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Bao T, Hou W, Wu X, Lu L, Zhang X, Yang ST. Engineering Clostridium cellulovorans for highly selective n-butanol production from cellulose in consolidated bioprocessing. Biotechnol Bioeng 2021; 118:2703-2718. [PMID: 33844271 DOI: 10.1002/bit.27789] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/06/2021] [Accepted: 04/09/2021] [Indexed: 01/05/2023]
Abstract
Cellulosic n-butanol from renewable lignocellulosic biomass has gained increased interest. Previously, we have engineered Clostridium cellulovorans, a cellulolytic acidogen, to overexpress the bifunctional butyraldehyde/butanol dehydrogenase gene adhE2 from C. acetobutylicum for n-butanol production from crystalline cellulose. However, butanol production by this engineered strain had a relatively low yield of approximately 0.22 g/g cellulose due to the coproduction of ethanol and acids. We hypothesized that strengthening the carbon flux through the central butyryl-CoA biosynthesis pathway and increasing intracellular NADH availability in C. cellulovorans adhE2 would enhance n-butanol production. In this study, thiolase (thlACA ) from C. acetobutylicum and 3-hydroxybutyryl-CoA dehydrogenase (hbdCT ) from C. tyrobutyricum were overexpressed in C. cellulovorans adhE2 to increase the flux from acetyl-CoA to butyryl-CoA. In addition, ferredoxin-NAD(P)+ oxidoreductase (fnr), which can regenerate the intracellular NAD(P)H and thus increase butanol biosynthesis, was also overexpressed. Metabolic flux analyses showed that mutants overexpressing these genes had a significantly increased carbon flux toward butyryl-CoA, which resulted in increased production of butyrate and butanol. The addition of methyl viologen as an electron carrier in batch fermentation further directed more carbon flux towards n-butanol biosynthesis due to increased reducing equivalent or NADH. The engineered strain C. cellulovorans adhE2-fnrCA -thlACA -hbdCT produced n-butanol from cellulose at a 50% higher yield (0.34 g/g), the highest ever obtained in batch fermentation by any known bacterial strain. The engineered C. cellulovorans is thus a promising host for n-butanol production from cellulosic biomass in consolidated bioprocessing.
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Affiliation(s)
- Teng Bao
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Wenjie Hou
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA.,College of Life Sciences, Northwest A&F University, Yangling, Shanxi, China
| | - Xuefeng Wu
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA.,School of Food and Biological Engineering, Hefei University of Technology, Hefei, China
| | - Li Lu
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Xian Zhang
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA.,School of Biotechnology, Jiangnan University, Wuxi, China
| | - Shang-Tian Yang
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA
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Segawa M, Wen C, Orita I, Nakamura S, Fukui T. Two NADH-dependent (S)-3-hydroxyacyl-CoA dehydrogenases from polyhydroxyalkanoate-producing Ralstonia eutropha. J Biosci Bioeng 2018; 127:294-300. [PMID: 30243533 DOI: 10.1016/j.jbiosc.2018.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/20/2018] [Accepted: 08/22/2018] [Indexed: 12/28/2022]
Abstract
Ralstonia eutropha H16 contains both NADH- and NADPH-dependent reduction activities to acetoacetyl-CoA, and the NADPH-dependent activity is mediated by PhaB paralogs with (R)-stereospecificity providing (R)-3-hydroxybutyryl (3HB)-CoA monomer for poly((R)-3-hydroxybutyrate) synthesis. In contrast, the gene encoding the NADH-dependent enzyme has not been identified to date. This study focused on the NADH-dependent dehydrogenase with (S)-stereospecificity in R. eutropha, as the (S)-specific reduction of acetoacetyl-CoA potentially competed with the polyester biosynthesis via (R)-3HB-CoA. The NADH-dependent reduction activity decreased to one-half when the gene for H16_A0282 (PaaH1), one of two homologs of clostridial NADH-3HB-CoA dehydrogenase, was deleted. The enzyme responsible for the remaining activity was partially purified and identified as H16_A0602 (Had) belonging to a different family from PaaH1. Gene disruption analysis elucidated that most of the NADH-dependent activity was mediated by PaaH1 and Had. The kinetic analysis using the recombinant enzymes indicated that PaaH1 and Had were both NADH-dependent 3-hydroxyacyl-CoA dehydrogenases with rather broad substrate specificity to 3-oxoacyl-CoAs of C4 to C8. The deletion of had in the R. eutropha strain previously engineered for biosynthesis of poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) led to decrease in the C6 composition of the copolyester synthesized from soybean oil, suggesting the role of Had in (S)-specific reduction of 3-oxohexanoyl-CoA with reverse β-oxidation direction. Crotonase ((S)-specific enoyl-CoA hydratase) in R. eutropha H16 was also partially purified and identified as H16_A3307.
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Affiliation(s)
- Mutsumi Segawa
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Cheng Wen
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Izumi Orita
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Satoshi Nakamura
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Toshiaki Fukui
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
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Reviving the Weizmann process for commercial n-butanol production. Nat Commun 2018; 9:3682. [PMID: 30206218 PMCID: PMC6134114 DOI: 10.1038/s41467-018-05661-z] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 07/11/2018] [Indexed: 12/25/2022] Open
Abstract
Developing a commercial process for the biological production of n-butanol is challenging as it needs to combine high titer, yield, and productivities. Here we engineer Clostridium acetobutylicum to stably and continuously produce n-butanol on a mineral media with glucose as sole carbon source. We further design a continuous process for fermentation of high concentration glucose syrup using in situ extraction of alcohols by distillation under low pressure and high cell density cultures to increase the titer, yield, and productivity of n-butanol production to the level of 550 g/L, 0.35 g/g, and 14 g/L/hr, respectively. This process provides a mean to produce n-butanol at performance levels comparable to that of corn wet milling ethanol plants using yeast as a biocatalyst. It may hold the potential to be scaled-up at pilot and industrial levels for the commercial production of n-butanol. Organic solvent n-butanol is produced mainly by petrochemical method. Here, the authors revive the historical Weizmann process by engineering Clostridium acetobutylicum strain and developing low pressure distillation and high cell density cultures for n-butanol continuous production at high-yield titer and productivity.
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Nimbalkar P, Khedkar MA, Parulekar RS, Chandgude VK, Sonawane KD, Chavan PV, Bankar SB. Role of Trace Elements as Cofactor: An Efficient Strategy toward Enhanced Biobutanol Production. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2018; 6:9304-9313. [PMID: 30271690 PMCID: PMC6156106 DOI: 10.1021/acssuschemeng.8b01611] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/02/2018] [Indexed: 05/07/2023]
Abstract
Metabolic engineering has the potential to steadily enhance product titers by inducing changes in metabolism. Especially, availability of cofactors plays a crucial role in improving efficacy of product conversion. Hence, the effect of certain trace elements was studied individually or in combinations, to enhance butanol flux during its biological production. Interestingly, nickel chloride (100 mg L-1) and sodium selenite (1 mg L-1) showed a nearly 2-fold increase in solvent titer, achieving 16.13 ± 0.24 and 12.88 ± 0.36 g L-1 total solvents with yields of 0.30 and 0.33 g g-1, respectively. Subsequently, the addition time (screened entities) was optimized (8 h) to further increase solvent production up to 18.17 ± 0.19 and 15.5 ± 0.13 g L-1 by using nickel and selenite, respectively. A significant upsurge in butanol dehydrogenase (BDH) levels was observed, which reflected in improved solvent productions. Additionally, a three-dimensional structure of BDH was also constructed using homology modeling and subsequently docked with substrate, cofactor, and metal ion to investigate proper orientation and molecular interactions.
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Affiliation(s)
- Pranhita
R. Nimbalkar
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University P.O.
Box 16100, FI-00076 Aalto, Finland
- Department
of Chemical Engineering, Bharati Vidyapeeth
Deemed University College of Engineering, Pune 411043, India
| | - Manisha A. Khedkar
- Department
of Chemical Engineering, Bharati Vidyapeeth
Deemed University College of Engineering, Pune 411043, India
| | | | - Vijaya K. Chandgude
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University P.O.
Box 16100, FI-00076 Aalto, Finland
| | - Kailas D. Sonawane
- Department
of Microbiology, Shivaji University, Kolhapur 416004, India
- Department
of Biochemistry, Structural Bioinformatics Unit, Shivaji University, Kolhapur 416004, India
| | - Prakash V. Chavan
- Department
of Chemical Engineering, Bharati Vidyapeeth
Deemed University College of Engineering, Pune 411043, India
| | - Sandip B. Bankar
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University P.O.
Box 16100, FI-00076 Aalto, Finland
- E-mail: ; . Tel.: +358 505777898
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McAnulty MJ, Poosarla VG, Li J, Soo VWC, Zhu F, Wood TK. Metabolic engineering of Methanosarcina acetivorans for lactate production from methane. Biotechnol Bioeng 2016; 114:852-861. [PMID: 27800599 DOI: 10.1002/bit.26208] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/13/2016] [Accepted: 10/25/2016] [Indexed: 01/12/2023]
Abstract
We previously demonstrated anaerobic conversion of the greenhouse gas methane into acetate using an engineered archaeon that produces methyl-coenzyme M reductase (Mcr) from unculturable microorganisms from a microbial mat in the Black Sea to create the first culturable prokaryote that reverses methanogenesis and grows anaerobically on methane. In this work, we further engineered the same host with the goal of converting methane into butanol. Instead, we discovered a process for converting methane to a secreted valuable product, L-lactate, with sufficient optical purity for synthesizing the biodegradable plastic poly-lactic acid. We determined that the 3-hydroxybutyryl-CoA dehydrogenase (Hbd) from Clostridium acetobutylicum is responsible for lactate production. This work demonstrates the first metabolic engineering of a methanogen with a synthetic pathway; in effect, we produce a novel product (lactate) from a novel substrate (methane) by cloning the three genes for Mcr and one for Hbd. We further demonstrate the utility of anaerobic methane conversion with an increased lactate yield compared to aerobic methane conversion to lactate. Biotechnol. Bioeng. 2017;114: 852-861. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Michael J McAnulty
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 168 020-4400
| | - Venkata Giridhar Poosarla
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 168 020-4400
| | - Jine Li
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 168 020-4400
| | - Valerie W C Soo
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 168 020-4400
| | - Fayin Zhu
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 168 020-4400
| | - Thomas K Wood
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 168 020-4400.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802-4400
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Reiße S, Haack M, Garbe D, Sommer B, Steffler F, Carsten J, Bohnen F, Sieber V, Brück T. In Vitro Bioconversion of Pyruvate to n-Butanol with Minimized Cofactor Utilization. Front Bioeng Biotechnol 2016; 4:74. [PMID: 27800475 PMCID: PMC5066087 DOI: 10.3389/fbioe.2016.00074] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 09/12/2016] [Indexed: 12/03/2022] Open
Abstract
Due to enhanced energy content and reduced hygroscopicity compared with ethanol, n-butanol is flagged as the next generation biofuel and platform chemical. In addition to conventional cellular systems, n-butanol bioproduction by enzyme cascades is gaining momentum due to simplified process control. In contrast to other bio-based alcohols like ethanol and isobutanol, cell-free n-butanol biosynthesis from the central metabolic intermediate pyruvate involves cofactors [NAD(P)H, CoA] and acetyl-CoA-dependent intermediates, which complicates redox and energy balancing of the reaction system. We have devised a biochemical process for cell-free n-butanol production that only involves three enzyme activities, thereby eliminating the need for acetyl-CoA. Instead, the process utilizes only NADH as the sole redox mediator. Central to this new process is the amino acid catalyzed enamine–aldol condensation, which transforms acetaldehyde directly into crotonaldehyde. Subsequently, crotonaldehyde is reduced to n-butanol applying a 2-enoate reductase and an alcohol dehydrogenase, respectively. In essence, we achieved conversion of the platform intermediate pyruvate to n-butanol utilizing a biocatalytic cascade comprising only three enzyme activities and NADH as reducing equivalent. With reference to previously reported cell-free n-butanol reaction cascades, we have eliminated five enzyme activities and the requirement of CoA as cofactor. Our proof-of-concept demonstrates that n-butanol was synthesized at neutral pH and 50°C. This integrated reaction concept allowed GC detection of all reaction intermediates and n-butanol production of 148 mg L−1 (2 mM), which compares well with other cell-free n-butanol production processes.
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Affiliation(s)
- Steven Reiße
- Department of Chemistry, Technical University of Munich, Garching, Germany; B&B Sustainable Innovations GmbH, Köln, Germany
| | - Martina Haack
- Department of Chemistry, Technical University of Munich , Garching , Germany
| | - Daniel Garbe
- Department of Chemistry, Technical University of Munich , Garching , Germany
| | - Bettina Sommer
- Department of Chemistry, Technical University of Munich , Garching , Germany
| | - Fabian Steffler
- Straubing Center of Science, Technical University of Munich , Straubing , Germany
| | - Jörg Carsten
- Straubing Center of Science, Technical University of Munich , Straubing , Germany
| | - Frank Bohnen
- B&B Sustainable Innovations GmbH , Köln , Germany
| | - Volker Sieber
- Straubing Center of Science, Technical University of Munich , Straubing , Germany
| | - Thomas Brück
- Department of Chemistry, Technical University of Munich, Garching, Germany; B&B Sustainable Innovations GmbH, Köln, Germany
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Diederichs S, Linn K, Lückgen J, Klement T, Grosch JH, Honda K, Ohtake H, Büchs J. High-level production of (5S)-hydroxyhexane-2-one by two thermostable oxidoreductases in a whole-cell catalytic approach. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcatb.2015.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Meiothermus ruber thiolase - a new process stable enzyme for improved butanol synthesis. Biochimie 2014; 103:16-22. [PMID: 24713333 DOI: 10.1016/j.biochi.2014.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 03/28/2014] [Indexed: 11/20/2022]
Abstract
Butanol is an important renewable building block for the chemical, textile, polymer and biofuels industry due to its increased energy density. Current biotechnological butanol production is a Clostridial based anaerobic fermentation process. Thiolase (EC 2.3.1.9/EC 2.3.1.16) is a key enzyme in this biosynthetic conversion of glucose to butanol. It catalyzes the condensation of two acetyl-CoA molecules, forming acetoacetyl-CoA, which is the first committed step in butanol biosynthesis. The well characterized clostridial thiolases are neither solvent nor thermo stable, which limits butanol yields. We have isolated and characterized a new thermo- (IT50 50 °C = 199 ± 0.1 h) and solvent stable (IS50 > 4%) thiolase derived from the thermophilic bacterium Meiothermus ruber. The observed catalytic constants were Km = 0.07 ± 0.01 mM and kcat = 0.80 ± 0.01 s(-1). In analogy to other thiolases, the enzyme was inhibited by NAD(+) (Ki = 38.7 ± 5.8 mM) and CoA (Ki = 105.1 ± 6.6 μM) but not NADH. The enzyme was stable under harsh process conditions (T = 50 °C, Butanol = 4% v/v) for prolonged time periods (τ = 7 h). The new enzyme provides for targeted in-vivo and in-vitro butanol biosynthesis under industrially relevant process conditions.
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