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Sobieraj K, Żebrowska-Różańska P, Siedlecka A, Łaczmański Ł, Białowiec A. Analysis of microbial community potentially involved in carbon monoxide production in compost and its functional assessment: Utilized pathways, enzymes, and genes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2025; 968:178860. [PMID: 39970559 DOI: 10.1016/j.scitotenv.2025.178860] [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: 11/28/2024] [Revised: 01/30/2025] [Accepted: 02/12/2025] [Indexed: 02/21/2025]
Abstract
Carbon monoxide (CO) is a valuable compound widely used in industry, and its biological production aligns with the bioeconomy principles. This study introduces a novel perspective by exploring biowaste composting as a potential source of CO production. Using 16S rDNA sequencing, microbial communities within two zones of a compost pile, with low (CO/L, 119 ppm) and high CO concentration (CO/H, 785 ppm), were characterized. The metabolic potential of microbial communities was investigated using PICRUSt2, an advanced tool for functional analysis. Results revealed higher alpha diversity in CO/H samples compared to CO/L, likely influenced by the lower temperature at the CO/H sampling site (50 °C vs. 62 °C in CO/L). Importantly, in the PCoA plots, samples clustered together depending on the sampling site. The microbial community composition was dominated by Bacilli (up to 98.8 % and 55.4 % of CO/L and CO/H samples, respectively). One of the key results was the detection of the Wood-Ljungdahl pathway, a metabolic route for CO production, in nearly all compost samples. This pathway was more abundant in CO/H samples (0.011-0.027 %) compared to CO/L samples (0.000-0.002 %). Moreover, 7 enzymes and 7 genes responsible for CO production and metabolism were detected in compost samples, suggesting that the observed CO formation is likely of biotic origin. The study for the first time underscored the potential of composting as a sustainable method for CO generation and validated PICRUSt2 as a reliable tool for uncovering biotic CO production mechanisms, offering valuable preliminary insights into the functional capabilities of microbial communities.
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Affiliation(s)
- Karolina Sobieraj
- Wrocław University of Environmental and Life Sciences, Department of Applied Bioeconomy, 37a Chełmońskiego Street, 51-630 Wrocław, Poland.
| | | | - Agata Siedlecka
- Wrocław University of Environmental and Life Sciences, Department of Applied Bioeconomy, 37a Chełmońskiego Street, 51-630 Wrocław, Poland.
| | - Łukasz Łaczmański
- Polish Academy of Sciences, Hirszfeld Institute of Immunology and Experimental Therapy, Weigla 12 Street, 53-114 Wrocław, Poland.
| | - Andrzej Białowiec
- Wrocław University of Environmental and Life Sciences, Department of Applied Bioeconomy, 37a Chełmońskiego Street, 51-630 Wrocław, Poland.
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Neto AS, Wainaina S, Chandolias K, Piatek P, Taherzadeh MJ. Exploring the Potential of Syngas Fermentation for Recovery of High-Value Resources: A Comprehensive Review. CURRENT POLLUTION REPORTS 2024; 11:7. [PMID: 39583010 PMCID: PMC11579188 DOI: 10.1007/s40726-024-00337-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 11/12/2024] [Indexed: 11/26/2024]
Abstract
Synthesis gas (syngas) fermentation represents a promising biological method for converting industrial waste gases, particularly carbon monoxide (CO) and carbon dioxide (CO₂) from industrial sources (e.g. steel production or municipal waste gasification), into high-value products such as biofuels, chemicals, and animal feed using acetogenic bacteria. This review identifies and addresses key challenges that hinder the large-scale adoption of this technology, including limitations in gas mass transfer, an incomplete understanding of microbial metabolic pathways, and suboptimal bioprocess conditions. Our findings emphasize the critical role of microbial strain selection and bioprocess optimization to enhance productivity and scalability, with a focus on utilizing diverse microbial consortia and efficient reactor systems. By examining recent advancements in microbial conditioning, operational parameters, and reactor design, this study provides actionable insights to improve syngas fermentation efficiency, suggesting pathways towards overcoming current technical barriers for its broader industrial application beyond the production of bulk chemicals.
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Affiliation(s)
- Alvaro S. Neto
- Swedish Centre for Resource Recovery, University of Borås, Borås, Sweden
| | | | | | - Pawel Piatek
- Division of Built Environment, RISE Research Institutes of Sweden, Gothenburg, Sweden
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de Smit SM, van Mameren TD, van Zwet K, van Veelen HPJ, Cristina Gagliano M, Strik DPBTB, Bitter JH. Integration of biocompatible hydrogen evolution catalyst developed from metal-mix solutions with microbial electrosynthesis. Bioelectrochemistry 2024; 158:108724. [PMID: 38714063 DOI: 10.1016/j.bioelechem.2024.108724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 04/29/2024] [Accepted: 05/01/2024] [Indexed: 05/09/2024]
Abstract
Microbial conversion of CO2 to multi-carbon compounds such as acetate and butyrate is a promising valorisation technique. For those reactions, the electrochemical supply of hydrogen to the biocatalyst is a viable approach. Earlier we have shown that trace metals from microbial growth media spontaneously form in situ electro-catalysts for hydrogen evolution. Here, we show biocompatibility with the successful integration of such metal mix-based HER catalyst for immediate start-up of microbial acetogenesis (CO2 to acetate). Also, n-butyrate formation started fast (after twenty days). Hydrogen was always produced in excess, although productivity decreased over the 36 to 50 days, possibly due to metal leaching from the cathode. The HER catalyst boosted microbial productivity in a two-step microbial community bioprocess: acetogenesis by a BRH-c20a strain and acetate elongation to n-butyrate by Clostridium sensu stricto 12 (related) species. These findings provide new routes to integrate electro-catalysts and micro-organisms showing respectively bio and electrochemical compatibility.
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Affiliation(s)
- Sanne M de Smit
- Environmental Technology, Wageningen University and Research, Wageningen, The Netherlands; Biobased Chemistry and Technology, Wageningen University and Research, Wageningen, The Netherlands
| | - Thomas D van Mameren
- Environmental Technology, Wageningen University and Research, Wageningen, The Netherlands
| | - Koen van Zwet
- Environmental Technology, Wageningen University and Research, Wageningen, The Netherlands
| | - H Pieter J van Veelen
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Leeuwarden, The Netherlands
| | - M Cristina Gagliano
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Leeuwarden, The Netherlands
| | - David P B T B Strik
- Environmental Technology, Wageningen University and Research, Wageningen, The Netherlands.
| | - Johannes H Bitter
- Biobased Chemistry and Technology, Wageningen University and Research, Wageningen, The Netherlands.
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García-Casado S, Muñoz R, Lebrero R. Enrichment of a mixed syngas-converting culture for volatile fatty acids and methane production. BIORESOURCE TECHNOLOGY 2024; 400:130646. [PMID: 38556063 DOI: 10.1016/j.biortech.2024.130646] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 03/26/2024] [Accepted: 03/29/2024] [Indexed: 04/02/2024]
Abstract
The present study evaluated the production potential of CH4, carboxylic acids and alcohols from a mixed culture enriched using synthetic syngas. The influence of syngas concentration on the microbial community and products productivity and selectivity was investigated. The results demonstrated the enrichment of a mesophilic mixed culture capable of converting CO and H2 mainly to CH4 and acetate, along with butyrate. The selectivity values showed that acetate production was enhanced during the first cycle in all conditions tested (up to 20 %), while CH4 was the main product generated during following cycles. Concretely, CH4 selectivity remained unaffected by syngas concentration, reaching a stable value of 41.6 ± 2.0 %. On the other hand, butyrate selectivity was only representative at the highest syngas concentration and lower pH values (26.1 ± 5.8 %), where the H2 consumption was completely inhibited. Thus, pH was identified as a key parameter for both butyrate synthesis and the development of hydrogenotrophic activity.
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Affiliation(s)
- Silvia García-Casado
- Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain
| | - Raúl Muñoz
- Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain
| | - Raquel Lebrero
- Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain.
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Baleeiro FCF, Varchmin L, Kleinsteuber S, Sträuber H, Neumann A. Formate-induced CO tolerance and methanogenesis inhibition in fermentation of syngas and plant biomass for carboxylate production. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:26. [PMID: 36805806 PMCID: PMC9936662 DOI: 10.1186/s13068-023-02271-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 01/29/2023] [Indexed: 02/19/2023]
Abstract
BACKGROUND Production of monocarboxylates using microbial communities is highly dependent on local and degradable biomass feedstocks. Syngas or different mixtures of H2, CO, and CO2 can be sourced from biomass gasification, excess renewable electricity, industrial off-gases, and carbon capture plants and co-fed to a fermenter to alleviate dependence on local biomass. To understand the effects of adding these gases during anaerobic fermentation of plant biomass, a series of batch experiments was carried out with different syngas compositions and corn silage (pH 6.0, 32 °C). RESULTS Co-fermentation of syngas with corn silage increased the overall carboxylate yield per gram of volatile solids (VS) by up to 29% (0.47 ± 0.07 g gVS-1; in comparison to 0.37 ± 0.02 g gVS-1 with a N2/CO2 headspace), despite slowing down biomass degradation. Ethylene and CO exerted a synergistic effect in preventing methanogenesis, leading to net carbon fixation. Less than 12% of the electrons were misrouted to CH4 when either 15 kPa CO or 5 kPa CO + 1.5 kPa ethylene was used. CO increased the selectivity to acetate and propionate, which accounted for 85% (electron equivalents) of all products at 49 kPa CO, by favoring lactic acid bacteria and actinobacteria over n-butyrate and n-caproate producers. Inhibition of n-butyrate and n-caproate production by CO happened even when an inoculum preacclimatized to syngas and lactate was used. Intriguingly, the effect of CO on n-butyrate and n-caproate production was reversed when formate was present in the broth. CONCLUSIONS The concept of co-fermenting syngas and plant biomass shows promise in three aspects: by making anaerobic fermentation a carbon-fixing process, by increasing the yields of short-chain carboxylates (propionate and acetate), and by minimizing electron losses to CH4. Moreover, a model was proposed for how formate can alleviate CO inhibition in certain acidogenic bacteria. Testing the fermentation of syngas and plant biomass in a continuous process could potentially improve selectivity to n-butyrate and n-caproate by enriching chain-elongating bacteria adapted to CO and complex biomass.
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Affiliation(s)
- Flávio C F Baleeiro
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
- Technical Biology, Institute of Process Engineering in Life Science, Karlsruhe Institute of Technology - KIT, Karlsruhe, Germany
| | - Lukas Varchmin
- Technical Biology, Institute of Process Engineering in Life Science, Karlsruhe Institute of Technology - KIT, Karlsruhe, Germany
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Heike Sträuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Anke Neumann
- Technical Biology, Institute of Process Engineering in Life Science, Karlsruhe Institute of Technology - KIT, Karlsruhe, Germany.
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Baleeiro FCF, Raab J, Kleinsteuber S, Neumann A, Sträuber H. Mixotrophic chain elongation with syngas and lactate as electron donors. Microb Biotechnol 2023; 16:322-336. [PMID: 36378491 PMCID: PMC9871530 DOI: 10.1111/1751-7915.14163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 11/16/2022] Open
Abstract
Feeding microbial communities with both organic and inorganic substrates can improve sustainability and feasibility of chain elongation processes. Sustainably produced H2 , CO2 , and CO can be co-fed to microorganisms as a source for acetyl-CoA, while a small amount of an ATP-generating organic substrate helps overcome the kinetic hindrances associated with autotrophic carboxylate production. Here, we operated two semi-continuous bioreactor systems with continuous recirculation of H2 , CO2 , and CO while co-feeding an organic model feedstock (lactate and acetate) to understand how a mixotrophic community is shaped during carboxylate production. Contrary to the assumption that H2 , CO2 , and CO support chain elongation via ethanol production in open cultures, significant correlations (p < 0.01) indicated that relatives of Clostridium luticellarii and Eubacterium aggregans produced carboxylates (acetate to n-caproate) while consuming H2 , CO2 , CO, and lactate themselves. After 100 days, the enriched community was dominated by these two bacteria coexisting in cyclic dynamics shaped by the CO partial pressure. Homoacetogenesis was strongest when the acetate concentration was low (3.2 g L-1 ), while heterotrophs had the following roles: Pseudoramibacter, Oscillibacter, and Colidextribacter contributed to n-caproate production and Clostridium tyrobutyricum and Acidipropionibacterium spp. grew opportunistically producing n-butyrate and propionate, respectively. The mixotrophic chain elongation community was more efficient in carboxylate production compared with the heterotrophic one and maintained average carbon fixation rates between 0.088 and 1.4 g CO2 equivalents L-1 days-1 . The extra H2 and CO consumed routed 82% more electrons to carboxylates and 50% more electrons to carboxylates longer than acetate. This study shows for the first time long-term, stable production of short- and medium-chain carboxylates with a mixotrophic community.
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Affiliation(s)
- Flávio C. F. Baleeiro
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
- Technical Biology, Institute of Process Engineering in Life ScienceKarlsruhe Institute of Technology – KITKarlsruheGermany
| | - Jana Raab
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Sabine Kleinsteuber
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Anke Neumann
- Technical Biology, Institute of Process Engineering in Life ScienceKarlsruhe Institute of Technology – KITKarlsruheGermany
| | - Heike Sträuber
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
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Wickham-Smith C, Malys N, Winzer K. Improving carbon monoxide tolerance of Cupriavidus necator H16 through adaptive laboratory evolution. Front Bioeng Biotechnol 2023; 11:1178536. [PMID: 37168609 PMCID: PMC10164946 DOI: 10.3389/fbioe.2023.1178536] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/06/2023] [Indexed: 05/13/2023] Open
Abstract
Background: The toxic gas carbon monoxide (CO) is abundantly present in synthesis gas (syngas) and certain industrial waste gases that can serve as feedstocks for the biological production of industrially significant chemicals and fuels. For efficient bacterial growth to occur, and to increase productivity and titres, a high resistance to the gas is required. The aerobic bacterium Cupriavidus necator H16 can grow on CO2 + H2, although it cannot utilise CO as a source of carbon and energy. This study aimed to increase its CO resistance through adaptive laboratory evolution. Results: To increase the tolerance of C. necator to CO, the organism was continually subcultured in the presence of CO both heterotrophically and autotrophically. Ten individual cultures were evolved heterotrophically with fructose in this manner and eventually displayed a clear growth advantage over the wild type strain. Next-generation sequencing revealed several mutations, including a single point mutation upstream of a cytochrome bd ubiquinol oxidase operon (cydA2B2), which was present in all evolved isolates. When a subset of these mutations was engineered into the parental H16 strain, only the cydA2B2 upstream mutation enabled faster growth in the presence of CO. Expression analysis, mutation, overexpression and complementation suggested that cydA2B2 transcription is upregulated in the evolved isolates, resulting in increased CO tolerance under heterotrophic but not autotrophic conditions. However, through subculturing on a syngas-like mixture with increasing CO concentrations, C. necator could also be evolved to tolerate high CO concentrations under autotrophic conditions. A mutation in the gene for the soluble [NiFe]-hydrogenase subunit hoxH was identified in the evolved isolates. When the resulting amino acid change was engineered into the parental strain, autotrophic CO resistance was conferred. A strain constitutively expressing cydA2B2 and the mutated hoxH gene exhibited high CO tolerance under both heterotrophic and autotrophic conditions. Conclusion: C. necator was evolved to tolerate high concentrations of CO, a phenomenon which was dependent on the terminal respiratory cytochrome bd ubiquinol oxidase when grown heterotrophically and the soluble [NiFe]-hydrogenase when grown autotrophically. A strain exhibiting high tolerance under both conditions was created and presents a promising chassis for syngas-based bioproduction processes.
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Rafieenia R, Atkinson E, Ledesma-Amaro R. Division of labor for substrate utilization in natural and synthetic microbial communities. Curr Opin Biotechnol 2022; 75:102706. [DOI: 10.1016/j.copbio.2022.102706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/07/2022] [Accepted: 02/15/2022] [Indexed: 01/30/2023]
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DePoy AN, King GM. Putative Nickel-Dependent Anaerobic Carbon Monoxide Uptake Occurs Commonly in Soils and Sediments at Ambient Temperature and Might Contribute to Atmospheric and Sub-Atmospheric Carbon Monoxide Uptake During Anoxic Conditions. Front Microbiol 2022; 13:736189. [PMID: 35401450 PMCID: PMC8987735 DOI: 10.3389/fmicb.2022.736189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 02/18/2022] [Indexed: 11/13/2022] Open
Abstract
Carbon monoxide (CO) occurs naturally in the atmosphere where it plays a critical role in tropospheric chemistry. Atmospheric CO uptake by soils has been well documented as an important CO sink and has been attributed to a group of aerobic bacteria that possess a molybdenum-dependent CO dehydrogenase (Mo-CODH). CO can also be oxidized by obligate Ni-dependent anaerobes (Ni-COX) that possess nickel-dependent CODHs (Ni-CODH) but relatively little is known about their ecology or their potential to contribute to CO dynamics within soils and sediments or to soil-atmosphere CO exchanges. Results from a series of assays undertaken with diverse soils and sediments and CO concentrations of 10 ppm and 25% with incubation temperatures of 10, 25, and 60°C revealed anaerobic uptake rates with 10 ppm CO that were comparable to those measured under oxic conditions; further, anaerobic CO uptake occurred without a lag and at atmospheric and sub-atmospheric CO concentrations. Assays with 25% CO revealed previously undocumented activity at 10°C and showed extensive activity at 25°C. Results from prior studies with isolates and soils suggest that anaerobic uptake at both 10 ppm and 25% CO concentrations might be attributed to Ni-COX. Collectively the results considerably expand the ecological range for Ni-COX and indicate that they could play previously unsuspected roles in soil CO dynamics.
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Li C, Zhu X, Angelidaki I. Syngas biomethanation: effect of biomass-gas ratio, syngas composition and pH buffer. BIORESOURCE TECHNOLOGY 2021; 342:125997. [PMID: 34583116 DOI: 10.1016/j.biortech.2021.125997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/15/2021] [Accepted: 09/19/2021] [Indexed: 06/13/2023]
Abstract
The concept of syngas biomethanation is attractive, however, it still needs improvement in optimizing the operational conditions. In the present study, syngas fermentations under different carbon monoxide (CO), carbon dioxide (CO2) and hydrogen (H2) compositions were conducted under two different biomass-gas ratio (BGR) systems. The results showed that high BGR enhanced the CO consumption rate, achieving a 60% enhancement with CO as the sole substrate. Stoichiometric H2 addition could successfully convert all the CO and CO2 to pure methane, however, higher H2 partial pressure might decline the CO consumption due to pH inhibition from consumption of bicarbonate. Microbial analysis showed different syngas composition could affect the bacteria community, while, archaea community was only slightly affected with Methanothermobacter as the dominant methanogen. This study provided strategy for efficient syngas biomethanation and deeper insight into effect of H2 addition on CO conversion under different BGR systems.
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Affiliation(s)
- Chunxing Li
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
| | - Xinyu Zhu
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
| | - Irini Angelidaki
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
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Conversion of Carbon Monoxide to Chemicals Using Microbial Consortia. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2021; 180:373-407. [PMID: 34811579 DOI: 10.1007/10_2021_180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Syngas, a gaseous mixture of CO, H2 and CO2, can be produced by gasification of carbon-containing materials, including organic waste materials or lignocellulosic biomass. The conversion of bio-based syngas to chemicals is foreseen as an important process in circular bioeconomy. Carbon monoxide is also produced as a waste gas in many industrial sectors (e.g., chemical, energy, steel). Often, the purity level of bio-based syngas and waste gases is low and/or the ratios of syngas components are not adequate for chemical conversion (e.g., by Fischer-Tropsch). Microbes are robust catalysts to transform impure syngas into a broad spectrum of products. Fermentation of CO-rich waste gases to ethanol has reached commercial scale (by axenic cultures of Clostridium species), but production of other chemical building blocks is underexplored. Currently, genetic engineering of carboxydotrophic acetogens is applied to increase the portfolio of products from syngas/CO, but the limited energy metabolism of these microbes limits product yields and applications (for example, only products requiring low levels of ATP for synthesis can be produced). An alternative approach is to explore microbial consortia, including open mixed cultures and synthetic co-cultures, to create a metabolic network based on CO conversion that can yield products such as medium-chain carboxylic acids, higher alcohols and other added-value chemicals.
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12
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He Y, Lens PNL, Veiga MC, Kennes C. Enhanced Ethanol Production From Carbon Monoxide by Enriched Clostridium Bacteria. Front Microbiol 2021; 12:754713. [PMID: 34777310 PMCID: PMC8585497 DOI: 10.3389/fmicb.2021.754713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/20/2021] [Indexed: 11/13/2022] Open
Abstract
Carbon monoxide (CO)-metabolizing Clostridium spp. were enriched from the biomass of a butanol-producing reactor. After six successive biomass transfers, ethanol production reached as much as 11.8 g/L with minor accumulation of acetic acid, under intermittent gas feeding conditions and over a wide pH range of 6.45-4.95. The molar ratio of ethanol to acetic acid exceeded 1.7 after the lag phase of 11 days and reached its highest value of 8.6 during the fermentation process after 25 days. Although butanol production was not significantly enhanced in the enrichment, the biomass was able to convert exogenous butyric acid (3.2 g/L) into butanol with nearly 100% conversion efficiency using CO as reducing power. This suggested that inhibition of butanol production from CO was caused by the lack of natural butyric acid production, expectedly induced by unsuitable pH values due to initial acidification resulting from the acetic acid production. The enriched Clostridium population also converted glucose to formic, acetic, propionic, and butyric acids in batch tests with daily pH adjustment to pH 6.0. The Clostridium genus was enriched with its relative abundance significantly increasing from 7% in the inoculum to 94% after five successive enrichment steps. Unidentified Clostridium species showed a very high relative abundance, reaching 73% of the Clostridium genus in the enriched sludge (6th transfer).
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Affiliation(s)
- Yaxue He
- Chemical Engineering Laboratory, Faculty of Sciences and Center for Advanced Scientific Research (CICA), BIOENGIN Group, University of A Coruña (UDC), A Coruña, Spain.,National University of Ireland Galway, Galway, Ireland
| | - Piet N L Lens
- National University of Ireland Galway, Galway, Ireland
| | - María C Veiga
- Chemical Engineering Laboratory, Faculty of Sciences and Center for Advanced Scientific Research (CICA), BIOENGIN Group, University of A Coruña (UDC), A Coruña, Spain
| | - Christian Kennes
- Chemical Engineering Laboratory, Faculty of Sciences and Center for Advanced Scientific Research (CICA), BIOENGIN Group, University of A Coruña (UDC), A Coruña, Spain
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13
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Singh P, Srivastava R. Utilization of bio-inspired catalyst for CO2 reduction into green fuels: Recent advancement and future perspectives. J CO2 UTIL 2021. [DOI: 10.1016/j.jcou.2021.101748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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14
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Duan H, He P, Shao L, Lü F. Functional genome-centric view of the CO-driven anaerobic microbiome. THE ISME JOURNAL 2021; 15:2906-2919. [PMID: 33911204 PMCID: PMC8443622 DOI: 10.1038/s41396-021-00983-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 03/17/2021] [Accepted: 04/09/2021] [Indexed: 02/02/2023]
Abstract
CO is a promising substrate for producing biochemicals and biofuels through mixed microbial cultures, where carboxydotrophs play a crucial role. The previous investigations of mixed microbial cultures focused primarily on overall community structures, but under-characterized taxa and intricate microbial interactions have not yet been precisely explicated. Here, we undertook DNA-SIP based metagenomics to profile the anaerobic CO-driven microbiomes under 95 and 35% CO atmospheres. The time-series analysis of the isotope-labeled amplicon sequencing revealed the essential roles of Firmicutes and Proteobacteria under high and low CO pressure, respectively, and Methanobacterium was the predominant archaeal genus. The functional enrichment analysis based on the isotope-labeled metagenomes suggested that the microbial cultures under high CO pressure had greater potential in expressing carboxylate metabolism and citrate cycle pathway. The genome-centric metagenomics reconstructed 24 discovered and 24 under-characterized metagenome-assembled genomes (MAGs), covering more than 94% of the metagenomic reads. The metabolic reconstruction of the MAGs described their potential functions in the CO-driven microbiomes. Some under-characterized taxa might be versatile in multiple processes; for example, under-characterized Rhodoplanes sp. and Desulfitobacterium_A sp. could encode the complete enzymes in CO oxidation and carboxylate production, improving functional redundancy. Finally, we proposed the putative microbial interactions in the conversion of CO to carboxylates and methane.
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Affiliation(s)
- Haowen Duan
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China
| | - Pinjing He
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, China
| | - Liming Shao
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, China
| | - Fan Lü
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China.
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
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15
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Joshi S, Robles A, Aguiar S, Delgado AG. The occurrence and ecology of microbial chain elongation of carboxylates in soils. THE ISME JOURNAL 2021; 15:1907-1918. [PMID: 33558687 PMCID: PMC8245554 DOI: 10.1038/s41396-021-00893-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 12/14/2020] [Accepted: 01/13/2021] [Indexed: 01/30/2023]
Abstract
Chain elongation is a growth-dependent anaerobic metabolism that combines acetate and ethanol into butyrate, hexanoate, and octanoate. While the model microorganism for chain elongation, Clostridium kluyveri, was isolated from a saturated soil sample in the 1940s, chain elongation has remained unexplored in soil environments. During soil fermentative events, simple carboxylates and alcohols can transiently accumulate up to low mM concentrations, suggesting in situ possibility of microbial chain elongation. Here, we examined the occurrence and microbial ecology of chain elongation in four soil types in microcosms and enrichments amended with chain elongation substrates. All soils showed evidence of chain elongation activity with several days of incubation at high (100 mM) and environmentally relevant (2.5 mM) concentrations of acetate and ethanol. Three soils showed substantial activity in soil microcosms with high substrate concentrations, converting 58% or more of the added carbon as acetate and ethanol to butyrate, butanol, and hexanoate. Semi-batch enrichment yielded hexanoate and octanoate as the most elongated products and microbial communities predominated by C. kluyveri and other Firmicutes genera not known to undergo chain elongation. Collectively, these results strongly suggest a niche for chain elongation in anaerobic soils that should not be overlooked in soil microbial ecology studies.
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Affiliation(s)
- Sayalee Joshi
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA
| | - Aide Robles
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, USA
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, Tempe, AZ, USA
| | - Samuel Aguiar
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, USA
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Anca G Delgado
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA.
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, USA.
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, Tempe, AZ, USA.
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16
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Leonov PS, Flores-Alsina X, Gernaey KV, Sternberg C. Microbial biofilms in biorefinery - Towards a sustainable production of low-value bulk chemicals and fuels. Biotechnol Adv 2021; 50:107766. [PMID: 33965529 DOI: 10.1016/j.biotechadv.2021.107766] [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: 10/07/2020] [Revised: 04/11/2021] [Accepted: 05/04/2021] [Indexed: 12/14/2022]
Abstract
Harnessing the potential of biocatalytic conversion of renewable biomass into value-added products is still hampered by unfavorable process economics. This has promoted the use of biofilms as an alternative to overcome the limitations of traditional planktonic systems. In this paper, the benefits and challenges of biofilm fermentations are reviewed with a focus on the production of low-value bulk chemicals and fuels from waste biomass. Our study demonstrates that biofilm fermentations can potentially improve productivities and product yields by increasing biomass retention and allowing for continuous operation at high dilution rates. Furthermore, we show that biofilms can tolerate hazardous environments, which improve the conversion of crude biomass under substrate and product inhibitory conditions. Additionally, we present examples for the improved conversion of pure and crude substrates into bulk chemicals by mixed microbial biofilms, which can benefit from microenvironments in biofilms for synergistic multi-species reactions, and improved resistance to contaminants. Finally, we suggest the use of mathematical models as useful tools to supplement experimental insights related to the effects of physico-chemical and biological phenomena on the process. Major challenges for biofilm fermentations arise from inconsistent fermentation performance, slow reactor start-up, biofilm carrier costs and carrier clogging, insufficient biofilm monitoring and process control, challenges in reactor sterilization and scale-up, and issues in recovering dilute products. The key to a successful commercialization of the technology is likely going to be an interdisciplinary approach. Crucial research areas might include genetic engineering combined with the development of specialized biofilm reactors, biofilm carrier development, in-situ biofilm monitoring, model-based process control, mixed microbial biofilm technology, development of suitable biofilm reactor scale-up criteria, and in-situ product recovery.
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Affiliation(s)
- Pascal S Leonov
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 221, 2800 Kgs. Lyngby, Denmark; Department of Chemical and Biochemical Engineering, Technical University of Denmark, Søltofts Plads, Building 228 A, 2800 Kgs. Lyngby, Denmark
| | - Xavier Flores-Alsina
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Søltofts Plads, Building 228 A, 2800 Kgs. Lyngby, Denmark
| | - Krist V Gernaey
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Søltofts Plads, Building 228 A, 2800 Kgs. Lyngby, Denmark
| | - Claus Sternberg
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 221, 2800 Kgs. Lyngby, Denmark.
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17
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DePoy AN, King GM, Ohta H. Anaerobic Carbon Monoxide Uptake by Microbial Communities in Volcanic Deposits at Different Stages of Successional Development on O-yama Volcano, Miyake-jima, Japan. Microorganisms 2020; 9:E12. [PMID: 33375160 PMCID: PMC7822213 DOI: 10.3390/microorganisms9010012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/14/2020] [Accepted: 12/21/2020] [Indexed: 12/19/2022] Open
Abstract
Research on Kilauea and O-yama Volcanoes has shown that microbial communities and their activities undergo major shifts in response to plant colonization and that molybdenum-dependent CO oxidizers (Mo-COX) and their activities vary with vegetation and deposit age. Results reported here reveal that anaerobic CO oxidation attributed to nickel-dependent CO oxidizers (Ni-COX) also occurs in volcanic deposits that encompass different developmental stages. Ni-COX at three distinct sites responded rapidly to anoxia and oxidized CO from initial concentrations of about 10 ppm to sub-atmospheric levels. CO was also actively consumed at initial 25% concentrations and 25 °C, and during incubations at 60 °C; however, uptake under the latter conditions was largely confined to an 800-year-old forested site. Analyses of microbial communities based on 16S rRNA gene sequences in treatments with and without 25% CO incubated at 25 °C or 60 °C revealed distinct responses to temperature and CO among the sites and evidence for enrichment of known and potentially novel Ni-COX. The results collectively show that CO uptake by volcanic deposits occurs under a wide range of conditions; that CO oxidizers in volcanic deposits may be more diverse than previously imagined; and that Ni-dependent CO oxidizers might play previously unsuspected roles in microbial succession.
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Affiliation(s)
- Amber N. DePoy
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA;
| | - Gary M. King
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA;
| | - Hiroyuki Ohta
- College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami-machi, Ibaraki 300-0393, Japan;
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18
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Li C, Zhu X, Angelidaki I. Carbon monoxide conversion and syngas biomethanation mediated by different microbial consortia. BIORESOURCE TECHNOLOGY 2020; 314:123739. [PMID: 32615449 DOI: 10.1016/j.biortech.2020.123739] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/21/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
Syngas biomethanation is an attractive process for extending application of gasification products. In the present study, anaerobic sludges from three methanogenic reactors feeding cattle manure (CS), sewage sludge (SS) and gaseous H2/CO2 (GS) were used to investigate the effect of microbial consortia composition on syngas biomethanation. The results showed that CS presented the highest CO consumption rate due to its highest relative abundance of CO consuming bacteria. The CO was mainly converted to acetate, and syntrophic acetate oxidization (SAO) bacteria converted acetate to H2/CO2 for hydrogenotrophic methanogenesis in CS and SS. However, acetate was accumulated in GS for lacking acetoclastic methanogens and SAO bacteria, leading to lower biomethanation efficiency. Additionally, adding stoichiometric H2 could convert CO and CO2 to nearly pure methane, while, the CO consumption rate declined in H2 added systems. The results present novel insights into microbial consortia on CO conversion and syngas biomethanation.
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Affiliation(s)
- Chunxing Li
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
| | - Xinyu Zhu
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
| | - Irini Angelidaki
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
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19
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Stegenta-Dąbrowska S, Drabczyński G, Sobieraj K, Koziel JA, Białowiec A. The Biotic and Abiotic Carbon Monoxide Formation During Aerobic Co-digestion of Dairy Cattle Manure With Green Waste and Sawdust. Front Bioeng Biotechnol 2019; 7:283. [PMID: 31737615 PMCID: PMC6828980 DOI: 10.3389/fbioe.2019.00283] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/04/2019] [Indexed: 11/24/2022] Open
Abstract
Carbon monoxide (CO), an air pollutant and a toxic gas to humans, can be generated during aerobic digestion of organic waste. CO is produced due to thermochemical processes, and also produced or consumed by cohorts of methanogenic, acetogenic, or sulfate-reducing bacteria. The exact mechanisms of biotic and abiotic formation of CO in aerobic digestion (particularly the effects of process temperature) are still not known. This study aimed to determine the temporal variation in CO concentrations during the aerobic digestion as a function of process temperature and activity of microorganisms. All experiments were conducted in controlled temperature reactors using homogeneous materials. The lab-scale tests with sterilized and non-sterilized mix of green waste, dairy cattle manure, sawdust (1:1:1 mass ratio) were carried out for 1 week at 10, 25, 30, 37, 40, 50, 60, 70°C to elucidate the biotic vs. abiotic effect. Gas concentrations of CO, O2, and CO2 inside the reactor were measured every 12 h. The CO concentrations observed for up to 30°C did not exceed 100 ppm v/v. For 50 and 60°C, significantly (p < 0.05) higher CO concentrations, reaching almost 600 ppm v/v, were observed. The regression analyses showed in both cases (sterile and non-sterile) a statistically significant effect (p < 0.05) of temperature on CO concentration, confirming that the increase in temperature causes an increase in CO concentration. The remaining factors (time, O2, and CO2 content) were not statistically significant (p > 0.05). A new polynomial model describing the effect of temperature, O2, and CO2 concentration on CO production during aerobic digestion of organic waste was formulated. It has been found that the proposed model for sterile variant had a better fit (R2 = 0.86) compared with non-sterile (R2 = 0.71). The model predicts CO emissions and could be considered for composting process optimization. The developed model could be further developed and useful for ambient air quality and occupational exposure to CO.
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Affiliation(s)
- Sylwia Stegenta-Dąbrowska
- Faculty of Life Sciences and Technology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Grzegorz Drabczyński
- Faculty of Life Sciences and Technology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Karolina Sobieraj
- Faculty of Life Sciences and Technology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Jacek A Koziel
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
| | - Andrzej Białowiec
- Faculty of Life Sciences and Technology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.,Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
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20
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Laskar M, Awata T, Kasai T, Katayama A. Anaerobic Dechlorination by a Humin-Dependent Pentachlorophenol-Dechlorinating Consortium under Autotrophic Conditions Induced by Homoacetogenesis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E2873. [PMID: 31405258 PMCID: PMC6720667 DOI: 10.3390/ijerph16162873] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 08/03/2019] [Accepted: 08/09/2019] [Indexed: 11/16/2022]
Abstract
Anoxic aquifers suffer from energy limitations due to the unavailability of organic substrates, as dictated by hydrogen (H2) for various electron-accepting processes. This deficiency often results in the accumulation of persistent organic pollutants, where bioremediation using organic compounds often leads to secondary contamination. This study involves the reductive dechlorination of pentachlorophenol (PCP) by dechlorinators that do not use H2 directly, but rather through a reduced state of humin-a solid-phase humic substance-as the extracellular electron donor, which requires an organic donor such as formate, lactate, etc. This shortcoming was addressed by the development of an anaerobic mixed culture that was capable of reductively dechlorinating PCP using humin under autotrophic conditions induced by homoacetogenesis. Here, H2 was used for carbon-dioxide fixation to acetate; the acetate produced was used for the reduction of humin; and consequently used for dechlorination through reduced humin. The 16SrRNA gene sequencing analysis showed Dehalobacter and Dehalobacterium as the possible dechlorinators, while Clostridium and Oxobacter were identified as the homoacetogens. Thus, this work contributes to the development of an anaerobic consortium that balanced H2 dependency, where efficiency of humin reduction extends the applicability of anaerobic microbial remediation in aquifers through autotrophy, syntrophy, and reductive dechlorination.
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Affiliation(s)
- Mahasweta Laskar
- Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan
| | - Takanori Awata
- National Institute for Land and Infrastructure Management, Tsukuba 305-0804, Japan
| | - Takuya Kasai
- Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan
- Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan
| | - Arata Katayama
- Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
- Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan.
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21
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Lee CR, Kim C, Song YE, Im H, Oh YK, Park S, Kim JR. Co-culture-based biological carbon monoxide conversion by Citrobacter amalonaticus Y19 and Sporomusa ovata via a reducing-equivalent transfer mediator. BIORESOURCE TECHNOLOGY 2018; 259:128-135. [PMID: 29549832 DOI: 10.1016/j.biortech.2018.02.129] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/27/2018] [Accepted: 02/28/2018] [Indexed: 06/08/2023]
Abstract
The biological conversion of carbon monoxide (CO) has been highlighted for the development of a C1 gas biorefinery process. Despite this, the toxicity and low reducing equivalent of CO uptake make biological conversion difficult. The use of synthetic co-cultures is an alternative way of enhancing the performance of CO bioconversion. This study evaluated a synthetic co-culture consisting of Citrobacter amalonaticus Y19 and Sporomusa ovata for acetate production from CO. In this consortium, the CO2 and H2 produced by the water-gas shift reaction of C. amalonaticus Y19, were utilized further by S. ovata. Higher acetate production was achieved in the co-culture system compared to the monoculture counterparts. Furthermore, syntrophic cooperation via various reducing equivalent carriers provided new insights into the synergistic metabolic benefits with a toxic and refractory substrate, such as CO. This study also suggests an appropriate model for examining the syntrophic interaction between microbial species in a mixed community.
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Affiliation(s)
- Cho Rong Lee
- School of Chemical and Biomolecular Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - Changman Kim
- School of Chemical and Biomolecular Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - Young Eun Song
- School of Chemical and Biomolecular Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - Hyeonsung Im
- School of Chemical and Biomolecular Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - You-Kwan Oh
- School of Chemical and Biomolecular Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea
| | - Sunghoon Park
- School of Energy and Chemical Engineering, UNIST, Ulsan, Republic of Korea
| | - Jung Rae Kim
- School of Chemical and Biomolecular Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea.
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22
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Esquivel-Elizondo S, Maldonado J, Krajmalnik-Brown R. Anaerobic carbon monoxide metabolism by Pleomorphomonas carboxyditropha sp. nov., a new mesophilic hydrogenogenic carboxydotroph. FEMS Microbiol Ecol 2018; 94:4980905. [DOI: 10.1093/femsec/fiy056] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 03/22/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sofia Esquivel-Elizondo
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287- 5701, USA
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5701, USA
| | - Juan Maldonado
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287- 5701, USA
- Center for Fundamental and Applied Microbiomics, The Biodesign Institute, Arizona State University, Tempe, AZ 85287–6101, USA
| | - Rosa Krajmalnik-Brown
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287- 5701, USA
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-5701, USA
- Center for Fundamental and Applied Microbiomics, The Biodesign Institute, Arizona State University, Tempe, AZ 85287–6101, USA
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23
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Esquivel-Elizondo S, Miceli J, Torres CI, Krajmalnik-Brown R. Impact of carbon monoxide partial pressures on methanogenesis and medium chain fatty acids production during ethanol fermentation. Biotechnol Bioeng 2017; 115:341-350. [DOI: 10.1002/bit.26471] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/27/2017] [Accepted: 10/06/2017] [Indexed: 12/30/2022]
Affiliation(s)
- Sofia Esquivel-Elizondo
- Swette Center for Environmental Biotechnology; The Biodesign Institute; Arizona State University; Tempe Arizona
- School of Sustainable Engineering and the Built Environment; Arizona State University; Tempe Arizona
| | - Joseph Miceli
- Virginia G. Piper Center for Personalized Diagnostics; The Biodesign Institute; Arizona State University; Tempe Arizona
| | - Cesar I. Torres
- School of Sustainable Engineering and the Built Environment; Arizona State University; Tempe Arizona
| | - Rosa Krajmalnik-Brown
- Swette Center for Environmental Biotechnology; The Biodesign Institute; Arizona State University; Tempe Arizona
- School of Sustainable Engineering and the Built Environment; Arizona State University; Tempe Arizona
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24
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Esquivel-Elizondo S, Delgado AG, Rittmann BE, Krajmalnik-Brown R. The effects of CO 2 and H 2 on CO metabolism by pure and mixed microbial cultures. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:220. [PMID: 28936234 PMCID: PMC5603099 DOI: 10.1186/s13068-017-0910-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/07/2017] [Indexed: 05/27/2023]
Abstract
BACKGROUND Syngas fermentation, the bioconversion of CO, CO2, and H2 to biofuels and chemicals, has undergone considerable optimization for industrial applications. Even more, full-scale plants for ethanol production from syngas fermentation by pure cultures are being built worldwide. The composition of syngas depends on the feedstock gasified and the gasification conditions. However, it remains unclear how different syngas mixtures affect the metabolism of carboxidotrophs, including the ethanol/acetate ratios. In addition, the potential application of mixed cultures in syngas fermentation and their advantages over pure cultures have not been deeply explored. In this work, the effects of CO2 and H2 on the CO metabolism by pure and mixed cultures were studied and compared. For this, a CO-enriched mixed culture and two isolated carboxidotrophs were grown with different combinations of syngas components (CO, CO:H2, CO:CO2, or CO:CO2:H2). RESULTS The CO metabolism of the mixed culture was somehow affected by the addition of CO2 and/or H2, but the pure cultures were more sensitive to changes in gas composition than the mixed culture. CO2 inhibited CO oxidation by the Pleomorphomonas-like isolate and decreased the ethanol/acetate ratio by the Acetobacterium-like isolate. H2 did not inhibit ethanol or H2 production by the Acetobacterium and Pleomorphomonas isolates, respectively, but decreased their CO consumption rates. As part of the mixed culture, these isolates, together with other microorganisms, consumed H2 and CO2 (along with CO) for all conditions tested and at similar CO consumption rates (2.6 ± 0.6 mmol CO L-1 day-1), while maintaining overall function (acetate production). Providing a continuous supply of CO by membrane diffusion caused the mixed culture to switch from acetate to ethanol production, presumably due to the increased supply of electron donor. In parallel with this change in metabolic function, the structure of the microbial community became dominated by Geosporobacter phylotypes, instead of Acetobacterium and Pleomorphomonas phylotypes. CONCLUSIONS These results provide evidence for the potential of mixed-culture syngas fermentation, since the CO-enriched mixed culture showed high functional redundancy, was resilient to changes in syngas composition, and was capable of producing acetate or ethanol as main products of CO metabolism.
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Affiliation(s)
- Sofia Esquivel-Elizondo
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701 USA
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ USA
| | - Anca G. Delgado
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701 USA
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ USA
| | - Bruce E. Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701 USA
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ USA
| | - Rosa Krajmalnik-Brown
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701 USA
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ USA
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