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Mazzoli R, Pescarolo S, Gilli G, Gilardi G, Valetti F. Hydrogen production pathways in Clostridia and their improvement by metabolic engineering. Biotechnol Adv 2024; 73:108379. [PMID: 38754796 DOI: 10.1016/j.biotechadv.2024.108379] [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: 12/04/2023] [Revised: 05/13/2024] [Accepted: 05/13/2024] [Indexed: 05/18/2024]
Abstract
Biological production of hydrogen has a tremendous potential as an environmentally sustainable technology to generate a clean fuel. Among the different available methods to produce biohydrogen, dark fermentation features the highest productivity and can be used as a means to dispose of organic waste biomass. Within this approach, Clostridia have the highest theoretical H2 production yield. Nonetheless, most strains show actual yields far lower than the theoretical maximum: improving their efficiency becomes necessary for achieving cost-effective fermentation processes. This review aims at providing a survey of the metabolic network involved in H2 generation in Clostridia and strategies used to improve it through metabolic engineering. Together with current achievements, a number of future perspectives to implement these results will be illustrated.
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Affiliation(s)
- Roberto Mazzoli
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy.
| | - Simone Pescarolo
- Biology applied to the environment, Laboratories of microbiology and ecotoxicology, Ecobioqual, Environment Park. Via Livorno 60, 10144 Torino, Italy
| | - Giorgio Gilli
- Department of Sciences of Public Health and Pediatrics, School of Medicine, University of Torino, Via Santena 5 bis, 10126 Torino, Italy
| | - Gianfranco Gilardi
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy
| | - Francesca Valetti
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy.
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Adachi Y, Inoue M, Yoshida T, Sako Y. Genetic Engineering of Carbon Monoxide-dependent Hydrogen-producing Machinery in Parageobacillus thermoglucosidasius. Microbes Environ 2021; 35. [PMID: 33087627 PMCID: PMC7734403 DOI: 10.1264/jsme2.me20101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The metabolic engineering of carbon monoxide (CO) oxidizers has the potential to create efficient biocatalysts to produce hydrogen and other valuable chemicals. We herein applied markerless gene deletion to CO dehydrogenase/energy-converting hydrogenase (CODH/ECH) in the thermophilic facultative anaerobe, Parageobacillus thermoglucosidasius. We initially compared the transformation efficiency of two strains, NBRC 107763T and TG4. We then disrupted CODH, ECH, and both enzymes in NBRC 107763T. The characterization of growth in all three disruptants under 100% CO demonstrated that both enzymes were essential for CO-dependent growth with hydrogen production in P. thermoglucosidasius. The present results will become a platform for the further metabolic engineering of this organism.
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Affiliation(s)
- Yuka Adachi
- Graduate School of Agriculture, Kyoto University
| | - Masao Inoue
- Graduate School of Agriculture, Kyoto University
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Wang S, Zhang T, Bao M, Su H, Xu P. Microbial Production of Hydrogen by Mixed Culture Technologies: A Review. Biotechnol J 2019; 15:e1900297. [PMID: 31556225 DOI: 10.1002/biot.201900297] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 09/05/2019] [Indexed: 12/18/2022]
Abstract
With its high energy content and clean combustion, hydrogen is recognized as a renewable clean energy source with enormous potential. Biological hydrogen production is a promising alternative with significant advantages over conventional petroleum-derived chemical processes. Sustainable hydrogen production from renewable resources such as cassava, wastewater, and other agricultural waste is economically feasible for industrial applications. So far, the major bottlenecks in large-scale biological hydrogen production are the low production rate and yield. This review discusses the various factors that affect the metabolic pathways of dark hydrogen production, and highlights the state-of-the-art development of mixed culture technology. The aim of this review is to provide suggestions for the future directions of mixed culture technology, as well as by-product valorization in dark fermentation.
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Affiliation(s)
- Shaojie Wang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Ting Zhang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Meidan Bao
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Haijia Su
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
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Navid A, Jiao Y, Wong SE, Pett-Ridge J. System-level analysis of metabolic trade-offs during anaerobic photoheterotrophic growth in Rhodopseudomonas palustris. BMC Bioinformatics 2019; 20:233. [PMID: 31072303 PMCID: PMC6509789 DOI: 10.1186/s12859-019-2844-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 04/24/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Living organisms need to allocate their limited resources in a manner that optimizes their overall fitness by simultaneously achieving several different biological objectives. Examination of these biological trade-offs can provide invaluable information regarding the biophysical and biochemical bases behind observed cellular phenotypes. A quantitative knowledge of a cell system's critical objectives is also needed for engineering of cellular metabolism, where there is interest in mitigating the fitness costs that may result from human manipulation. RESULTS To study metabolism in photoheterotrophs, we developed and validated a genome-scale model of metabolism in Rhodopseudomonas palustris, a metabolically versatile gram-negative purple non-sulfur bacterium capable of growing phototrophically on various carbon sources, including inorganic carbon and aromatic compounds. To quantitatively assess trade-offs among a set of important biological objectives during different metabolic growth modes, we used our new model to conduct an 8-dimensional multi-objective flux analysis of metabolism in R. palustris. Our results revealed that phototrophic metabolism in R. palustris is light-limited under anaerobic conditions, regardless of the available carbon source. Under photoheterotrophic conditions, R. palustris prioritizes the optimization of carbon efficiency, followed by ATP production and biomass production rate, in a Pareto-optimal manner. To achieve maximum carbon fixation, cells appear to divert limited energy resources away from growth and toward CO2 fixation, even in the presence of excess reduced carbon. We also found that to achieve the theoretical maximum rate of biomass production, anaerobic metabolism requires import of additional compounds (such as protons) to serve as electron acceptors. Finally, we found that production of hydrogen gas, of potential interest as a candidate biofuel, lowers the cellular growth rates under all circumstances. CONCLUSIONS Photoheterotrophic metabolism of R. palustris is primarily regulated by the amount of light it can absorb and not the availability of carbon. However, despite carbon's secondary role as a regulating factor, R. palustris' metabolism strives for maximum carbon efficiency, even when this increased efficiency leads to slightly lower growth rates.
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Affiliation(s)
- Ali Navid
- Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 USA
| | - Yongqin Jiao
- Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 USA
| | - Sergio Ernesto Wong
- Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 USA
| | - Jennifer Pett-Ridge
- Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 USA
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Abomohra AEF, Elshobary M. Biodiesel, Bioethanol, and Biobutanol Production from Microalgae. MICROALGAE BIOTECHNOLOGY FOR DEVELOPMENT OF BIOFUEL AND WASTEWATER TREATMENT 2019:293-321. [DOI: 10.1007/978-981-13-2264-8_13] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Ghimire A, Kumar G, Sivagurunathan P, Shobana S, Saratale GD, Kim HW, Luongo V, Esposito G, Munoz R. Bio-hythane production from microalgae biomass: Key challenges and potential opportunities for algal bio-refineries. BIORESOURCE TECHNOLOGY 2017; 241:525-536. [PMID: 28601770 DOI: 10.1016/j.biortech.2017.05.156] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 05/23/2017] [Accepted: 05/25/2017] [Indexed: 06/07/2023]
Abstract
The interest in microalgae for wastewater treatment and liquid bio-fuels production (i.e. biodiesel and bioethanol) is steadily increasing due to the energy demand of the ultra-modern technological world. The associated biomass and by-product residues generated from these processes can be utilized as a feedstock in anaerobic fermentation for the production of gaseous bio-fuels. In this context, dark fermentation coupled with anaerobic digestion can be a potential technology for the production of hydrogen and methane from these residual algal biomasses. The mixture of these gaseous bio-fuels, known as hythane, has superior characteristics and is increasingly regarded as an alternative to fossil fuels. This review provides the current developments achieved in the conversion of algal biomass to bio-hythane (H2+CH4).
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Affiliation(s)
- Anish Ghimire
- Department of Environmental Science and Engineering, Kathmandu University, P.O. Box 6250, Kathmandu, Nepal
| | - Gopalakrishnan Kumar
- Green Processing, Bioremediation and Alternative Energies Research Group (GPBAE), Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Viet Nam.
| | - Periyasamy Sivagurunathan
- Center for Materials Cycles and Waste Management Research, National Institute for Environmental Studies, Tsukuba, Japan
| | - Sutha Shobana
- Department of Chemistry and Research Centre, Aditanar College of Arts and Science, Virapandianpatnam, Tiruchendur, Tamil Nadu, India
| | - Ganesh D Saratale
- Department of Food Science and Biotechnology, Dongguk University - Seoul, Ilsandong-gu, Goyang-si, Gyonggido 10326, Republic of Korea
| | - Hyun Woo Kim
- Department of Environmental Engineering, Chonbuk National University, Republic of Korea
| | - Vincenzo Luongo
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125 Naples, Italy
| | - Giovanni Esposito
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Di Biasio 43, 03043 Cassino (FR), Italy
| | - Raul Munoz
- Department of Chemical Engineering and Environmental Technology, University of Valladolid, Doctor Mergelina s/n, 47011 Valladolid, Spain
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Sundara Sekar B, Seol E, Park S. Co-production of hydrogen and ethanol from glucose in Escherichia coli by activation of pentose-phosphate pathway through deletion of phosphoglucose isomerase ( pgi) and overexpression of glucose-6-phosphate dehydrogenase ( zwf) and 6-phosphogluconate dehydrogenase ( gnd). BIOTECHNOLOGY FOR BIOFUELS 2017; 10:85. [PMID: 28360941 PMCID: PMC5372246 DOI: 10.1186/s13068-017-0768-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/22/2017] [Indexed: 05/13/2023]
Abstract
BACKGROUND Biologically, hydrogen (H2) can be produced through dark fermentation and photofermentation. Dark fermentation is fast in rate and simple in reactor design, but H2 production yield is unsatisfactorily low as <4 mol H2/mol glucose. To address this challenge, simultaneous production of H2 and ethanol has been suggested. Co-production of ethanol and H2 requires enhanced formation of NAD(P)H during catabolism of glucose, which can be accomplished by diversion of glycolytic flux from the Embden-Meyerhof-Parnas (EMP) pathway to the pentose-phosphate (PP) pathway in Escherichia coli. However, the disruption of pgi (phosphoglucose isomerase) for complete diversion of carbon flux to the PP pathway made E. coli unable to grow on glucose under anaerobic condition. RESULTS Here, we demonstrate that, when glucose-6-phosphate dehydrogenase (Zwf) and 6-phosphogluconate dehydrogenase (Gnd), two major enzymes of the PP pathway, are homologously overexpressed, E. coli Δpgi can recover its anaerobic growth capability on glucose. Further, with additional deletions of ΔhycA, ΔhyaAB, ΔhybBC, ΔldhA, and ΔfrdAB, the recombinant Δpgi mutant could produce 1.69 mol H2 and 1.50 mol ethanol from 1 mol glucose. However, acetate was produced at 0.18 mol mol-1 glucose, indicating that some carbon is metabolized through the Entner-Doudoroff (ED) pathway. To further improve the flux via the PP pathway, heterologous zwf and gnd from Leuconostoc mesenteroides and Gluconobacter oxydans, respectively, which are less inhibited by NADPH, were overexpressed. The new recombinant produced more ethanol at 1.62 mol mol-1 glucose along with 1.74 mol H2 mol-1 glucose, which are close to the theoretically maximal yields, 1.67 mol mol-1 each for ethanol and H2. However, the attempt to delete the ED pathway in the Δpgi mutant to operate the PP pathway as the sole glycolytic route, was unsuccessful. CONCLUSIONS By deletion of pgi and overexpression of heterologous zwf and gnd in E. coli ΔhycA ΔhyaAB ΔhybBC ΔldhA ΔfrdAB, two important biofuels, ethanol and H2, could be successfully co-produced at high yields close to their theoretical maximums. The strains developed in this study should be applicable for the production of other biofuels and biochemicals, which requires supply of excessive reducing power under anaerobic conditions.
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Affiliation(s)
- Balaji Sundara Sekar
- Department of Chemical and Biomolecular Engineering, Pusan National University, 2, Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan, 46241 Republic of Korea
| | - Eunhee Seol
- Department of Chemical and Biomolecular Engineering, Pusan National University, 2, Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan, 46241 Republic of Korea
| | - Sunghoon Park
- Department of Chemical and Biomolecular Engineering, Pusan National University, 2, Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan, 46241 Republic of Korea
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9
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Innovation in biological production and upgrading of methane and hydrogen for use as gaseous transport biofuel. Biotechnol Adv 2016; 34:451-472. [DOI: 10.1016/j.biotechadv.2015.12.009] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 12/15/2015] [Accepted: 12/15/2015] [Indexed: 01/22/2023]
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Sundara Sekar B, Seol E, Mohan Raj S, Park S. Co-production of hydrogen and ethanol by pfkA-deficient Escherichia coli with activated pentose-phosphate pathway: reduction of pyruvate accumulation. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:95. [PMID: 27134652 PMCID: PMC4850720 DOI: 10.1186/s13068-016-0510-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 04/19/2016] [Indexed: 05/26/2023]
Abstract
BACKGROUND Fermentative hydrogen (H2) production suffers from low carbon-to-H2 yield, to which problem, co-production of ethanol and H2 has been proposed as a solution. For improved co-production of H2 and ethanol, we developed Escherichia coli BW25113 ΔhycA ΔhyaAB ΔhybBC ΔldhA ΔfrdAB Δpta-ackA ΔpfkA (SH8*) and overexpressed Zwf and Gnd, the key enzymes in the pentose-phosphate (PP) pathway (SH8*_ZG). However, the amount of accumulated pyruvate, which was significant (typically 0.20 mol mol(-1) glucose), reduced the co-production yield. RESULTS In this study, as a means of reducing pyruvate accumulation and improving co-production of H2 and ethanol, we developed and studied E. coli SH9*_ZG with functional acetate production pathway for conversion of acetyl-CoA to acetate (pta-ackA (+)). Our results indicated that the presence of the acetate pathway completely eliminated pyruvate accumulation and substantially improved the co-production of H2 and ethanol, enabling yields of 1.88 and 1.40 mol, respectively, from 1 mol glucose. These yields, significantly, are close to the theoretical maximums of 1.67 mol H2 and 1.67 mol ethanol. To better understand the glycolytic flux distribution, glycolytic flux prediction and RT-PCR analyses were performed. CONCLUSION The presence of the acetate pathway along with activation of the PP pathway eliminated pyruvate accumulation, thereby significantly improving co-production of H2 and ethanol. Our strategy is applicable to anaerobic production of biofuels and biochemicals, both of which processes demand high NAD(P)H.
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Affiliation(s)
- Balaji Sundara Sekar
- />Department of Chemical and Biomolecular Engineering, Pusan National University, 2, Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan, 46241 Republic of Korea
| | - Eunhee Seol
- />Department of Chemical and Biomolecular Engineering, Pusan National University, 2, Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan, 46241 Republic of Korea
| | - Subramanian Mohan Raj
- />Centre for Research and Development, PRIST University, Trichy–Thanjavur Road, Vallam, Thanjavur, TN 613 403 India
| | - Sunghoon Park
- />Department of Chemical and Biomolecular Engineering, Pusan National University, 2, Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan, 46241 Republic of Korea
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Tomazetto G, Wibberg D, Schlüter A, Oliveira VM. New FeFe-hydrogenase genes identified in a metagenomic fosmid library from a municipal wastewater treatment plant as revealed by high-throughput sequencing. Res Microbiol 2014; 166:9-19. [PMID: 25446611 DOI: 10.1016/j.resmic.2014.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Revised: 10/08/2014] [Accepted: 11/04/2014] [Indexed: 12/18/2022]
Abstract
A fosmid metagenomic library was constructed with total community DNA obtained from a municipal wastewater treatment plant (MWWTP), with the aim of identifying new FeFe-hydrogenase genes encoding the enzymes most important for hydrogen metabolism. The dataset generated by pyrosequencing of a fosmid library was mined to identify environmental gene tags (EGTs) assigned to FeFe-hydrogenase. The majority of EGTs representing FeFe-hydrogenase genes were affiliated with the class Clostridia, suggesting that this group is the main hydrogen producer in the MWWTP analyzed. Based on assembled sequences, three FeFe-hydrogenase genes were predicted based on detection of the L2 motif (MPCxxKxxE) in the encoded gene product, confirming true FeFe-hydrogenase sequences. These sequences were used to design specific primers to detect fosmids encoding FeFe-hydrogenase genes predicted from the dataset. Three identified fosmids were completely sequenced. The cloned genomic fragments within these fosmids are closely related to members of the Spirochaetaceae, Bacteroidales and Firmicutes, and their FeFe-hydrogenase sequences are characterized by the structure type M3, which is common to clostridial enzymes. FeFe-hydrogenase sequences found in this study represent hitherto undetected sequences, indicating the high genetic diversity regarding these enzymes in MWWTP. Results suggest that MWWTP have to be considered as reservoirs for new FeFe-hydrogenase genes.
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Affiliation(s)
- Geizecler Tomazetto
- Division of Microbial Resources, Research Center for Chemistry, Biology and Agriculture (CPQBA), Campinas University - UNICAMP, CP 6171, CEP 13081-970 Campinas, SP, Brazil.
| | - Daniel Wibberg
- Institute for Genome Research and Systems Biology, CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Andreas Schlüter
- Institute for Genome Research and Systems Biology, CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Valéria M Oliveira
- Division of Microbial Resources, Research Center for Chemistry, Biology and Agriculture (CPQBA), Campinas University - UNICAMP, CP 6171, CEP 13081-970 Campinas, SP, Brazil.
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Engineering Hydrogenases for H2 Production: Bolts and Goals. MICROBIAL BIOENERGY: HYDROGEN PRODUCTION 2014. [DOI: 10.1007/978-94-017-8554-9_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Reconstitution of supramolecular organization involved in energy metabolism at electrochemical interfaces for biosensing and bioenergy production. Anal Bioanal Chem 2013; 406:1011-27. [DOI: 10.1007/s00216-013-7465-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 10/01/2013] [Accepted: 10/25/2013] [Indexed: 12/26/2022]
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Ghosh D, Bisaillon A, Hallenbeck PC. Increasing the metabolic capacity of Escherichia coli for hydrogen production through heterologous expression of the Ralstonia eutropha SH operon. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:122. [PMID: 23977944 PMCID: PMC3765991 DOI: 10.1186/1754-6834-6-122] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 08/21/2013] [Indexed: 06/01/2023]
Abstract
BACKGROUND Fermentative hydrogen production is an attractive means for the sustainable production of this future energy carrier but is hampered by low yields. One possible solution is to create, using metabolic engineering, strains which can bypass the normal metabolic limits to substrate conversion to hydrogen. Escherichia coli can degrade a variety of sugars to hydrogen but can only convert electrons available at the pyruvate node to hydrogen, and is unable to use the electrons available in NADH generated during glycolysis. RESULTS Here, the heterologous expression of the soluble [NiFe] hydrogenase from Ralstonia eutropha H16 (the SH hydrogenase) was used to demonstrate the introduction of a pathway capable of deriving substantial hydrogen from the NADH generated by fermentation. Successful expression was demonstrated by in vitro assay of enzyme activity. Moreover, expression of SH restored anaerobic growth on glucose to adhE strains, normally blocked for growth due to the inability to re-oxidize NADH. Measurement of in vivo hydrogen production showed that several metabolically engineered strains were capable of using the SH hydrogenase to derive 2 mol H2 per mol of glucose consumed, close to the theoretical maximum. CONCLUSION Previous introduction of heterologous [NiFe] hydrogenase in E. coli led to NAD(P)H dependent activity, but hydrogen production levels were very low. Here we have shown for the first time substantial in vivo hydrogen production by a heterologously expressed [NiFe] hydrogenase, the soluble NAD-dependent H2ase of R. eutropha (SH hydrogenase). This hydrogenase was able to couple metabolically generated NADH to hydrogen production, thus rescuing an alcohol dehydrogenase (adhE) mutant. This enlarges the range of metabolism available for hydrogen production, thus potentially opening the door to the creation of greatly improved hydrogen production. Strategies for further increasing yields should revolve around making additional NADH available.
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Affiliation(s)
- Dipankar Ghosh
- Département de Microbiologie et Immunologie, Université de Montréal, CP 6128 Succursale Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Ariane Bisaillon
- Département de Microbiologie et Immunologie, Université de Montréal, CP 6128 Succursale Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Patrick C Hallenbeck
- Département de Microbiologie et Immunologie, Université de Montréal, CP 6128 Succursale Centre-ville, Montréal, Québec, Canada H3C 3J7
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Lim JH, Seo SW, Kim SY, Jung GY. Refactoring redox cofactor regeneration for high-yield biocatalysis of glucose to butyric acid in Escherichia coli. BIORESOURCE TECHNOLOGY 2013; 135:568-73. [PMID: 23127832 DOI: 10.1016/j.biortech.2012.09.091] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Revised: 09/23/2012] [Accepted: 09/25/2012] [Indexed: 05/20/2023]
Abstract
In this study, the native redox cofactor regeneration system in Escherichia coli was engineered for the production of butyric acid. The synthetic butyrate pathway, which regenerates NAD(+) from NADH using butyrate as the only final electron acceptor, enabled high-yield production of butyric acid from glucose (83.4% of the molar theoretical yield). The high selectivity for butyrate, with a butyrate/acetate ratio of 41, suggests dramatically improved industrial potential for the production of butyric acid from nonnative hosts compared to the native producers (Clostridium species). Furthermore, this strategy could be broadly utilized for the production of various other useful chemicals in the fields of metabolic engineering and synthetic biology.
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Affiliation(s)
- Jae Hyung Lim
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang, Gyeongbuk 790-784, South Korea
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Mazzoli R. Development of microorganisms for cellulose-biofuel consolidated bioprocessings: metabolic engineers' tricks. Comput Struct Biotechnol J 2012; 3:e201210007. [PMID: 24688667 PMCID: PMC3962139 DOI: 10.5936/csbj.201210007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 10/22/2012] [Accepted: 10/24/2012] [Indexed: 01/04/2023] Open
Abstract
Cellulose waste biomass is the most abundant and attractive substrate for "biorefinery strategies" that are aimed to produce high-value products (e.g. solvents, fuels, building blocks) by economically and environmentally sustainable fermentation processes. However, cellulose is highly recalcitrant to biodegradation and its conversion by biotechnological strategies currently requires economically inefficient multistep industrial processes. The need for dedicated cellulase production continues to be a major constraint to cost-effective processing of cellulosic biomass. Research efforts have been aimed at developing recombinant microorganisms with suitable characteristics for single step biomass fermentation (consolidated bioprocessing, CBP). Two paradigms have been applied for such, so far unsuccessful, attempts: a) "native cellulolytic strategies", aimed at conferring high-value product properties to natural cellulolytic microorganisms; b) "recombinant cellulolytic strategies", aimed to confer cellulolytic ability to microorganisms exhibiting high product yields and titers. By starting from the description of natural enzyme systems for plant biomass degradation and natural metabolic pathways for some of the most valuable product (i.e. butanol, ethanol, and hydrogen) biosynthesis, this review describes state-of-the-art bottlenecks and solutions for the development of recombinant microbial strains for cellulosic biofuel CBP by metabolic engineering. Complexed cellulases (i.e. cellulosomes) benefit from stronger proximity effects and show enhanced synergy on insoluble substrates (i.e. crystalline cellulose) with respect to free enzymes. For this reason, special attention was held on strategies involving cellulosome/designer cellulosome-bearing recombinant microorganisms.
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Affiliation(s)
- Roberto Mazzoli
- Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy
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Keskin T, Hallenbeck PC. Hydrogen production from sugar industry wastes using single-stage photofermentation. BIORESOURCE TECHNOLOGY 2012; 112:131-6. [PMID: 22420990 DOI: 10.1016/j.biortech.2012.02.077] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 02/14/2012] [Accepted: 02/16/2012] [Indexed: 05/08/2023]
Abstract
Beet molasses and black strap are two major waste streams of the sugar industry. They both contain high amounts of sucrose, making them suitable substrates for biological hydrogen production. Photofermentation, usually used to convert organic acids to hydrogen, has the potential capacity to effectively use a variety of feed stocks, including sugars. A comparative study on photofermentative biohydrogen production from beet molasses, black strap, and sucrose was conducted. With yields of 10.5 mol H(2)/mol sucrose for beet molasses (1g/l sugar); 8 mol H(2)/mol sucrose for black strap (1g/l sugar) and 14 mol H(2)/mol sucrose for pure sucrose, a one stage photofermentation system appears promising as an alternative to two-stage systems given the potential savings in energy input and operational costs.
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Affiliation(s)
- Tugba Keskin
- Département de Microbiologie et Immunologie, Université de Montréal, CP 6128 Succursale Centre-ville, Montréal, Québec, Canada
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Hallenbeck PC, Abo-Hashesh M, Ghosh D. Strategies for improving biological hydrogen production. BIORESOURCE TECHNOLOGY 2012; 110:1-9. [PMID: 22342581 DOI: 10.1016/j.biortech.2012.01.103] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/15/2012] [Accepted: 01/19/2012] [Indexed: 05/21/2023]
Abstract
Biological hydrogen production presents a possible avenue for the large scale sustainable generation of hydrogen needed to fuel a future hydrogen economy. Amongst the possible approaches that are under active investigation and that will be briefly discussed; biophotolysis, photofermentation, microbial electrolysis, and dark fermentation, dark fermentation has the additional advantages of largely relying on already developed bioprocess technology and of potentially using various waste streams as feedstock. However, the major roadblock to developing a practical process has been the low yields, typically around 25%, well below those achievable for the production of other biofuels from the same feedstocks. Moreover, low yields also lead to the generation of side products whose large scale production would generate a waste disposal problem. Here recent attempts to overcome these barriers are reviewed and recent progress in efforts to increase hydrogen yields through physiological manipulation, metabolic engineering and the use of two-stage systems are described.
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Affiliation(s)
- Patrick C Hallenbeck
- Département de microbiologie et immunologie, Université de Montréal, CP 6128, Centre-ville, Montréal, Canada PQ H3C 3J7.
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Yang H, Gandhi H, Shi L, Kreuzer HW, Ostrom NE, Hegg EL. Using gas chromatography/isotope ratio mass spectrometry to determine the fractionation factor for H2 production by hydrogenases. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2012; 26:61-68. [PMID: 22215579 DOI: 10.1002/rcm.5298] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Hydrogenases catalyze the reversible formation of H(2), and they are key enzymes in the biological cycling of H(2). H isotopes have the potential to be a very useful tool in quantifying hydrogen ion trafficking in biological H(2) production processes, but there are several obstacles that have thus far limited the application of this tool. Here, we describe a new method that overcomes some of these barriers and is specifically designed to measure isotopic fractionation during enzyme-catalyzed H(2) evolution. A key feature of this technique is that purified hydrogenases are employed, allowing precise control over the reaction conditions and therefore a high level of precision. In addition, a custom-designed high-throughput gas chromatograph/isotope ratio mass spectrometer is employed to measure the isotope ratio of the H(2). Using our new approach, we determined that the fractionation factor for H(2) production by the [NiFe]-hydrogenase from Desulfovibrio fructosovorans is 0.273 ± 0.006. This result indicates that, as expected, protons are highly favored over deuterium ions during H(2) evolution. Potential applications of this newly developed method are discussed.
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Affiliation(s)
- Hui Yang
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824-1319, USA
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Kontur WS, Noguera DR, Donohue TJ. Maximizing reductant flow into microbial H2 production. Curr Opin Biotechnol 2011; 23:382-9. [PMID: 22036711 DOI: 10.1016/j.copbio.2011.10.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/03/2011] [Accepted: 10/04/2011] [Indexed: 01/08/2023]
Abstract
Developing microbes into a sustainable source of hydrogen gas (H2) will require maximizing intracellular reductant flow toward the H2-producing enzymes. Recent attempts to increase H2 production in dark fermentative bacteria include increasing oxidation of organic substrates through metabolic engineering and expression of exogenous hydrogenases. In photofermentative bacteria, H2 production can be increased by minimizing reductant flow into competing pathways such as biomass formation and the Calvin cycle. One method of directing reductant toward H2 production being investigated in oxygenic phototrophs, which could potentially be applied to other H2-producing organisms, is the tethering of electron donors and acceptors, such as hydrogenase and photosystem I, to create new intermolecular electron transfer pathways.
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Affiliation(s)
- Wayne S Kontur
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States; DOE Great Lakes Bioenergy Research Center, Madison, WI, United States
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