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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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Rajesh Banu J, Ginni G, Kavitha S, Yukesh Kannah R, Kumar V, Adish Kumar S, Gunasekaran M, Tyagi VK, Kumar G. Polyhydroxyalkanoates synthesis using acidogenic fermentative effluents. Int J Biol Macromol 2021; 193:2079-2092. [PMID: 34774601 DOI: 10.1016/j.ijbiomac.2021.11.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 11/29/2022]
Abstract
Polyhydroxyalkanoates (PHA) are natural polyesters synthesized by microbes which consume excess amount of carbon and less amount of nutrients. It is biodegradable in nature, and it synthesized from renewable resources. It is considered as a future polymer, which act as an attractive replacement to petrochemical based polymers. The main hindrance to the commercial application of PHA is the high manufacturing cost. This article provides an overview of different cost-effective substrates, their characteristics and composition, major strains involved in economical production of PHA and biosynthetic pathways leading to accumulation of PHA. This review also covers the operational parameters, various fermentative modes including batch, fed-batch, repeated fed-batch and continuous fed-batch systems, along with advanced feeding strategies such as single pulse carbon feeding, feed forward control, intermittent carbon feeding, feast famine conditions to observe their effects for improving PHA synthesis and associated challenges. In addition, it also presents the economic analysis and future perspectives for the commercialization of PHA production process thereby making the process sustainable and lucrative with the possibility of commercial biomanufacturing.
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Affiliation(s)
- J Rajesh Banu
- Department of Life Sciences, Central University of Tamil Nadu, Neelakudi, Thiruvarur, Tamil Nadu 610005, India
| | - G Ginni
- Department of Civil Engineering, Amrita College of Engineering and Technology, Amritagiri, Nagercoil, Tamil Nadu, 629901, India
| | - S Kavitha
- Department of Civil Engineering, Anna University Regional Campus, Tirunelveli, Tamil Nadu, 627007, India
| | - R Yukesh Kannah
- Department of Civil Engineering, Anna University Regional Campus, Tirunelveli, Tamil Nadu, 627007, India; Department of Civil Engineering, National Institute of Technology Tiruchirappalli, Tamil Nadu, 620015, India
| | - Vinod Kumar
- School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, United Kingdom
| | - S Adish Kumar
- Department of Civil Engineering, Anna University Regional Campus, Tirunelveli, Tamil Nadu, 627007, India
| | - M Gunasekaran
- Department of Physics, Anna University Regional Campus, Tirunelveli, Tamil Nadu, 627007, India
| | - Vinay Kumar Tyagi
- Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Gopalakrishnan Kumar
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea; Institute of Chemistry, Bioscience and Environmental Engineering, Faculty of Science and Technology, University of Stavanger, Box 8600 Forus, 4036 Stavanger, Norway.
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Kageyama Y, Tomita H, Isono T, Satoh T, Matsumoto K. Artificial polyhydroxyalkanoate poly[2-hydroxybutyrate-block-3-hydroxybutyrate] elastomer-like material. Sci Rep 2021; 11:22446. [PMID: 34789822 PMCID: PMC8599675 DOI: 10.1038/s41598-021-01828-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/03/2021] [Indexed: 11/09/2022] Open
Abstract
The first polyhydroxyalkanoate (PHA) block copolymer poly(2-hydroxybutyrate-b-3-hydroxybutyrate) [P(2HB-b-3HB)] was previously synthesized using engineered Escherichia coli expressing a chimeric PHA synthase PhaCAR with monomer sequence-regulating capacity. In the present study, the physical properties of the block copolymer and its relevant random copolymer P(2HB-ran-3HB) were evaluated. Stress-strain tests on the P(88 mol% 2HB-b-3HB) film showed an increasing stress value during elongation up to 393%. In addition, the block copolymer film exhibited slow contraction behavior after elongation, indicating that P(2HB-b-3HB) is an elastomer-like material. In contrast, the P(92 mol% 2HB-ran-3HB) film, which was stretched up to 692% with nearly constant stress, was stretchable but not elastic. The differential scanning calorimetry and wide-angle X-ray diffraction analyses indicated that the P(2HB-b-3HB) contained the amorphous P(2HB) phase and the crystalline P(3HB) phase, whereas P(2HB-ran-3HB) was wholly amorphous. Therefore, the elasticity of P(2HB-b-3HB) can be attributed to the presence of the crystalline P(3HB) phase and a noncovalent crosslinked structure by the crystals. These results show the potential of block PHAs as elastic materials.
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Affiliation(s)
- Yuki Kageyama
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, N13W8, Kitaku, Sapporo, 060-8628, Japan
| | - Hiroya Tomita
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, N13W8, Kitaku, Sapporo, 060-8628, Japan
| | - Takuya Isono
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, N13W8, Kitaku, Sapporo, 060-8628, Japan
| | - Toshifumi Satoh
- 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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Goswami M, Rekhi P, Debnath M, Ramakrishna S. Microbial Polyhydroxyalkanoates Granules: An Approach Targeting Biopolymer for Medical Applications and Developing Bone Scaffolds. Molecules 2021; 26:860. [PMID: 33562111 PMCID: PMC7915662 DOI: 10.3390/molecules26040860] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/28/2021] [Accepted: 02/02/2021] [Indexed: 12/16/2022] Open
Abstract
Microbial polyhydroxyalkanoates (PHA) are proteinaceous storage granules ranging from 100 nm to 500 nm. Bacillus sp. serve as unique bioplastic sources of short-chain length and medium-chain length PHA showcasing properties such as biodegradability, thermostability, and appreciable mechanical strength. The PHA can be enhanced by adding functional groups to make it a more industrially useful biomaterial. PHA blends with hydroxyapatite to form nanocomposites with desirable features of compressibility. The reinforced matrices result in nanocomposites that possess significantly improved mechanical and thermal properties both in solid and melt states along with enhanced gas barrier properties compared to conventional filler composites. These superior qualities extend the polymeric composites' applications to aggressive environments where the neat polymers are likely to fail. This nanocomposite can be used in different industries as nanofillers, drug carriers for packaging essential hormones and microcapsules, etc. For fabricating a bone scaffold, electrospun nanofibrils made from biocomposite of hydroxyapatite and polyhydroxy butyrate, a form of PHA, can be incorporated with the targeted tissue. The other methods for making a polymer scaffold, includes gas foaming, lyophilization, sol-gel, and solvent casting method. In this review, PHA as a sustainable eco-friendly NextGen biomaterial from bacterial sources especially Bacillus cereus, and its application for fabricating bone scaffold using different strategies for bone regeneration have been discussed.
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Affiliation(s)
- Moushmi Goswami
- Department of Biosciences, Manipal University Jaipur, Rajasthan 303007, India; (M.G.); (P.R.)
| | - Pavni Rekhi
- Department of Biosciences, Manipal University Jaipur, Rajasthan 303007, India; (M.G.); (P.R.)
| | - Mousumi Debnath
- Department of Biosciences, Manipal University Jaipur, Rajasthan 303007, India; (M.G.); (P.R.)
| | - Seeram Ramakrishna
- Department of Mechanical Engineering, National University of Singapore, Singapore 119260, Singapore;
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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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