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Nawab S, Zhang Y, Ullah MW, Lodhi AF, Shah SB, Rahman MU, Yong YC. Microbial host engineering for sustainable isobutanol production from renewable resources. Appl Microbiol Biotechnol 2024; 108:33. [PMID: 38175234 DOI: 10.1007/s00253-023-12821-9] [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: 09/10/2023] [Revised: 12/10/2023] [Accepted: 12/18/2023] [Indexed: 01/05/2024]
Abstract
Due to the limited resources and environmental problems associated with fossil fuels, there is a growing interest in utilizing renewable resources for the production of biofuels through microbial fermentation. Isobutanol is a promising biofuel that could potentially replace gasoline. However, its production efficiency is currently limited by the use of naturally isolated microorganisms. These naturally isolated microorganisms often encounter problems such as a limited range of substrates, low tolerance to solvents or inhibitors, feedback inhibition, and an imbalanced redox state. This makes it difficult to improve their production efficiency through traditional process optimization methods. Fortunately, recent advancements in genetic engineering technologies have made it possible to enhance microbial hosts for the increased production of isobutanol from renewable resources. This review provides a summary of the strategies and synthetic biology approaches that have been employed in the past few years to improve naturally isolated or non-natural microbial hosts for the enhanced production of isobutanol by utilizing different renewable resources. Furthermore, it also discusses the challenges that are faced by engineered microbial hosts and presents future perspectives to enhancing isobutanol production. KEY POINTS: • Promising potential of isobutanol to replace gasoline • Engineering of native and non-native microbial host for isobutanol production • Challenges and opportunities for enhanced isobutanol production.
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Affiliation(s)
- Said Nawab
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - YaFei Zhang
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Muhammad Wajid Ullah
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Adil Farooq Lodhi
- Department of Microbiology, Faculty of Biological and Health Sciences, Hazara University, Mansehra, Pakistan
| | - Syed Bilal Shah
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Mujeeb Ur Rahman
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Yang-Chun Yong
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China.
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Santolin L, Riedel SL, Brigham CJ. Synthetic biology toolkit of Ralstonia eutropha (Cupriavidus necator). Appl Microbiol Biotechnol 2024; 108:450. [PMID: 39207499 PMCID: PMC11362209 DOI: 10.1007/s00253-024-13284-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 08/09/2024] [Accepted: 08/12/2024] [Indexed: 09/04/2024]
Abstract
Synthetic biology encompasses many kinds of ideas and techniques with the common theme of creating something novel. The industrially relevant microorganism, Ralstonia eutropha (also known as Cupriavidus necator), has long been a subject of metabolic engineering efforts to either enhance a product it naturally makes (polyhydroxyalkanoate) or produce novel bioproducts (e.g., biofuels and other small molecule compounds). Given the metabolic versatility of R. eutropha and the existence of multiple molecular genetic tools and techniques for the organism, development of a synthetic biology toolkit is underway. This toolkit will allow for novel, user-friendly design that can impart new capabilities to R. eutropha strains to be used for novel application. This article reviews the different synthetic biology techniques currently available for modifying and enhancing bioproduction in R. eutropha. KEY POINTS: • R. eutropha (C. necator) is a versatile organism that has been examined for many applications. • Synthetic biology is being used to design more powerful strains for bioproduction. • A diverse synthetic biology toolkit is being developed to enhance R. eutropha's capabilities.
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Affiliation(s)
- Lara Santolin
- Technische Universität Berlin, Institute of Biotechnology, Chair of Bioprocess Engineering, Berlin, Germany
| | - Sebastian L Riedel
- Berliner Hochschule Für Technik, Department VIII - Mechanical Engineering, Event Technology and Process Engineering, Environmental and Bioprocess Engineering Laboratory, Berlin, Germany.
| | - Christopher J Brigham
- Department of Bioengineering, University of Massachusetts Dartmouth, North Dartmouth, MA, USA.
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Jenkins Sánchez LR, Sips LM, Van Bogaert INA. Just passing through: Deploying aquaporins in microbial cell factories. Biotechnol Prog 2024:e3497. [PMID: 39051848 DOI: 10.1002/btpr.3497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 07/05/2024] [Accepted: 07/10/2024] [Indexed: 07/27/2024]
Abstract
As microbial membranes are naturally impermeable to even the smallest biomolecules, transporter proteins are physiologically essential for normal cell functioning. This makes transporters a key target area for engineering enhanced cell factories. As part of the wider cellular transportome, aquaporins (AQPs) are responsible for transporting small polar solutes, encompassing many compounds which are of great interest for industrial biotechnology, including cell feedstocks, numerous commercially relevant polyols and even weak organic acids. In this review, examples of cell factory engineering by targeting AQPs are presented. These AQP modifications aid in redirecting carbon fluxes and boosting bioconversions either by enhanced feedstock uptake, improved intermediate retention, increasing product export into the media or superior cell viability against stressors with applications in both bacterial and yeast production platforms. Additionally, the future potential for AQP deployment and targeting is discussed, showcasing hurdles and considerations of this strategy as well as recent advances and future directions in the field. By leveraging the natural diversity of AQPs and breakthroughs in channel protein engineering, these transporters are poised to be promising tools capable of enhancing a wide variety of biotechnological processes.
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Affiliation(s)
- Liam Richard Jenkins Sánchez
- BioPort Group, Centre for Synthetic Biology, Department of Biotechnology, Faculty of Bio-science Engineering, Ghent University, Ghent, Belgium
| | - Lobke Maria Sips
- BioPort Group, Centre for Synthetic Biology, Department of Biotechnology, Faculty of Bio-science Engineering, Ghent University, Ghent, Belgium
| | - Inge Noëlle Adriënne Van Bogaert
- BioPort Group, Centre for Synthetic Biology, Department of Biotechnology, Faculty of Bio-science Engineering, Ghent University, Ghent, Belgium
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Hudson EP. The Calvin Benson cycle in bacteria: New insights from systems biology. Semin Cell Dev Biol 2024; 155:71-83. [PMID: 37002131 DOI: 10.1016/j.semcdb.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 02/21/2023] [Accepted: 03/16/2023] [Indexed: 03/31/2023]
Abstract
The Calvin Benson cycle in phototrophic and chemolithoautotrophic bacteria has ecological and biotechnological importance, which has motivated study of its regulation. I review recent advances in our understanding of how the Calvin Benson cycle is regulated in bacteria and the technologies used to elucidate regulation and modify it, and highlight differences between and photoautotrophic and chemolithoautotrophic models. Systems biology studies have shown that in oxygenic phototrophic bacteria, Calvin Benson cycle enzymes are extensively regulated at post-transcriptional and post-translational levels, with multiple enzyme activities connected to cellular redox status through thioredoxin. In chemolithoautotrophic bacteria, regulation is primarily at the transcriptional level, with effector metabolites transducing cell status, though new methods should now allow facile, proteome-wide exploration of biochemical regulation in these models. A biotechnological objective is to enhance CO2 fixation in the cycle and partition that carbon to a product of interest. Flux control of CO2 fixation is distributed over multiple enzymes, and attempts to modulate gene Calvin cycle gene expression show a robust homeostatic regulation of growth rate, though the synthesis rates of products can be significantly increased. Therefore, de-regulation of cycle enzymes through protein engineering may be necessary to increase fluxes. Non-canonical Calvin Benson cycles, if implemented with synthetic biology, could have reduced energy demand and enzyme loading, thus increasing the attractiveness of these bacteria for industrial applications.
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Affiliation(s)
- Elton P Hudson
- Department of Protein Science, Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
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Morlino MS, Serna García R, Savio F, Zampieri G, Morosinotto T, Treu L, Campanaro S. Cupriavidus necator as a platform for polyhydroxyalkanoate production: An overview of strains, metabolism, and modeling approaches. Biotechnol Adv 2023; 69:108264. [PMID: 37775073 DOI: 10.1016/j.biotechadv.2023.108264] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/18/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023]
Abstract
Cupriavidus necator is a bacterium with a high phenotypic diversity and versatile metabolic capabilities. It has been extensively studied as a model hydrogen oxidizer, as well as a producer of polyhydroxyalkanoates (PHA), plastic-like biopolymers with a high potential to substitute petroleum-based materials. Thanks to its adaptability to diverse metabolic lifestyles and to the ability to accumulate large amounts of PHA, C. necator is employed in many biotechnological processes, with particular focus on PHA production from waste carbon sources. The large availability of genomic information has enabled a characterization of C. necator's metabolism, leading to the establishment of metabolic models which are used to devise and optimize culture conditions and genetic engineering approaches. In this work, the characteristics of available C. necator strains and genomes are reviewed, underlining how a thorough comprehension of the genetic variability of C. necator is lacking and it could be instrumental for wider application of this microorganism. The metabolic paradigms of C. necator and how they are connected to PHA production and accumulation are described, also recapitulating the variety of carbon substrates used for PHA accumulation, highlighting the most promising strategies to increase the yield. Finally, the review describes and critically analyzes currently available genome-scale metabolic models and reduced metabolic network applications commonly employed in the optimization of PHA production. Overall, it appears that the capacity of C. necator of performing CO2 bioconversion to PHA is still underexplored, both in biotechnological applications and in metabolic modeling. However, the accurate characterization of this organism and the efforts in using it for gas fermentation can help tackle this challenging perspective in the future.
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Affiliation(s)
- Maria Silvia Morlino
- Department of Biology, University of Padua, via U. Bassi 58/b, 35131 Padova, Italy
| | - Rebecca Serna García
- CALAGUA - Unidad Mixta UV-UPV, Departament d'Enginyeria Química, Universitat de València, Avinguda de la Universitat s/n, 46100 Burjassot, Valencia, Spain
| | - Filippo Savio
- Department of Biology, University of Padua, via U. Bassi 58/b, 35131 Padova, Italy
| | - Guido Zampieri
- Department of Biology, University of Padua, via U. Bassi 58/b, 35131 Padova, Italy
| | - Tomas Morosinotto
- Department of Biology, University of Padua, via U. Bassi 58/b, 35131 Padova, Italy
| | - Laura Treu
- Department of Biology, University of Padua, via U. Bassi 58/b, 35131 Padova, Italy.
| | - Stefano Campanaro
- Department of Biology, University of Padua, via U. Bassi 58/b, 35131 Padova, Italy
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Tang R, Yuan X, Yang J. Problems and corresponding strategies for converting CO 2 into value-added products in Cupriavidus necator H16 cell factories. Biotechnol Adv 2023; 67:108183. [PMID: 37286176 DOI: 10.1016/j.biotechadv.2023.108183] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/17/2023] [Accepted: 05/31/2023] [Indexed: 06/09/2023]
Abstract
Elevated CO2 emissions have substantially altered the worldwide climate, while the excessive reliance on fossil fuels has exacerbated the energy crisis. Therefore, the conversion of CO2 into fuel, petroleum-based derivatives, drug precursors, and other value-added products is expected. Cupriavidus necator H16 is the model organism of the "Knallgas" bacterium and is considered to be a microbial cell factory as it can convert CO2 into various value-added products. However, the development and application of C. necator H16 cell factories has several limitations, including low efficiency, high cost, and safety concerns arising from the autotrophic metabolic characteristics of the strains. In this review, we first considered the autotrophic metabolic characteristics of C. necator H16, and then categorized and summarized the resulting problems. We also provided a detailed discussion of some corresponding strategies concerning metabolic engineering, trophic models, and cultivation mode. Finally, we provided several suggestions for improving and combining them. This review might help in the research and application of the conversion of CO2 into value-added products in C. necator H16 cell factories.
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Affiliation(s)
- Ruohao Tang
- Energy-rich Compounds Production by Photosynthetic Carbon Fixation Research Center, Shandong Key Lab of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, Shandong Province, People's Republic of China; Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, Shandong Province, People's Republic of China
| | - Xianzheng Yuan
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, Shandong Province, People's Republic of China
| | - Jianming Yang
- Energy-rich Compounds Production by Photosynthetic Carbon Fixation Research Center, Shandong Key Lab of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, Shandong Province, People's Republic of China.
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Wang S, Zhou X, Wu S, Zhao M, Hu Z. Transcriptomic and metabolomic analyses revealed regulation mechanism of mixotrophic Cylindrotheca sp. glycerol utilization and biomass promotion. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:84. [PMID: 37208696 DOI: 10.1186/s13068-023-02338-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/08/2023] [Indexed: 05/21/2023]
Abstract
BACKGROUND Diatoms have been viewed as ideal cell factories for production of some high-value bioactive metabolites, such as fucoxanthin, but their applications are restrained by limited biomass yield. Mixotrophy, by using both CO2 and organic carbon source, is believed effective to crack the bottleneck of biomass accumulation and achieve a sustainable bioproduct supply. RESULTS Glycerol, among tested carbon sources, was proved as the sole that could significantly promote growth of Cylindrotheca sp. with illumination, a so-called growth pattern, mixotrophy. Biomass and fucoxanthin yields of Cylindrotheca sp., grown in medium with glycerol (2 g L-1), was increased by 52% and 29%, respectively, as compared to the autotrophic culture (control) without compromise in photosynthetic performance. As Cylindrotheca sp. was unable to use glycerol without light, a time-series transcriptomic analysis was carried out to elucidate the light regulation on glycerol utilization. Among the genes participating in glycerol utilization, GPDH1, TIM1 and GAPDH1, showed the highest dependence on light. Their expressions decreased dramatically when the alga was transferred from light into darkness. Despite the reduced glycerol uptake in the dark, expressions of genes associating with pyrimidine metabolism and DNA replication were upregulated when Cylindrotheca sp. was cultured mixotrophically. Comparative transcriptomic and metabolomic analyses revealed amino acids and aminoacyl-tRNA metabolisms were enhanced at different timepoints of diurnal cycles in mixotrophic Cylindrotheca sp., as compared to the control. CONCLUSIONS Conclusively, this study not only provides an alternative for large-scale cultivation of Cylindrotheca, but also pinpoints the limiting enzymes subject to further metabolic manipulation. Most importantly, the novel insights in this study should aid to understand the mechanism of biomass promotion in mixotrophic Cylindrotheca sp.
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Affiliation(s)
- Song Wang
- Guangdong Technology Research Center for Marine Algal Bioengineering; Guangdong Provincial Key Laboratory for Plant Epigenetics; Shenzhen Engineering Laboratory for Marine Algal Biotechnology; Longhua Innovation Institute for Biotechnology; College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Xiyi Zhou
- Guangdong Technology Research Center for Marine Algal Bioengineering; Guangdong Provincial Key Laboratory for Plant Epigenetics; Shenzhen Engineering Laboratory for Marine Algal Biotechnology; Longhua Innovation Institute for Biotechnology; College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Sha Wu
- Guangdong Technology Research Center for Marine Algal Bioengineering; Guangdong Provincial Key Laboratory for Plant Epigenetics; Shenzhen Engineering Laboratory for Marine Algal Biotechnology; Longhua Innovation Institute for Biotechnology; College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Mengkai Zhao
- Guangdong Technology Research Center for Marine Algal Bioengineering; Guangdong Provincial Key Laboratory for Plant Epigenetics; Shenzhen Engineering Laboratory for Marine Algal Biotechnology; Longhua Innovation Institute for Biotechnology; College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Zhangli Hu
- Guangdong Technology Research Center for Marine Algal Bioengineering; Guangdong Provincial Key Laboratory for Plant Epigenetics; Shenzhen Engineering Laboratory for Marine Algal Biotechnology; Longhua Innovation Institute for Biotechnology; College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China.
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Zhang L, Jiang Z, Tsui TH, Loh KC, Dai Y, Tong YW. A Review on Enhancing Cupriavidus necator Fermentation for Poly(3-hydroxybutyrate) (PHB) Production From Low-Cost Carbon Sources. Front Bioeng Biotechnol 2022; 10:946085. [PMID: 35928944 PMCID: PMC9343952 DOI: 10.3389/fbioe.2022.946085] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
In the context of a circular economy, bioplastic production using biodegradable materials such as poly(3-hydroxybutyrate) (PHB) has been proposed as a promising solution to fundamentally solve the disposal issue of plastic waste. PHB production techniques through fermentation of PHB-accumulating microbes such as Cupriavidus necator have been revolutionized over the past several years with the development of new strategies such as metabolic engineering. This review comprehensively summarizes the latest PHB production technologies via Cupriavidus necator fermentation. The mechanism of the biosynthesis pathway for PHB production was first assessed. PHB production efficiencies of common carbon sources, including food waste, lignocellulosic materials, glycerol, and carbon dioxide, were then summarized and critically analyzed. The key findings in enhancing strategies for PHB production in recent years, including pre-treatment methods, nutrient limitations, feeding optimization strategies, and metabolism engineering strategies, were summarized. Furthermore, technical challenges and future prospects of strategies for enhanced production efficiencies of PHB were also highlighted. Based on the overview of the current enhancing technologies, more pilot-scale and larger-scale tests are essential for future implementation of enhancing strategies in full-scale biogas plants. Critical analyses of various enhancing strategies would facilitate the establishment of more sustainable microbial fermentation systems for better waste management and greater efficiency of PHB production.
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Affiliation(s)
- Le Zhang
- NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore
- Energy and Environmental Sustainability for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), Singapore, Singapore
| | - Zicheng Jiang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore
| | - To-Hung Tsui
- NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore
- Energy and Environmental Sustainability for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), Singapore, Singapore
| | - Kai-Chee Loh
- Energy and Environmental Sustainability for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), Singapore, Singapore
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore
| | - Yanjun Dai
- Energy and Environmental Sustainability for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), Singapore, Singapore
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yen Wah Tong
- NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore
- Energy and Environmental Sustainability for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), Singapore, Singapore
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore
- *Correspondence: Yen Wah Tong,
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