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Thiele I, Santolin L, Detels S, Osele R, Neubauer P, Riedel SL. High-cell-density fed-batch strategy to manufacture tailor-made P(HB-co-HHx) by engineered Ralstonia eutropha at laboratory scale and pilot scale. Microb Biotechnol 2024; 17:e14488. [PMID: 38850269 PMCID: PMC11162103 DOI: 10.1111/1751-7915.14488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 05/06/2024] [Accepted: 05/12/2024] [Indexed: 06/10/2024] Open
Abstract
The transition towards a sustainable bioeconomy requires the development of highly efficient bioprocesses that enable the production of bulk materials at a competitive price. This is particularly crucial for driving the commercialization of polyhydroxyalkanoates (PHAs) as biobased and biodegradable plastic substitutes. Among these, the copolymer poly(hydroxybutyrate-co-hydroxyhexanoate) (P(HB-co-HHx)) shows excellent material properties that can be tuned by regulating its monomer composition. In this study, we developed a high-cell-density fed-batch strategy using mixtures of fructose and canola oil to modulate the molar composition of P(HB-co-HHx) produced by Ralstonia eutropha Re2058/pCB113 at 1-L laboratory scale up to 150-L pilot scale. With cell densities >100 g L-1 containing 70-80 wt% of PHA with tunable HHx contents in the range of 9.0-14.6 mol% and productivities of up to 1.5 g L-1 h-1, we demonstrate the tailor-made production of P(HB-co-HHx) at an industrially relevant scale. Ultimately, this strategy enables the production of PHA bioplastics with defined material properties on the kilogram scale, which is often required for testing and adapting manufacturing processes to target diverse applications.
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Affiliation(s)
- Isabel Thiele
- Chair of Bioprocess Engineering, Institute of BiotechnologyTechnische Universität BerlinBerlinGermany
| | - Lara Santolin
- Chair of Bioprocess Engineering, Institute of BiotechnologyTechnische Universität BerlinBerlinGermany
| | - Svea Detels
- Chair of Bioprocess Engineering, Institute of BiotechnologyTechnische Universität BerlinBerlinGermany
| | - Riccardo Osele
- Chair of Bioprocess Engineering, Institute of BiotechnologyTechnische Universität BerlinBerlinGermany
- Department of BiotechnologyUniversity of VeronaVeronaItaly
| | - Peter Neubauer
- Chair of Bioprocess Engineering, Institute of BiotechnologyTechnische Universität BerlinBerlinGermany
| | - Sebastian L. Riedel
- Chair of Bioprocess Engineering, Institute of BiotechnologyTechnische Universität BerlinBerlinGermany
- Environmental and Bioprocess Engineering Laboratory, Department VIII – Mechanical Engineering, Event Technology and Process EngineeringBerliner Hochschule für TechnikBerlinGermany
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Thiele I, Santolin L, Meyer K, Machatschek R, Bölz U, Tarazona NA, Riedel SL. Microbially synthesized poly(hydroxybutyrate-co-hydroxyhexanoate) with low to moderate hydroxyhexanoate content: Properties and applications. Int J Biol Macromol 2024; 263:130188. [PMID: 38373562 DOI: 10.1016/j.ijbiomac.2024.130188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/25/2024] [Accepted: 02/12/2024] [Indexed: 02/21/2024]
Abstract
Plastic pollution is the biggest environmental concern of our time. Breakdown products like micro- and nano-plastics inevitably enter the food chain and pose unprecedented health risks. In this scenario, bio-based and biodegradable plastic alternatives have been given a momentum aiming to bridge a transition towards a more sustainable future. Polyhydroxyalkanoates (PHAs) are one of the few thermoplastic polymers synthesized 100 % via biotechnological routes which fully biodegrade in common natural environments. Poly(hydroxybutyrate-co-hydroxyhexanoate) [P(HB-co-HHx)] is a PHA copolymer with great potential for the commodity polymers industry, as its mechanical properties can be tailored through fine-tuning of its molar HHx content. We have recently developed a strategy that enables for reliable tailoring of the monomer content of P(HB-co-HHx). Nevertheless, there is often a lack of comprehensive investigation of the material properties of PHAs to evaluate whether they actually mimic the functionalities of conventional plastics. We present a detailed study of P(HB-co-HHx) copolymers with low to moderate hydroxyhexanoate content to understand how the HHx monomer content influences the thermal and mechanical properties and to link those to their abiotic degradation. By increasing the HHx fractions in the range of 2 - 14 mol%, we impart an extension of the processing window and application range as the melting temperature (Tm) and glass temperature (Tg) of the copolymers decrease from Tm 165 °C to 126 °C, Tg 4 °C to -5.9 °C, accompanied by reduced crystallinity from 54 % to 20 %. Elongation at break was increased from 5.7 % up to 703 % at 14 mol% HHx content, confirming that the range examined was sufficiently large to obtain ductile and brittle copolymers, while tensile strength was maintained throughout the studied range. Finally, accelerated abiotic degradation was shown to be slowed down with an increasing HHx fraction decreasing from 70 % to 55 % in 12 h.
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Affiliation(s)
- Isabel Thiele
- Technische Universität Berlin, Institute of Biotechnology, Chair of Bioprocess Engineering, Berlin, Germany
| | - Lara Santolin
- Technische Universität Berlin, Institute of Biotechnology, Chair of Bioprocess Engineering, Berlin, Germany
| | - Klas Meyer
- Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany
| | | | - Uwe Bölz
- HPX Polymers GmbH, Tutzing, Germany
| | - Natalia A Tarazona
- Institute of Active Polymers, Helmholtz-Zentrum Hereon, Teltow, Germany.
| | - Sebastian L Riedel
- Technische Universität Berlin, Institute of Biotechnology, Chair of Bioprocess Engineering, Berlin, Germany; Berliner Hochschule für Technik, Department VIII - Mechanical Engineering, Event Technology and Process Engineering, Environmental and Bioprocess Engineering Laboratory, Berlin, Germany.
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Di Stadio G, Orita I, Nakamura R, Fukui T. Gas fermentation combined with water electrolysis for production of polyhydroxyalkanoate copolymer from carbon dioxide by engineered Ralstonia eutropha. BIORESOURCE TECHNOLOGY 2024; 394:130266. [PMID: 38159815 DOI: 10.1016/j.biortech.2023.130266] [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: 11/21/2023] [Revised: 12/24/2023] [Accepted: 12/25/2023] [Indexed: 01/03/2024]
Abstract
A recycled-gas closed-circuit culture system was developed for safe autotrophic cultivation of a hydrogen-oxidizing, polyhydroxyalkanoate (PHA)-producing Ralstonia eutropha, using a non-combustible gas mixture with low-concentration of H2 supplied by water electrolysis. Automated feedback regulation of gas flow enabled input of H2, CO2, and O2 well balanced with the cellular demands, leading to constant gas composition throughout the cultivation. The engineered strain of R. eutropha produced 1.71 g/L of poly(3-hydroxybutyrate-co-12.5 mol% 3-hydroxyhexanoate) on a gas mixture of H2/CO2/O2/N2 = 4:12:7:77 vol% with a 69.2 wt% cellular content. Overexpression of can encoding cytosolic carbonic anhydrase increased the 3HHx fraction up to 19.6 mol%. The yields of biomass and PHA on input H2 were determined to be 72.9 % and 63.1 %, corresponding to 51.0 % and 44.2 % yield on electricity, respectively. The equivalent solar-to-biomass/PHA efficiencies were estimated to be 2.1-3.8 %, highlighting the high energy conversion capability of R. eutropha.
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Affiliation(s)
- Gabriele Di Stadio
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Izumi Orita
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Ryuhei Nakamura
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan; Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science (CSRS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Toshiaki Fukui
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
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Huong KH, Orita I, Fukui T. Microaerobic insights into production of polyhydroxyalkanoates containing 3-hydroxyhexanoate via native reverse β-oxidation from glucose in Ralstonia eutropha H16. Microb Cell Fact 2024; 23:21. [PMID: 38221622 PMCID: PMC10788006 DOI: 10.1186/s12934-024-02294-4] [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: 10/17/2023] [Accepted: 01/01/2024] [Indexed: 01/16/2024] Open
Abstract
BACKGROUND Ralstonia eutropha H16, a facultative chemolitoautotroph, is an important workhorse for bioindustrial production of useful compounds such as polyhydroxyalkanoates (PHAs). Despite the extensive studies to date, some of its physiological properties remain not fully understood. RESULTS This study demonstrated that the knallgas bacterium exhibited altered PHA production behaviors under slow-shaking condition, as compared to its usual aerobic condition. One of them was a notable increase in PHA accumulation, ranging from 3.0 to 4.5-fold in the mutants lacking of at least two NADPH-acetoacetyl-CoA reductases (PhaB1, PhaB3 and/or phaB2) when compared to their respective aerobic counterpart, suggesting the probable existence of (R)-3HB-CoA-providing route(s) independent on PhaBs. Interestingly, PHA production was still considerably high even with an excess nitrogen source under this regime. The present study further uncovered the conditional activation of native reverse β-oxidation (rBOX) allowing formation of (R)-3HHx-CoA, a crucial precursor for poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)], solely from glucose. This native rBOX led to the natural incorporation of 3.9 mol% 3HHx in a triple phaB-deleted mutant (∆phaB1∆phaB1∆phaB2-C2). Gene deletion experiments elucidated that the native rBOX was mediated by previously characterized (S)-3HB-CoA dehydrogenases (PaaH1/Had), β-ketothiolase (BktB), (R)-2-enoyl-CoA hydratase (PhaJ4a), and unknown crotonase(s) and reductase(s) for crotonyl-CoA to butyryl-CoA conversion prior to elongation. The introduction of heterologous enzymes, crotonyl-CoA carboxylase/reductase (Ccr) and ethylmalonyl-CoA decarboxylase (Emd) along with (R)-2-enoyl-CoA hydratase (PhaJ) aided the native rBOX, resulting in remarkably high 3HHx composition (up to 37.9 mol%) in the polyester chains under the low-aerated condition. CONCLUSION These findings shed new light on the robust characteristics of Ralstonia eutropha H16 and have the potential for the development of new strategies for practical P(3HB-co-3HHx) copolyesters production from sugars under low-aerated conditions.
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Affiliation(s)
- Kai-Hee Huong
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan
| | - Izumi Orita
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan
| | - Toshiaki Fukui
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan.
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González-Rojo S, Paniagua-García AI, Díez-Antolínez R. Biotransformation of starch-based wastewater into bioplastics: Optimization of poly(3-hydroxybutyrate) production by Cupriavidus necator DSM 545 using potato wastewater hydrolysate. WATER RESEARCH 2023; 247:120766. [PMID: 37897996 DOI: 10.1016/j.watres.2023.120766] [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: 07/27/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 10/30/2023]
Abstract
Biodegradable biopolymers, such as polyhydroxyalkanoates (PHAs), have emerged as an alternative to petrochemical-based plastics. The present work explores the production of PHAs based on the biotransformation of potato processing wastewater and addresses two different strategies for PHA recovery. To this end, culture conditions for PHA synthesis by Cupriavidus necator DSM 545 were optimized on a laboratory scale using a response surface methodology-based experimental design. Optimal conditions rendered a PHB, poly(3-hydroxybutyrate), accumulation of 83.74 ± 2.37 % (5.1 ± 0.2 gL-1), a 1.4-fold increase compared to the initial conditions. Moreover, polymer extraction with non-halogenated agent improved PHB recovery compared to chloroform method (PHB yield up to 78.78 ± 0.57 %), while maintaining PHB purity. (99.83 ± 4.95 %). Overall, the present work demonstrated the potential valorization of starch-based wastewater by biotransformation into PHBs, a high value-added product, and showed that recovery approaches more eco-friendly than the traditional treatments could be applied to PHB recovery to some extent.
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Affiliation(s)
- S González-Rojo
- Centro de Biocombustibles y Bioproductos, Instituto Tecnológico Agrario de Castilla y León (ITACyL), Polígono Agroindustrial del Órbigo p. 2-6, Villarejo de Órbigo 24358, León, Spain.
| | - A I Paniagua-García
- Centro de Biocombustibles y Bioproductos, Instituto Tecnológico Agrario de Castilla y León (ITACyL), Polígono Agroindustrial del Órbigo p. 2-6, Villarejo de Órbigo 24358, León, Spain
| | - R Díez-Antolínez
- Centro de Biocombustibles y Bioproductos, Instituto Tecnológico Agrario de Castilla y León (ITACyL), Polígono Agroindustrial del Órbigo p. 2-6, Villarejo de Órbigo 24358, León, Spain
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Jämsä T, Tervasmäki P, Pitkänen JP, Salusjärvi L. Inactivation of poly(3-hydroxybutyrate) (PHB) biosynthesis in 'Knallgas' bacterium Xanthobacter sp. SoF1. AMB Express 2023; 13:75. [PMID: 37452197 PMCID: PMC10349022 DOI: 10.1186/s13568-023-01577-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 06/25/2023] [Indexed: 07/18/2023] Open
Abstract
Aerobic hydrogen-oxidizing 'Knallgas' bacteria are promising candidates for microbial cell factories due to their ability to use hydrogen and carbon dioxide as the sole energy and carbon sources, respectively. These bacteria can convert atmospheric CO2 to chemicals which could help to mitigate climate change by replacing fossil fuel-based chemicals. A known method to enhance the product yield is to disrupt competing metabolic pathways in the host organism. One such pathway in many 'Knallgas' bacteria is polyhydroxybutyrate (PHB) biosynthesis. In this study, the PHB biosynthesis genes of a non-model 'Knallgas' bacterium Xanthobacter sp. SoF1 were identified. Consequently, the phaA, phaB and phaC genes were individually deleted and the resulting knockouts were evaluated for their ability to produce PHB in autotrophic shake flask and small-scale bioreactor cultivations. The results demonstrate that PHB production was inactivated in the phaC1 knockout strain, which advances the development of Xanthobacter sp. SoF1 as a production host.
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Affiliation(s)
- Tytti Jämsä
- VTT Technical Research Centre of Finland Ltd., 02150, Espoo, Finland.
| | | | | | - Laura Salusjärvi
- VTT Technical Research Centre of Finland Ltd., 02150, Espoo, Finland
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Santolin L, Thiele I, Neubauer P, Riedel SL. Tailoring the HHx monomer content of P(HB- co-HHx) by flexible substrate compositions: scale-up from deep-well-plates to laboratory bioreactor cultivations. Front Bioeng Biotechnol 2023; 11:1081072. [PMID: 37214303 PMCID: PMC10193151 DOI: 10.3389/fbioe.2023.1081072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 04/18/2023] [Indexed: 05/24/2023] Open
Abstract
The enhanced material properties exhibited by the microbially synthetized polyhydroxyalkanoate (PHA) copolymer poly(hydroxybutyrate-co-hydroxyhexanoate) [P(HB-co-HHx)] evidence that this naturally biodegrading biopolymer could replace various functionalities of established petrochemical plastics. In fact, the thermal processability, toughness and degradation rate of P(HB-co-HHx) can be tuned by modulating its HHx molar content enabling to manufacture polymers à-la-carte. We have developed a simple batch strategy to precisely control the HHx content of P(HB-co-HHx) to obtain tailor-made PHAs with defined properties. By adjusting the ratio of fructose to canola oil as substrates for the cultivation of recombinant Ralstonia eutropha Re2058/pCB113, the molar fraction of HHx in P(HB-co-HHx) could be adjusted within a range of 2-17 mol% without compromising polymer yields. The chosen strategy proved to be robust from the mL-scale in deep-well-plates to 1-L batch bioreactor cultivations.
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Affiliation(s)
- Lara Santolin
- Technische Universität Berlin, Institute of Biotechnology, Chair of Bioprocess Engineering, Berlin, Germany
| | - Isabel Thiele
- Technische Universität Berlin, Institute of Biotechnology, Chair of Bioprocess Engineering, Berlin, Germany
| | - Peter Neubauer
- Technische Universität Berlin, Institute of Biotechnology, Chair of Bioprocess Engineering, Berlin, Germany
| | - Sebastian L. Riedel
- Technische Universität Berlin, Institute of Biotechnology, Chair of Bioprocess Engineering, Berlin, Germany
- Berliner Hochschule für Technik, Department VIII – Mechanical Engineering, Event Technology and Process Engineering, Laboratory of Environmental and Bioprocess Engineering, Berlin, Germany
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Min Song H, Chan Joo J, Hyun Lim S, Jin Lim H, Lee S, Jae Park S. Production of polyhydroxyalkanoates containing monomers conferring amorphous and elastomeric properties from renewable resources: Current status and future perspectives. BIORESOURCE TECHNOLOGY 2022; 366:128114. [PMID: 36283671 DOI: 10.1016/j.biortech.2022.128114] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/06/2022] [Accepted: 10/08/2022] [Indexed: 06/16/2023]
Abstract
Petrochemical-based plastics cause environmental pollution and threaten humans and ecosystems. Polyhydroxyalkanoate (PHA) is considered a promising alternative to nondegradable plastics since it is eco-friendly and biodegradable polymer having similar properties to conventional plastics. PHA's material properties are generally determined by composition and type of monomers in PHA. PHA can be designed in tailor-made manner for their suitable application areas. Among many monomers in PHAs, ω-hydroxalkanoates such as 3-hydroxypropionate (3HP), 4-hydroxybutyrate (4HB), 5-hydroxyvalerate (5HV), and 6-hydroxyhexanoate (6HHx) and medium-chain-length 3-hydroxyalkanoate such as 3-hydroxyhexanoate (3HHx) and 4-hydroxyvalerate (4HV), have been examined as potential monomers able to confer amorphous and elastomer properties when these are incorporated as comonomer in poly(3-hydroxybutyrate) copolymer that has 3HB as main monomer along with comonomers in different monomer fraction. Herein, recent advances in production of PHAs designed to have amorphous and elastomeric properties from renewable sources such as lignocellulose, levulinic acid, crude glycerol, and waste oil are discussed.
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Affiliation(s)
- Hye Min Song
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Jeong Chan Joo
- Department of Biotechnology, The Catholic University of Korea, Bucheon-si, Gyeonggi-do 14662, Republic of Korea
| | - Seo Hyun Lim
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Hye Jin Lim
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Siseon Lee
- Department of Biotechnology, The Catholic University of Korea, Bucheon-si, Gyeonggi-do 14662, Republic of Korea
| | - Si Jae Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea.
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