101
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Shen L, Hu H, Ji H, Zhang C, He N, Li Q, Wang Y. Production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from excess activated sludge as a promising substitute of pure culture. BIORESOURCE TECHNOLOGY 2015; 189:236-242. [PMID: 25898084 DOI: 10.1016/j.biortech.2015.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 03/31/2015] [Accepted: 04/02/2015] [Indexed: 06/04/2023]
Abstract
This study aimed to investigate the feasibility and technology to harvest poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) by mixed culture. Copolymer PHBHHx, usually fermented by pure strains, was reported to be synthesized from activated sludge for the first time. Sodium laurate was used as the sole carbon substrate for sludge acclimation and PHBHHx accumulation. Batch experiments were designed to look into the impact of the carbon, nitrogen, phosphorus and oxygen supply on PHBHHx production. The results showed that the acclimated excess sludge was able to produce PHBHHx, and the maximum output (505.6 mg/L PHBHHx containing 6.34 mol% HHx) was achieved with conditions of the continuous aeration, nitrogen and phosphorus limitation, and adequate carbon source implemented by pulse feeding 0.5 g/L sodium laurate every 4h. Moreover, composition and structure of the PHBHHx from sludge were found similar to that from pure culture, according to literature, FTIR and NMR spectra. Finally, high-throughput sequencing technique characterized that phylum Chlorobi and genus Leadbetterella should be critical groups for PHBHHx synthesis in the sludge community.
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Affiliation(s)
- Liang Shen
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Hongyou Hu
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Hongfang Ji
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Chuanpan Zhang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Ning He
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Qingbiao Li
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Yuanpeng Wang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China.
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102
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New Insight into the Role of the Calvin Cycle: Reutilization of CO2 Emitted through Sugar Degradation. Sci Rep 2015; 5:11617. [PMID: 26130086 PMCID: PMC4486974 DOI: 10.1038/srep11617] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/01/2015] [Indexed: 01/25/2023] Open
Abstract
Ralstonia eutropha is a facultative chemolithoautotrophic bacterium that uses the Calvin–Benson–Bassham (CBB) cycle for CO2 fixation. This study showed that R. eutropha strain H16G incorporated 13CO2, emitted by the oxidative decarboxylation of [1-13C1]-glucose, into key metabolites of the CBB cycle and finally into poly(3-hydroxybutyrate) [P(3HB)] with up to 5.6% 13C abundance. The carbon yield of P(3HB) produced from glucose by the strain H16G was 1.2 times higher than that by the CBB cycle-inactivated mutants, in agreement with the possible fixation of CO2 estimated from the balance of energy and reducing equivalents through sugar degradation integrated with the CBB cycle. The results proved that the ‘gratuitously’ functional CBB cycle in R. eutropha under aerobic heterotrophic conditions participated in the reutilization of CO2 emitted during sugar degradation, leading to an advantage expressed as increased carbon yield of the storage compound. This is a new insight into the role of the CBB cycle, and may be applicable for more efficient utilization of biomass resources.
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103
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Application of a non-halogenated solvent, methyl ethyl ketone (MEK) for recovery of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB-co-HV)] from bacterial cells. BIOTECHNOL BIOPROC E 2015. [DOI: 10.1007/s12257-014-0546-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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104
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Sato S, Maruyama H, Fujiki T, Matsumoto K. Regulation of 3-hydroxyhexanoate composition in PHBH synthesized by recombinant Cupriavidus necator H16 from plant oil by using butyrate as a co-substrate. J Biosci Bioeng 2015; 120:246-51. [PMID: 25805434 DOI: 10.1016/j.jbiosc.2015.01.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 01/13/2015] [Accepted: 01/19/2015] [Indexed: 11/29/2022]
Abstract
A (R)-3-hydroxyhexanoate (3HH) composition-regulating technology for poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) production was developed using recombinant Cupriavidus necator H16 with butyrate as a co-substrate. A new (R)-3-hydroxyhexanoyl-CoA ((R)-3HH-CoA) synthesis pathway was designed and enhanced by replacing the PHA synthase gene (phaC1) of C. necator by the phaCAcNSDG (encoding the N149S and D171G mutant of PHA synthase from Aeromonas caviae) and deactivation of the phaA gene (encoding (β-ketothiolase) from C. necator H16 chromosome). The effect of butyrate as co-substrate was assessed in high-cell-density fed-batch cultures of several C. necator mutants, and the 3HH fraction was successfully increased by adding butyrate to the culture. Moreover, overexpression of BktB (encoding the second β-ketothiolase with broad substrate specificity) enhanced the (R)-3HH-CoA synthesis pathway in the phaA deactivated mutant of C. necator by promoting the condensation of acetyl-CoA and butyryl-CoA into 3-ketohexanoyl-CoA. Consequently, PHBH containing 4.2-13.0 mol% 3HH was produced from butyrate and palm kernel oil by the genetically modified C. necator H16 strains.
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Affiliation(s)
- Shunsuke Sato
- GP Business Development Division, Kaneka Corporation, 1-8 Miyamae-machi, Takasago-cho, Takasago, Hyogo 676-8688, Japan.
| | - Hiroyuki Maruyama
- GP Business Development Division, Kaneka Corporation, 1-8 Miyamae-machi, Takasago-cho, Takasago, Hyogo 676-8688, Japan
| | - Tetsuya Fujiki
- GP Business Development Division, Kaneka Corporation, 1-8 Miyamae-machi, Takasago-cho, Takasago, Hyogo 676-8688, Japan
| | - Keiji Matsumoto
- GP Business Development Division, Kaneka Corporation, 1-8 Miyamae-machi, Takasago-cho, Takasago, Hyogo 676-8688, Japan
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105
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Heinrich D, Raberg M, Steinbüchel A. Synthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from unrelated carbon sources in engineered Rhodospirillum rubrum. FEMS Microbiol Lett 2015; 362:fnv038. [PMID: 25761750 DOI: 10.1093/femsle/fnv038] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2015] [Indexed: 11/12/2022] Open
Abstract
Different genes encoding pyridine nucleotide transhydrogenases (pntAB, udhA) and acetoacetyl-CoA reductases (phaB) were heterologously overexpressed in Rhodospirillum rubrum S1. A recombinant strain, which harbored the gene encoding the membrane-bound transhydrogenase PntAB from Escherichia coli MG1655 and the phaB1 gene coding for an NADPH-dependent acetoacetyl-CoA reductase from Ralstonia eutropha H16, accumulated poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [Poly(3HB-co-3HV)] with a 3HV fraction of up to 13 mol% from fructose. This was a 13-fold increase of the 3HV content when compared to the wild-type strain. Higher contents of 3HV are known to reduce the brittleness of this polymer, which is advantageous for most applications. The engineered R. rubrum strain was also able to synthesize this industrially relevant copolymer from CO2 and CO from artificial synthesis gas (syngas) with a 3HV content of 56 mol%. The increased incorporation of 3HV was attributed to an excess of propionyl-CoA, which was generated from threonine and related amino acids to compensate for the intracellular redox imbalance resulting from the transhydrogenase reaction. Thereby, our study presents a novel, molecular approach to alter the composition of bacterial PHAs independently from external precursor supply. Moreover, this study also provides a promising production strain for syngas-derived second-generation biopolymers.
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Affiliation(s)
- Daniel Heinrich
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, D-48149 Münster, Germany
| | - Matthias Raberg
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, D-48149 Münster, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, D-48149 Münster, Germany; Environmental Sciences Department, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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106
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Huschner F, Grousseau E, Brigham CJ, Plassmeier J, Popovic M, Rha C, Sinskey AJ. Development of a feeding strategy for high cell and PHA density fed-batch fermentation of Ralstonia eutropha H16 from organic acids and their salts. Process Biochem 2015. [DOI: 10.1016/j.procbio.2014.12.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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107
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Engineering of Escherichia coli for the biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from glucose. Appl Microbiol Biotechnol 2015; 99:2593-602. [PMID: 25586585 DOI: 10.1007/s00253-015-6380-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 12/28/2014] [Accepted: 12/31/2014] [Indexed: 12/28/2022]
Abstract
The copolymer poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(HB-co-HHx)] has the potential to serve as a biodegradable tissue engineering material. However, the production of this kind of copolymer still suffers from high cost and uncertainty. We describe here the design of metabolic pathways to synthesize P(HB-co-HHx) directly from glucose using recombinant Escherichia coli. By combining the BktB-dependent condensation pathway with the inverted β-oxidation cycle pathway, we were able to synthesize a P(HB-co-HHx) copolymer with a 10 mol% HHx fraction in recombinant E. coli. After optimizing the host strain and employing thioesterase mutant strains, the engineered E. coli produced 12.9 wt% P(HB-co-HHx) with a 13.2 mol% 3HHx fraction.
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108
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Gruber S, Hagen J, Schwab H, Koefinger P. Reprint of “Versatile and stable vectors for efficient gene expression in Ralstonia eutropha H16”. J Biotechnol 2014; 192 Pt B:410-8. [DOI: 10.1016/j.jbiotec.2014.09.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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109
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Insomphun C, Xie H, Mifune J, Kawashima Y, Orita I, Nakamura S, Fukui T. Improved artificial pathway for biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) with high C6-monomer composition from fructose in Ralstonia eutropha. Metab Eng 2014; 27:38-45. [PMID: 25446974 DOI: 10.1016/j.ymben.2014.10.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 09/25/2014] [Accepted: 10/06/2014] [Indexed: 02/06/2023]
Abstract
Poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) [P(3HB-co-3HHx)], a flexible and practical kind of polyhydroxyalkanoates, is generally produced from plant oils and fatty acids by several wild and recombinant bacteria. This study established an improved artificial pathway for the biosynthesis of P(3HB-co-3HHx) with high 3HHx composition from structurally unrelated fructose in Ralstonia eutropha. Depression of (R)-specific reduction of acetoacetyl-CoA by the deletion of phaB1 was an effective modification for formation of the C6-monomer unit from fructose driven by crotonyl-CoA carboxylase/reductase (Ccr). Co-overexpression of phaJ4a, which encodes medium-chain-length (R)-enoyl-CoA hydratase, with ccr promoted the incorporation of both 3HB and 3HHx units. Further introduction of emdMm, a synthetic gene encoding ethylmalonyl-CoA decarboxylase derived from mouse, was remarkably effective for P(3HB-co-3HHx) biosynthesis, probably by converting ethylmalonyl-CoA generated by the reductive carboxylase activity of Ccr back into butyryl-CoA. A high cellular content of P(3HB-co-3HHx) composed of 22mol% 3HHx could be produced from fructose by the engineered strain of R. eutropha with ΔphaB1 genotype expressing ccr, phaJ4a, and emd.
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Affiliation(s)
- Chayatip Insomphun
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Huan Xie
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Jun Mifune
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Yui Kawashima
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Izumi Orita
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Satoshi Nakamura
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Toshiaki Fukui
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
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110
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Gruber S, Hagen J, Schwab H, Koefinger P. Versatile and stable vectors for efficient gene expression in Ralstonia eutropha H16. J Biotechnol 2014; 186:74-82. [DOI: 10.1016/j.jbiotec.2014.06.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 06/11/2014] [Accepted: 06/25/2014] [Indexed: 10/25/2022]
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111
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Biazar E. Polyhydroxyalkanoates as Potential Biomaterials for Neural Tissue Regeneration. INT J POLYM MATER PO 2014. [DOI: 10.1080/00914037.2014.886227] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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112
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Fukui T, Mukoyama M, Orita I, Nakamura S. Enhancement of glycerol utilization ability of Ralstonia eutropha H16 for production of polyhydroxyalkanoates. Appl Microbiol Biotechnol 2014; 98:7559-68. [PMID: 24878751 DOI: 10.1007/s00253-014-5831-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 05/13/2014] [Accepted: 05/13/2014] [Indexed: 11/25/2022]
Abstract
Ralstonia eutropha H16 is a well-studied bacterium with respect to biosynthesis of polyhydroxyalkanoates (PHAs), which has attracted attentions as biodegradable bio-based plastics. However, this strain shows quite poor growth on glycerol of which bulk supply has been increasing as a major by-product of biodiesel industries. This study examined enhancement of glycerol assimilation ability of R. eutropha H16 by introduction of the genes of aquaglyceroporin (glpF) and glycerol kinase (glpK) from Escherichia coli. Although introduction of glpFK Ec into the strain H16 using a multi-copy vector was not successful, a recombinant strain possessing glpFK Ec within the chromosome showed much faster growth on glycerol than H16. Further analyses clarified that weak expression of glpK Ec alone allowed to establish efficient glycerol assimilation pathway, indicating that the poor growth of H16 on glycerol was caused by insufficient kination activity to glycerol, as well as this strain had a potential ability for uptake of extracellular glycerol. The engineered strains expressing glpFK Ec or glpK Ec produced large amounts of poly[(R)-3-hydroxybutyrate] [P(3HB)] from glycerol with much higher productivity than H16. Unlike other glycerol-utilizable wild strains of R. eutropha, the H16-derived engineered strains accumulated P(3HB) with no significant decrease in molecular weights on glycerol, and the polydispersity index of the glycerol-based P(3HB) synthesized by the strains expressing glpFK Ec was lower than those by the parent strains. The present study demonstrated possibility of R. eutropha H16-based platform for production of useful compounds from inexpensive glycerol.
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Affiliation(s)
- Toshiaki Fukui
- Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan,
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113
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Jeon JM, Brigham CJ, Kim YH, Kim HJ, Yi DH, Kim H, Rha C, Sinskey AJ, Yang YH. Biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(HB-co-HHx)) from butyrate using engineered Ralstonia eutropha. Appl Microbiol Biotechnol 2014; 98:5461-9. [DOI: 10.1007/s00253-014-5617-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/11/2014] [Accepted: 02/11/2014] [Indexed: 12/23/2022]
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114
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Isopropanol production with engineered Cupriavidus necator as bioproduction platform. Appl Microbiol Biotechnol 2014; 98:4277-90. [DOI: 10.1007/s00253-014-5591-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/04/2014] [Accepted: 02/04/2014] [Indexed: 10/25/2022]
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115
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Gai CS, Lu J, Brigham CJ, Bernardi AC, Sinskey AJ. Insights into bacterial CO2 metabolism revealed by the characterization of four carbonic anhydrases in Ralstonia eutropha H16. AMB Express 2014; 4:2. [PMID: 24410804 PMCID: PMC3904209 DOI: 10.1186/2191-0855-4-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 12/23/2013] [Indexed: 11/17/2022] Open
Abstract
Carbonic anhydrase (CA) enzymes catalyze the interconversion of CO2 and bicarbonate. These enzymes play important roles in cellular metabolism, CO2 transport, ion transport, and internal pH regulation. Understanding the metabolic role of CAs in the chemolithoautotropic bacterium Ralstonia eutropha is important for the development of high performance fermentation processes based on the bacterium’s capability to fix carbon using the Calvin-Benson-Bassham (CBB) cycle. Analysis of the R. eutropha H16 genome sequence revealed the presence of four CA genes: can, can2, caa and cag. We evaluated the importance of each of the CAs in the metabolism of R. eutropha by examination of growth and enzyme activity in gene deletion, complementation, and overexpression strains. All four purified CAs were capable of performing the interconversion of CO2 and HCO3–, although the equilibrium towards the formation of CO2 or HCO3– differs with each CA. Deletion of can, encoding a β-CA, affected the growth of R. eutropha; however the growth defect could be compensated by adding CO2 to the culture. Deletion of the caa, encoding an α-CA, had the strongest deleterious influence on cell growth. Strains with deletion or overexpression of can2 or cag genes exhibited similar behavior to wild type under most of the conditions tested. In this work, Caa was studied in greater detail using microscopy and complementation experiments, which helped confirm its periplasmic localization and determine its importance for robust growth of R. eutropha. A hypothesis for the coordinated role of these four enzymes in the metabolism of R. eutropha is proposed.
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116
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Ternon C, Grousseau E, Gunther J, Gorret N, Guillouet S, Sinskey A, Aceves-Lara C, Roux G. Dynamic model for isopropanol production by Cupriavidus necator. ACTA ACUST UNITED AC 2014. [DOI: 10.3182/20140824-6-za-1003.02267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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117
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Riedel SL, Lu J, Stahl U, Brigham CJ. Lipid and fatty acid metabolism in Ralstonia eutropha: relevance for the biotechnological production of value-added products. Appl Microbiol Biotechnol 2013; 98:1469-83. [PMID: 24343766 DOI: 10.1007/s00253-013-5430-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 11/21/2013] [Accepted: 11/22/2013] [Indexed: 11/27/2022]
Abstract
Lipid and fatty acid metabolism has been well studied in model microbial organisms like Escherichia coli and Bacillus subtilis. The major precursor of fatty acid biosynthesis is also the major product of fatty acid degradation (β-oxidation), acetyl-CoA, which is a key metabolite for all organisms. Controlling carbon flux to fatty acid biosynthesis and from β-oxidation allows for the biosynthesis of natural products of biotechnological importance. Ralstonia eutropha can utilize acetyl-CoA from fatty acid metabolism to produce intracellular polyhydroxyalkanoate (PHA). R. eutropha can also be engineered to utilize fatty acid metabolism intermediates to produce different PHA precursors. Metabolism of lipids and fatty acids can be rerouted to convert carbon into other value-added compounds like biofuels. This review discusses the lipid and fatty acid metabolic pathways in R. eutropha and how they can be used to construct reagents for the biosynthesis of products of industrial importance. Specifically, how the use of lipids or fatty acids as the sole carbon source in R. eutropha cultures adds value to these biotechnological products will be discussed here.
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Affiliation(s)
- Sebastian L Riedel
- Department of Applied and Molecular Microbiology, Technische Universität Berlin, Seestr. 13, 13353, Berlin, Germany
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118
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Construction of a stable plasmid vector for industrial production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) by a recombinant Cupriavidus necator H16 strain. J Biosci Bioeng 2013; 116:677-81. [DOI: 10.1016/j.jbiosc.2013.05.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/15/2013] [Accepted: 05/19/2013] [Indexed: 11/30/2022]
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119
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Pathway and protein engineering approaches to produce novel and commodity small molecules. Curr Opin Biotechnol 2013; 24:1137-43. [DOI: 10.1016/j.copbio.2013.02.019] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 02/07/2013] [Accepted: 02/20/2013] [Indexed: 11/19/2022]
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120
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Yang JE, Choi SY, Shin JH, Park SJ, Lee SY. Microbial production of lactate-containing polyesters. Microb Biotechnol 2013; 6:621-36. [PMID: 23718266 PMCID: PMC3815930 DOI: 10.1111/1751-7915.12066] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 04/19/2013] [Accepted: 04/22/2013] [Indexed: 12/31/2022] Open
Abstract
Due to our increasing concerns on environmental problems and limited fossil resources, biobased production of chemicals and materials through biorefinery has been attracting much attention. Optimization of the metabolic performance of microorganisms, the key biocatalysts for the efficient production of the desired target bioproducts, has been achieved by metabolic engineering. Metabolic engineering allowed more efficient production of polyhydroxyalkanoates, a family of microbial polyesters. More recently, non-natural polyesters containing lactate as a monomer have also been produced by one-step fermentation of engineered bacteria. Systems metabolic engineering integrating traditional metabolic engineering with systems biology, synthetic biology, protein/enzyme engineering through directed evolution and structural design, and evolutionary engineering, enabled microorganisms to efficiently produce natural and non-natural products. Here, we review the strategies for the metabolic engineering of microorganisms for the in vivo biosynthesis of lactate-containing polyesters and for the optimization of whole cell metabolism to efficiently produce lactate-containing polyesters. Also, major problems to be solved to further enhance the production of lactate-containing polyesters are discussed.
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Affiliation(s)
- Jung Eun Yang
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Program), Center for Systems and Synthetic Biotechnology, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
- Institute for the BioCentury, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - So Young Choi
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Program), Center for Systems and Synthetic Biotechnology, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
- Institute for the BioCentury, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - Jae Ho Shin
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Program), Center for Systems and Synthetic Biotechnology, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
- Institute for the BioCentury, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
| | - Si Jae Park
- Department of Environmental Engineering and Energy (Undergraduate program), Myongji UniversitySan 38-2, Nam-dong, Cheoin-gu, Yongin-si, Gyeonggido, 449-728, Korea
- Department of Energy Science and Technology (Graduate program), Myongji UniversitySan 38-2, Nam-dong, Cheoin-gu, Yongin-si, Gyeonggido, 449-728, Korea
| | - Sang Yup Lee
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Program), Center for Systems and Synthetic Biotechnology, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
- Institute for the BioCentury, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
- Department of Bio and Brain Engineering, Department of Biological Sciences, BioProcess Engineering Research Center, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
- Bioinformatics Research Center, KAIST291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea
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121
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Metabolic engineering of Ralstonia eutropha for the biosynthesis of 2-hydroxyacid-containing polyhydroxyalkanoates. Metab Eng 2013; 20:20-8. [DOI: 10.1016/j.ymben.2013.08.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Revised: 07/20/2013] [Accepted: 08/14/2013] [Indexed: 01/22/2023]
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122
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Modification of β-oxidation pathway in Ralstonia eutropha for production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from soybean oil. J Biosci Bioeng 2013; 117:184-190. [PMID: 23999062 DOI: 10.1016/j.jbiosc.2013.07.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/16/2013] [Accepted: 07/31/2013] [Indexed: 11/22/2022]
Abstract
Ralstonia eutropha H16 is a useful platform for metabolic engineering aiming at efficient production of polyhydroxyalkanaotes being attracted as practical bioplastics. This study focused on bifunctional (S)-specific 2-enoyl-CoA hydratase/(S)-3-hydroxyacyl-CoA dehydrogenase encoded by fadB to obtain information regarding β-oxidation in this bacterium and to achieve compositional regulation of poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) [P(3HB-co-3HHx)] synthesized from soybean oil. In addition to two FadB homologs (FadB1 and FadB') encoded within the previously identified β-oxidation gene clusters on the chromosome 1, a gene of third homolog (FadB2) was found on chromosome 2 of R. eutropha. The fadB homologs were disrupted in R. eutropha strain NSDG expressing a mutant gene of PHA synthase from Aeromonas caviae. The gene disruptions affected neither growth nor PHA production on fructose. On soybean oil, fadB' deletion led to reduction of PHA quantity attributed to decrease of 3HB unit, while fadB1 deletion slightly increased 3HHx composition without serious negative impact on both cell growth and PHA biosynthesis. Double deletion of fadB1 and fadB' significantly impaired the cell growth and PHA biosynthesis, indicating the major roles of fadB1 and fadB' in β-oxidation. When fadB1 was deleted in several engineered strains of R. eutropha possessing additional (R)-enoyl-CoA hydratase gene(s), the net amounts of 3HHx unit in the PHA fractions showed 6-21% increase probably due to slightly enhanced supply of medium-chain-length 2-enoyl-CoAs through the partially impaired β-oxidation. These results demonstrated that modification of β-oxidation by fadB1 deletion was effective for increasing 3HHx composition in the copolyesters produced from soybean oil.
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123
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Przybylski D, Rohwerder T, Harms H, Yaneva N, Müller RH. Synthesis of the building block 2-hydroxyisobutyrate from fructose and butyrate by Cupriavidus necator H16. Appl Microbiol Biotechnol 2013; 97:8875-85. [PMID: 23942876 DOI: 10.1007/s00253-013-5064-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 06/11/2013] [Accepted: 06/13/2013] [Indexed: 11/27/2022]
Abstract
2-Hydroxyisobutyryl-coenzyme A mutase, originally discovered in the context of methyl tert-butyl ether degradation in Aquincola tertiaricarbonis L108, catalyzes the isomerization of 3-hydroxybutyryl-coenzyme A (3-HB-CoA) to 2-hydroxyisobutyryl-CoA. It thus constitutes the basis for a biotechnological route from practically any renewable carbon to 2-hydroxyisobutyrate (2-HIB) via the common metabolite 3-hydroxybutyrate. At first sight, recombinant Cupriavidus necator H16 expressing the mutase seems to be well suited for such a synthesis process, as a strong overflow metabolism via (R)-3-HB-CoA is easily induced in this bacterium possessing the poly-3-hydroxybutyrate metabolism. However, the recently established stereospecificity of the mutase, dominantly preferring the (S)-enantiomer of 3-HB-CoA, calls for a closer investigation of C. necator as potential 2-HIB production strain and raised the question about the strain's potential to yield 2-HIB from substrates directly providing (S)-3-HB-CoA. We compared two mutase-expressing C. necator H16 strains for their capability to synthesize 2-HIB from fructose and butyrate, delivering either (R)- or (S)-3-HB-CoA. Our results indicate that due to the enantiospecificity of the mutase, fructose is a weaker substrate for 2-HIB synthesis than butyrate. Production rates achieved with the PHB-negative strain H16 PHB(-)4 on butyrate were higher than on fructose. Using the wild-type did not significantly improve the production rates as the latter showed a 34-fold and a 5-fold lower 2-HIB synthesis rate compared to H16 PHB(-)4 on fructose and butyrate, respectively. Moreover, both strains showed concomitant excretion of undesired side products, such as pyruvate and 3-hydroxybutyrate, significantly decreasing the 2-HIB yield.
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Affiliation(s)
- Denise Przybylski
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research (UFZ), Permoserstrasse 15, 04318, Leipzig, Germany
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124
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Madkour MH, Heinrich D, Alghamdi MA, Shabbaj II, Steinbüchel A. PHA Recovery from Biomass. Biomacromolecules 2013; 14:2963-72. [DOI: 10.1021/bm4010244] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mohamed H. Madkour
- Institut
für Molekulare Mikrobiologie und Biotechnologie, Westfälische
Wilhelms-Universität Münster, and ‡Environmental Sciences Department,
Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, 21589,
Saudi-Arabia
| | - Daniel Heinrich
- Institut
für Molekulare Mikrobiologie und Biotechnologie, Westfälische
Wilhelms-Universität Münster, and ‡Environmental Sciences Department,
Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, 21589,
Saudi-Arabia
| | - Mansour A. Alghamdi
- Institut
für Molekulare Mikrobiologie und Biotechnologie, Westfälische
Wilhelms-Universität Münster, and ‡Environmental Sciences Department,
Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, 21589,
Saudi-Arabia
| | - Ibraheem I. Shabbaj
- Institut
für Molekulare Mikrobiologie und Biotechnologie, Westfälische
Wilhelms-Universität Münster, and ‡Environmental Sciences Department,
Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, 21589,
Saudi-Arabia
| | - Alexander Steinbüchel
- Institut
für Molekulare Mikrobiologie und Biotechnologie, Westfälische
Wilhelms-Universität Münster, and ‡Environmental Sciences Department,
Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, 21589,
Saudi-Arabia
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125
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Tripathi L, Wu LP, Dechuan M, Chen J, Wu Q, Chen GQ. Pseudomonas putida KT2442 as a platform for the biosynthesis of polyhydroxyalkanoates with adjustable monomer contents and compositions. BIORESOURCE TECHNOLOGY 2013; 142:225-231. [PMID: 23743426 DOI: 10.1016/j.biortech.2013.05.027] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 06/02/2023]
Abstract
The β-oxidation weakened Pseudomonas putida were established as a platform for the production of polyhydroxyalkanoates (PHA) with adjustable monomer compositions and micro-structures. When mutant P. putida KTOYO6ΔC (phaPCJA.c) was cultivated on mixtures of sodium butyrate and sodium hexanoate (C4:C6), random copolymers of P(3HB-co-3HHx) consisting of 3-hydroxybutyrate (3HB), 3-hydroxyhexanoate (3HHx), were accumulated with 3HHx content ranged from 19 mol% to 75 mol%. While recombinant P. putida KTQQ20 grown on mixtures of sodium hexanoate and decanoic acid (C6:C10), produced random copolymers of P(3HHx-co-3HD) consisting of 3-hydroxyhexanoate (3HHx) and 3-hydroxydecanoate (3HD), the monomer fraction of 3HHx ranged from 16 mol% to 63 mol%. The comonomer compositions were easily regulated by varying the fatty acid concentrations. P. putida KTQQ20 produced a novel diblock copolymer P3HHx-b-P(3HD-co-3HDD) consisting of 49 mol% P3HHx and 51 mol% P(3HD-co-3HDD) [35.25 mol% 3HDD (3-hydroxydodecanoate)], which was characterized by (13)C NMR, HMBC NMR, DSC, GPC and universal testing machine.
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Affiliation(s)
- Lakshmi Tripathi
- 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
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126
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Detection of phase-dependent transcriptomic changes and Rubisco-mediated CO2 fixation into poly (3-hydroxybutyrate) under heterotrophic condition in Ralstonia eutropha H16 based on RNA-seq and gene deletion analyses. BMC Microbiol 2013; 13:169. [PMID: 23879744 PMCID: PMC3734047 DOI: 10.1186/1471-2180-13-169] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 07/12/2013] [Indexed: 11/16/2022] Open
Abstract
Background Ralstonia eutropha H16 is well known to produce polyhydroxyalkanoates (PHAs), which are potential bio-based biodegradable plastics, in an efficient manner as an energy storage material under unbalanced growth conditions. To obtain further knowledge of PHA biosynthesis, this study performed a quantitative transcriptome analysis based on deep sequencing of the complementary DNA generated from the RNA (RNA-seq) of R. eutropha H16. Results Total RNAs were extracted from R. eutropha cells in growth, PHA production, and stationary phases on fructose. rRNAs in the preparation were removed by repeated treatments with magnetic beads specific to bacterial rRNAs, and then the 36 bp sequences were determined using an Illumina high-throughput sequencer. The RNA-seq results indicated the induction of gene expression for transcription, translation, cell division, peptidoglycan biosynthesis, pilus and flagella assembly, energy conservation, and fatty acid biosynthesis in the growth phase; and the repression trends of genes involved in central metabolisms in the PHA production phase. Interestingly, the transcription of genes for Calvin-Benson-Bassham (CBB) cycle and several genes for β-oxidation were significantly induced in the PHA production phase even when the cells were grown on fructose. Moreover, incorporation of 13C was observed in poly(3-hydroxybutyrate) synthesized by R. eutropha H16 from fructose in the presence of NaH13CO3, and further gene deletion analyses revealed that both of the two ribulose 1,5-bisphosphate carboxylase (Rubiscos) in CBB cycle were actually functional in CO2 fixation under the heterotrophic condition. Conclusions The results revealed the phase-dependent transcriptomic changes and a CO2 fixation capability under heterotrophic conditions by PHA-producing R. eutropha.
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127
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Zhu C, Chiu S, Nakas JP, Nomura CT. Bioplastics from waste glycerol derived from biodiesel industry. J Appl Polym Sci 2013. [DOI: 10.1002/app.39157] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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128
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Advanced bacterial polyhydroxyalkanoates: Towards a versatile and sustainable platform for unnatural tailor-made polyesters. Biotechnol Adv 2012; 30:1196-206. [DOI: 10.1016/j.biotechadv.2011.11.007] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 11/01/2011] [Accepted: 11/15/2011] [Indexed: 11/22/2022]
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129
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Wong YM, Brigham CJ, Rha C, Sinskey AJ, Sudesh K. Biosynthesis and characterization of polyhydroxyalkanoate containing high 3-hydroxyhexanoate monomer fraction from crude palm kernel oil by recombinant Cupriavidus necator. BIORESOURCE TECHNOLOGY 2012; 121:320-327. [PMID: 22858502 DOI: 10.1016/j.biortech.2012.07.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 06/03/2012] [Accepted: 07/09/2012] [Indexed: 06/01/2023]
Abstract
The potential of plant oils as sole carbon sources for production of P(3HB-co-3HHx) copolymer containing a high 3HHx monomer fraction using the recombinant Cupriavidus necator strain Re2160/pCB113 has been investigated. Various types and concentrations of plant oils were evaluated for efficient conversion of P(3HB-co-3HHx) copolymer. Crude palm kernel oil (CPKO) at a concentration of 2.5 g/L was found to be most suitable for production of copolymer with a 3HHx content of approximately 70 mol%. The time profile of these cells was also examined in order to study the trend of 3HHx monomer incorporation, PHA production and PHA synthase activity. (1)H NMR and (13)C NMR analyses confirmed the presence of P(3HB-co-3HHx) copolymer containing a high 3HHx monomer fraction, in which monomers were not randomly distributed. The results of various characterization analyses revealed that the copolymers containing a high 3HHx monomer fraction demonstrated soft and flexible mechanical properties.
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Affiliation(s)
- Yoke-Ming Wong
- Ecobiomaterial Research Laboratory, School of Biological Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
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130
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Riedel SL, Brigham CJ, Budde CF, Bader J, Rha C, Stahl U, Sinskey AJ. Recovery of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fromRalstonia eutrophacultures with non-halogenated solvents. Biotechnol Bioeng 2012; 110:461-70. [DOI: 10.1002/bit.24713] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 07/18/2012] [Accepted: 08/06/2012] [Indexed: 11/07/2022]
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131
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Ashby RD, Solaiman DKY, Strahan GD, Zhu C, Tappel RC, Nomura CT. Glycerine and levulinic acid: renewable co-substrates for the fermentative synthesis of short-chain poly(hydroxyalkanoate) biopolymers. BIORESOURCE TECHNOLOGY 2012; 118:272-280. [PMID: 22705534 DOI: 10.1016/j.biortech.2012.05.092] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 05/14/2012] [Accepted: 05/19/2012] [Indexed: 06/01/2023]
Abstract
Glycerine (a biodiesel co-product) and levulinic acid (a pulp and paper co-product) were used as co-substrates for the fermentative synthesis of short-chain polyhydroxyalkanoate (sc-PHA) biopolymers with tunable monomer and molecular weight characteristics. Pseudomonas oleovorans NRRL B-14682 utilized glycerine alone to produce poly(3-hydroxybutyrate) (PHB). When levulinic acid was added to the media at shake-flask scale in concentrations ≤0.6 wt.%, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB/V) copolymers were produced with 3-HV contents ranging from 37 to 97 mol%; a glycerine:levulinic acid ratio of 0.2%:0.8% (w/v) resulted in poly(3-hydroxyvalerate) (PHV). Ten-liter batch fermentations using glycerine:levulinic acid ratios of 1%:0, 0.75%:0.25%, 0.5%:0.5% and 0.25%:0.75% (w/v) resulted in PHB, P(73%-3HB-co-27%-3HV), P(30%-3HB-co-70%-3HV) and PHV with increasing number average molecular weights (×10(3) g/mol) of 328, 511, 728 and 1330, respectively, owing to glycerine-based chain termination. These results provide a novel means by which glycerine and levulinic acid can be used collectively to produce an array of distinct sc-PHA biopolymers.
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Affiliation(s)
- Richard D Ashby
- Eastern Regional Research Center, Agricultural Research Service, US Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
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132
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Genetically modified strains of Ralstonia eutropha H16 with β-ketothiolase gene deletions for production of copolyesters with defined 3-hydroxyvaleric acid contents. Appl Environ Microbiol 2012; 78:5375-83. [PMID: 22636005 DOI: 10.1128/aem.00824-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
β-Ketothiolases catalyze the first step of poly(3-hydroxybutyrate) [poly(3HB)] biosynthesis in bacteria by condensation of two acetyl coenzyme A (acetyl-CoA) molecules to acetoacetyl-CoA and also take part in the degradation of fatty acids. During growth on propionate or valerate, Ralstonia eutropha H16 produces the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [poly(3HB-co-3HV)]. In R. eutropha, 15 β-ketothiolase homologues exist. The synthesis of 3-hydroxybutyryl-CoA (3HB-CoA) could be significantly reduced in an 8-fold mutant (Lindenkamp et al., Appl. Environ. Microbiol. 76:5373-5382, 2010). In this study, a 9-fold mutant deficient in nine β-ketothiolase gene homologues (phaA, bktB, H16_A1713, H16_B1771, H16_A1528, H16_B0381, H16_B1369, H16_A0170, and pcaF) was generated. In order to examine the polyhydroxyalkanoate production capacity when short- or long-chain and even- or odd-chain-length fatty acids were provided as carbon sources, the growth and storage behavior of several mutants from the previous study and the newly generated 9-fold mutant were analyzed. Propionate, valerate, octanoate, undecanoic acid, or oleate was chosen as the sole carbon source. On octanoate, no significant differences in growth or storage behavior were observed between wild-type R. eutropha and the mutants. In contrast, during the growth on oleate of a multiple mutant lacking phaA, bktB, and H16_A0170, diminished poly(3HB) accumulation occurred. Surprisingly, the amount of accumulated poly(3HB) in the multiple mutants grown on gluconate differed; it was much lower than that on oleate. The β-ketothiolase activity toward acetoacetyl-CoA in H16ΔphaA and all the multiple mutants remained 10-fold lower than the activity of the wild type, regardless of which carbon source, oleate or gluconate, was employed. During growth on valerate as a sole carbon source, the 9-fold mutant accumulated almost a poly(3-hydroxyvalerate) [poly(3HV)] homopolyester with 99 mol% 3HV constituents.
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133
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Characterization of an extracellular lipase and its chaperone from Ralstonia eutropha H16. Appl Microbiol Biotechnol 2012; 97:2443-54. [DOI: 10.1007/s00253-012-4115-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 04/16/2012] [Accepted: 04/16/2012] [Indexed: 11/25/2022]
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134
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Brigham CJ, Reimer EN, Rha C, Sinskey AJ. Examination of PHB Depolymerases in Ralstonia eutropha: Further Elucidation of the Roles of Enzymes in PHB Homeostasis. AMB Express 2012; 2:26. [PMID: 22537946 PMCID: PMC3430594 DOI: 10.1186/2191-0855-2-26] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 04/26/2012] [Indexed: 11/29/2022] Open
Abstract
Polyhydroxyalkanoates (PHA) are biodegradable polymers that are attractive materials for use in tissue engineering and medical device manufacturing. Ralstonia eutropha is regarded as the model organism for PHA biosynthesis. We examined the effects of PHA depolymerase (PhaZ) expression on PHA homeostasis in R. eutropha strains. In order to analyze the impact of PhaZs on R. eutropha granule architecture, we performed electron microscopy on several phaZ knockout strains and the wild type strain grown under PHA production conditions. Analysis of the acquired micrographs was based on stereology: the ratio of granule area and cell area was determined, along with total granule count per full-size cell image. Cells bearing a phaZ2 knockout mutation alone or in conjunction with a phaZ1 mutation were found to have a high granule volume per cell volume and a higher granule count compared to wild type. A phaZ quadruple knockout strain appeared to have a low granule volume per cell volume and a low granule count per cell. Cells bearing a phaZ3 knockout were found to have a higher granule count than the wild type, whereas granule volume per cell volume was similar. Accordingly, we hypothesize that PhaZs have not only an impact on PHA degradation but also on the 3-dimensional granule architecture. Based on our data, PhaZ2 is postulated to affect granule density. This work increased our knowledge about PHA depolymerases in R. eutropha, including enzymes that had previously been uncharacterized.
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Affiliation(s)
- Christopher J Brigham
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | | | - ChoKyun Rha
- Biomaterials Science and Engineering Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Anthony J Sinskey
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Division of Health Sciences Technology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Engineering Systems Division, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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135
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Tappel RC, Wang Q, Nomura CT. Precise control of repeating unit composition in biodegradable poly(3-hydroxyalkanoate) polymers synthesized by Escherichia coli. J Biosci Bioeng 2012; 113:480-6. [DOI: 10.1016/j.jbiosc.2011.12.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 12/09/2011] [Accepted: 12/12/2011] [Indexed: 11/27/2022]
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136
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Cho M, Brigham CJ, Sinskey AJ, Stubbe J. Purification of polyhydroxybutyrate synthase from its native organism, Ralstonia eutropha: implications for the initiation and elongation of polymer formation in vivo. Biochemistry 2012; 51:2276-88. [PMID: 22369488 DOI: 10.1021/bi2013596] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Class I polyhydroxybutyrate (PHB) synthase (PhaC) from Ralstonia eutropha catalyzes the formation of PHB from (R)-3-hydroxybutyryl-CoA, ultimately resulting in the formation of insoluble granules. Previous mechanistic studies of R. eutropha PhaC, purified from Escherichia coli (PhaC(Ec)), demonstrated that the polymer elongation rate is much faster than the initiation rate. In an effort to identify a factor(s) from the native organism that might prime the synthase and increase the rate of polymer initiation, an N-terminally Strep2-tagged phaC (Strep2-PhaC(Re)) was constructed and integrated into the R. eutropha genome in place of wild-type phaC. Strep2-PhaC(Re) was expressed and purified by affinity chromatography from R. eutropha grown in nutrient-rich TSB medium for 4 h (peak production PHB, 15% cell dry weight) and 24 h (PHB, 2% cell dry weight). Analysis of the purified PhaC by size exclusion chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and gel permeation chromatography revealed that it unexpectedly copurified with the phasin protein, PhaP1, and with soluble PHB (M(w) = 350 kDa) in a "high-molecular weight" (HMW) complex and in monomeric/dimeric (M/D) forms with no associated PhaP1 or PHB. Assays for monitoring the formation of PHB in the HMW complex showed no lag phase in CoA release, in contrast to M/D forms of PhaC(Re) (and PhaC(Ec)), suggesting that PhaC in the HMW fraction has been isolated in a PHB-primed form. The presence of primed and nonprimed PhaC suggests that the elongation rate for PHB formation is also faster than the initiation rate in vivo. A modified micelle model for granule genesis is proposed to accommodate the reported observations.
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Affiliation(s)
- Mimi Cho
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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137
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Bassas-Galia M, Nogales B, Arias S, Rohde M, Timmis K, Molinari G. Plant original Massilia isolates producing polyhydroxybutyrate, including one exhibiting high yields from glycerol. J Appl Microbiol 2012; 112:443-54. [DOI: 10.1111/j.1365-2672.2011.05228.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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138
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Brigham CJ, Zhila N, Shishatskaya E, Volova TG, Sinskey AJ. Manipulation of Ralstonia eutropha carbon storage pathways to produce useful bio-based products. Subcell Biochem 2012; 64:343-366. [PMID: 23080259 DOI: 10.1007/978-94-007-5055-5_17] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Ralstonia eutrophais a Gram-negative betaproteobacterium found natively in soils that can utilize a wide array of carbon sources for growth, and can store carbon intracellularly in the form of polyhydroxyalkanoate. Many aspects of R. eutrophamake it a good candidate for use in biotechnological production of polyhydroxyalkanoate and other bio-based, value added compounds. Manipulation of the organism's carbon flux is a cornerstone to success in developing it as a biotechnologically relevant organism. Here, we examine the methods of controlling and adapting the flow of carbon in R. eutrophametabolism and the wide range of compounds that can be synthesized as a result. The presence of many different carbon utilization pathways and the custom genetic toolkit for manipulation of those pathways gives R. eutrophaa versatility that allows it to be a biotechnologically important organism.
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Affiliation(s)
- Christopher J Brigham
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
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139
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Characterization and functional analyses of R-specific enoyl coenzyme A hydratases in polyhydroxyalkanoate-producing Ralstonia eutropha. Appl Environ Microbiol 2011; 78:493-502. [PMID: 22081565 DOI: 10.1128/aem.06937-11] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A genome survey of polyhydroxyalkanoate (PHA)-producing Ralstonia eutropha H16 detected the presence of 16 orthologs of R-specific enoyl coenzyme A (enoyl-CoA) hydratase, among which three proteins shared high homologies with the enzyme specific to enoyl-CoAs of medium chain length encoded by phaJ4 from Pseudomonas aeruginosa (phaJ4(Pa)). The recombinant forms of the three proteins, termed PhaJ4a(Re) to PhaJ4c(Re), actually showed enoyl-CoA hydratase activity with R specificity, and the catalytic efficiencies were elevated as the substrate chain length increased from C(4) to C(8). PhaJ4a(Re) and PhaJ4b(Re) showed >10-fold-higher catalytic efficiency than PhaJ4c(Re). The functions of the new PhaJ4 proteins were investigated using previously engineered R. eutropha strains as host strains; these strains are capable of synthesizing poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) [P(3HB-co-3HHx)] from soybean oil. Deletion of phaJ4a(Re) from the chromosome resulted in significant decrease of 3HHx composition in the accumulated copolyester, whereas no change was observed with deletion of phaJ4b(Re) or phaJ4c(Re), indicating that only PhaJ4a(Re) was one of the major enzymes supplying the (R)-3HHx-CoA monomer through β-oxidation. Introduction of phaJ4a(Re) or phaJ4b(Re) into the R. eutropha strains using a broad-host-range vector enhanced the 3HHx composition of the copolyesters, but the introduction of phaJ4c(Re) did not. The two genes were then inserted into the pha operon on chromosome 1 of the engineered R. eutropha by homologous recombination. These modifications enabled the biosynthesis of P(3HB-co-3HHx) composed of a larger 3HHx fraction without a negative impact on cell growth and PHA production on soybean oil, especially when phaJ4a(Re) or phaJ4b(Re) was tandemly introduced with phaJ(Ac) from Aeromonas caviae.
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Cai L, Tan D, Aibaidula G, Dong XR, Chen JC, Tian WD, Chen GQ. Comparative genomics study of polyhydroxyalkanoates (PHA) and ectoine relevant genes from Halomonas sp. TD01 revealed extensive horizontal gene transfer events and co-evolutionary relationships. Microb Cell Fact 2011; 10:88. [PMID: 22040376 PMCID: PMC3227634 DOI: 10.1186/1475-2859-10-88] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 11/01/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Halophilic bacteria have shown their significance in industrial production of polyhydroxyalkanoates (PHA) and are gaining more attention for genetic engineering modification. Yet, little information on the genomics and PHA related genes from halophilic bacteria have been disclosed so far. RESULTS The draft genome of moderately halophilic bacterium, Halomonas sp. TD01, a strain of great potential for industrial production of short-chain-length polyhydroxyalkanoates (PHA), was analyzed through computational methods to reveal the osmoregulation mechanism and the evolutionary relationship of the enzymes relevant to PHA and ectoine syntheses. Genes involved in the metabolism of PHA and osmolytes were annotated and studied in silico. Although PHA synthase, depolymerase, regulator/repressor and phasin were all involved in PHA metabolic pathways, they demonstrated different horizontal gene transfer (HGT) events between the genomes of different strains. In contrast, co-occurrence of ectoine genes in the same genome was more frequently observed, and ectoine genes were more likely under coincidental horizontal gene transfer than PHA related genes. In addition, the adjacent organization of the homologues of PHA synthase phaC1 and PHA granule binding protein phaP was conserved in the strain TD01, which was also observed in some halophiles and non-halophiles exclusively from γ-proteobacteria. In contrast to haloarchaea, the proteome of Halomonas sp. TD01 did not show obvious inclination towards acidity relative to non-halophilic Escherichia coli MG1655, which signified that Halomonas sp. TD01 preferred the accumulation of organic osmolytes to ions in order to balance the intracellular osmotic pressure with the environment. CONCLUSIONS The accessibility of genome information would facilitate research on the genetic engineering of halophilic bacteria including Halomonas sp. TD01.
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Affiliation(s)
- Lei Cai
- Department of Biological Sciences and Biotechnology, MOE Key Lab, Bioinformatics (& System Biology), Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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Riedel SL, Bader J, Brigham CJ, Budde CF, Yusof ZAM, Rha C, Sinskey AJ. Production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) by Ralstonia eutropha in high cell density palm oil fermentations. Biotechnol Bioeng 2011; 109:74-83. [DOI: 10.1002/bit.23283] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Revised: 07/06/2011] [Accepted: 07/22/2011] [Indexed: 11/08/2022]
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