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Bing RG, Ford KC, Willard DJ, Manesh MJH, Straub CT, Laemthong T, Alexander BH, Tanwee T, O'Quinn HC, Poole FL, Vailionis J, Zhang Y, Rodionov D, Adams MWW, Kelly RM. Engineering ethanologenicity into the extremely thermophilic bacterium Anaerocellum (f. Caldicellulosiriuptor) bescii. Metab Eng 2024; 86:99-114. [PMID: 39305946 DOI: 10.1016/j.ymben.2024.09.007] [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: 06/17/2024] [Revised: 08/19/2024] [Accepted: 09/15/2024] [Indexed: 09/27/2024]
Abstract
The anaerobic bacterium Anaerocellum (f. Caldicellulosiruptor) bescii natively ferments the carbohydrate content of plant biomass (including microcrystalline cellulose) into predominantly acetate, H2, and CO2, and smaller amounts of lactate, alanine and valine. While this extreme thermophile (growth Topt 78 °C) is not natively ethanologenic, it has been previously metabolically engineered with this property, albeit initially yielding low solvent titers (∼15 mM). Herein we report significant progress on improving ethanologenicity in A. bescii, such that titers above 130 mM have now been achieved, while concomitantly improving selectivity by minimizing acetate formation. Metabolic engineering progress has benefited from improved molecular genetic tools and better understanding of A. bescii growth physiology. Heterologous expression of a mutated thermophilic alcohol dehydrogenase (AdhE) modified for co-factor requirement, coupled with bioreactor operation strategies related to pH control, have been key to enhanced ethanol generation and fermentation product specificity. Insights gained from metabolic modeling of A. bescii set the stage for its further improvement as a metabolic engineering platform.
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Affiliation(s)
- Ryan G Bing
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Kathryne C Ford
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Daniel J Willard
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Mohamad J H Manesh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Christopher T Straub
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Tunyaboon Laemthong
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Benjamin H Alexander
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Tania Tanwee
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Hailey C O'Quinn
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Farris L Poole
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Jason Vailionis
- Department of Cell and Molecular Biology, College of the Environment and Life Sciences, University of Rhode Island, Kingston, RI, USA
| | - Ying Zhang
- Department of Cell and Molecular Biology, College of the Environment and Life Sciences, University of Rhode Island, Kingston, RI, USA
| | - Dmitry Rodionov
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Robert M Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA.
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Bhattacharya A, Majtorp L, Birgersson S, Wiemann M, Sreenivas K, Verbrugghe P, Van Aken O, Van Niel EWJ, Stålbrand H. Cross-Feeding and Enzymatic Catabolism for Mannan-Oligosaccharide Utilization by the Butyrate-Producing Gut Bacterium Roseburia hominis A2-183. Microorganisms 2022; 10:microorganisms10122496. [PMID: 36557749 PMCID: PMC9784577 DOI: 10.3390/microorganisms10122496] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/01/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
β-Mannan is abundant in the human diet and in hemicellulose derived from softwood. Linear or galactose-substituted β-mannan-oligosaccharides (MOS/GMOSs) derived from β-mannan are considered emerging prebiotics that could stimulate health-associated gut microbiota. However, the underlying mechanisms are not yet resolved. Therefore, this study investigated the cross-feeding and metabolic interactions between Bifidobacterium adolescentis ATCC 15703, an acetate producer, and Roseburia hominis A2-183 DSMZ 16839, a butyrate producer, during utilization of MOS/GMOSs. Cocultivation studies suggest that both strains coexist due to differential MOS/GMOS utilization, along with the cross-feeding of acetate from B. adolescentis E194a to R. hominis A2-183. The data suggest that R. hominis A2-183 efficiently utilizes MOS/GMOS in mono- and cocultivation. Notably, we observed the transcriptional upregulation of certain genes within a dedicated MOS/GMOS utilization locus (RhMosUL), and an exo-oligomannosidase (RhMan113A) gene located distally in the R. hominis A2-183 genome. Significantly, biochemical analysis of β-1,4 mannan-oligosaccharide phosphorylase (RhMOP130A), α-galactosidase (RhGal36A), and exo-oligomannosidase (RhMan113A) suggested their potential synergistic role in the initial utilization of MOS/GMOSs. Thus, our results enhance the understanding of MOS/GMOS utilization by potential health-promoting human gut microbiota and highlight the role of cross-feeding and metabolic interactions between two secondary mannan degraders inhabiting the same ecological niche in the gut.
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Affiliation(s)
- Abhishek Bhattacharya
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden; (L.M.); (S.B.); (M.W.)
- Correspondence: (A.B.); (H.S.)
| | - Lovisa Majtorp
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden; (L.M.); (S.B.); (M.W.)
| | - Simon Birgersson
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden; (L.M.); (S.B.); (M.W.)
| | - Mathias Wiemann
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden; (L.M.); (S.B.); (M.W.)
| | - Krishnan Sreenivas
- Applied Microbiology, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden; (K.S.); (E.W.J.V.N.)
| | - Phebe Verbrugghe
- Department of Food Technology, Engineering and Nutrition, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden;
| | - Olivier Van Aken
- Department of Biology, Lund University, Sölvegatan 35, 223 62 Lund, Sweden;
| | - Ed W. J. Van Niel
- Applied Microbiology, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden; (K.S.); (E.W.J.V.N.)
| | - Henrik Stålbrand
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden; (L.M.); (S.B.); (M.W.)
- Correspondence: (A.B.); (H.S.)
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Honarmandrad Z, Kucharska K, Gębicki J. Processing of Biomass Prior to Hydrogen Fermentation and Post-Fermentative Broth Management. Molecules 2022; 27:7658. [PMID: 36364485 PMCID: PMC9658980 DOI: 10.3390/molecules27217658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/02/2022] [Accepted: 11/04/2022] [Indexed: 09/10/2023] Open
Abstract
Using bioconversion and simultaneous value-added product generation requires purification of the gaseous and the liquid streams before, during, and after the bioconversion process. The effect of diversified process parameters on the efficiency of biohydrogen generation via biological processes is a broad object of research. Biomass-based raw materials are often applied in investigations regarding biohydrogen generation using dark fermentation and photo fermentation microorganisms. The literature lacks information regarding model mixtures of lignocellulose and starch-based biomass, while the research is carried out based on a single type of raw material. The utilization of lignocellulosic and starch biomasses as the substrates for bioconversion processes requires the decomposition of lignocellulosic polymers into hexoses and pentoses. Among the components of lignocelluloses, mainly lignin is responsible for biomass recalcitrance. The natural carbohydrate-lignin shields must be disrupted to enable lignin removal before biomass hydrolysis and fermentation. The matrix of chemical compounds resulting from this kind of pretreatment may significantly affect the efficiency of biotransformation processes. Therefore, the actual state of knowledge on the factors affecting the culture of dark fermentation and photo fermentation microorganisms and their adaptation to fermentation of hydrolysates obtained from biomass requires to be monitored and a state of the art regarding this topic shall become a contribution to the field of bioconversion processes and the management of liquid streams after fermentation. The future research direction should be recognized as striving to simplification of the procedure, applying the assumptions of the circular economy and the responsible generation of liquid and gas streams that can be used and purified without large energy expenditure. The optimization of pre-treatment steps is crucial for the latter stages of the procedure.
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Affiliation(s)
| | - Karolina Kucharska
- Department of Process Engineering and Chemical Technology, Faculty of Chemistry, Gdansk University of Technology, 11/12 Gabriela Narutowicza Street, 80-233 Gdansk, Poland
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