1
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Miebach K, Finger M, Scherer AMK, Maaß CA, Büchs J. Hydrogen online monitoring based on thermal conductivity for anaerobic microorganisms. Biotechnol Bioeng 2023; 120:2199-2213. [PMID: 37462090 DOI: 10.1002/bit.28502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/06/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023]
Abstract
H2 -producing microorganisms are a promising source of sustainable biohydrogen. However, most H2 -producing microorganisms are anaerobes, which are difficult to cultivate and characterize. While several methods for measuring H2 exist, common H2 sensors often require oxygen, making them unsuitable for anaerobic processes. Other sensors can often not be operated at high gas humidity. Thus, we applied thermal conductivity (TC) sensors and developed a parallelized, online H2 monitoring for time-efficient characterization of H2 production by anaerobes. Since TC sensors are nonspecific for H2 , the cross-sensitivity of the sensors was evaluated regarding temperature, gas humidity, and CO2 concentrations. The systems' measurement range was validated with two anaerobes: a high H2 -producer (Clostridium pasteurianum) and a low H2 -producer (Phocaeicola vulgatus). Online monitoring of H2 production in shake flask cultivations was demonstrated, and H2 transfer rates were derived. Combined with online CO2 and pressure measurements, molar gas balances of the cultivations were closed, and an anaerobic respiration quotient was calculated. Thus, insight into the effect of medium components and inhibitory cultivation conditions on H2 production with the model anaerobes was gained. The presented online H2 monitoring method can accelerate the characterization of anaerobes for biohydrogen production and reveal metabolic changes without expensive equipment and offline analysis.
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Affiliation(s)
- Katharina Miebach
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Aachen, Germany
| | - Maurice Finger
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Aachen, Germany
| | | | | | - Jochen Büchs
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Aachen, Germany
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2
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Alleman AB, Peters JW. Mechanisms for Generating Low Potential Electrons across the Metabolic Diversity of Nitrogen-Fixing Bacteria. Appl Environ Microbiol 2023; 89:e0037823. [PMID: 37154716 PMCID: PMC10231201 DOI: 10.1128/aem.00378-23] [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] [Indexed: 05/10/2023] Open
Abstract
The availability of fixed nitrogen is a limiting factor in the net primary production of all ecosystems. Diazotrophs overcome this limit through the conversion of atmospheric dinitrogen to ammonia. Diazotrophs are phylogenetically diverse bacteria and archaea that exhibit a wide range of lifestyles and metabolisms, including obligate anaerobes and aerobes that generate energy through heterotrophic or autotrophic metabolisms. Despite the diversity of metabolisms, all diazotrophs use the same enzyme, nitrogenase, to reduce N2. Nitrogenase is an O2-sensitive enzyme that requires a high amount of energy in the form of ATP and low potential electrons carried by ferredoxin (Fd) or flavodoxin (Fld). This review summarizes how the diverse metabolisms of diazotrophs utilize different enzymes to generate low potential reducing equivalents for nitrogenase catalysis. These enzymes include substrate-level Fd oxidoreductases, hydrogenases, photosystem I or other light-driven reaction centers, electron bifurcating Fix complexes, proton motive force-driven Rnf complexes, and Fd:NAD(P)H oxidoreductases. Each of these enzymes is critical for generating low potential electrons while simultaneously integrating the native metabolism to balance nitrogenase's overall energy needs. Understanding the diversity of electron transport systems to nitrogenase in various diazotrophs will be essential to guide future engineering strategies aimed at expanding the contributions of biological nitrogen fixation in agriculture.
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Affiliation(s)
- Alexander B. Alleman
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA
| | - John W. Peters
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
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3
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Zhang C, Traitrongsat P, Zeng AP. Electrochemically mediated bioconversion and integrated purification greatly enhanced co-production of 1,3-propanediol and organic acids from glycerol in an industrial bioprocess. Bioprocess Biosyst Eng 2023; 46:565-575. [PMID: 36648555 DOI: 10.1007/s00449-022-02841-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 12/13/2022] [Indexed: 01/18/2023]
Abstract
In this study, we show how electrochemically mediated bioconversion can greatly increase the co-production of 1,3-propanediol and organic acids from glycerol in an industrial bioprocess using a Clostridum pasteurianum mutant. Remarkably, an enhanced butyrate formation was observed due to a weakened butanol pathway of the mutant. This allowed the strain to have a higher ATP generation for an enhanced growth, higher glycerol consumption and PDO production. The PDO titer reached as high as 120.67 g/L at a cathodic current of -400 mA, which is 33% higher than that without electricity, with a concurrent increase of butyric acid by 80%. To fully recover the increased PDO and organic acids, a novel downstream process combining thin film evaporation of PDO and esterification of organic acids with ethanol was developed. This enables the efficient co-production of PDO, ethyl acetate and ethyl butyrate with a high overall carbon use of 87%.
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Affiliation(s)
- Chijian Zhang
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Hamburg, Germany.,Hua An Tang Biotech Group Co., Ltd, Guangzhou, China
| | - Pawin Traitrongsat
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Hamburg, Germany
| | - An-Ping Zeng
- Center of Synthetic Biology and Integrated Bioengineering, School of Engineering, Westlake University, Hangzhou, China. .,Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Hamburg, Germany.
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4
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Zhang F, Zhang K, Zhang Z, Chen HQ, Chen XW, Xian XY, Wu YR. Efficient isopropanol-butanol-ethanol (IBE) fermentation by a gene-modified solventogenic Clostridium species under the co-utilization of Fe(III) and butyrate. BIORESOURCE TECHNOLOGY 2023; 373:128751. [PMID: 36805829 DOI: 10.1016/j.biortech.2023.128751] [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: 12/27/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
To elevate the efficiency of acetone-butanol-ethanol (ABE) fermentation by the wild-type strain WK, an optimal co-utilization system (20 mM Fe3+ and 5 g/L butyrate) was established to bring about a 22.22% increment in the yield of ABE mixtures with a significantly enhanced productivity (0.32 g/L/h). With the heterologous introduction of the secondary alcohol dehydrogenase encoded gene (adh), more than 95% of acetone was eliminated to convert 4.5 g/L isopropanol with corresponding increased butanol and ethanol production by 21.08% and 65.45% in the modified strain WK::adh. Under the optimal condition, strain WK::adh was capable of producing a total of 25.46 g/L IBE biosolvents with an enhanced productivity of 0.35 g/L/h by 45.83% over the original conditions. This work for the first time successfully established a synergetic system of co-utilizing Fe(III) and butyrate to demonstrate a feasible and efficient manner for generating the value-added biofuels through the metabolically engineered solventogenic clostridial strain.
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Affiliation(s)
- Feifei Zhang
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Kan Zhang
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Zhiqian Zhang
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Hai-Qi Chen
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Xiao-Wei Chen
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Xing-You Xian
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China
| | - Yi-Rui Wu
- Tidetron Bioworks Technology (Guangzhou) Co., Ltd., Guangzhou Qianxiang Bioworks Co., Ltd., Guangzhou, Guangdong 510000, China.
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5
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Rajpurohit H, Eiteman MA. Nutrient-Limited Operational Strategies for the Microbial Production of Biochemicals. Microorganisms 2022; 10:2226. [PMID: 36363817 PMCID: PMC9695796 DOI: 10.3390/microorganisms10112226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 10/31/2022] [Accepted: 11/07/2022] [Indexed: 08/24/2023] Open
Abstract
Limiting an essential nutrient has a profound impact on microbial growth. The notion of growth under limited conditions was first described using simple Monod kinetics proposed in the 1940s. Different operational modes (chemostat, fed-batch processes) were soon developed to address questions related to microbial physiology and cell maintenance and to enhance product formation. With more recent developments of metabolic engineering and systems biology, as well as high-throughput approaches, the focus of current engineers and applied microbiologists has shifted from these fundamental biochemical processes. This review draws attention again to nutrient-limited processes. Indeed, the sophisticated gene editing tools not available to pioneers offer the prospect of metabolic engineering strategies which leverage nutrient limited processes. Thus, nutrient- limited processes continue to be very relevant to generate microbially derived biochemicals.
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Affiliation(s)
| | - Mark A. Eiteman
- School of Chemical, Materials and Biomedical Engineering, University of Georgia, Athens, GA 30602, USA
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6
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Hong Y, Nguyen T, Arbter P, Utesch T, Zeng A. Phenotype analysis of cultivation processes via unsupervised machine learning: Demonstration for Clostridium pasteurianum. Eng Life Sci 2022; 22:85-99. [PMID: 35140556 PMCID: PMC8811730 DOI: 10.1002/elsc.202100114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/02/2021] [Accepted: 11/19/2021] [Indexed: 11/23/2022] Open
Abstract
A novel approach of phenotype analysis of fermentation-based bioprocesses based on unsupervised learning (clustering) is presented. As a prior identification of phenotypes and conditional interrelations is desired to control fermentation performance, an automated learning method to output reference phenotypes (defined as vector of biomass-specific rates) was developed and the necessary computing process and parameters were assessed. For its demonstration, time series data of 90 Clostridium pasteurianum cultivations were used which feature a broad spectrum of solventogenic and acidogenic phenotypes, while 14 clusters of phenotypic manifestations were identified. The analysis of reference phenotypes showed distinct differences, where potential conditionalities were exemplary isolated. Further, cluster-based balancing of carbon and ATP or the use of reference phenotypes as indicator for bioprocess monitoring were demonstrated to highlight the perks of this approach. Overall, such analysis depends strongly on the quality of the data and experimental validations will be required before conclusions. However, the automated, streamlined and abstracted approach diminishes the need of individual evaluation of all noisy dataset and showed promising results, which could be transferred to strains with comparably wide-ranging phenotypic manifestations or as indicators for repeated bioprocesses with clearly defined target.
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Affiliation(s)
- Yaeseong Hong
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyTUHHHamburgGermany
| | - Tom Nguyen
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyTUHHHamburgGermany
| | - Philipp Arbter
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyTUHHHamburgGermany
| | - Tyll Utesch
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyTUHHHamburgGermany
| | - An‐Ping Zeng
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyTUHHHamburgGermany
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7
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Berthomieu R, Pérez-Bernal MF, Santa-Catalina G, Desmond-Le Quéméner E, Bernet N, Trably E. Mechanisms underlying Clostridium pasteurianum's metabolic shift when grown with Geobacter sulfurreducens. Appl Microbiol Biotechnol 2021; 106:865-876. [PMID: 34939136 DOI: 10.1007/s00253-021-11736-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/08/2021] [Accepted: 12/11/2021] [Indexed: 10/19/2022]
Abstract
Recently, a study showed that glycerol fermentation by Clostridium pasteurianum could be metabolically redirected when the electroactive bacterium Geobacter sulfurreducens was added in the culture. It was assumed that this metabolic shift of the fermentative species resulted from an interspecies electron transfer. The aim of this study was to find out the mechanisms used for this interaction and how they affect the metabolism of C. pasteurianum. To get insights into the mechanisms involved, several coculture setups and RNA sequencing with differential expression analysis were performed. As a result, a putative interaction model was proposed: G. sulfurreducens produces cobamide molecules that possibly modify C. pasteurianum metabolic pathway at the key enzyme glycerol dehydratase, and affect its vanadium nitrogenase expression. In addition, the results suggested that G. sulfurreducens' electrons could enter C. pasteurianum through its transmembrane flavin-bound polyferredoxin and cellular cytochrome b5-rubredoxin interplay, putatively reinforcing the metabolic shift. Unravelling the mechanisms behind the interaction between fermentative and electroactive bacteria helps to better understand the role of bacterial interactions in fermentation setups. KEY POINTS: • C. pasteurianum-G. sulfurreducens interaction inducing a metabolic shift is mediated • C. pasteurianum's metabolic shift in coculture might be induced by cobamides • Electrons possibly enter C. pasteurianum through a multiflavin polyferredoxin.
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Affiliation(s)
| | | | | | | | | | - Eric Trably
- INRAE, Univ Montpellier, LBE, Narbonne, France.
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8
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Bioconversion of Lignocellulosic Biomass into Value Added Products under Anaerobic Conditions: Insight into Proteomic Studies. Int J Mol Sci 2021; 22:ijms222212249. [PMID: 34830131 PMCID: PMC8624197 DOI: 10.3390/ijms222212249] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/07/2021] [Accepted: 11/09/2021] [Indexed: 01/14/2023] Open
Abstract
Production of biofuels and other value-added products from lignocellulose breakdown requires the coordinated metabolic activity of varied microorganisms. The increasing global demand for biofuels encourages the development and optimization of production strategies. Optimization in turn requires a thorough understanding of the microbial mechanisms and metabolic pathways behind the formation of each product of interest. Hydrolysis of lignocellulosic biomass is a bottleneck in its industrial use and often affects yield efficiency. The accessibility of the biomass to the microorganisms is the key to the release of sugars that are then taken up as substrates and subsequently transformed into the desired products. While the effects of different metabolic intermediates in the overall production of biofuel and other relevant products have been studied, the role of proteins and their activity under anaerobic conditions has not been widely explored. Shifts in enzyme production may inform the state of the microorganisms involved; thus, acquiring insights into the protein production and enzyme activity could be an effective resource to optimize production strategies. The application of proteomic analysis is currently a promising strategy in this area. This review deals on the aspects of enzymes and proteomics of bioprocesses of biofuels production using lignocellulosic biomass as substrate.
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9
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Arbter P, Sabra W, Utesch T, Hong Y, Zeng A. Metabolomic and kinetic investigations on the electricity-aided production of butanol by Clostridium pasteurianum strains. Eng Life Sci 2021; 21:181-195. [PMID: 33716617 PMCID: PMC7923553 DOI: 10.1002/elsc.202000035] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 10/18/2020] [Accepted: 11/11/2020] [Indexed: 12/03/2022] Open
Abstract
In this contribution, we studied the effect of electro-fermentation on the butanol production of Clostridium pasteurianum strains by a targeted metabolomics approach. Two strains were examined: an electrocompetent wild type strain (R525) and a mutant strain (dhaB mutant) lacking formation of 1,3-propanediol (PDO). The dhaB-negative strain was able to grow on glycerol without formation of PDO, but displayed a high initial intracellular NADH/NAD ratio which was lowered subsequently by upregulation of the butanol production pathway. Both strains showed a 3-5 fold increase of the intracellular NADH/NAD ratio when exposed to cathodic current in a bioelectrochemical system (BES). This drove an activation of the butanol pathway and resulted in a higher molar butanol to PDO ratio for the R525 strain. Nonetheless, macroscopic electron balances suggest that no significant amount of electrons derived from the BES was harvested by the cells. Overall, this work points out that electro-fermentation can be used to trigger metabolic pathways and improve product formation, even when the used microbe cannot be considered electroactive. Accordingly, further studies are required to unveil the underlying (regulatory) mechanisms.
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Affiliation(s)
- Philipp Arbter
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyHamburgGermany
| | - Wael Sabra
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyHamburgGermany
| | - Tyll Utesch
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyHamburgGermany
| | - Yaeseong Hong
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyHamburgGermany
| | - An‐Ping Zeng
- Institute of Bioprocess and Biosystems EngineeringHamburg University of TechnologyHamburgGermany
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10
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Jiang Y, Wu R, Lu J, Dong W, Zhou J, Zhang W, Xin F, Jiang M. Quantitative proteomic analysis to reveal expression differences for butanol production from glycerol and glucose by Clostridium sp. strain CT7. Microb Cell Fact 2021; 20:12. [PMID: 33422075 PMCID: PMC7797090 DOI: 10.1186/s12934-021-01508-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 01/02/2021] [Indexed: 11/16/2022] Open
Abstract
Clostridium sp. strain CT7 is a new emerging microbial cell factory with high butanol production ratio owing to its non-traditional butanol fermentation mode with uncoupled acetone and 1,3-propanediol formation. Significant changes of metabolic products profile were shown in glycerol- and glucose-fed strain CT7, especially higher butanol and lower volatile fatty acids (VFAs) production occurred from glycerol-fed one. However, the mechanism of this interesting phenomenon was still unclear. To better elaborate the bacterial response towards glycerol and glucose, the quantitative proteomic analysis through iTRAQ strategy was performed to reveal the regulated proteomic expression levels under different substrates. Proteomics data showed that proteomic expression levels related with carbon metabolism and solvent generation under glycerol media were highly increased. In addition, the up-regulation of hydrogenases, ferredoxins and electron-transferring proteins may attribute to the internal redox balance, while the earlier triggered sporulation response in glycerol-fed media may be associated with the higher butanol production. This study will pave the way for metabolic engineering of other industrial microorganisms to obtain efficient butanol production from glycerol.
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Affiliation(s)
- Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China
| | - Ruofan Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China
| | - Jiasheng Lu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, 211800, Nanjing, P.R. China
| | - Jie Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, 211800, Nanjing, P.R. China
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, 211800, Nanjing, P.R. China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, 211800, Nanjing, P.R. China.
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11
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Hong Y, Arbter P, Wang W, Rojas LN, Zeng AP. Introduction of glycine synthase enables uptake of exogenous formate and strongly impacts the metabolism in Clostridium pasteurianum. Biotechnol Bioeng 2020; 118:1366-1380. [PMID: 33331660 DOI: 10.1002/bit.27658] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 11/11/2022]
Abstract
Autotrophic or mixotrophic use of one-carbon (C1) compounds is gaining importance for sustainable bioproduction. In an effort to integrate the reductive glycine pathway (rGP) as a highly promising pathway for the assimilation of CO2 and formate, genes coding for glycine synthase system from Gottschalkia acidurici were successfully introduced into Clostridium pasteurianum, a non-model host microorganism with industrial interests. The mutant harboring glycine synthase exhibited assimilation of exogenous formate and reduced CO2 formation. Further metabolic data clearly showed large impacts of expression of glycine synthase on the product metabolism of C. pasteurianum. In particular, 2-oxobutyrate (2-OB) was observed for the first time as a metabolic intermediate of C. pasteurianum and its secretion was solely triggered by the expression of glycine synthase. The perturbation of C1 metabolism is discussed regarding its interactions with pathways of the central metabolism, acidogenesis, solventogenesis, and amino acid metabolism. The secretion of 2-OB is considered as a consequence of metabolic and redox instabilities due to the activity of glycine synthase and may represent a common metabolic response of Clostridia in enhanced use of C1 compounds.
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Affiliation(s)
- Yaeseong Hong
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Hamburg, Germany
| | - Philipp Arbter
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Hamburg, Germany
| | - Wei Wang
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Hamburg, Germany
| | - Lilian N Rojas
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Hamburg, Germany
| | - An-Ping Zeng
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Hamburg, Germany.,Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, China
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12
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Self-Synchronized Oscillatory Metabolism of Clostridium pasteurianum in Continuous Culture. Processes (Basel) 2020. [DOI: 10.3390/pr8020137] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
By monitoring the real-time gas production (CO2 and H2) and redox potential at high sampling frequency in continuous culture of Clostridium pasteurianum on glycerol as sole carbohydrate, the self-synchronized oscillatory metabolism was revealed and studied. The oscillations in CO2 and H2 production were in sync with each other and with both redox potential and glycerol in the continuous stirred tank reactor (CSTR). There is strong evidence that the mechanism for this is in the regulation of the oxidative pathway of glycerol metabolism, including glycolysis, and points toward complex, concerted cycles of enzyme inhibition and activation by pathway intermediates and/or redox equivalents. The importance of understanding such an “oscillatory metabolism” is for developing a stable and highly productive industrial fermentation process for butanol production, as unstable oscillations are unproductive. It is shown that the oscillatory metabolism can be eradicated and reinstated and that the period of oscillations can be altered by modification of the operating parameters. Synchronized oscillatory metabolism impacted the product profile such that it lowered the selectivity for butanol and increased the selectivity for ethanol. This elucidates a possible cause for the variability in the product profile of C. pasteurianum that has been reported in many previous studies.
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13
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Munch G, Schulte A, Mann M, Dinger R, Regestein L, Rehmann L, Büchs J. Online measurement of CO2 and total gas production in parallel anaerobic shake flask cultivations. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2019.107418] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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14
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Clostridium sp. as Bio-Catalyst for Fuels and Chemicals Production in a Biorefinery Context. Catalysts 2019. [DOI: 10.3390/catal9110962] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Clostridium sp. is a genus of anaerobic bacteria capable of metabolizing several substrates (monoglycerides, diglycerides, glycerol, carbon monoxide, cellulose, and more), into valuable products. Biofuels, such as ethanol and butanol, and several chemicals, such as acetone, 1,3-propanediol, and butyric acid, can be produced by these organisms through fermentation processes. Among the most well-known species, Clostridium carboxidivorans, C. ragsdalei, and C. ljungdahlii can be highlighted for their ability to use gaseous feedstocks (as syngas), obtained from the gasification or pyrolysis of waste material, to produce ethanol and butanol. C. beijerinckii is an important species for the production of isopropanol and butanol, with the advantage of using hydrolysate lignocellulosic material, which is produced in large amounts by first-generation ethanol industries. High yields of 1,3 propanediol by C. butyricum are reported with the use of another by-product from fuel industries, glycerol. In this context, several Clostridium wild species are good candidates to be used as biocatalysts in biochemical or hybrid processes. In this review, literature data showing the technical viability of these processes are presented, evidencing the opportunity to investigate them in a biorefinery context.
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15
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Zeng AP. New bioproduction systems for chemicals and fuels: Needs and new development. Biotechnol Adv 2019; 37:508-518. [DOI: 10.1016/j.biotechadv.2019.01.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/04/2019] [Accepted: 01/05/2019] [Indexed: 11/17/2022]
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16
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Schmitz R, Sabra W, Arbter P, Hong Y, Utesch T, Zeng AP. Improved electrocompetence and metabolic engineering of Clostridium pasteurianum reveals a new regulation pattern of glycerol fermentation. Eng Life Sci 2018; 19:412-422. [PMID: 32625019 DOI: 10.1002/elsc.201800118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/06/2018] [Accepted: 11/16/2018] [Indexed: 12/11/2022] Open
Abstract
Clostridium pasteurianum produces industrially valuable chemicals such as n-butanol and 1,3-propanediol from fermentations of glycerol and glucose. Metabolic engineering for increased yields of selective compounds is not well established in this microorganism. In order to study carbon fluxes and to selectively increase butanol yields, we integrated the latest advances in genome editing to obtain an electrocompetent Clostridium pasteurianum strain for further engineering. Deletion of the glycerol dehydratase large subunit (dhaB) using an adapted S. pyogenes Type II CRISPR/Cas9 nickase system resulted in a 1,3-propanediol-deficient mutant producing butanol as the main product. Surprisingly, the mutant was able to grow on glycerol as the sole carbon source. In spite of reduced growth, butanol yields were highly increased. Metabolic flux analysis revealed an important role of the newly identified electron bifurcation pathway for crotonyl-CoA to butyryl-CoA conversion in the regulation of redox balance. Compared to the parental strain, the electron bifurcation pathway flux of the dhaB mutant increased from 8 to 46% of the overall flux from crotonyl-CoA to butyryl-CoA and butanol, indicating a new, 1,3-propanediol-independent pattern of glycerol fermentation in Clostridium pasteurianum.
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Affiliation(s)
- Rebekka Schmitz
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany
| | - Wael Sabra
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany
| | - Philipp Arbter
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany
| | - Yaeseong Hong
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany
| | - Tyll Utesch
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany
| | - An-Ping Zeng
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany
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Yang Y, Nie X, Jiang Y, Yang C, Gu Y, Jiang W. Metabolic regulation in solventogenic clostridia: regulators, mechanisms and engineering. Biotechnol Adv 2018; 36:905-914. [DOI: 10.1016/j.biotechadv.2018.02.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 01/05/2018] [Accepted: 02/20/2018] [Indexed: 12/31/2022]
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Utesch T, Zeng AP. A novel All-in-One electrolysis electrode and bioreactor enable better study of electrochemical effects and electricity-aided bioprocesses. Eng Life Sci 2018; 18:600-610. [PMID: 32624940 DOI: 10.1002/elsc.201700198] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/21/2018] [Accepted: 04/19/2018] [Indexed: 11/11/2022] Open
Abstract
An autoclavable All-in-One electrolysis electrode in a rod shape assembly is developed as a new tool for bioelectrochemical systems and electricity-aided bioprocesses. It can replace the classic two-chamber bioelectrochemical system for electrolysis reactions, be inserted into conventional bioreactors and is easily adaptable as electrocatalytic surface or generator of super-fine bubbles (H2 and O2) for bioconversion processes. Whereas the bioreactor itself functions as the working electrode chamber, a well-integrated inner counter electrode chamber enables water electrolysis without the normally encountered undesired ion-transfer effect. The efficiencies of the electrode are characterized and its advantages and usefulness compared to the classic H-Cell bioelectrochemical system (BES) are demonstrated with glycerol fermentations by Clostridium pasteurianum DSM 525.
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Affiliation(s)
- Tyll Utesch
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany
| | - An-Ping Zeng
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany
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Xin F, Chen T, Jiang Y, Lu J, Dong W, Zhang W, Ma J, Zhang M, Jiang M. Enhanced biobutanol production with high yield from crude glycerol by acetone uncoupled Clostridium sp. strain CT7. BIORESOURCE TECHNOLOGY 2017; 244:575-581. [PMID: 28803108 DOI: 10.1016/j.biortech.2017.08.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 08/01/2017] [Accepted: 08/02/2017] [Indexed: 05/06/2023]
Abstract
This study reports a unique acetone uncoupled Clostridium species strain CT7, which shows efficient capability of glycerol utilization with high butanol ratio. Medium compositions, such as substrate concentration, micronutrients and pH show significant effects on butanol production from glycerol by strain CT7. To further maximize butanol production, fermentation conditions were optimized by using response surface methodology (RSM). Final butanol production of 16.6g/L with yield of 0.43g/g consumed glycerol was obtained, representing the highest butanol production and yield from glycerol in the batch fermentation mode. Furthermore, strain CT7 could directly convert crude glycerol to 11.8g/L of butanol without any pretreatment. Hence, strain CT7 shows immense potential for biofuels production using waste glycerol as cheap substrate.
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Affiliation(s)
- Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China
| | - Tianpeng Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Jiasheng Lu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China
| | - Jiangfeng Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China
| | - Min Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China.
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