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Gindt ME, Lück R, Deppenmeier U. Genetic optimization of the human gut bacterium Phocaeicola vulgatus for enhanced succinate production. Appl Microbiol Biotechnol 2024; 108:465. [PMID: 39283347 PMCID: PMC11405475 DOI: 10.1007/s00253-024-13303-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 08/30/2024] [Accepted: 09/03/2024] [Indexed: 09/22/2024]
Abstract
The demand for sustainably produced bulk chemicals is constantly rising. Succinate serves as a fundamental component in various food, chemical, and pharmaceutical products. Succinate can be produced from sustainable raw materials using microbial fermentation and enzyme-based technologies. Bacteroides and Phocaeicola species, widely distributed and prevalent gut commensals, possess enzyme sets for the metabolization of complex plant polysaccharides and synthesize succinate as a fermentative end product. This study employed novel molecular techniques to enhance succinate yields in the natural succinate producer Phocaeicola vulgatus by directing the metabolic carbon flow toward succinate formation. The deletion of the gene encoding the methylmalonyl-CoA mutase (Δmcm, bvu_0309-0310) resulted in a 95% increase in succinate production, as metabolization to propionate was effectively blocked. Furthermore, deletion of genes encoding the lactate dehydrogenase (Δldh, bvu_2499) and the pyruvate:formate lyase (Δpfl, bvu_2880) eliminated the formation of fermentative end products lactate and formate. By overproducing the transketolase (TKT, BVU_2318) in the triple deletion mutant, succinate production increased from 3.9 mmol/g dry weight in the wild type to 10.9 mmol/g dry weight. Overall, succinate yield increased by 180% in the new mutant strain P. vulgatus Δmcm Δldh Δpfl pG106_tkt relative to the parent strain. This approach is a proof of concept, verifying the genetic accessibility of P. vulgatus, and forms the basis for targeted genetic optimization. The increase of efficiency highlights the huge potential of P. vulgatus as a succinate producer with applications in sustainable bioproduction processes. KEY POINTS: • Deleting methylmalonyl-CoA mutase gene in P. vulgatus doubled succinate production • Triple deletion mutant with transketolase overexpression increased succinate yield by 180% • P. vulgatus shows high potential for sustainable bulk chemical production via genetic optimization.
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Affiliation(s)
- Mélanie E Gindt
- Institute of Microbiology and Biotechnology, University of Bonn, Meckenheimer Allee 168, 53115, Bonn, Germany
| | - Rebecca Lück
- Institute of Microbiology and Biotechnology, University of Bonn, Meckenheimer Allee 168, 53115, Bonn, Germany
| | - Uwe Deppenmeier
- Institute of Microbiology and Biotechnology, University of Bonn, Meckenheimer Allee 168, 53115, Bonn, Germany.
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Döring C, Basen M. Propionate production by Bacteroidia gut bacteria and its dependence on substrate concentrations differs among species. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:95. [PMID: 38987848 PMCID: PMC11238397 DOI: 10.1186/s13068-024-02539-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 06/20/2024] [Indexed: 07/12/2024]
Abstract
BACKGROUND Propionate is a food preservative and platform chemical, but no biological process competes with current petrochemical production routes yet. Although propionate production has been described for gut bacteria of the class Bacteroidia, which also carry great capacity for the degradation of plant polymers, knowledge on propionate yields and productivities across species is scarce. This study aims to compare propionate production from glucose within Bacteroidia and characterize good propionate producers among this group. RESULTS We collected published information on propionate producing Bacteroidia, and selected ten species to be further examined. These species were grown under defined conditions to compare their product formation. While propionate, acetate, succinate, lactate and formate were produced, the product ratios varied greatly among the species. The two species with highest propionate yield, B. propionicifaciens (0.39 gpro/ggluc) and B. graminisolvens (0.25 gpro/ggluc), were further examined. Product formation and growth behavior differed significantly during CO2-limited growth and in resting cells experiments, as only B. graminisolvens depended on external-added NaHCO3, while their genome sequences only revealed few differences in the major catabolic pathways. Carbon mass and electron balances in experiments with resting cells were closed under the assumption that the oxidative pentose pathway was utilized for glucose oxidation next to glycolysis in B. graminisolvens. Finally, during pH-controlled fed-batch cultivation B. propionicifaciens and B. graminisolvens grew up to cell densities (OD600) of 8.1 and 9.8, and produced 119 mM and 33 mM of propionate from 130 and 105 mM glucose, respectively. A significant production of other acids, particularly lactate (25 mM), was observed in B. graminisolvens only. CONCLUSIONS We obtained the first broad overview and comparison of propionate production in Bacteroidia strains. A closer look at two species with comparably high propionate yields, showed significant differences in their physiology. Further studies may reveal the molecular basis for high propionate yields in Bacteroidia, paving the road towards their biotechnological application for conversion of biomass-derived sugars to propionate.
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Affiliation(s)
- Carolin Döring
- Department of Microbiology, Institute of Biological Sciences, University of Rostock, Albert-Einstein-Straße 3, 18059, Rostock, Germany
| | - Mirko Basen
- Department of Microbiology, Institute of Biological Sciences, University of Rostock, Albert-Einstein-Straße 3, 18059, Rostock, Germany.
- Department of Maritime Systems, Interdisciplinary Faculty, University of Rostock, Rostock, Germany.
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Inciuraite R, Gedgaudas R, Lukosevicius R, Tilinde D, Ramonaite R, Link A, Kasetiene N, Malakauskas M, Kiudelis G, Jonaitis LV, Kupcinskas J, Juzenas S, Skieceviciene J. Constituents of stable commensal microbiota imply diverse colonic epithelial cell reactivity in patients with ulcerative colitis. Gut Pathog 2024; 16:16. [PMID: 38521943 PMCID: PMC10960424 DOI: 10.1186/s13099-024-00612-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 03/15/2024] [Indexed: 03/25/2024] Open
Abstract
BACKGROUND Despite extensive research on microbiome alterations in ulcerative colitis (UC), the role of the constituent stable microbiota remains unclear. RESULTS This study, employing 16S rRNA-gene sequencing, uncovers a persistent microbial imbalance in both active and quiescent UC patients compared to healthy controls. Using co-occurrence and differential abundance analysis, the study highlights microbial constituents, featuring Phocaeicola, Collinsella, Roseburia, Holdemanella, and Bacteroides, that are not affected during the course of UC. Co-cultivation experiments, utilizing commensal Escherichia coli and Phocaeicola vulgatus, were conducted with intestinal epithelial organoids derived from active UC patients and controls. These experiments reveal a tendency for a differential response in tight junction formation and maintenance in colonic epithelial cells, without inducing pathogen recognition and stress responses, offering further insights into the roles of these microorganisms in UC pathogenesis. These experiments also uncover high variation in patients' response to the same bacteria, which indicate the need for more comprehensive, stratified analyses with an expanded sample size. CONCLUSION This study reveals that a substantial part of the gut microbiota remains stable throughout progression of UC. Functional experiments suggest that members of core microbiota - Escherichia coli and Phocaeicola vulgatus - potentially differentially regulate the expression of tight junction gene in the colonic epithelium of UC patients and healthy individuals.
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Affiliation(s)
- Ruta Inciuraite
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania.
| | - Rolandas Gedgaudas
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
- Department of Gastroenterology, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Rokas Lukosevicius
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Deimante Tilinde
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Rima Ramonaite
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Alexander Link
- Department of Gastroenterology, Hepatology and Infectious Diseases, Otto-von-Guericke University Hospital Magdeburg, Magdeburg, Germany
| | - Neringa Kasetiene
- Department of Food Safety and Quality, Academy of Veterinary, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Mindaugas Malakauskas
- Department of Food Safety and Quality, Academy of Veterinary, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Gediminas Kiudelis
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
- Department of Gastroenterology, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Laimas Virginijus Jonaitis
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
- Department of Gastroenterology, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Juozas Kupcinskas
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
- Department of Gastroenterology, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Simonas Juzenas
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Jurgita Skieceviciene
- Institute for Digestive Research, Academy of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania.
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Keitel L, Braun K, Finger M, Kosfeld U, Yordanov S, Büchs J. Carbon dioxide and trace oxygen concentrations impact growth and product formation of the gut bacterium Phocaeicola vulgatus. BMC Microbiol 2023; 23:391. [PMID: 38062358 PMCID: PMC10701953 DOI: 10.1186/s12866-023-03127-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 11/17/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND The promising yet barely investigated anaerobic species Phocaeicola vulgatus (formerly Bacteroides vulgatus) plays a vital role for human gut health and effectively produces organic acids. Among them is succinate, a building block for high-value-added chemicals. Cultivating anaerobic bacteria is challenging, and a detailed understanding of P. vulgatus growth and metabolism is required to improve succinate production. One significant aspect is the influence of different gas concentrations. CO2 is required for the growth of P. vulgatus. However, it is a greenhouse gas that should not be wasted. Another highly interesting aspect is the sensitivity of P. vulgatus towards O2. In this work, the effects of varying concentrations of both gases were studied in the in-house developed Respiratory Activity MOnitoring System (RAMOS), which provides online monitoring of CO2, O2, and pressure under gassed conditions. The RAMOS was combined with a gas mixing system to test CO2 and O2 concentrations in a range of 0.25-15.0 vol% and 0.0-2.5 vol%, respectively. RESULTS Changing the CO2 concentration in the gas supply revealed a CO2 optimum of 3.0 vol% for total organic acid production and 15.0 vol% for succinate production. It was demonstrated that the organic acid composition changed depending on the CO2 concentration. Furthermore, unrestricted growth of P. vulgatus up to an O2 concentration of 0.7 vol% in the gas supply was proven. The viability decreased rapidly at concentrations larger than or equal to 1.3 vol% O2. CONCLUSIONS The study showed that P. vulgatus requires little CO2, has a distinct O2 tolerance and is therefore well suited for industrial applications.
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Affiliation(s)
- Laura Keitel
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Kristina Braun
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Maurice Finger
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Udo Kosfeld
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Stanislav Yordanov
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Jochen Büchs
- Chair of Biochemical Engineering (AVT.BioVT), RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany.
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