560, Japan
| | - Seiichi Taguchi
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan; Engineering Biology Research Center, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
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Matsumoto K. Toward the production of block copolymers in microbial cells: achievements and perspectives. Appl Microbiol Biotechnol 2024; 108:164. [PMID: 38252290 PMCID: PMC10803391 DOI: 10.1007/s00253-023-12973-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/27/2023] [Accepted: 12/01/2023] [Indexed: 01/23/2024]
Abstract
The microbial production of polyhydroxyalkanoate (PHA) block copolymers has attracted research interests because they can be expected to exhibit excellent physical properties. Although post-polymerization conjugation and/or extension have been used for PHA block copolymer synthesis, the discovery of the first sequence-regulating PHA synthase, PhaCAR, enabled the direct synthesis of PHA-PHA type block copolymers in microbial cells. PhaCAR spontaneously synthesizes block copolymers from a mixture of substrates. To date, Escherichia coli and Ralstonia eutropha have been used as host strains, and therefore, sequence regulation is not a host-specific phenomenon. The monomer sequence greatly influences the physical properties of the polymer. For example, a random copolymer of 3-hydroxybutyrate and 2-hydroxybutyrate deforms plastically, while a block copolymer of approximately the same composition exhibits elastic deformation. The structure of the PHA block copolymer can be expanded by in vitro evolution of the sequence-regulating PHA synthase. An engineered variant of PhaCAR can synthesize poly(D-lactate) as a block copolymer component, which allows for greater flexibility in the molecular design of block copolymers. Therefore, creating sequence-regulating PHA synthases with a further broadened substrate range will expand the variety of properties of PHA materials. This review summarizes and discusses the sequence-regulating PHA synthase, analytical methods for verifying block sequence, properties of block copolymers, and mechanisms of sequence regulation. KEY POINTS: • Spontaneous monomer sequence regulation generates block copolymers • Poly(D-lactate) segment can be synthesized using a block copolymerization system • Block copolymers exhibit characteristic properties.
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Affiliation(s)
- Ken'ichiro Matsumoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Kitaku, Sapporo, N13W8060-8628, Japan.
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Yanagawa K, Kajikawa A, Sakakibara S, Kumeta H, Tomita H, Matsumoto K. Real-time NMR analysis of polyhydroxyalkanoate synthase reaction that synthesizes block copolymer comprising glycolate and 3-hydroxybutyrate. Biophys Chem 2023; 296:107001. [PMID: 36913888 DOI: 10.1016/j.bpc.2023.107001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/02/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023]
Abstract
The sequence-regulating polyhydroxyalkanoate (PHA) synthase PhaCAR spontaneously synthesizes the homo-random block copolymer, poly[3-hydroxybutyrate (3HB)]-b-poly[glycolate (GL)-ran-3HB]. In this study, a real-time in vitro chasing system was established using a high-resolution 800 MHz nuclear magnetic resonance (NMR) and 13C-labeled monomers to monitor the polymerization of GL-CoA and 3HB-CoA into this atypical copolymer. Consequently, PhaCAR initially consumed only 3HB-CoA and subsequently consumed both substrates. The structure of the nascent polymer was analyzed by extracting it with deuterated hexafluoro-isopropanol. In the primary reaction product, a 3HB-3HB dyad was detected, and GL-3HB linkages were subsequently formed. According to these results, the P(3HB) homopolymer segment is synthesized prior to the random copolymer segment. This is the first report of its kind which proposes the application of real-time NMR to a PHA synthase assay, paving the way for elucidating the mechanisms of PHA block copolymerization.
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Affiliation(s)
- Kengo Yanagawa
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Japan
| | - Ayaka Kajikawa
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Japan
| | - Sayaka Sakakibara
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Japan
| | - Hiroyuki Kumeta
- Faculty of Advanced Life Science, Hokkaido University, Japan
| | - Hiroya Tomita
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, N13W8, Kitaku, Sapporo 060-8628, Japan
| | - Ken'ichiro Matsumoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, N13W8, Kitaku, Sapporo 060-8628, Japan.
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Control of D-lactic acid content in P(LA-3HB) copolymer in the yeast Saccharomyces cerevisiae using a synthetic gene expression system. Metab Eng Commun 2022; 14:e00199. [PMID: 35571351 PMCID: PMC9095885 DOI: 10.1016/j.mec.2022.e00199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 03/26/2022] [Accepted: 04/22/2022] [Indexed: 11/22/2022] Open
Abstract
The fully biobased polyhydroxyalkanoate (PHA) polymers provide interesting alternatives for petrochemical derived plastic materials. The mechanical properties of some PHAs, including the common poly(3-hydroxybutyrate) (PHB), are limited, but tunable by addition of other monomers into the polymer chain. In this study we present a precise synthetic biology method to adjust lactate monomer fraction of a polymer by controlling the monomer formation in vivo at gene expression level, independent of cultivation conditions. We used the modified doxycycline-based Tet-On approach to adjust the expression of the stereospecific D-lactate dehydrogenase gene (ldhA) from Leuconostoc mesenteroides to control D-lactic acid formation in yeast Saccharomyces cerevisiae. The synthetic Tet-On transcription factor with a VP16 activation domain was continuously expressed and its binding to a synthetic promoter with eight transcription factor specific binding sites upstream of the ldhA gene was controlled with the doxycycline concentration in the media. The increase in doxycycline concentration correlated positively with ldhA expression, D-lactic acid production, poly(D-lactic acid) (PDLA) accumulation in vivo, and D-lactic acid content in the poly(D-lactate-co-3-hydroxybutyrate) P(LA-3HB) copolymer. We demonstrated that the D-lactic acid content of the P(LA-3HB) copolymer can be adjusted linearly from 6 mol% to 93 mol% in vivo in S. cerevisiae. These results highlight the power of controlling gene expression and monomer formation in the tuning of the polymer composition. In addition, we obtained 5.6% PDLA and 19% P(LA-3HB) of the cell dry weight (CDW), which are over two- and five-fold higher accumulation levels, respectively, than reported in the previous studies with yeast. We also compared two engineered PHA synthases and discovered that in S. cerevisiae the PHA synthase PhaC1437Ps6-19 produced P(LA-3HB) copolymers with lower D-lactic acid content, but with higher molecular weight, in comparison to the PHA synthase PhaC1Pre. P(LA-3HB) monomer structure was adjusted with controlled gene expression. Expression of D-lactate dehydrogenase (ldhA) was controlled with Tet-On approach. Lactic acid content in copolymer P(LA-3HB) was adjusted from 6 mol% up to 93 mol%. 5.6% PDLA and 19% P(LA-3HB) of cell dry weight (CDW) were obtained in S. cerevisiae. PhaC1437Ps6-19 P(LA-3HB) had lower D-lactic acid % than PhaC1Pre P(LA-3HB).
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Guo P, Luo Y, Wu J, Wu H. Recent advances in the microbial synthesis of lactate-based copolymer. BIORESOUR BIOPROCESS 2021; 8:106. [PMID: 38650297 PMCID: PMC10992027 DOI: 10.1186/s40643-021-00458-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 10/12/2021] [Indexed: 11/10/2022] Open
Abstract
Due to the increasing environmental pollution of un-degradable plastics and the consumption of non-renewable resources, more attention has been attracted by new bio-degradable/based polymers produced from renewable resources. Polylactic acid (PLA) is one of the most representative bio-based materials, with obvious advantages and disadvantages, and has a wide range of applications in industry, medicine, and research. By copolymerizing to make up for its deficiencies, the obtained copolymers have more excellent properties. The development of a one-step microbial metabolism production process of the lactate (LA)-based copolymers overcomes the inherent shortcomings in the traditional chemical synthesis process. The most common lactate-based copolymer is poly(lactate-co-3-hydroxybutyrate) [P(LA-co-3HB)], within which the difference of LA monomer fraction will cause the change in the material properties. It is necessary to regulate LA monomer fraction by appropriate methods. Based on synthetic biology and systems metabolic engineering, this review mainly focus on how did the different production strategies (such as enzyme engineering, fermentation engineering, etc.) of P(LA-co-3HB) optimize the chassis cells to efficiently produce it. In addition, the metabolic engineering strategies of some other lactate-based copolymers are also introduced in this article. These studies would facilitate to expand the application fields of the corresponding materials.
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Affiliation(s)
- Pengye Guo
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Yuanchan Luo
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Ju Wu
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Hui Wu
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai, 200237, China.
- Key Laboratory of Bio-Based Material Engineering of China National Light Industry Council, 130 Meilong Road, Shanghai, 200237, China.
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7
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Ylinen A, Maaheimo H, Anghelescu-Hakala A, Penttilä M, Salusjärvi L, Toivari M. Production of D-lactic acid containing polyhydroxyalkanoate polymers in yeast Saccharomyces cerevisiae. J Ind Microbiol Biotechnol 2021; 48:6253250. [PMID: 33899921 PMCID: PMC9113173 DOI: 10.1093/jimb/kuab028] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/13/2021] [Indexed: 11/13/2022]
Abstract
Polyhydroxyalkanoates (PHAs) provide biodegradable and bio-based alternatives to conventional plastics. Incorporation of 2-hydroxy acid monomers into polymer, in addition to 3-hydroxy acids, offers possibility to tailor the polymer properties. In this study, poly(D-lactic acid) (PDLA) and copolymer P(LA-3HB) were produced and characterized for the first time in the yeast Saccharomyces cerevisiae. Expression of engineered PHA synthase PhaC1437Ps6–19, propionyl-CoA transferase Pct540Cp, acetyl-CoA acetyltransferase PhaA, and acetoacetyl-CoA reductase PhaB1 resulted in accumulation of 3.6% P(LA-3HB) and expression of engineered enzymes PhaC1Pre and PctMe resulted in accumulation of 0.73% PDLA of the cell dry weight (CDW). According to NMR, P(LA-3HB) contained D-lactic acid repeating sequences. For reference, expression of PhaA, PhaB1, and PHA synthase PhaC1 resulted in accumulation 11% poly(hydroxybutyrate) (PHB) of the CDW. Weight average molecular weights of these polymers were comparable to similar polymers produced by bacterial strains, 24.6, 6.3, and 1 130 kDa for P(LA-3HB), PDLA, and PHB, respectively. The results suggest that yeast, as a robust and acid tolerant industrial production organism, could be suitable for production of 2-hydroxy acid containing PHAs from sugars or from 2-hydroxy acid containing raw materials. Moreover, the wide substrate specificity of PHA synthase enzymes employed increases the possibilities for modifying copolymer properties in yeast in the future.
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Affiliation(s)
- Anna Ylinen
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Hannu Maaheimo
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | | | - Merja Penttilä
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Espoo, Finland.,Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, P.O. Box 11000, FI-00076 Aalto, Espoo, Finland
| | - Laura Salusjärvi
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Mervi Toivari
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Espoo, Finland
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8
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Nduko JM, Taguchi S. Microbial Production of Biodegradable Lactate-Based Polymers and Oligomeric Building Blocks From Renewable and Waste Resources. Front Bioeng Biotechnol 2021; 8:618077. [PMID: 33614605 PMCID: PMC7889595 DOI: 10.3389/fbioe.2020.618077] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/17/2020] [Indexed: 12/20/2022] Open
Abstract
Polyhydroxyalkanoates (PHAs) are naturally occurring biopolymers produced by microorganisms. PHAs have become attractive research biomaterials in the past few decades owing to their extensive potential industrial applications, especially as sustainable alternatives to the fossil fuel feedstock-derived products such as plastics. Among the biopolymers are the bioplastics and oligomers produced from the fermentation of renewable plant biomass. Bioplastics are intracellularly accumulated by microorganisms as carbon and energy reserves. The bioplastics, however, can also be produced through a biochemistry process that combines fermentative secretory production of monomers and/or oligomers and chemical synthesis to generate a repertoire of biopolymers. PHAs are particularly biodegradable and biocompatible, making them a part of today's commercial polymer industry. Their physicochemical properties that are similar to those of petrochemical-based plastics render them potential renewable plastic replacements. The design of efficient tractable processes using renewable biomass holds key to enhance their usage and adoption. In 2008, a lactate-polymerizing enzyme was developed to create new category of polyester, lactic acid (LA)-based polymer and related polymers. This review aims to introduce different strategies including metabolic and enzyme engineering to produce LA-based biopolymers and related oligomers that can act as precursors for catalytic synthesis of polylactic acid. As the cost of PHA production is prohibitive, the review emphasizes attempts to use the inexpensive plant biomass as substrates for LA-based polymer and oligomer production. Future prospects and challenges in LA-based polymer and oligomer production are also highlighted.
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Affiliation(s)
- John Masani Nduko
- Department of Dairy and Food Science and Technology, Faculty of Agriculture, Egerton University, Egerton, Kenya
| | - Seiichi Taguchi
- Department of Chemistry for Life Sciences and Agriculture, Faculty of Life Sciences and Agriculture, Tokyo University of Agriculture, Tokyo, Japan
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9
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Arai S, Sakakibara S, Mareschal R, Ooi T, Zinn M, Matsumoto K. Biosynthesis of Random-Homo Block Copolymer Poly[Glycolate- ran-3-Hydroxybutyrate (3HB)]- b-Poly(3HB) Using Sequence-Regulating Chimeric Polyhydroxyalkanoate Synthase in Escherichia coli. Front Bioeng Biotechnol 2020; 8:612991. [PMID: 33364233 PMCID: PMC7752996 DOI: 10.3389/fbioe.2020.612991] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/16/2020] [Indexed: 11/13/2022] Open
Abstract
Glycolate (GL)-containing polyhydroxyalkanoate (PHA) was synthesized in Escherichia coli expressing the engineered chimeric PHA synthase PhaC AR and coenzyme A transferase. The cells produced poly[GL-co-3-hydroxybutyrate (3HB)] with the supplementation of GL and 3HB, thus demonstrating that PhaC AR is the first known class I PHA synthase that is capable of incorporating GL units. The triad sequence analysis using 1H nuclear magnetic resonance indicated that the obtained polymer was composed of two distinct regions, a P(GL-ran-3HB) random segment and P(3HB) homopolymer segment. The random segment was estimated to contain a 71 mol% GL molar ratio, which was much greater than the value (15 mol%) previously achieved by using PhaC1 P s STQK. Differential scanning calorimetry analysis of the polymer films supported the presence of random copolymer and homopolymer phases. The solvent fractionation of the polymer indicated the presence of a covalent linkage between these segments. Therefore, it was concluded that PhaC AR synthesized a novel random-homo block copolymer, P(GL-ran-3HB)-b-P(3HB).
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Affiliation(s)
- Shuzo Arai
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Sayaka Sakakibara
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Robin Mareschal
- Department of Engineering, Hokkaido University, Sapporo, Japan
- Institute of Life Technologies, University of Applied Sciences and Arts Western Switzerland (HES-SO Valais-Wallis), Sion, Switzerland
| | - Toshihiko Ooi
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Manfred Zinn
- Institute of Life Technologies, University of Applied Sciences and Arts Western Switzerland (HES-SO Valais-Wallis), Sion, Switzerland
| | - Ken’ichiro Matsumoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Japan
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10
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Miyahara Y, Hiroe A, Tsuge T, Taguchi S. Microbial Secretion Platform for 3‐Hydroxybutyrate Oligomer and Its End‐Capped Forms Using Chain Transfer Reaction‐Mediated Polyhydroxyalkanoate Synthases. Biotechnol J 2019; 14:e1900201. [DOI: 10.1002/biot.201900201] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 10/27/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Yuki Miyahara
- Department of Chemistry for Life Sciences and Agriculture, Faculty of Life Sciences Tokyo University of Agriculture 1‐1‐1 Sakuragaoka, Setagaya Tokyo 156–8502 Japan
- MIRAI, JST 4‐1‐8 Honcho Kawaguchi Saitama 332‐0012 Japan
| | - Ayaka Hiroe
- Department of Chemistry for Life Sciences and Agriculture, Faculty of Life Sciences Tokyo University of Agriculture 1‐1‐1 Sakuragaoka, Setagaya Tokyo 156–8502 Japan
- MIRAI, JST 4‐1‐8 Honcho Kawaguchi Saitama 332‐0012 Japan
| | - Takeharu Tsuge
- Department of Materials Science and Engineering, Major in Human Centered Science and Biomedical Engineering School of Materials and Chemical Technology, Tokyo Institute of Technology 4259 J2‐47 Nagatsuta‐cho, Midori‐ku Yokohama‐shi Kanagawa 226–8502 Japan
- MIRAI, JST 4‐1‐8 Honcho Kawaguchi Saitama 332‐0012 Japan
| | - Seiichi Taguchi
- Department of Chemistry for Life Sciences and Agriculture, Faculty of Life Sciences Tokyo University of Agriculture 1‐1‐1 Sakuragaoka, Setagaya Tokyo 156–8502 Japan
- CREST, JST 4‐1‐8 Honcho Kawaguchi Saitama 332‐0012 Japan
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11
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Polyhydroxyalkanoates based copolymers. Int J Biol Macromol 2019; 140:522-537. [PMID: 31437500 DOI: 10.1016/j.ijbiomac.2019.08.147] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/09/2019] [Accepted: 08/17/2019] [Indexed: 11/23/2022]
Abstract
Polyhydroxyalkanoates (PHAs) belong to a family of natural polyesters and are produced under unbalanced growth conditions as intracellular carbon and energy reserves by a wide variety of microorganisms. Being biodegradable, biocompatible and environmental friendly thermoplastics, the PHAs are considered as future polymers to replace petrochemicals based plastics. In this review, the introduction section deals with the brief discussion on PHA nature, availability, raw materials for production, processing etc. This is followed by the discussions on modifications. The copolymer syntheses by bacterial and chemical methods have been discussed. Under chemical methods, unsaturated side chains and their derivatives, oligomer, coupling, macro-initiating, trans-esterification, radiation grafting, click chemistry, ring opening and several miscellaneous polymerization methods have been elaborated. A brief discussion on applications has been incorporated. The last section includes conclusion and future perspectives.
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12
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Biosynthesis of novel lactate-based polymers containing medium-chain-length 3-hydroxyalkanoates by recombinant Escherichia coli strains from glucose. J Biosci Bioeng 2019; 128:191-197. [DOI: 10.1016/j.jbiosc.2019.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/10/2019] [Accepted: 01/15/2019] [Indexed: 11/22/2022]
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Matsumoto K, Kageyama Y. Increased Production and Molecular Weight of Artificial Polyhydroxyalkanoate Poly(2-hydroxybutyrate) Above the Glass Transition Temperature Threshold. Front Bioeng Biotechnol 2019; 7:177. [PMID: 31428606 PMCID: PMC6689969 DOI: 10.3389/fbioe.2019.00177] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/09/2019] [Indexed: 11/13/2022] Open
Abstract
Poly(2-hydroxybutyrate) [P(2HB)] is an artificial polyhydroxyalkanoate (PHA) synthesized using engineered 2-hydroxyalkanoate-polymerizing PHA synthase. In the present study, the effect of temperature on P(2HB) synthesis was investigated. Recombinant Escherichia coli harboring PHA synthetic genes were cultivated with 2HB and 3-hydroxybutyrate (3HB) supplementation at varied temperatures ranging from 24 to 36°C for the synthesis of P(2HB) and natural PHA P(3HB), respectively. P(2HB) production and its molecular weight increased considerably at a threshold temperature of 32-34°C. The trend was not observed during the synthesis of P(3HB). Notably, the threshold temperature was close to the glass transition temperature (T g) of P(2HB) (30°C), while the T g of P(3HB) (4°C) was much lower than the cultivation temperature. The results suggest that thermal motion of the polymer chains influenced the production and molecular weight of the obtained polymer. According to the results, the production and molecular weight of PHA drastically changes at the threshold temperature, which is linked to the T g of the polymer. The hypothesis should be applicable to PHAs in general, and potentially explains the inability to biosynthesize high-molecular-weight polylactate homopolymer with a T g of 60°C.
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Affiliation(s)
- Ken'ichiro Matsumoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Yuki Kageyama
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Japan
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