1
|
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] [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.
Collapse
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.
| |
Collapse
|
2
|
Neoh SZ, Tan HT, Trakunjae C, Chek MF, Vaithanomsat P, Hakoshima T, Sudesh K. N-terminal truncation of PhaC BP-M-CPF4 and its effect on PHA production. Microb Cell Fact 2024; 23:52. [PMID: 38360657 PMCID: PMC10867992 DOI: 10.1186/s12934-024-02329-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 02/07/2024] [Indexed: 02/17/2024] Open
Abstract
BACKGROUND Among the polyhydroxyalkanoate (PHA), poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] [P(3HB-co-3HHx)] is reported to closely resemble polypropylene and low-density polyethylene. Studies have shown that PHA synthase (PhaC) from mangrove soil (PhaCBP-M-CPF4) is an efficient PhaC for P(3HB-co-3HHx) production and N-termini of PhaCs influence its substrate specificity, dimerization, granule morphology, and molecular weights of PHA produced. This study aims to further improve PhaCBP-M-CPF4 through N-terminal truncation. RESULTS The N-terminal truncated mutants of PhaCBP-M-CPF4 were constructed based on the information of the predicted secondary and tertiary structures using PSIPRED server and AlphaFold2 program, respectively. The N-terminal truncated PhaCBP-M-CPF4 mutants were evaluated in C. necator mutant PHB-4 based on the cell dry weight, PHA content, 3HHx molar composition, molecular weights, and granule morphology of the PHA granules. The results showed that most transformants harbouring the N-terminal truncated PhaCBP-M-CPF4 showed a reduction in PHA content and cell dry weight except for PhaCBP-M-CPF4 G8. PhaCBP-M-CPF4 G8 and A27 showed an improved weight-average molecular weight (Mw) of PHA produced due to lower expression of the truncated PhaCBP-M-CPF4. Transformants harbouring PhaCBP-M-CPF4 G8, A27, and T74 showed a reduction in the number of granules. PhaCBP-M-CPF4 G8 produced higher Mw PHA in mostly single larger PHA granules with comparable production as the full-length PhaCBP-M-CPF4. CONCLUSION This research showed that N-terminal truncation had effects on PHA accumulation, substrate specificity, Mw, and granule morphology. This study also showed that N-terminal truncation of the amino acids that did not adopt any secondary structure can be an alternative to improve PhaCs for the production of PHA with higher Mw in mostly single larger granules.
Collapse
Affiliation(s)
- Soon Zher Neoh
- Ecobiomaterial Research Laboratory, School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Penang, Malaysia
| | - Hua Tiang Tan
- Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Chanaporn Trakunjae
- Kasetsart Agricultural and Agro-Industrial Product Improvement Institute (KAPI), Kasetsart University, Bangkok, 10900, Thailand
| | - Min Fey Chek
- Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Pilanee Vaithanomsat
- Kasetsart Agricultural and Agro-Industrial Product Improvement Institute (KAPI), Kasetsart University, Bangkok, 10900, Thailand
| | - Toshio Hakoshima
- Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Kumar Sudesh
- Ecobiomaterial Research Laboratory, School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Penang, Malaysia.
| |
Collapse
|
3
|
Hernández-Herreros N, Rivero-Buceta V, Pardo I, Prieto MA. Production of poly(3-hydroxybutyrate)/poly(lactic acid) from industrial wastewater by wild-type Cupriavidus necator H16. WATER RESEARCH 2024; 249:120892. [PMID: 38007895 DOI: 10.1016/j.watres.2023.120892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 11/13/2023] [Accepted: 11/16/2023] [Indexed: 11/28/2023]
Abstract
The massive production of urban and industrial wastes has created a clear need for alternative waste management processes. One of the more promising strategies is to use waste as raw material for the production of biopolymers such as polyhydroxyalkanoates (PHAs). In this work, a lactate-enriched stream obtained by anaerobic digestion (AD) of wastewater (WW) from a candy production plant was used as a feedstock for PHA production in wild-type Cupriavidus necator H16. Unexpectedly, we observed the accumulation of poly(3-hydroxybutyrate)/poly(lactic acid) (P(3HB)/PLA), suggesting that the non-engineered strain already possesses the metabolic potential to produce these polymers of interest. The systematic study of factors, such as incubation time, nitrogen and lactate concentration, influencing the synthesis of P(3HB)/PLA allowed the production of a panel of polymers in a resting cell system with tailored lactic acid (LA) content according to the GC-MS of the biomass. Further biomass extraction suggested the presence of methanol soluble low molecular weight molecules containing LA, while 1 % LA could be detected in the purified polymer fraction. These results suggested that the cells are producing a blend of polymers. A proteomic analysis of C. necator resting cells under P(3HB)/PLA production conditions provides new insights into the latent pathways involved in this process. This study is a proof of concept demonstrating that LA can polymerize in a non-modified organism and paves the way for new metabolic engineering approaches for lactic acid polymer production in the model bacterium C. necator H16.
Collapse
Affiliation(s)
- Natalia Hernández-Herreros
- Microbial & Plant Biotechnology Department. Polymer Biotechnology Group. Biological Research Centre Margarita Salas, Spanish National Research Council (CIB-CSIC), Madrid, Spain; Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), Madrid, Spain
| | - Virginia Rivero-Buceta
- Microbial & Plant Biotechnology Department. Polymer Biotechnology Group. Biological Research Centre Margarita Salas, Spanish National Research Council (CIB-CSIC), Madrid, Spain; Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), Madrid, Spain
| | - Isabel Pardo
- Microbial & Plant Biotechnology Department. Polymer Biotechnology Group. Biological Research Centre Margarita Salas, Spanish National Research Council (CIB-CSIC), Madrid, Spain; Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), Madrid, Spain
| | - M Auxiliadora Prieto
- Microbial & Plant Biotechnology Department. Polymer Biotechnology Group. Biological Research Centre Margarita Salas, Spanish National Research Council (CIB-CSIC), Madrid, Spain; Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), Madrid, Spain.
| |
Collapse
|
4
|
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.
Collapse
Affiliation(s)
- Ken'ichiro Matsumoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Kitaku, Sapporo, N13W8060-8628, Japan.
| |
Collapse
|
5
|
Ishihara S, Orita I, Matsumoto K, Fukui T. (R/S)-lactate/2-hydroxybutyrate dehydrogenases in and biosynthesis of block copolyesters by Ralstonia eutropha. Appl Microbiol Biotechnol 2023; 107:7557-7569. [PMID: 37773219 PMCID: PMC10656315 DOI: 10.1007/s00253-023-12797-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 10/01/2023]
Abstract
Bacterial polyhydroxyalkanoates (PHAs) are promising bio-based biodegradable polyesters. It was recently reported that novel PHA block copolymers composed of (R)-3-hydroxybutyrate (3HB) and (R)-2-hydroxybutyrate (2HB) were synthesized by Escherichia coli expressing PhaCAR, a chimeric enzyme of PHA synthases derived from Aeromonas caviae and Ralstonia eutropha. In this study, the sequence-regulating PhaCAR was applied in the natural PHA-producing bacterium, R. eutropha. During the investigation, (R/S)-2HB was found to exhibit strong growth inhibitory effects on the cells of R. eutropha. This was probably due to formation of excess 2-ketobutyrate (2KB) from (R/S)-2HB and the consequent L-valine depletion caused by dominant L-isoleucine synthesis attributed to the excess 2KB. Deletion analyses for genes of lactate dehydrogenase homologs identified cytochrome-dependent D-lactate dehydrogenase (Dld) and [Fe-S] protein-dependent L-lactate dehydrogenase as the enzymes responsible for sensitivity to (R)-2HB and (S)-2HB, respectively. The engineered R. eutropha strain (phaCAR+, ldhACd-hadACd+ encoding clostridial (R)-2-hydroxyisocaproate dehydrogenase and (R)-2-hydoroxyisocaproate CoA transferase, ∆dld) synthesized PHA containing 10 mol% of 2HB when cultivated on glucose with addition of sodium (RS)-2HB, and the 2HB composition in PHA increased up to 35 mol% by overexpression phaCAR. The solvent fractionation and NMR analyses showed that the resulting PHAs were most likely to be block polymers consisting of P(3HB-co-3HV) and P(2HB) segments, suggesting that PhaCAR functions as the sequence-regulating PHA synthase independently from genetic and metabolic backgrounds of the host cell. KEY POINTS: (R/S)-2-hydroxubutyrates (2HB) caused l-valine deletion in Ralstonia eutropha (R)- and (S)-lactate/2HB dehydrogenases functional in R. eutropha were identified The engineered R. eutropha synthesized block copolymers of 2HB-containing polyhydroxyalkanoates on glucose and 2HB.
Collapse
Affiliation(s)
- Shizuru Ishihara
- School of Life Science and Technology, Tokyo Institute of Technology, B-37 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan
| | - Izumi Orita
- School of Life Science and Technology, Tokyo Institute of Technology, B-37 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan
| | - Ken'ichiro Matsumoto
- Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo, 060-8628, Japan
| | - Toshiaki Fukui
- School of Life Science and Technology, Tokyo Institute of Technology, B-37 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan.
| |
Collapse
|
6
|
Aghaali Z, Naghavi MR. Biotechnological Approaches for Enhancing Polyhydroxyalkanoates (PHAs) Production: Current and Future Perspectives. Curr Microbiol 2023; 80:345. [PMID: 37731015 DOI: 10.1007/s00284-023-03452-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 08/19/2023] [Indexed: 09/22/2023]
Abstract
The benefits of biotechnology are not limited to genetic engineering, but it also displays its great impact on industrial uses of crops (e.g., biodegradable plastics). Polyhydroxyalkanoates (PHAs) make a diverse class of bio-based and biodegradable polymers naturally synthesized by numerous microorganisms. However, several C3 and C4 plants have also been genetically engineered to produce PHAs. The highest production yield of PHAs was obtained with a well-known C3 plant, Arabidopsis thaliana, upto 40% of the dry weight of the leaf. This review summarizes all biotechnological mechanisms that have been adopted with the goal of increasing PHAs production in bacteria and plant species alike. Moreover, the possibility of using some methods that have not been applied in bioplastic science are discussed with special attention to plants. These include producing PHAs in transgenic hairy roots and cell suspension cultures, making transformed bacteria and plants via transposons, constructing an engineered metabolon, and overexpressing of phaP and the ABC operon concurrently. Taken together, that biotechnology will be highly beneficial for reducing plastic pollution through the implementation of biotechnological strategies is taken for granted.
Collapse
Affiliation(s)
- Zahra Aghaali
- Department of Genetic and Plant Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
| | - Mohammad Reza Naghavi
- Division of Biotechnology, Department of Agronomy and Plant Breeding, College of Agricultural and Natural Resources, University of Tehran, Karaj, Iran.
| |
Collapse
|
7
|
Goswami L, Kushwaha A, Napathorn SC, Kim BS. Valorization of organic wastes using bioreactors for polyhydroxyalkanoate production: Recent advancement, sustainable approaches, challenges, and future perspectives. Int J Biol Macromol 2023; 247:125743. [PMID: 37423435 DOI: 10.1016/j.ijbiomac.2023.125743] [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: 03/05/2023] [Revised: 06/23/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023]
Abstract
Microbial polyhydroxyalkanoates (PHA) are encouraging biodegradable polymers, which may ease the environmental problems caused by petroleum-derived plastics. However, there is a growing waste removal problem and the high price of pure feedstocks for PHA biosynthesis. This has directed to the forthcoming requirement to upgrade waste streams from various industries as feedstocks for PHA production. This review covers the state-of-the-art progress in utilizing low-cost carbon substrates, effective upstream and downstream processes, and waste stream recycling to sustain entire process circularity. This review also enlightens the use of various batch, fed-batch, continuous, and semi-continuous bioreactor systems with flexible results to enhance the productivity and simultaneously cost reduction. The life-cycle and techno-economic analyses, advanced tools and strategies for microbial PHA biosynthesis, and numerous factors affecting PHA commercialization were also covered. The review includes the ongoing and upcoming strategies viz. metabolic engineering, synthetic biology, morphology engineering, and automation to expand PHA diversity, diminish production costs, and improve PHA production with an objective of "zero-waste" and "circular bioeconomy" for a sustainable future.
Collapse
Affiliation(s)
- Lalit Goswami
- Department of Chemical Engineering, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | - Anamika Kushwaha
- Department of Chemical Engineering, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | | | - Beom Soo Kim
- Department of Chemical Engineering, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea.
| |
Collapse
|
8
|
Senba H, Nishikawa A, Kimura Y, Tanaka S, Matsumoto JI, Doi M, Takenaka S. Improvement in salt-tolerance of Aspergillus oryzae γ-glutamyl transpeptidase via protein chimerization with Aspergillus sydowii homolog. Enzyme Microb Technol 2023; 167:110240. [PMID: 37084614 DOI: 10.1016/j.enzmictec.2023.110240] [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: 03/01/2023] [Revised: 04/09/2023] [Accepted: 04/10/2023] [Indexed: 04/23/2023]
Abstract
γ-Glutamyl transpeptidase is one of the key enzymes involved in glutamate production during high-salt fermentation of soy sauce and miso by koji mold, Aspergillus oryzae. However, the activity of γ-glutamyl transpeptidase from A. oryzae (AOggtA) is markedly reduced in the presence of NaCl, thus classifying it as a non-salt-tolerant enzyme. In contrast, the homologous protein from the xerophilic mold, A. sydowii (ASggtA) maintains its activity under high-salt conditions. Therefore, in this study, a chimeric enzyme, ASAOggtA, was designed and engineered to improve salt-tolerance in AOggtA by swapping the N-terminal region, based on sequence and structure comparisons between salt-tolerant ASggtA and non-salt-tolerant AOggtA. The parental AOggtA and ASggtA and their chimera, ASAOggtA, were heterologously expressed in A. oryzae and purified. The chimeric enzyme inherited the superior activity and stability from each of the two parent enzymes. ASAOggtA showed > 2-fold greater tolerance than AOggtA in the presence of 18% NaCl. In addition, the chimera showed a broader range of pH stability and greater thermostability than ASggtA. AOggtA and ASAOggtA were sy over the range pH 3.0 to pH 10.5. Thermal stability was found to be in the order AOggtA (57.5 °C, t1/2 = 32.5 min) > ASAOggtA (55 °C, t1/2 = 20.5 min) > ASggtA (50 °C, t1/2 = 12.5 min). The catalytic and structural characteristics indicated that non-salt-tolerant AOggtA would not undergo irreversible structural changes in the presence of NaCl, but rather a temporary conformational change, which might result in reducing the substrate binding and catalytic activity, on the basis of kinetic properties. In addition, the chimeric enzyme showed hydrolytic activity toward L-glutamine that was as high as that of AOggtA. The newly-designed chimeric ASAOggtA might have potential applications in high-salt fermentation, such as miso and shoyu, to increase the content of the umami-flavor amino acid, L-glutamate.
Collapse
Affiliation(s)
- Hironori Senba
- Division of Agrobioscience, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan; Ozeki Corp, Gen Res Lab, 4-9 Imazu, Nishinomiya, Hyogo 6638227, Japan
| | - Arisa Nishikawa
- Division of Agrobioscience, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Yukihiro Kimura
- Division of Agrobioscience, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
| | - Shinichi Tanaka
- Marutomo Co., Ltd, 1696 Kominato, Iyo, Ehime 799-3192, Japan
| | | | - Mikiharu Doi
- Marutomo Co., Ltd, 1696 Kominato, Iyo, Ehime 799-3192, Japan
| | - Shinji Takenaka
- Division of Agrobioscience, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
| |
Collapse
|
9
|
Gao Q, Yang H, Wang C, Xie XY, Liu KX, Lin Y, Han SY, Zhu M, Neureiter M, Lin Y, Ye JW. Advances and trends in microbial production of polyhydroxyalkanoates and their building blocks. Front Bioeng Biotechnol 2022; 10:966598. [PMID: 35928942 PMCID: PMC9343942 DOI: 10.3389/fbioe.2022.966598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 07/01/2022] [Indexed: 11/13/2022] Open
Abstract
With the rapid development of synthetic biology, a variety of biopolymers can be obtained by recombinant microorganisms. Polyhydroxyalkanoates (PHA) is one of the most popular one with promising material properties, such as biodegradability and biocompatibility against the petrol-based plastics. This study reviews the recent studies focusing on the microbial synthesis of PHA, including chassis engineering, pathways engineering for various substrates utilization and PHA monomer synthesis, and PHA synthase modification. In particular, advances in metabolic engineering of dominant workhorses, for example Halomonas, Ralstonia eutropha, Escherichia coli and Pseudomonas, with outstanding PHA accumulation capability, were summarized and discussed, providing a full landscape of diverse PHA biosynthesis. Meanwhile, we also introduced the recent efforts focusing on structural analysis and mutagenesis of PHA synthase, which significantly determines the polymerization activity of varied monomer structures and PHA molecular weight. Besides, perspectives and solutions were thus proposed for achieving scale-up PHA of low cost with customized material property in the coming future.
Collapse
Affiliation(s)
- Qiang Gao
- Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, QH, China
| | - Hao Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Chi Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Xin-Ying Xie
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Kai-Xuan Liu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Ying Lin
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shuang-Yan Han
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Mingjun Zhu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Markus Neureiter
- Institute for Environmental Biotechnology, Department of Agrobiotechnology, University of Natural Resources and Life Sciences, Tulln, Austria
- *Correspondence: Markus Neureiter, ; Yina Lin, ; Jian-Wen Ye,
| | - Yina Lin
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
- *Correspondence: Markus Neureiter, ; Yina Lin, ; Jian-Wen Ye,
| | - Jian-Wen Ye
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
- *Correspondence: Markus Neureiter, ; Yina Lin, ; Jian-Wen Ye,
| |
Collapse
|
10
|
Satoh K, Kawakami T, Isobe N, Pasquier L, Tomita H, Zinn M, Matsumoto K. Versatile aliphatic polyester biosynthesis system for producing random and block copolymers composed of 2-, 3-, 4-, 5-, and 6-hydroxyalkanoates using the sequence-regulating polyhydroxyalkanoate synthase PhaC AR. Microb Cell Fact 2022; 21:84. [PMID: 35568875 PMCID: PMC9107728 DOI: 10.1186/s12934-022-01811-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/01/2022] [Indexed: 11/13/2022] Open
Abstract
Background Polyhydroxyalkanoates (PHAs) are microbial polyesters synthesized by PHA synthases. Naturally occurring PHA copolymers possess a random monomer sequence. The development of PhaCAR, a unique sequence-regulating PHA synthase, has enabled the spontaneous biosynthesis of PHA block copolymers. PhaCAR synthesizes both a block copolymer poly(2-hydroxybutyrate)-b-poly(3-hydroxybutyrate) [P(2HB)-b-P(3HB)], and a random copolymer, poly(3HB-co-3-hydroxyhexanoate), indicating that the combination of monomers determines the monomer sequence. Therefore, in this study, we explored the substrate scope of PhaCAR and the monomer sequences of the resulting copolymers to identify the determinants of the monomer sequence. PhaCAR is a class I PHA synthase that is thought to incorporate long-main-chain hydroxyalkanoates (LMC HAs, > C3 in the main [backbone] chain). Thus, the LMC monomers, 4-hydroxy-2-methylbutyrate (4H2MB), 5-hydroxyvalerate (5HV), and 6-hydroxyhexanoate (6HHx), as well as 2HB, 3HB, and 3-hydroxypropionate (3HP) were tested. Results Recombinant Escherichia coli harboring PhaCAR, CoA transferase and CoA ligase genes was used for PHA production. The medium contained the monomer precursors, 2HB, 3HB, 3HP, 4H2MB, 5HV, and 6HHx, either individually or in combination. As a result, homopolymers were obtained only for 3HB and 3HP. Moreover, 3HB and 3HP were randomly copolymerized by PhaCAR. 3HB-based binary copolymers P(3HB-co-LMC HA)s containing up to 2.9 mol% 4H2MB, 4.8 mol% 5HV, or 1.8 mol% 6HHx were produced. Differential scanning calorimetry analysis of the copolymers indicated that P(3HB-co-LMC HA)s had a random sequence. In contrast, combining 3HP and 2HB induced the synthesis of P(3HP)-b-P(2HB). Similarly, P(2HB) segment-containing block copolymers P(3HB-co-LMC HA)-b-P(2HB)s were synthesized. Binary copolymers of LMC HAs and 2HB were not obtained, indicating that the 3HB or 3HP unit is essential to the polymer synthesis. Conclusion PhaCAR possesses a wide substrate scope towards 2-, 3-, 4-, 5-, and 6-hydroxyalkanoates. 3HB or 3HP units are essential for polymer synthesis using PhaCAR. The presence of a 2HB monomer is key to synthesizing block copolymers, such as P(3HP)-b-P(2HB) and P(3HB-co-LMC HA)-b-P(2HB)s. The copolymers that did not contain 2HB units had a random sequence. This study’s results provide insights into the mechanism of sequence regulation by PhaCAR and pave the way for designing PHA block copolymers. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01811-7.
Collapse
Affiliation(s)
- Keigo Satoh
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, N13W8, Kitaku, Sapporo, 060-8628, Japan
| | - Tomoya Kawakami
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, N13W8, Kitaku, Sapporo, 060-8628, Japan
| | - Nagi Isobe
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, N13W8, Kitaku, Sapporo, 060-8628, Japan
| | - Loïc Pasquier
- Department of Engineering, Hokkaido University, N13W8, Kitaku, Sapporo, 060-8628, Japan.,Institute of Life Technologies, University of Applied Sciences and Arts Western Switzerland (HES-SO Valais-Wallis), Sion, Switzerland
| | - Hiroya Tomita
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, N13W8, Kitaku, Sapporo, 060-8628, 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, N13W8, Kitaku, Sapporo, 060-8628, Japan.
| |
Collapse
|
11
|
Tomita H, Satoh K, Nomura CT, Matsumoto K. Biosynthesis of poly(glycolate-co-3-hydroxybutyrate-co-3-hydroxyhexanoate) in Escherichia coli expressing sequence-regulating polyhydroxyalkanoate synthase and medium-chain-length 3-hydroxyalkanoic acid coenzyme A ligase. Biosci Biotechnol Biochem 2022; 86:217-223. [PMID: 34788370 DOI: 10.1093/bbb/zbab198] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022]
Abstract
Chimeric polyhydroxyalkanoate synthase PhaCAR is characterized by the capacity to incorporate unusual glycolate (GL) units and spontaneously synthesize block copolymers. The GL and 3-hydroxybutyrate (3HB) copolymer synthesized by PhaCAR is a random-homo block copolymer, poly(GL-ran-3HB)-b-poly(3HB). In the present study, medium-chain-length 3-hydroxyhexanoate (3HHx) units were incorporated into this copolymer using PhaCAR for the first time. The coenzyme A (CoA) ligase from Pseudomonas oleovorans (AlkK) serves as a simple 3HHx-CoA supplying route in Escherichia coli from exogenously supplemented 3HHx. NMR analyses of the obtained polymers revealed that 3HHx units were randomly connected to 3HB units, whereas GL units were heterogeneously distributed. Therefore, the polymer is composed of 2 segments: P(3HB-co-3HHx) and P(GL-co-3HB-co-3HHx). The thermal and mechanical properties of the terpolymer indicate no contiguous P(3HB) segments in the material, consistent with the NMR results. Therefore, PhaCAR synthesized the novel block copolymer P(3HB-co-3HHx)-b-P(GL-co-3HB-co-3HHx), which is the first block polyhydroxyalkanoate copolymer comprising 2 copolymer segments.
Collapse
Affiliation(s)
- Hiroya Tomita
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Kitaku, Sapporo, Japan
| | - Keigo Satoh
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kitaku, Sapporo, Japan
| | | | - Ken'ichiro Matsumoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Kitaku, Sapporo, Japan
| |
Collapse
|
12
|
Phan HT, Hosoe Y, Guex M, Tomoi M, Tomita H, Zinn M, Matsumoto K. Directed Evolution of Sequence-Regulating Polyhydroxyalkanoate Synthase to Synthesize a Medium-Chain-Length-Short-Chain-Length (MCL-SCL) Block Copolymer. Biomacromolecules 2022; 23:1221-1231. [PMID: 34991313 DOI: 10.1021/acs.biomac.1c01480] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Sequence-regulating polyhydroxyalkanoate synthase PhaCAR is a chimeric enzyme comprising PhaCs from Aeromonas caviae and Ralstonia eutropha (Cupriavidus necator). It spontaneously synthesizes a short-chain-length (SCL, ≤C5) block copolymer poly(2-hydroxybutyrate)-b-poly(3-hydroxybutyrate) [P(2HB)-b-P(3HB)] from a mixture of monomer substrates. In this study, directed evolution of PhaCAR was performed to increase its activity toward a medium-chain-length (MCL, C6-12) monomer, 3-hydroxyhexanoyl (3HHx)-coenzyme A (CoA). Random mutagenesis and selection based on P(3HB-co-3HHx) production in Escherichia coli found that beneficial mutations N149D and F314L increase the 3HHx fraction. The site-directed saturation mutagenesis at position 314, which is adjacent to the catalytic center C315, demonstrated that F314H synthesizes the P(3HHx) homopolymer. The F314H mutant exhibited increased activity toward 3HHx-CoA compared with the parent enzyme, whereas the activity toward 3HB-CoA decreased. The predicted tertiary structure of PhaCAR by AlphaFold2 provided insight into the mechanism of the beneficial mutations. In addition, this finding enabled the synthesis of a new PHA block copolymer, P(3HHx)-b-P(2HB). Solvent fractionation indicated the presence of a covalent linkage between the polymer segments. This novel MCL-SCL block copolymer considerably expands the range of the molecular design of PHA block copolymers.
Collapse
Affiliation(s)
- Hien Thi Phan
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Yumi Hosoe
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Maureen Guex
- Institute of Life Technologies, University of Applied Sciences and Arts Western Switzerland (HES-SO Valais-Wallis), 1950 Sion, Switzerland
| | - Masayoshi Tomoi
- Course of Applied Chemistry, Department of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Hiroya Tomita
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Manfred Zinn
- Institute of Life Technologies, University of Applied Sciences and Arts Western Switzerland (HES-SO Valais-Wallis), 1950 Sion, Switzerland
| | - Ken'ichiro Matsumoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| |
Collapse
|
13
|
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: 8] [Impact Index Per Article: 2.7] [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.
Collapse
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.
| |
Collapse
|
14
|
Silva JB, Pereira JR, Marreiros BC, Reis MA, Freitas F. Microbial production of medium-chain length polyhydroxyalkanoates. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.01.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
15
|
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).
Collapse
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
| |
Collapse
|
16
|
Choi SY, Cho IJ, Lee Y, Kim YJ, Kim KJ, Lee SY. Microbial Polyhydroxyalkanoates and Nonnatural Polyesters. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1907138. [PMID: 32249983 DOI: 10.1002/adma.201907138] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/20/2020] [Indexed: 06/11/2023]
Abstract
Microorganisms produce diverse polymers for various purposes such as storing genetic information, energy, and reducing power, and serving as structural materials and scaffolds. Among these polymers, polyhydroxyalkanoates (PHAs) are microbial polyesters synthesized and accumulated intracellularly as a storage material of carbon, energy, and reducing power under unfavorable growth conditions in the presence of excess carbon source. PHAs have attracted considerable attention for their wide range of applications in industrial and medical fields. Since the first discovery of PHA accumulating bacteria about 100 years ago, remarkable advances have been made in the understanding of PHA biosynthesis and metabolic engineering of microorganisms toward developing efficient PHA producers. Recently, nonnatural polyesters have also been synthesized by metabolically engineered microorganisms, which opened a new avenue toward sustainable production of more diverse plastics. Herein, the current state of PHAs and nonnatural polyesters is reviewed, covering mechanisms of microbial polyester biosynthesis, metabolic pathways, and enzymes involved in biosynthesis of short-chain-length PHAs, medium-chain-length PHAs, and nonnatural polyesters, especially 2-hydroxyacid-containing polyesters, metabolic engineering strategies to produce novel polymers and enhance production capabilities and fermentation, and downstream processing strategies for cost-effective production of these microbial polyesters. In addition, the applications of PHAs and prospects are discussed.
Collapse
Affiliation(s)
- So Young Choi
- Metabolic and Biomolecular Engineering National Research Laboratory, Systems Metabolic Engineering and Systems Healthcare 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), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - In Jin Cho
- Metabolic and Biomolecular Engineering National Research Laboratory, Systems Metabolic Engineering and Systems Healthcare 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), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Youngjoon Lee
- Metabolic and Biomolecular Engineering National Research Laboratory, Systems Metabolic Engineering and Systems Healthcare 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), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Yeo-Jin Kim
- School of Life Sciences (KNU Creative BioResearch Group), KNU Institute for Microorganisms, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, Republic of Korea
| | - Kyung-Jin Kim
- School of Life Sciences (KNU Creative BioResearch Group), KNU Institute for Microorganisms, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, Republic of Korea
| | - Sang Yup Lee
- Metabolic and Biomolecular Engineering National Research Laboratory, Systems Metabolic Engineering and Systems Healthcare 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), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
- BioProcess Engineering Research Center and Bioinformatics Research Center, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| |
Collapse
|
17
|
Cha D, Ha HS, Lee SK. Metabolic engineering of Pseudomonas putida for the production of various types of short-chain-length polyhydroxyalkanoates from levulinic acid. BIORESOURCE TECHNOLOGY 2020; 309:123332. [PMID: 32305015 DOI: 10.1016/j.biortech.2020.123332] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/01/2020] [Accepted: 04/03/2020] [Indexed: 06/11/2023]
Abstract
Poly(3-hydroxybutyrate), a short-chain-length polyhydroxyalkanoate (scl-PHA), is considered as a good alternative to conventional synthetic plastics. However, various biopolymers with diverse characteristics are still in demand. In this study, four different types of scl-PHA were successfully produced by engineering levulinic acid (LA) utilization metabolic pathway and expressing heterologous PHA synthase (PhaEC), acetyl-CoA acetyltransferase (PhaA), and acetyl-CoA reductase (PhaB) in Pseudomonas putida EM42. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)], poly(3-hydroxyvalerate-co-4-hydroxyvalerate) [P(3HV-co-4HV)] and poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxyvalerate) [P(3HB-co-3HV-co-4HV)] were produced by the natural LA pathway, poly(4-hydroxyvalerate) by lvaAB-deleted LA pathway, and P(3HV-co-4HV) and P(3HB-co-3HV-co-4HV) with relatively high 3HV by fadB-deleted LA pathway. PHA with different monomer fractions could be produced using different PHA synthases. Scl-PHA contents reached approximately 40% of cell dry mass under non-optimized flask culture. This demonstrates that the LA catabolic pathway may be a good alternative route to provide monomers for the production of various types of PHA.
Collapse
Affiliation(s)
- Daegeun Cha
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Hyo Seok Ha
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Sung Kuk Lee
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea; Department of Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea.
| |
Collapse
|
18
|
Synergy of valine and threonine supplementation on poly(2-hydroxybutyrate-block-3-hydroxybutyrate) synthesis in engineered Escherichia coli expressing chimeric polyhydroxyalkanoate synthase. J Biosci Bioeng 2019; 129:302-306. [PMID: 31635918 DOI: 10.1016/j.jbiosc.2019.09.018] [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] [Received: 08/06/2019] [Revised: 09/13/2019] [Accepted: 09/26/2019] [Indexed: 01/06/2023]
Abstract
The engineered chimeric polyhydroxyalkanoate (PHA) synthase PhaCAR is composed of N-terminal portion of Aeromonas caviae PHA synthase and C-terminal portion of Ralstonia eutropha (Cupriavidus necator) PHA synthase. PhaCAR has a unique and useful capacity to synthesize the block PHA copolymer poly(2-hydroxybutyrate-block-3-hydroxybutyrate) [P(2HB-b-3HB)] in engineered Escherichia coli from exogenous 2HB and 3HB. In the present study, we initially attempted to incorporate the amino acid-derived 2-hydroxyalkanoate (2HA) units using PhaCAR and the 2HA-CoA-supplying enzymes lactate dehydrogenase (LdhA) and CoA transferase (HadA). Cells harboring the genes for PhaCAR, LdhA, and HadA, as well as for the 3HB-CoA-supplying enzymes β-ketothiolase and acetoacetyl-CoA reductase, were cultivated with supplementation of four hydrophobic amino acids, i.e., leucine, valine (Val), isoleucine (Ile), and phenylalanine, in the medium. No hydrophobic amino acid-derived monomers were incorporated into the polymer, which was most likely because of the strict substrate specificity of PhaCAR; however, P(2HB-co-3HB) was unexpectedly produced with Val supplementation. The copolymer was likely P(2HB-b-3HB) based on proton nuclear magnetic resonance analysis. Based on the endogenous pathways in E. coli, 2HB units are likely derived from threonine (Thr) through deamination and dihydroxylation. In fact, dual supplementation with Thr and Val showed synergy on the 2HB fraction of the polymer. Val supplementation promoted the 2HB synthesis likely by inhibiting the metabolism of 2-ketobutyrate into Ile and/or activating Thr dehydratase. In conclusion, the LdhA/HadA/PhaCAR pathway served as the system for the synthesis of P(2HB-b-3HB) from biomass-derived carbon sources.
Collapse
|
19
|
Zheng Y, Chen JC, Ma YM, Chen GQ. Engineering biosynthesis of polyhydroxyalkanoates (PHA) for diversity and cost reduction. Metab Eng 2019; 58:82-93. [PMID: 31302223 DOI: 10.1016/j.ymben.2019.07.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 06/23/2019] [Accepted: 07/11/2019] [Indexed: 11/29/2022]
Abstract
PHA, a family of natural biopolymers aiming to replace non-degradable plastics for short-term usages, has been developed to include various structures such as short-chain-length (scl) and medium-chain-length (mcl) monomers as well as their copolymers. However, PHA market has been grown slowly since 1980s due to limited variety with good mechanical properties and the high production cost. Here, we review most updated strategies or approaches including metabolic engineering, synthetic biology and morphology engineering on expanding PHA diversity, reducing production cost and enhancing PHA production. The extremophilic Halomonas spp. are taken as examples to show the feasibility and challenges to develop next generation industrial biotechnology (NGIB) for producing PHA more competitively.
Collapse
Affiliation(s)
- Yang Zheng
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China; School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jin-Chun Chen
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China; School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yi-Ming Ma
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China; School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Guo-Qiang Chen
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China; School of Life Sciences, Tsinghua University, Beijing, 100084, China; Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China; Center for Nano- and Micro-Mechanics, Tsinghua University, Beijing, 100084, China; Dept of Chemical Engineering, Tsinghua University, Beijing, 100084, China.
| |
Collapse
|
20
|
Chek MF, Hiroe A, Hakoshima T, Sudesh K, Taguchi S. PHA synthase (PhaC): interpreting the functions of bioplastic-producing enzyme from a structural perspective. Appl Microbiol Biotechnol 2018; 103:1131-1141. [DOI: 10.1007/s00253-018-9538-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/20/2018] [Accepted: 11/22/2018] [Indexed: 02/07/2023]
|
21
|
Matsumoto K, Hori C, Fujii R, Takaya M, Ooba T, Ooi T, Isono T, Satoh T, Taguchi S. Dynamic Changes of Intracellular Monomer Levels Regulate Block Sequence of Polyhydroxyalkanoates in Engineered Escherichia coli. Biomacromolecules 2018; 19:662-671. [DOI: 10.1021/acs.biomac.7b01768] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Ken’ichiro Matsumoto
- Division of Applied Chemistry, Faculty
of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Chiaki Hori
- Division of Applied Chemistry, Faculty
of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Ryunosuke Fujii
- Division of Applied Chemistry, Faculty
of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Masahiro Takaya
- Division of Applied Chemistry, Faculty
of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Takashi Ooba
- Division of Applied Chemistry, Faculty
of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Toshihiko Ooi
- Division of Applied Chemistry, Faculty
of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Takuya Isono
- Division of Applied Chemistry, Faculty
of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Toshifumi Satoh
- Division of Applied Chemistry, Faculty
of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Seiichi Taguchi
- Division of Applied Chemistry, Faculty
of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| |
Collapse
|
22
|
Chen GQ, Hajnal I, Wu H, Lv L, Ye J. Engineering Biosynthesis Mechanisms for Diversifying Polyhydroxyalkanoates. Trends Biotechnol 2016; 33:565-574. [PMID: 26409776 DOI: 10.1016/j.tibtech.2015.07.007] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 07/24/2015] [Accepted: 07/30/2015] [Indexed: 11/15/2022]
Abstract
Polyhydroxyalkanoates (PHA) are a family of diverse biopolyesters synthesized by bacteria. PHA diversity, as reflected by its monomers, homopolymers, random and block copolymers, as well as functional polymers, can now be generated by engineering the three basic synthesis pathways including the acetoacetyl-CoA pathway, in situ fatty acid synthesis, and/or β-oxidation cycles, as well as PHA synthase specificity. It is now possible to tailor the PHA structures via genome editing or process engineering. The increasing PHA diversity and maturing PHA production technology should lead to more focused research into their low-cost and/or high-value applications.
Collapse
Affiliation(s)
- Guo-Qiang Chen
- Ministry of Education Key Lab of Bioinformatics, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Protein Therapeutics, Tsinghua University, Beijing 100084, China.
| | - Ivan Hajnal
- Ministry of Education Key Lab of Bioinformatics, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Hong Wu
- Ministry of Education Key Lab of Bioinformatics, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Li Lv
- Ministry of Education Key Lab of Bioinformatics, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jianwen Ye
- Ministry of Education Key Lab of Bioinformatics, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| |
Collapse
|
23
|
Contribution of the distal pocket residue to the acyl-chain-length specificity of (R)-specific enoyl-coenzyme A hydratases from Pseudomonas spp. Appl Environ Microbiol 2015; 81:8076-83. [PMID: 26386053 DOI: 10.1128/aem.02412-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 09/09/2015] [Indexed: 11/20/2022] Open
Abstract
(R)-Specific enoyl-coenzyme A (enoyl-CoA) hydratases (PhaJs) are capable of supplying monomers from fatty acid β-oxidation to polyhydroxyalkanoate (PHA) biosynthesis. PhaJ1Pp from Pseudomonas putida showed broader substrate specificity than did PhaJ1Pa from Pseudomonas aeruginosa, despite sharing 67% amino acid sequence identity. In this study, the substrate specificity characteristics of two Pseudomonas PhaJ1 enzymes were investigated by site-directed mutagenesis, chimeragenesis, X-ray crystallographic analysis, and homology modeling. In PhaJ1Pp, the replacement of valine with isoleucine at position 72 resulted in an increased preference for enoyl-coenzyme A (CoA) elements with shorter chain lengths. Conversely, at the same position in PhaJ1Pa, the replacement of isoleucine with valine resulted in an increased preference for enoyl-CoAs with longer chain lengths. These changes suggest a narrowing and broadening in the substrate specificity range of the PhaJ1Pp and PhaJ1Pa mutants, respectively. However, the substrate specificity remains broader in PhaJ1Pp than in PhaJ1Pa. Additionally, three chimeric PhaJ1 enzymes, composed from PhaJ1Pp and PhaJ1Pa, all showed significant hydratase activity, and their substrate preferences were within the range exhibited by the parental PhaJ1 enzymes. The crystal structure of PhaJ1Pa was determined at a resolution of 1.7 Å, and subsequent homology modeling of PhaJ1Pp revealed that in the acyl-chain binding pocket, the amino acid at position 72 was the only difference between the two structures. These results indicate that the chain-length specificity of PhaJ1 is determined mainly by the bulkiness of the amino acid residue at position 72, but that other factors, such as structural fluctuations, also affect specificity.
Collapse
|
24
|
Leong YK, Show PL, Ooi CW, Ling TC, Lan JCW. Current trends in polyhydroxyalkanoates (PHAs) biosynthesis: Insights from the recombinant Escherichia coli. J Biotechnol 2014; 180:52-65. [DOI: 10.1016/j.jbiotec.2014.03.020] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 03/03/2014] [Accepted: 03/11/2014] [Indexed: 10/25/2022]
|
25
|
Production of P(3-hydroxybutyrate-co-3-hydroxyhexanoate-co-3-hydroxyoctanoate) Terpolymers Using a Chimeric PHA Synthase in RecombinantRalstonia eutrophaandPseudomonas putida. Biosci Biotechnol Biochem 2014; 74:1716-8. [DOI: 10.1271/bbb.100242] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
26
|
Theodorou EC, Theodorou MC, Kyriakidis DA. Regulation of poly-(R)-(3-hydroxybutyrate-co-3-hydroxyvalerate) biosynthesis by the AtoSCDAEB regulon in phaCAB+ Escherichia coli. Appl Microbiol Biotechnol 2013; 97:5259-74. [PMID: 23546423 DOI: 10.1007/s00253-013-4843-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/06/2013] [Accepted: 03/07/2013] [Indexed: 11/28/2022]
Abstract
AtoSC two-component system (TCS) upregulates the high-molecular weight poly-(R)-3-hydroxybutyrate (PHB) biosynthesis in recombinant phaCAB (+) Escherichia coli strains, with the Cupriavidus necator phaCAB operon. We report here that AtoSC upregulates also the copolymer P(3HB-co-3HV) biosynthesis in phaCAB (+) E. coli. Acetoacetate-induced AtoSC maximized P(3HB-co-3HV) to 1.27 g/l with a 3HV fraction of 25.5 % wt. and biopolymer content of 75 % w/w in a time-dependent process. The atoSC locus deletion in the ∆atoSC strains resulted in 4.5-fold P(3HB-co-3HV) reduction, while the 3HV fraction of the copolymer was restricted to only 6.4 % wt. The ∆atoSC phenotype was restored by extrachromosomal introduction of AtoSC. Deletion of the atoDAEB operon triggered a significant decrease in P(3HB-co-3HV) synthesis and 3HV content in ∆atoDAEB strains. However, the acetoacetate-induced AtoSC in those strains increased P(3HB-co-3HV) to 0.8 g/l with 21 % 3HV, while AtoC or AtoS expression increased P(3HB-co-3HV) synthesis 3.6- or 2.4-fold, respectively, upon acetoacetate. Complementation of the ∆atoDAEB phenotype was achieved by the extrachromosomal introduction of the atoSCDAEB regulon. Individual inhibition of β-oxidation and mainly fatty acid biosynthesis pathways by acrylic acid or cerulenin, respectively, reduced P(3HB-co-3HV) biosynthesis. Under those conditions, introduction of atoSC or atoSCDAEB regulon was capable of upregulating biopolymer accumulation. Concurrent inhibition of both the fatty acid metabolic pathways eliminated P(3HB-co-3HV) production. P(3HB-co-3HV) upregulation in phaCAB (+) E. coli by AtoSC signaling through atoDAEB operon and its participation in the fatty acids metabolism interplay provide additional perceptions of AtoSC critical involvement in E. coli regulatory processes towards biotechnologically improved polyhydroxyalkanoates biosynthesis.
Collapse
Affiliation(s)
- Evangelos C Theodorou
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR-54124, Greece.
| | | | | |
Collapse
|
27
|
Gao X, Yuan XX, Shi ZY, Guo YY, Shen XW, Chen JC, Wu Q, Chen GQ. Production of copolyesters of 3-hydroxybutyrate and medium-chain-length 3-hydroxyalkanoates by E. coli containing an optimized PHA synthase gene. Microb Cell Fact 2012; 11:130. [PMID: 22978778 PMCID: PMC3503839 DOI: 10.1186/1475-2859-11-130] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Accepted: 09/12/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Microbial polyhydroxyalkanoates (PHA) are biopolyesters consisting of diverse monomers. PHA synthase PhaC2Ps cloned from Pseudomonas stutzeri 1317 is able to polymerize short-chain-length (scl) 3-hydroxybutyrate (3HB) monomers and medium-chain-length (mcl) 3-hydroxyalkanoates (3HA) with carbon chain lengths ranging from C6 to C12. However, the scl and mcl PHA production in Escherichia coli expressing PhaC2Ps is limited with very low PHA yield. RESULTS To improve the production of PHA with a wide range of monomer compositions in E. coli, a series of optimization strategies were applied on the PHA synthase PhaC2Ps. Codon optimization of the gene and mRNA stabilization with a hairpin structure were conducted and the function of the optimized PHA synthase was tested in E. coli. The transcript was more stable after the hairpin structure was introduced, and western blot analysis showed that both codon optimization and hairpin introduction increased the protein expression level. Compared with the wild type PhaC2Ps, the optimized PhaC2Ps increased poly-3-hydroxybutyrate (PHB) production by approximately 16-fold to 30% of the cell dry weight. When grown on dodecanoate, the recombinant E. coli harboring the optimized gene phaC2PsO with a hairpin structure in the 5' untranslated region was able to synthesize 4-fold more PHA consisting of 3HB and medium-chain-length 3HA compared to the recombinant harboring the wild type phaC2Ps. CONCLUSIONS The levels of both PHB and scl-mcl PHA in E. coli were significantly increased by series of optimization strategies applied on PHA synthase PhaC2Ps. These results indicate that strategies including codon optimization and mRNA stabilization are useful for heterologous PHA synthase expression and therefore enhance PHA production.
Collapse
Affiliation(s)
- Xue Gao
- MOE Key Lab of Bioinformatics, Department of Biological Science and Biotechnology, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Ochi A, Matsumoto K, Ooba T, Sakai K, Tsuge T, Taguchi S. Engineering of class I lactate-polymerizing polyhydroxyalkanoate synthases from Ralstonia eutropha that synthesize lactate-based polyester with a block nature. Appl Microbiol Biotechnol 2012; 97:3441-7. [PMID: 22801709 DOI: 10.1007/s00253-012-4231-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 06/05/2012] [Accepted: 06/05/2012] [Indexed: 10/28/2022]
Abstract
Class I polyhydroxyalkanoate (PHA) synthase from Ralstonia eutropha (PhaCRe) was engineered so as to acquire an unusual lactate (LA)-polymerizing activity. To achieve this, the site-directed saturation mutagenesis of PhaCRe was conducted at position 510, which corresponds to position 481 in the initially discovered class II LA-polymerizing PHA synthase (PhaC1PsSTQK), a mutation in which (Gln481Lys) was shown to be essential to its LA-polymerizing activity (Taguchi et al., Proc Natl Acad Sci USA 105(45):17323-17327, 2008). The LA-polymerizing activity of the PhaCReA510X mutants was evaluated based on the incorporation of LA units into the P[3-hydroxybutyrate(3HB)] backbone in vivo using recombinant Escherichia coli LS5218. Among 19 PhaCRe(A510X) mutants, 15 synthesized P (LA-co-3HB), indicating that the 510 residue plays a critical role in LA polymerization. The polymer synthesized by PhaCReA510S was fractionated using gel permeation chromatography in order to remove the low molecular weight fractions. The (13)C and (1)H NMR analyses of the high molecular weight fraction revealed that the polymer was a P(7 mol% LA-co-3HB) copolymer with a weight-averaged molecular weight of 3.2 × 10(5) Da. Interestingly, the polymer contained an unexpectedly high ratio of an LA-LA -LA triad sequence, suggesting that the polymer synthesized by PhaCRe mutant may not be a random copolymer, but presumably had a block sequence.
Collapse
Affiliation(s)
- Anna Ochi
- Division of Biotechnology and Molecular Chemistry, Graduate School of Engineering, Hokkaido University, N13-W8, Kita-ku, Sapporo 060-8628, Japan
| | | | | | | | | | | |
Collapse
|
29
|
Theodorou EC, Theodorou MC, Kyriakidis DA. Involvement of the AtoSCDAEB regulon in the high molecular weight poly-(R)-3-hydroxybutyrate biosynthesis in phaCAB+ Escherichia coli. Metab Eng 2012; 14:354-65. [DOI: 10.1016/j.ymben.2012.03.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 03/14/2012] [Accepted: 03/19/2012] [Indexed: 11/16/2022]
|
30
|
Wang Q, Xia Y, Chen Q, Qi Q. Incremental truncation of PHA synthases results in altered product specificity. Enzyme Microb Technol 2012; 50:293-7. [DOI: 10.1016/j.enzmictec.2012.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 02/16/2012] [Accepted: 02/18/2012] [Indexed: 10/28/2022]
|
31
|
Nduko JM, Matsumoto K, Taguchi S. Biological Lactate-Polymers Synthesized by One-Pot Microbial Factory: Enzyme and Metabolic Engineering. ACS SYMPOSIUM SERIES 2012. [DOI: 10.1021/bk-2012-1105.ch014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- John Masani Nduko
- Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Ken’ichiro Matsumoto
- Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Seiichi Taguchi
- Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| |
Collapse
|
32
|
Current advances in microbial cell factories for lactate-based polyesters driven by lactate-polymerizing enzymes: Towards the further creation of new LA-based polyesters. Polym Degrad Stab 2010. [DOI: 10.1016/j.polymdegradstab.2010.01.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
33
|
Enzymatic and whole-cell synthesis of lactate-containing polyesters: toward the complete biological production of polylactate. Appl Microbiol Biotechnol 2009; 85:921-32. [DOI: 10.1007/s00253-009-2374-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 11/18/2009] [Accepted: 11/18/2009] [Indexed: 10/20/2022]
|