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Diallo M, Kengen SWM, López-Contreras AM. Sporulation in solventogenic and acetogenic clostridia. Appl Microbiol Biotechnol 2021; 105:3533-3557. [PMID: 33900426 PMCID: PMC8102284 DOI: 10.1007/s00253-021-11289-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/03/2021] [Accepted: 04/07/2021] [Indexed: 02/07/2023]
Abstract
The Clostridium genus harbors compelling organisms for biotechnological production processes; while acetogenic clostridia can fix C1-compounds to produce acetate and ethanol, solventogenic clostridia can utilize a wide range of carbon sources to produce commercially valuable carboxylic acids, alcohols, and ketones by fermentation. Despite their potential, the conversion by these bacteria of carbohydrates or C1 compounds to alcohols is not cost-effective enough to result in economically viable processes. Engineering solventogenic clostridia by impairing sporulation is one of the investigated approaches to improve solvent productivity. Sporulation is a cell differentiation process triggered in bacteria in response to exposure to environmental stressors. The generated spores are metabolically inactive but resistant to harsh conditions (UV, chemicals, heat, oxygen). In Firmicutes, sporulation has been mainly studied in bacilli and pathogenic clostridia, and our knowledge of sporulation in solvent-producing or acetogenic clostridia is limited. Still, sporulation is an integral part of the cellular physiology of clostridia; thus, understanding the regulation of sporulation and its connection to solvent production may give clues to improve the performance of solventogenic clostridia. This review aims to provide an overview of the triggers, characteristics, and regulatory mechanism of sporulation in solventogenic clostridia. Those are further compared to the current knowledge on sporulation in the industrially relevant acetogenic clostridia. Finally, the potential applications of spores for process improvement are discussed.Key Points• The regulatory network governing sporulation initiation varies in solventogenic clostridia.• Media composition and cell density are the main triggers of sporulation.• Spores can be used to improve the fermentation process.
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Affiliation(s)
- Mamou Diallo
- Wageningen Food and Biobased Research, Wageningen, The Netherlands.
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, The Netherlands.
| | - Servé W M Kengen
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, The Netherlands
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Seo SO, Lu T, Jin YS, Blaschek HP. A comparative phenotypic and genomic analysis of Clostridium beijerinckii mutant with enhanced solvent production. J Biotechnol 2021; 329:49-55. [PMID: 33556425 DOI: 10.1016/j.jbiotec.2021.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/24/2021] [Accepted: 02/01/2021] [Indexed: 12/14/2022]
Abstract
The acetone-butanol-ethanol (ABE) fermentation by solventogenic clostridia has a long history of industrial butanol production. The Clostridium beijerinckii mutant BA101 has been widely studied for ABE fermentation owing to its enhanced butanol production capacity. Here, we characterized the BA101 mutant under controlled environmental conditions in parallel with the parental strain C. beijerinckii NCIMB 8052. To investigate the correlation between phenotype and genotype, we carried out the genome sequencing of BA101. Through comparative genomic analysis, several mutations in the genes encoding transcriptional regulator, sensor kinase, and phosphatase were identified in the BA101 genome as well as other sibling mutants. Among them, the SNP in the Cbei_3078 gene encoding PAS/PAC sensor hybrid histidine kinase was unique to the BA101 strain. The identified mutations relevant to the observed physiological behaviors of BA101 could be potential genetic targets for rational engineering of solventogenic clostridia toward desired phenotypes.
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Affiliation(s)
- Seung-Oh Seo
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Department of Food Science and Nutrition, The Catholic University of Korea, Bucheon, 14662, Republic of Korea
| | - Ting Lu
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Department of Bioengineering and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Yong-Su Jin
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
| | - Hans P Blaschek
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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Vasylkivska M, Branska B, Sedlar K, Jureckova K, Provaznik I, Patakova P. Phenotypic and Genomic Analysis of Clostridium beijerinckii NRRL B-598 Mutants With Increased Butanol Tolerance. Front Bioeng Biotechnol 2020; 8:598392. [PMID: 33224939 PMCID: PMC7674653 DOI: 10.3389/fbioe.2020.598392] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/20/2020] [Indexed: 11/19/2022] Open
Abstract
N-Butanol, a valuable solvent and potential fuel extender, can be produced via acetone-butanol-ethanol (ABE) fermentation. One of the main drawbacks of ABE fermentation is the high toxicity of butanol to producing cells, leading to cell membrane disruption, low culture viability and, consequently, low produced concentrations of butanol. The goal of this study was to obtain mutant strains of Clostridium beijerinckii NRRL B-598 with improved butanol tolerance using random chemical mutagenesis, describe changes in their phenotypes compared to the wild-type strain and reveal changes in the genome that explain improved tolerance or other phenotypic changes. Nine mutant strains with stable improved features were obtained by three different approaches and, for two of them, ethidium bromide (EB), a known substrate of efflux pumps, was used for either selection or as a mutagenic agent. It is the first utilization of this approach for the development of butanol-tolerant mutants of solventogenic clostridia, for which generally there is a lack of knowledge about butanol efflux or efflux mechanisms and their regulation. Mutant strains exhibited increase in butanol tolerance from 36% up to 127% and the greatest improvement was achieved for the strains for which EB was used as a mutagenic agent. Additionally, increased tolerance to other substrates of efflux pumps, EB and ethanol, was observed in all mutants and higher antibiotic tolerance in some of the strains. The complete genomes of mutant strains were sequenced and revealed that improved butanol tolerance can be attributed to mutations in genes encoding typical stress responses (chemotaxis, autolysis or changes in cell membrane structure), but, also, to mutations in genes X276_07980 and X276_24400, encoding efflux pump regulators. The latter observation confirms the importance of efflux in butanol stress response of the strain and offers new targets for rational strain engineering.
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Affiliation(s)
- Maryna Vasylkivska
- Department of Biotechnology, University of Chemistry and Technology, Prague, Prague, Czechia
| | - Barbora Branska
- Department of Biotechnology, University of Chemistry and Technology, Prague, Prague, Czechia
| | - Karel Sedlar
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Katerina Jureckova
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Ivo Provaznik
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Petra Patakova
- Department of Biotechnology, University of Chemistry and Technology, Prague, Prague, Czechia
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Wu Y, Wang Z, Xin X, Bai F, Xue C. Synergetic Engineering of Central Carbon, Energy, and Redox Metabolisms for High Butanol Production and Productivity by Clostridium acetobutylicum. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c01187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Youduo Wu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
- Engineering Research Center of Application and Transformation for Synthetic Biology, Dalian University of Technology, Dalian 116024, China
| | - Zhenzhong Wang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Xin Xin
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Fengwu Bai
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chuang Xue
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
- Engineering Research Center of Application and Transformation for Synthetic Biology, Dalian University of Technology, Dalian 116024, China
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Wen Z, Li Q, Liu J, Jin M, Yang S. Consolidated bioprocessing for butanol production of cellulolytic Clostridia: development and optimization. Microb Biotechnol 2020; 13:410-422. [PMID: 31448546 PMCID: PMC7017829 DOI: 10.1111/1751-7915.13478] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/02/2019] [Accepted: 08/04/2019] [Indexed: 12/20/2022] Open
Abstract
Butanol is an important bulk chemical, as well as a promising renewable gasoline substitute, that is commonly produced by solventogenic Clostridia. The main cost of cellulosic butanol fermentation is caused by cellulases that are required to saccharify lignocellulose, since solventogenic Clostridia cannot efficiently secrete cellulases. However, cellulolytic Clostridia can natively degrade lignocellulose and produce ethanol, acetate, butyrate and even butanol. Therefore, cellulolytic Clostridia offer an alternative to develop consolidated bioprocessing (CBP), which combines cellulase production, lignocellulose hydrolysis and co-fermentation of hexose/pentose into butanol in one step. This review focuses on CBP advances for butanol production of cellulolytic Clostridia and various synthetic biotechnologies that drive these advances. Moreover, the efforts to optimize the CBP-enabling cellulolytic Clostridia chassis are also discussed. These include the development of genetic tools, pentose metabolic engineering and the improvement of butanol tolerance. Designer cellulolytic Clostridia or consortium provide a promising approach and resource to accelerate future CBP for butanol production.
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Affiliation(s)
- Zhiqiang Wen
- School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing210094China
| | - Qi Li
- College of Life SciencesSichuan Normal UniversityLongquan, Chengdu610101China
| | - Jinle Liu
- Key Laboratory of Synthetic BiologyCAS Center for Excellence in Molecular Plant SciencesShanghai Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
| | - Mingjie Jin
- School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing210094China
| | - Sheng Yang
- Key Laboratory of Synthetic BiologyCAS Center for Excellence in Molecular Plant SciencesShanghai Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
- Huzhou Center of Industrial BiotechnologyShanghai Institutes of Biological SciencesChinese Academy of SciencesShanghai200032China
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Sedlar K, Kolek J, Gruber M, Jureckova K, Branska B, Csaba G, Vasylkivska M, Zimmer R, Patakova P, Provaznik I. A transcriptional response of Clostridium beijerinckii NRRL B-598 to a butanol shock. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:243. [PMID: 31636702 PMCID: PMC6790243 DOI: 10.1186/s13068-019-1584-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 10/04/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND One of the main obstacles preventing solventogenic clostridia from achieving higher yields in biofuel production is the toxicity of produced solvents. Unfortunately, regulatory mechanisms responsible for the shock response are poorly described on the transcriptomic level. Although the strain Clostridium beijerinckii NRRL B-598, a promising butanol producer, has been studied under different conditions in the past, its transcriptional response to a shock caused by butanol in the cultivation medium remains unknown. RESULTS In this paper, we present a transcriptional response of the strain during a butanol challenge, caused by the addition of butanol to the cultivation medium at the very end of the acidogenic phase, using RNA-Seq. We resequenced and reassembled the genome sequence of the strain and prepared novel genome and gene ontology annotation to provide the most accurate results. When compared to samples under standard cultivation conditions, samples gathered during butanol shock represented a well-distinguished group. Using reference samples gathered directly before the addition of butanol, we identified genes that were differentially expressed in butanol challenge samples. We determined clusters of 293 down-regulated and 301 up-regulated genes whose expression was affected by the cultivation conditions. Enriched term "RNA binding" among down-regulated genes corresponded to the downturn of translation and the cluster contained a group of small acid-soluble spore proteins. This explained phenotype of the culture that had not sporulated. On the other hand, up-regulated genes were characterized by the term "protein binding" which corresponded to activation of heat-shock proteins that were identified within this cluster. CONCLUSIONS We provided an overall transcriptional response of the strain C. beijerinckii NRRL B-598 to butanol shock, supplemented by auxiliary technologies, including high-pressure liquid chromatography and flow cytometry, to capture the corresponding phenotypic response. We identified genes whose regulation was affected by the addition of butanol to the cultivation medium and inferred related molecular functions that were significantly influenced. Additionally, using high-quality genome assembly and custom-made gene ontology annotation, we demonstrated that this settled terminology, widely used for the analysis of model organisms, could also be applied to non-model organisms and for research in the field of biofuels.
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Affiliation(s)
- Karel Sedlar
- Department of Biomedical Engineering, Brno University of Technology, Technicka 12, 616 00 Brno, Czech Republic
| | - Jan Kolek
- Department of Biotechnology, University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague, Czech Republic
| | - Markus Gruber
- Institut für Informatik, Ludwig-Maximilians-Universität München, Amalienstraße 17, 80333 Munich, Germany
| | - Katerina Jureckova
- Department of Biomedical Engineering, Brno University of Technology, Technicka 12, 616 00 Brno, Czech Republic
| | - Barbora Branska
- Department of Biotechnology, University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague, Czech Republic
| | - Gergely Csaba
- Institut für Informatik, Ludwig-Maximilians-Universität München, Amalienstraße 17, 80333 Munich, Germany
| | - Maryna Vasylkivska
- Department of Biotechnology, University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague, Czech Republic
| | - Ralf Zimmer
- Institut für Informatik, Ludwig-Maximilians-Universität München, Amalienstraße 17, 80333 Munich, Germany
| | - Petra Patakova
- Department of Biotechnology, University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague, Czech Republic
| | - Ivo Provaznik
- Department of Biomedical Engineering, Brno University of Technology, Technicka 12, 616 00 Brno, Czech Republic
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Patakova P, Kolek J, Sedlar K, Koscova P, Branska B, Kupkova K, Paulova L, Provaznik I. Comparative analysis of high butanol tolerance and production in clostridia. Biotechnol Adv 2018; 36:721-738. [DOI: 10.1016/j.biotechadv.2017.12.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/05/2017] [Accepted: 12/12/2017] [Indexed: 12/24/2022]
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Seo SO, Janssen H, Magis A, Wang Y, Lu T, Price ND, Jin YS, Blaschek HP. Genomic, Transcriptional, and Phenotypic Analysis of the Glucose Derepressed Clostridium beijerinckii Mutant Exhibiting Acid Crash Phenotype. Biotechnol J 2017; 12. [PMID: 28762642 DOI: 10.1002/biot.201700182] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/07/2017] [Indexed: 01/08/2023]
Abstract
Clostridium beijerinckii is a predominant solventogenic bacterium that is used for the ABE fermentation. Various C. beijerinckii mutants are constructed for desirable phenotypes. The C. beijerinckii mutant BA105 harboring a glucose derepression phenotype was previously isolated and demonstrated the enhanced amylolytic activity in the presence of glucose. Despite its potential use, BA105 is not further characterized and utilized. Therefore, the authors investigate fermentation phenotypes of BA105 in this study. Under the typical batch fermentation conditions, BA105 consistently exhibits acid crash phenotype resulting in limited glucose uptake and cell growth. However, when the culture pH is maintained above 5.5, BA105 exhibits the increased glucose uptake and butanol production than did the wild-type. To further analyze BA105, the authors perform genome sequencing and RNA sequencing. Genome analysis identifies two SNPs unique to BA105, in the upstream region of AbrB regulator (Cbei_4885) and the ROK family glucokinase (Cbei_4895) which are involved in catabolite repression and regulation of sugar metabolism. Transcriptional analysis of BA105 reveals significant differential expression of the genes associated with the PTS sugar transport system and acid production. This study improves understanding of the acid crash phenomenon and provides the genetic basis underlying the catabolite derepression phenotype of C. beijericnkii.
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Affiliation(s)
- Seung-Oh Seo
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Holger Janssen
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | | | - Yi Wang
- Biosystems Engineering Department, Auburn University, Auburn, AL, 36849, USA
| | - Ting Lu
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,Department of Bioengineering and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | | | - Yong-Su Jin
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Hans P Blaschek
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,The Integrated Bioprocessing Research Laboratory (IBRL), University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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Evidence of mixotrophic carbon-capture by n-butanol-producer Clostridium beijerinckii. Sci Rep 2017; 7:12759. [PMID: 28986542 PMCID: PMC5630571 DOI: 10.1038/s41598-017-12962-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 09/13/2017] [Indexed: 12/17/2022] Open
Abstract
Recent efforts to combat increasing greenhouse gas emissions include their capture into advanced biofuels, such as butanol. Traditionally, biobutanol research has been centered solely on its generation from sugars. Our results show partial re-assimilation of CO2 and H2 by n-butanol-producer C. beijerinckii. This was detected as synchronous CO2/H2 oscillations by direct (real-time) monitoring of their fermentation gasses. Additional functional analysis demonstrated increased total carbon recovery above heterotrophic values associated to mixotrophic assimilation of synthesis gas (H2, CO2 and CO). This was further confirmed using 13C-Tracer experiments feeding 13CO2 and measuring the resulting labeled products. Genome- and transcriptome-wide analysis revealed transcription of key C-1 capture and additional energy conservation genes, including partial Wood-Ljungdahl and complete reversed pyruvate ferredoxin oxidoreductase / pyruvate-formate-lyase-dependent (rPFOR/Pfl) pathways. Therefore, this report provides direct genetic and physiological evidences of mixotrophic inorganic carbon-capture by C. beijerinckii.
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Lee SH, Kim S, Kim JY, Cheong NY, Kim KH. Enhanced butanol fermentation using metabolically engineered Clostridium acetobutylicum with ex situ recovery of butanol. BIORESOURCE TECHNOLOGY 2016; 218:909-917. [PMID: 27441828 DOI: 10.1016/j.biortech.2016.07.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Revised: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 06/06/2023]
Abstract
In this study, metabolic target reactions for strain engineering were searched via intracellular coenzyme A (CoA) metabolite analysis. The metabolic reactions catalyzed by thiolase (AtoB) and aldehyde-alcohol dehydrogenase (AdhE1) were considered potential rate-limiting steps. In addition, CoA transferase (CtfAB) was highlighted as being important for the assimilation of organic acids, in order to achieve high butanol production. Based on this quantitative analysis, the BEKW_E1AB-atoB strain was constructed by overexpressing the thl (atoB), adhE1, and ctfAB genes in Clostridium acetobutylicum strain BEKW, which has the phosphotransacetylase (pta) and butyrate kinase (buk) genes knocked out. After 100h of continuous fermentation coupled with adsorptive ex situ butanol recovery, the concentrations found after considering desorption, yield, and productivity for the BEKW_E1AB-atoB strain were 55.7g/L, 0.38g/g, and 2.64g/L/h, respectively. The level of butanol production achieved (2.64g/L/h) represents the highest reported value obtained after adsorptive, long-term fermentation.
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Affiliation(s)
- Sang-Hyun Lee
- Department of Biotechnology, Graduate School, Korea University, Seoul 02841, South Korea
| | - Sooah Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul 02841, South Korea
| | - Jung Yeon Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul 02841, South Korea
| | - Nam Yong Cheong
- Environmental Analysis Division, Korea Apparel Testing & Research Institute, Anyang 14088, South Korea
| | - Kyoung Heon Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul 02841, South Korea.
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Dash S, Ng CY, Maranas CD. Metabolic modeling of clostridia: current developments and applications. FEMS Microbiol Lett 2016; 363:fnw004. [PMID: 26755502 DOI: 10.1093/femsle/fnw004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2016] [Indexed: 12/12/2022] Open
Abstract
Anaerobic Clostridium spp. is an important bioproduction microbial genus that can produce solvents and utilize a broad spectrum of substrates including cellulose and syngas. Genome-scale metabolic (GSM) models are increasingly being put forth for various clostridial strains to explore their respective metabolic capabilities and suitability for various bioconversions. In this study, we have selected representative GSM models for six different clostridia (Clostridium acetobutylicum, C. beijerinckii, C. butyricum, C. cellulolyticum, C. ljungdahlii and C. thermocellum) and performed a detailed model comparison contrasting their metabolic repertoire. We also discuss various applications of these GSM models to guide metabolic engineering interventions as well as assessing cellular physiology.
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Affiliation(s)
- Satyakam Dash
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802-1503, USA
| | - Chiam Yu Ng
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802-1503, USA
| | - Costas D Maranas
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802-1503, USA
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12
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Sandoval-Espinola WJ, Chinn M, Bruno-Barcena JM. Inoculum optimization ofClostridium beijerinckiifor reproducible growth. FEMS Microbiol Lett 2015; 362:fnv164. [DOI: 10.1093/femsle/fnv164] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2015] [Indexed: 11/13/2022] Open
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Mitchell WJ. The Phosphotransferase System in Solventogenic Clostridia. J Mol Microbiol Biotechnol 2015; 25:129-42. [DOI: 10.1159/000375125] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The acetone-butanol-ethanol fermentation employing solventogenic clostridia was a major industrial process during the 20th century, but declined for economic reasons. In recent times, interest in the process has been revived due to the perceived potential of butanol as a superior biofuel. Redevelopment of an efficient fermentation process will require a detailed understanding of the physiology of carbohydrate utilization by the bacteria. Genome sequences have revealed that, as in other anaerobes, the phosphotransferase system (PTS) and associated regulatory functions are likely to play an important role in sugar uptake and its regulation. The genomes of <i>Clostridium acetobutylicum</i> and <i>C. beijerinckii</i> encode 13 and 43 phosphotransferases, respectively. Characterization of clostridial phosphotransferases has demonstrated that they are involved in the uptake and phosphorylation of hexoses, hexose derivatives and disaccharides, although the functions of many systems remain to be determined. Glucose is a dominant sugar which represses the utilization of other carbon sources, including the non-PTS pentose sugars xylose and arabinose, by the clostridia. Targeting of the CcpA-dependent mechanism of carbon catabolite repression has been shown to be an effective strategy for reducing the repressive effects of glucose, indicating potential for developing strains with improved fermentation performance.
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Complete Genome Sequence of Solvent-Tolerant Clostridium beijerinckii Strain SA-1. GENOME ANNOUNCEMENTS 2014; 2:2/6/e01310-14. [PMID: 25523769 PMCID: PMC4271159 DOI: 10.1128/genomea.01310-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report the complete genome sequence of Clostridium beijerinckii SA-1, derived by directed evolution from C. beijerinckii NCIMB 8052, selecting for enhanced solvent tolerance. This sequence allows for accurate placement of SA-1 as C. beijerinckii, permits functional analyses of mutant phenotypes, and suggests methods for distinguishing SA-1 from its parent.
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