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Sun M, Gao AX, Liu X, Bai Z, Wang P, Ledesma-Amaro R. Microbial conversion of ethanol to high-value products: progress and challenges. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:115. [PMID: 39160588 PMCID: PMC11334397 DOI: 10.1186/s13068-024-02546-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 07/03/2024] [Indexed: 08/21/2024]
Abstract
Industrial biotechnology heavily relies on the microbial conversion of carbohydrate substrates derived from sugar- or starch-rich crops. This dependency poses significant challenges in the face of a rising population and food scarcity. Consequently, exploring renewable, non-competing carbon sources for sustainable bioprocessing becomes increasingly important. Ethanol, a key C2 feedstock, presents a promising alternative, especially for producing acetyl-CoA derivatives. In this review, we offer an in-depth analysis of ethanol's potential as an alternative carbon source, summarizing its distinctive characteristics when utilized by microbes, microbial ethanol metabolism pathway, and microbial responses and tolerance mechanisms to ethanol stress. We provide an update on recent progress in ethanol-based biomanufacturing and ethanol biosynthesis, discuss current challenges, and outline potential research directions to guide future advancements in this field. The insights presented here could serve as valuable theoretical support for researchers and industry professionals seeking to harness ethanol's potential for the production of high-value products.
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Affiliation(s)
- Manman Sun
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China
- Institute of Hefei Artificial Intelligence Breeding Accelerator, Hefei, 230000, China
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London, SW7 2AZ, UK
| | - Alex Xiong Gao
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, 999077, China
| | - Xiuxia Liu
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214112, China
| | - Zhonghu Bai
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214112, China.
| | - Peng Wang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China.
- Institute of Hefei Artificial Intelligence Breeding Accelerator, Hefei, 230000, China.
| | - Rodrigo Ledesma-Amaro
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London, SW7 2AZ, UK.
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2
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Meriläinen E, Efimova E, Santala V, Santala S. Carbon-wise utilization of lignin-related compounds by synergistically employing anaerobic and aerobic bacteria. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:78. [PMID: 38851749 PMCID: PMC11161944 DOI: 10.1186/s13068-024-02526-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
BACKGROUND Lignin is a highly abundant but strongly underutilized natural resource that could serve as a sustainable feedstock for producing chemicals by microbial cell factories. Because of the heterogeneous nature of the lignin feedstocks, the biological upgrading of lignin relying on the metabolic routes of aerobic bacteria is currently considered as the most promising approach. However, the limited substrate range and the inefficient catabolism of the production hosts hinder the upgrading of lignin-related aromatics. Particularly, the aerobic O-demethylation of the methoxyl groups in aromatic substrates is energy-limited, inhibits growth, and results in carbon loss in the form of CO2. RESULTS In this study, we present a novel approach for carbon-wise utilization of lignin-related aromatics by the integration of anaerobic and aerobic metabolisms. In practice, we employed an acetogenic bacterium Acetobacterium woodii for anaerobic O-demethylation of aromatic compounds, which distinctively differs from the aerobic O-demethylation; in the process, the carbon from the methoxyl groups is fixed together with CO2 to form acetate, while the aromatic ring remains unchanged. These accessible end-metabolites were then utilized by an aerobic bacterium Acinetobacter baylyi ADP1. By utilizing this cocultivation approach, we demonstrated an upgrading of guaiacol, an abundant but inaccessible substrate to most microbes, into a plastic precursor muconate, with a nearly equimolar yields (0.9 mol/mol in a small-scale cultivation and 1.0 mol/mol in a one-pot bioreactor cultivation). The process required only a minor genetic engineering, namely a single gene knock-out. Noticeably, by employing a metabolic integration of the two bacteria, it was possible to produce biomass and muconate by utilizing only CO2 and guaiacol as carbon sources. CONCLUSIONS By the novel approach, we were able to overcome the issues related to aerobic O-demethylation of methoxylated aromatic substrates and demonstrated carbon-wise conversion of lignin-related aromatics to products with yields unattainable by aerobic processes. This study highlights the power of synergistic integration of distinctive metabolic features of bacteria, thus unlocking new opportunities for harnessing microbial cocultures in upgrading challenging feedstocks.
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Affiliation(s)
- Ella Meriläinen
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Ville Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland.
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3
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Wang H, Tan HY, Lian J, Zhou K. Nanopore sequencing improves construction of customized CRISPR-based gene activation libraries. Biotechnol Bioeng 2024; 121:1543-1553. [PMID: 38293815 DOI: 10.1002/bit.28664] [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: 08/30/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 02/01/2024]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-based screening has emerged as a powerful tool for identifying new gene targets for desired cellular phenotypes. The construction of guide RNA (gRNA) pools largely determines library quality and is usually performed using Golden Gate assembly or Gibson assembly. To date, library construction methods have not been systematically compared, and the quality check of each batch has been slow. In this study, an in-house nanopore sequencing workflow was established for assessing the current methods of gRNA pool construction. The bias of pool construction was reduced by employing the polymerase-mediated non-amplifying method. Then, a small gRNA pool was utilized to characterize stronger activation domains, specifically MED2 (a subunit of mediator complex) and HAP4 (a heme activator protein), as well as to identify better gRNA choices for dCas12a-based gene activation in Saccharomyces cerevisiae. Furthermore, based on the better CRISPRa tool identified in this study, a custom gRNA pool, which consisted of 99 gRNAs targeting central metabolic pathways, was designed and employed to screen for gene targets that could improve ethanol utilization in S. cerevisiae. The nanopore sequencing-based workflow demonstrated here should provide a cost-effective approach for assessing the quality of customized gRNA library, leading to faster and more efficient genetic and metabolic engineering in S. cerevisiae.
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Affiliation(s)
- Handing Wang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore
| | - Heng Yih Tan
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore
| | - Jiazhang Lian
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
| | - Kang Zhou
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore
- Cluster of Food, Chemical and Biotechnology, Singapore Institute of Technology, Singapore
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4
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Chen PR, Xia PF. Carbon recycling with synthetic CO 2 fixation pathways. Curr Opin Biotechnol 2024; 85:103023. [PMID: 38007984 DOI: 10.1016/j.copbio.2023.103023] [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: 09/15/2023] [Revised: 11/01/2023] [Accepted: 11/07/2023] [Indexed: 11/28/2023]
Abstract
Carbon dioxide (CO2) is the node of alleviating global climate change and supporting living organisms on Earth. Currently, the warming climate and the growing population demand enhanced CO2 fixation for a sustainable future, which stimulates innovations in biotechnology to tackle these challenges. To this endeavor, synthetic biology and metabolic engineering are enabling a promising approach to engineer synthetic carbon fixation in heterotrophic organisms combining the advantages of both autotrophs and heterotrophs. Here, we review the current advances in constructing synthetic CO2 fixation pathways and discuss the underlying design principles with confronting challenges. Moreover, we highlight the application scenarios of these designs at different concentrations of CO2, and how sustainable bioproduction can be improved. We also foresee the future of engineering synthetic carbon fixation pathways for carbon recycling.
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Affiliation(s)
- Pei-Ru Chen
- School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Peng-Fei Xia
- School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
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5
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Amalia L, Chang CY, Wang SSS, Yeh YC, Tsai SL. Recent advances in the biological depolymerization and upcycling of polyethylene terephthalate. Curr Opin Biotechnol 2024; 85:103053. [PMID: 38128200 DOI: 10.1016/j.copbio.2023.103053] [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: 10/01/2023] [Revised: 11/16/2023] [Accepted: 11/28/2023] [Indexed: 12/23/2023]
Abstract
Polyethylene terephthalate (PET) is favored for its exceptional properties and widespread daily use. This review highlights recent advancements that enable the development of biological tools for PET decomposition, transforming PET into valuable platform chemicals and materials in upcycling processes. Enhancing PET hydrolases' catalytic activity and efficiency through protein engineering strategies is a priority, facilitating more effective PET waste management. Efforts to create novel PET hydrolases for large-scale PET depolymerization continue, but cost-effectiveness remains challenging. Hydrolyzed monomers must add additional value to make PET recycling economically attractive. Valorization of hydrolysis products through the upcycling process is expected to produce new compounds with different values and qualities from the initial polymer, making the decomposed monomers more appealing. Advances in synthetic biology and enzyme engineering hold promise for PET upcycling. While biological depolymerization offers environmental benefits, further research is needed to make PET upcycling sustainable and economically feasible.
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Affiliation(s)
- Lita Amalia
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
| | - Chia-Yu Chang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Steven S-S Wang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Chun Yeh
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Shen-Long Tsai
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
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6
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Chen S, Jin Y, Yang N, Wei L, Xu D, Xu X. Improving microbial production of value-added products through the intervention of magnetic fields. BIORESOURCE TECHNOLOGY 2024; 393:130087. [PMID: 38042431 DOI: 10.1016/j.biortech.2023.130087] [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: 08/10/2023] [Revised: 10/17/2023] [Accepted: 11/20/2023] [Indexed: 12/04/2023]
Abstract
The magnetic field application is emerging as an auxiliary physical strategy to facilitate rapid biomass accumulation and intracellular production of compounds. However, the underlying mechanisms and principles governing the application of magnetic fields for microbial growth and biotransformation are not yet fully understood. Therefore, a better understanding of interdisciplinary technologies integration, expanded magnetic field application, and scaled-up industrial implementation is crucial. In this review, the magnetic field characteristics, magnetic field-assisted fermentation devices, and the working mechanism of magnetic field have been reviewed comprehensively from both physical and microbiological perspectives. The review suggests that magnetic fields affect the biochemical processes in microorganisms by mediating nutrient transport across membranes, electron transfer during photosynthesis and respiration, enzyme activity and gene expression. Moreover, the recent advances in magnetic field application for microbial fermentation and conversion in biochemical, food and agricultural fields have been summarized.
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Affiliation(s)
- Sirui Chen
- School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
| | - Yamei Jin
- State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China.
| | - Na Yang
- State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
| | - Liwen Wei
- School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
| | - Dan Xu
- State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
| | - Xueming Xu
- State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China
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Wagner N, Bade F, Straube E, Rabe K, Frazão CJR, Walther T. In vivo implementation of a synthetic metabolic pathway for the carbon-conserving conversion of glycolaldehyde to acetyl-CoA. Front Bioeng Biotechnol 2023; 11:1125544. [PMID: 36845174 PMCID: PMC9947464 DOI: 10.3389/fbioe.2023.1125544] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 01/30/2023] [Indexed: 02/11/2023] Open
Abstract
Ethylene glycol (EG) derived from plastic waste or CO2 can serve as a substrate for microbial production of value-added chemicals. Assimilation of EG proceeds though the characteristic intermediate glycolaldehyde (GA). However, natural metabolic pathways for GA assimilation have low carbon efficiency when producing the metabolic precursor acetyl-CoA. In alternative, the reaction sequence catalyzed by EG dehydrogenase, d-arabinose 5-phosphate aldolase, d-arabinose 5-phosphate isomerase, d-ribulose 5-phosphate 3-epimerase (Rpe), d-xylulose 5-phosphate phosphoketolase, and phosphate acetyltransferase may enable the conversion of EG into acetyl-CoA without carbon loss. We investigated the metabolic requirements for in vivo function of this pathway in Escherichia coli by (over)expressing constituting enzymes in different combinations. Using 13C-tracer experiments, we first examined the conversion of EG to acetate via the synthetic reaction sequence and showed that, in addition to heterologous phosphoketolase, overexpression of all native enzymes except Rpe was required for the pathway to function. Since acetyl-CoA could not be reliably quantified by our LC/MS-method, the distribution of isotopologues in mevalonate, a stable metabolite that is exclusively derived from this intermediate, was used to probe the contribution of the synthetic pathway to biosynthesis of acetyl-CoA. We detected strong incorporation of 13C carbon derived from labeled GA in all intermediates of the synthetic pathway. In presence of unlabeled co-substrate glycerol, 12.4% of the mevalonate (and therefore acetyl-CoA) was derived from GA. The contribution of the synthetic pathway to acetyl-CoA production was further increased to 16.1% by the additional expression of the native phosphate acyltransferase enzyme. Finally, we demonstrated that conversion of EG to mevalonate was feasible albeit at currently extremely small yields.
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Affiliation(s)
- Nils Wagner
- TU Dresden, Institute of Natural Materials Technology, Dresden, Germany
| | - Frederik Bade
- TU Dresden, Institute of Natural Materials Technology, Dresden, Germany
| | - Elly Straube
- TU Dresden, Institute of Natural Materials Technology, Dresden, Germany
| | - Kenny Rabe
- TU Dresden, Institute of Natural Materials Technology, Dresden, Germany
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8
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Ricci L, Seifert A, Bernacchi S, Fino D, Pirri CF, Re A. Leveraging substrate flexibility and product selectivity of acetogens in two-stage systems for chemical production. Microb Biotechnol 2022; 16:218-237. [PMID: 36464980 PMCID: PMC9871533 DOI: 10.1111/1751-7915.14172] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/31/2022] [Accepted: 11/08/2022] [Indexed: 12/09/2022] Open
Abstract
Carbon dioxide (CO2 ) stands out as sustainable feedstock for developing a circular carbon economy whose energy supply could be obtained by boosting the production of clean hydrogen from renewable electricity. H2 -dependent CO2 gas fermentation using acetogenic microorganisms offers a viable solution of increasingly demonstrated value. While gas fermentation advances to achieve commercial process scalability, which is currently limited to a few products such as acetate and ethanol, it is worth taking the best of the current state-of-the-art technology by its integration within innovative bioconversion schemes. This review presents multiple scenarios where gas fermentation by acetogens integrate into double-stage biotechnological production processes that use CO2 as sole carbon feedstock and H2 as energy carrier for products' synthesis. In the integration schemes here reviewed, the first stage can be biotic or abiotic while the second stage is biotic. When the first stage is biotic, acetogens act as a biological platform to generate chemical intermediates such as acetate, formate and ethanol that become substrates for a second fermentation stage. This approach holds the potential to enhance process titre/rate/yield metrics and products' spectrum. Alternatively, when the first stage is abiotic, the integrated two-stage scheme foresees, in the first stage, the catalytic transformation of CO2 into C1 products that, in the second stage, can be metabolized by acetogens. This latter scheme leverages the metabolic flexibility of acetogens in efficient utilization of the products of CO2 abiotic hydrogenation, namely formate and methanol, to synthesize multicarbon compounds but also to act as flexible catalysts for hydrogen storage or production.
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Affiliation(s)
- Luca Ricci
- Department of Applied Science and TechnologyPolitecnico di TorinoTurinItaly,Centre for Sustainable Future TechnologiesFondazione Istituto Italiano di TecnologiaTurinItaly
| | | | | | - Debora Fino
- Department of Applied Science and TechnologyPolitecnico di TorinoTurinItaly,Centre for Sustainable Future TechnologiesFondazione Istituto Italiano di TecnologiaTurinItaly
| | - Candido Fabrizio Pirri
- Department of Applied Science and TechnologyPolitecnico di TorinoTurinItaly,Centre for Sustainable Future TechnologiesFondazione Istituto Italiano di TecnologiaTurinItaly
| | - Angela Re
- Department of Applied Science and TechnologyPolitecnico di TorinoTurinItaly,Centre for Sustainable Future TechnologiesFondazione Istituto Italiano di TecnologiaTurinItaly
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Lu J, Wang Y, Xu M, Fei Q, Gu Y, Luo Y, Wu H. Efficient biosynthesis of 3-hydroxypropionic acid from ethanol in metabolically engineered Escherichia coli. BIORESOURCE TECHNOLOGY 2022; 363:127907. [PMID: 36087655 DOI: 10.1016/j.biortech.2022.127907] [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: 07/26/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
Engineering microbial cell factories to convert CO2-based feedstock into chemicals and fuels provide a feasible carbon-neutral route for the third-generation biorefineries. Ethanol became one of the major products of syngas fermentation by engineered acetogens. The key building block chemical 3-hydroxypropionic acid (3-HP) can be synthesized from ethanol by the malonyl-CoA pathway with CO2 fixation. In this study, the effect of two ethanol consumption pathways on 3-HP synthesis were studied as well as the effect of TCA cycle, gluconeogenesis pathway, and transhydrogenase. And the 3-HP synthesis pathway was also optimized. The engineered strain synthesized 1.66 g/L of 3-HP with a yield of 0.24 g/g. Furthermore, the titer and the yield of 3-HP increased to 13.17 g/L and 0.57 g/g in the whole-cell biocatalysis system. This study indicated that ethanol as feedstock had the potential to synthesize 3-HP, which provided an alternative route for future biorefinery.
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Affiliation(s)
- Juefeng Lu
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Yuying Wang
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Mingcheng Xu
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Qiang Fei
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Yang Gu
- Key Laboratory of Synthetic Biology, The State Key Laboratory of Plant Carbon-Nitrogen Assimilation, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yuanchan Luo
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Hui Wu
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China; Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai 200237, China; Key Laboratory of Bio-based Material Engineering of China National Light Industry Council, 130 Meilong Road, Shanghai 200237, China.
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Carruthers DN, Lee TS. Translating advances in microbial bioproduction to sustainable biotechnology. Front Bioeng Biotechnol 2022; 10:968437. [PMID: 36082166 PMCID: PMC9445250 DOI: 10.3389/fbioe.2022.968437] [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: 06/14/2022] [Accepted: 07/21/2022] [Indexed: 11/24/2022] Open
Abstract
Advances in synthetic biology have radically changed our ability to rewire microorganisms and significantly improved the scalable production of a vast array of drop-in biopolymers and biofuels. The success of a drop-in bioproduct is contingent on market competition with petrochemical analogues and weighted upon relative economic and environmental metrics. While the quantification of comparative trade-offs is critical for accurate process-level decision making, the translation of industrial ecology to synthetic biology is often ambiguous and assessment accuracy has proven challenging. In this review, we explore strategies for evaluating industrial biotechnology through life cycle and techno-economic assessment, then contextualize how recent developments in synthetic biology have improved process viability by expanding feedstock availability and the productivity of microbes. By juxtaposing biological and industrial constraints, we highlight major obstacles between the disparate disciplines that hinder accurate process evaluation. The convergence of these disciplines is crucial in shifting towards carbon neutrality and a circular bioeconomy.
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Affiliation(s)
- David N. Carruthers
- Joint BioEnergy Institute, Emeryville, CA, United States
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Taek Soon Lee
- Joint BioEnergy Institute, Emeryville, CA, United States
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
- *Correspondence: Taek Soon Lee,
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11
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Zhang C, Ottenheim C, Weingarten M, Ji L. Microbial Utilization of Next-Generation Feedstocks for the Biomanufacturing of Value-Added Chemicals and Food Ingredients. Front Bioeng Biotechnol 2022; 10:874612. [PMID: 35480982 PMCID: PMC9035589 DOI: 10.3389/fbioe.2022.874612] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/14/2022] [Indexed: 12/04/2022] Open
Abstract
Global shift to sustainability has driven the exploration of alternative feedstocks beyond sugars for biomanufacturing. Recently, C1 (CO2, CO, methane, formate and methanol) and C2 (acetate and ethanol) substrates are drawing great attention due to their natural abundance and low production cost. The advances in metabolic engineering, synthetic biology and industrial process design have greatly enhanced the efficiency that microbes use these next-generation feedstocks. The metabolic pathways to use C1 and C2 feedstocks have been introduced or enhanced into industrial workhorses, such as Escherichia coli and yeasts, by genetic rewiring and laboratory evolution strategies. Furthermore, microbes are engineered to convert these low-cost feedstocks to various high-value products, ranging from food ingredients to chemicals. This review highlights the recent development in metabolic engineering, the challenges in strain engineering and bioprocess design, and the perspectives of microbial utilization of C1 and C2 feedstocks for the biomanufacturing of value-added products.
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Affiliation(s)
- Congqiang Zhang
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- *Correspondence: Congqiang Zhang, ,
| | - Christoph Ottenheim
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Melanie Weingarten
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - LiangHui Ji
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
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12
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Ju SB, Seo MJ, Yeom SJ. In Vitro One-Pot 3-Hydroxypropanal Production from Cheap C1 and C2 Compounds. Int J Mol Sci 2022; 23:ijms23073990. [PMID: 35409349 PMCID: PMC8999356 DOI: 10.3390/ijms23073990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/02/2022] [Accepted: 04/02/2022] [Indexed: 12/04/2022] Open
Abstract
One- or two-carbon (C1 or C2) compounds have been considered attractive substrates because they are inexpensive and abundant. Methanol and ethanol are representative C1 and C2 compounds, which can be used as bio-renewable platform feedstocks for the biotechnological production of value-added natural chemicals. Methanol-derived formaldehyde and ethanol-derived acetaldehyde can be converted to 3-hydroxypropanal (3-HPA) via aldol condensation. 3-HPA is used in food preservation and as a precursor for 3-hydroxypropionic acid and 1,3-propanediol that are starting materials for manufacturing biocompatible plastic and polytrimethylene terephthalate. In this study, 3-HPA was biosynthesized from formaldehyde and acetaldehyde using deoxyribose-5-phosphate aldolase from Thermotoga maritima (DERATma) and cloned and expressed in Escherichia coli for 3-HPA production. Under optimum conditions, DERATma produced 7 mM 3-HPA from 25 mM substrate (formaldehyde and acetaldehyde) for 60 min with 520 mg/L/h productivity. To demonstrate the one-pot 3-HPA production from methanol and ethanol, we used methanol dehydrogenase from Lysinibacillus xylanilyticus (MDHLx) and DERATma. One-pot 3-HPA production via aldol condensation of formaldehyde and acetaldehyde from methanol and ethanol, respectively, was investigated under optimized reaction conditions. This is the first report on 3-HPA production from inexpensive alcohol substrates (methanol and ethanol) by cascade reaction using DERATma and MDHLx.
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Affiliation(s)
- Su-Bin Ju
- School of Biological Sciences and Biotechnology, Graduate School, Chonnam National University, Yong-bong-ro 77, Gwangju 61186, Korea;
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Korea;
| | - Min-Ju Seo
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Korea;
| | - Soo-Jin Yeom
- School of Biological Sciences and Biotechnology, Graduate School, Chonnam National University, Yong-bong-ro 77, Gwangju 61186, Korea;
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Korea;
- Correspondence:
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Kato J, Gotoh T, Nakashimada Y. Removal of Acetic Acid from Bacterial Culture Media by Adsorption onto a Two-Component Composite Polymer Gel. Gels 2022; 8:gels8030154. [PMID: 35323267 PMCID: PMC8950367 DOI: 10.3390/gels8030154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/22/2022] [Accepted: 02/28/2022] [Indexed: 11/17/2022] Open
Abstract
Organic acids, including acetic acid, are the metabolic products of many microorganisms. Acetic acid is a target product useful in the fermentation process. However, acetic acid has an inhibitory effect on microorganisms and limits fermentation. Thus, it would be beneficial to recover the acid from the culture medium. However, conventional recovery processes are expensive and environmentally unfriendly. Here, we report the use of a two-component hydrogel to adsorb dissociated and undissociated acetic acid from the culture medium. The Langmuir model revealed the maximum adsorption amount to be 44.8 mg acetic acid/g of dry gel at neutral pH value. The adsorption capacity was similar to that of an ion-exchange resin. In addition, the hydrogel maintained its adsorption capability in a culture medium comprising complex components, whereas the ion-exchange did not adsorb in this medium. The adsorbed acetic acid was readily desorbed using a solution containing a high salt concentration. Thus, the recovered acetic acid can be utilized for subsequent processes, and the gel-treated fermentation broth can be reused for the next round of fermentation. Use of this hydrogel may prove to be a more sustainable downstream process to recover biosynthesized acetic acid.
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Affiliation(s)
- Junya Kato
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8530, Hiroshima, Japan;
| | - Takehiko Gotoh
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Hiroshima, Japan
- Correspondence: (T.G.); (Y.N.)
| | - Yutaka Nakashimada
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8530, Hiroshima, Japan;
- Correspondence: (T.G.); (Y.N.)
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