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Mijnendonckx K, Bleyen N, Van Gompel A, Coninx I, Leys N. pH and microbial community determine the denitrifying activity in the presence of nitrate-containing radioactive waste. Front Microbiol 2022; 13:968220. [PMID: 36338040 PMCID: PMC9634998 DOI: 10.3389/fmicb.2022.968220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/20/2022] [Indexed: 01/24/2023] Open
Abstract
An important fraction of the currently stored volume of long-lived intermediate-level radioactive waste in Belgium contains large amounts of NaNO3 homogeneously dispersed in a hard bituminous matrix. Geological disposal of this waste form in a water-saturated sedimentary formation such as Boom Clay will result in the leaching of high concentrations of NaNO3, which could cause a geochemical perturbation of the surrounding clay, possibly affecting some of the favorable characteristics of the host formation. In addition, hyper-alkaline conditions are expected for thousands of years, imposed by the cementitious materials used as backfill material. Microbial nitrate reduction is a well-known process and can result in the accumulation of nitrite or nitrogenous gases. This could lead to the oxidation of redox-active Boom Clay components, which could (locally) decrease the reducing capacity of the clay formation. Here, we compared nitrate reduction processes between two microbial communities at different pH related to a geological repository environment and in the presence of a nitrate-containing waste simulate during 1 year in batch experiments. We showed that the microbial community from in Boom Clay borehole water was able to carry out nitrate reduction in the presence of acetate at pH 10.5, although the maximum rate of 1.3 ± 0.2 mM NO3 -/day was much lower compared to that observed at pH 9 (2.9 mM NO3 -/day). However, microbial activity at pH 10.5 was likely limited by a phosphate shortage. This study further confirmed that the Harpur Hill sediment harbors a microbial community adapted to high pH conditions. It reduced twice as much nitrate at pH 10.5 compared to pH 9 and the maximum nitrate reduction rate was higher at pH 10.5 compared to that at pH 9, i.e., 3.4 ± 0.8 mM NO3 -/day versus 2.2 ± 0.4 mM NO3 -/day. Both communities were able to form biofilms on non-radioactive Eurobitum. However, for both microbial communities, pH 12.5 seems to be a limiting condition for microbial activity as no nitrate reduction nor biofilm was observed. Nevertheless, pH alone is not sufficient to eliminate microbial presence, but it can induce a significant shift in the microbial community composition and reduce its nitrate reducing activity. Furthermore, at the interface between the cementitious disposal gallery and the clay host rock, the pH will not be sufficiently high to inhibit microbial nitrate reduction.
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Affiliation(s)
- Kristel Mijnendonckx
- Unit of Microbiology, SCK CEN, Mol, Belgium,*Correspondence: Kristel Mijnendonckx,
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Bleyen N, Smets S, Small J, Moors H, Leys N, Albrecht A, De Cannière P, Schwyn B, Wittebroodt C, Valcke E. Impact of the electron donor on in situ microbial nitrate reduction in Opalinus Clay: results from the Mont Terri rock laboratory (Switzerland). Swiss J Geosci 2017; 110:355-374. [PMID: 32214982 PMCID: PMC7081829 DOI: 10.1007/s00015-016-0256-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 12/17/2016] [Indexed: 06/10/2023]
Abstract
At the Mont Terri rock laboratory (Switzerland), an in situ experiment is being carried out to examine the fate of nitrate leaching from nitrate-containing bituminized radioactive waste, in a clay host rock for geological disposal. Such a release of nitrate may cause a geochemical perturbation of the clay, possibly affecting some of the favorable characteristics of the host rock. In this in situ experiment, combined transport and reactivity of nitrate is studied inside anoxic and water-saturated chambers in a borehole in the Opalinus Clay. Continuous circulation of the solution from the borehole to the surface equipment allows a regular sampling and online monitoring of its chemical composition. In this paper, in situ microbial nitrate reduction in the Opalinus Clay is discussed, in the presence or absence of additional electron donors relevant for the disposal concept and likely to be released from nitrate-containing bituminized radioactive waste: acetate (simulating bitumen degradation products) and H2 (originating from radiolysis and corrosion in the repository). The results of these tests indicate that-in case microorganisms would be active in the repository or the surrounding clay-microbial nitrate reduction can occur using electron donors naturally present in the clay (e.g. pyrite, dissolved organic matter). Nevertheless, non-reactive transport of nitrate in the clay is expected to be the main process. In contrast, when easily oxidizable electron donors would be available (e.g. acetate and H2), the microbial activity will be strongly stimulated. Both in the presence of H2 and acetate, nitrite and nitrogenous gases are predominantly produced, although some ammonium can also be formed when H2 is present. The reduction of nitrate in the clay could have an impact on the redox conditions in the pore-water and might also lead to a gas-related perturbation of the host rock, depending on the electron donor used during denitrification.
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Affiliation(s)
- Nele Bleyen
- 1Belgian Nuclear Research Centre SCK•CEN, Boeretang 200, 2400 Mol, Belgium
| | - Steven Smets
- 1Belgian Nuclear Research Centre SCK•CEN, Boeretang 200, 2400 Mol, Belgium
| | - Joe Small
- 2National Nuclear Laboratory NLL, Chadwick House, Birchwood Park, WA3 6AS Warrington, UK
| | - Hugo Moors
- 1Belgian Nuclear Research Centre SCK•CEN, Boeretang 200, 2400 Mol, Belgium
| | - Natalie Leys
- 1Belgian Nuclear Research Centre SCK•CEN, Boeretang 200, 2400 Mol, Belgium
| | - Achim Albrecht
- 3Agence Nationale pour la Gestion des Déchets Radioactifs Andra, 1-7, Rue Jean-Monnet, 92298 Châtenay-Malabry Cedex, France
| | - Pierre De Cannière
- 4Federal Agency for Nuclear Control FANC, Rue Ravenstein 36, 1000 Brussels, Belgium
| | - Bernhard Schwyn
- 5National Cooperative for the Disposal of Radioactive Waste NAGRA, Hardstrasse 73, 5430 Wettingen, Switzerland
| | - Charles Wittebroodt
- 6Institut de Radioprotection et de Sûreté Nucléaire IRSN, 31, Avenue de la Division Leclerc, 92260 Fontenay-Aux-Roses, France
| | - Elie Valcke
- 1Belgian Nuclear Research Centre SCK•CEN, Boeretang 200, 2400 Mol, Belgium
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Mariën A, Valcke E, Bleyen N, Van Geet M, Wevers M. The use of μCT and ESEM in the study of the osmosis-induced water uptake by Eurobitum bituminized radioactive waste. Microsc Microanal 2012; 18:1163-1180. [PMID: 23046634 DOI: 10.1017/s1431927612001092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Laboratory water uptake tests are performed at the Belgian Nuclear Research Centre SCK•CEN to obtain insight into the hydromechanical behavior of Eurobitum bituminized radioactive waste under geological disposal conditions. Small nonradioactive and radioactive Eurobitum samples are hydrated in restricted swelling conditions (i.e., nearly constant volume conditions and constant stress conditions). Microfocus X-ray computer tomography (μCT) proves to be a very suitable technique to follow up the ingress of water in the samples. μCT analyses demonstrate that, under the studied hydration conditions, the water uptake by Eurobitum samples is a diffusion controlled process. A characterization of the partially leached samples with environmental scanning electron microscopy (ESEM) shows that the hydration of salt crystals and the subsequent dilution of the salt solution result in an increase in pore size that is limited to a few tens of μm in restricted swelling conditions. The μCT and ESEM analyses allow improvement in the understanding of water uptake by Eurobitum in restricted swelling conditions. In this article we discuss the μCT and ESEM analyses of nonradioactive Eurobitum samples that were hydrated for 2 to 4 years at a constant stress of 1, 22, 33, and 44 bar or in nearly constant volume conditions.
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Affiliation(s)
- An Mariën
- Waste and Disposal Expert Group, The Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, 2400 Mol, Belgium.
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Tuntufye HN, Ons E, Pham ADN, Luyten T, Van Gerven N, Bleyen N, Goddeeris BM. Escherichia coli ghosts or live E. coli expressing the ferri-siderophore receptors FepA, FhuE, IroN and IutA do not protect broiler chickens against avian pathogenic E. coli (APEC). Vet Microbiol 2012; 159:470-8. [PMID: 22633153 DOI: 10.1016/j.vetmic.2012.04.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 04/27/2012] [Accepted: 04/28/2012] [Indexed: 10/28/2022]
Abstract
The aim of this study was to investigate if immunization with the ferri-siderophore receptors FepA, FhuE, IroN and IutA could protect chickens against avian pathogenic Escherichia coli (APEC) infection. The antigens were administered as recombinant proteins in the outer membrane (OM) of E. coli strain BL21 Star DE3. In a first immunization experiment, live E. coli expressing all 4 recombinant ferri-siderophore receptors (BL21(L)) were given intranasally. In a second immunization experiment, a mixture of E. coli ghosts containing recombinant FepA and IutA and ghosts containing recombinant FhuE and IroN was evaluated. For both experiments non-recombinant counterparts of the tentative vaccines were administered as placebo. At the time of challenge, the IgG antibody response for BL21(L) and a mixture of E. coli ghosts containing recombinant FepA and IutA and ghosts containing recombinant FhuE and IroN was significantly higher in all immunized groups as compared to the negative control groups (LB or PBS) confirming successful immunization. Although neither of the tentative vaccines could prevent lesions and mortality upon APEC infection, immunization with bacterial ghosts resulted in a decrease in mortality from 50% (PBS) to 31% (non-recombinant ghosts) or 20% (recombinant ghosts) and these differences were not found to be significant.
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Affiliation(s)
- Huruma Nelwike Tuntufye
- Division of Gene Technology, Department of Biosystems, Faculty of Bioscience Engineering, K.U.Leuven, Kasteelpark Arenberg 30, B-3001 Heverlee, Belgium.
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Abstract
Avian pathogenic Escherichia coli are known to cause significant losses in the poultry industry worldwide. Although prophylactic measures based on vaccination are advisable, until now no full heterologous protection against colibacillosis has been achieved. Since iron is an essential nutrient to these bacteria, the aim of this study was to investigate the prevalence of 12 outer-membrane iron receptor genes in 239 pathogenic strains isolated from clinical cases of colibacillosis in chickens. Five multiplex polymerase chain reactions were developed as a tool for efficient screening. Among the 239 avian E. coli isolates, 100% were positive for fhuE and fepA, 96.2% for fiu, 92.9% for cir, 92.5% for iroN, 87.4% for iutA, 63.2% for fecA, 53.1% for fyuA, 46.9% for fhuA, 45.6% for ireA, 41.8% for chuA and 4.6% for iha.
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Affiliation(s)
- Ellen Ons
- Department of Biosystems, Faculty of Bioscience Engineering, Laboratory of Livestock Physiology, Immunology and Genetics, K.U. Leuven, Heverlee, Belgium.
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Bleyen N, Ons E, De Gussem M, Goddeeris BM. Passive immunization againstHistomonas meleagridisdoes not protect turkeys from an experimental infection. Avian Pathol 2009; 38:71-6. [DOI: 10.1080/03079450802641255] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Vandemaele F, Bleyen N, Abuaboud O, vanderMeer E, Jacobs A, Goddeeris BM. Immunization with the biologically active lectin domain of PapGII induces strong adhesion-inhibiting antibody responses but not protection against avian pathogenic Escherichia coli. Avian Pathol 2007; 35:238-49. [PMID: 16753616 DOI: 10.1080/03079450600710997] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The aim of this study was to investigate whether immunization with the sugar binding domain of PapGII (PapGII196) was able to protect chickens against avian pathogenic Escherichia coli. PapGII196 was expressed, purified by Ni-NTA column chromatography and shown to retain its biological activity, as demonstrated by binding to its receptor, globoside. PapGII196 was tested as a vaccine in specific pathogen free broilers and also by vaccinating breeders and assessing protection in their offspring, and using aerosol exposure or air sac inoculation for challenge. Notwithstanding a strong anti-PapGII196 serum IgG response in vaccinated birds in all experiments and inhibition of haemagglutination by serum from PapGII196-vaccinated birds, chickens were not protected against avian pathogenic E. coli. These findings suggest that PapGII may not be a useful candidate for inclusion in vaccines against avian pathogenic E. coli.
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Affiliation(s)
- Fréderic Vandemaele
- Laboratory of Livestock Physiology and Immunology, Faculty of Bioscience Engineering, Catholic University Leuven, Kasteelpark Arenberg 30, 3001, Leuven, Belgium.
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Bleyen N, De Gussem K, De Gussem J, Goddeeris BM. Specific detection of Histomonas meleagridis in turkeys by a PCR assay with an internal amplification control. Vet Parasitol 2006; 143:206-13. [PMID: 17069975 DOI: 10.1016/j.vetpar.2006.09.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Revised: 08/18/2006] [Accepted: 09/05/2006] [Indexed: 11/29/2022]
Abstract
Histomoniasis or blackhead is a disease of gallinaceous birds, caused by the protozoon Histomonas meleagridis. Since traditional diagnostics for the detection of this disease are complex and far less sensitive than molecular tools, a PCR would provide a more rapid and sensitive alternative. However, intestinal material and droppings, which are preferably used in epidemiological studies of histomoniasis, often contain PCR inhibitory substances. To detect these false negative results, the use of an internal amplification control is essential. Nevertheless, the recently developed PCR tests lack this internal control. Therefore, a new PCR assay with H. meleagridis specific primers was developed which does include an internal amplification control. The diagnostic value of the PCR assay was evaluated in comparison to three other conventional H. meleagridis specific PCR tests (HIS5, HM1 and HM2). None of the organ samples originating from uninfected turkeys, showed positive PCR results in any of the tests. Among the lesion-positive, inhibition-free samples, 95.4% were positive by our PCR assay, while only 50, 66.7 and 83.3% of the lesion-positive organs tested positive by the HM1, the HIS5 and the HM2 PCR respectively. In conclusion, our PCR offers the use of the internal control to detect false negative results and an increased sensitivity, and thus should be useful for routine diagnosis of H. meleagridis in poultry.
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Affiliation(s)
- Nele Bleyen
- Division of Gene Technology, Department of Biosystems, Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 30, B-3001 Leuven, Belgium.
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Vandemaele F, Ververken C, Bleyen N, Geys J, D'Hulst C, Addwebi T, van Empel P, Goddeeris BM. Immunization with the binding domain of FimH, the adhesin of type 1 fimbriae, does not protect chickens against avian pathogenicEscherichia coli. Avian Pathol 2005; 34:264-72. [PMID: 16191712 DOI: 10.1080/03079450500112682] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The aim of this study was to investigate whether vaccination with the sugar-binding domain of FimH (FimH156) was able to protect chickens against avian pathogenic Escherichia coli (APEC). FimH156 was expressed and purified using Ni-NTA affinity chromatography. Binding of FimH156 to mannosylated bovine serum albumin demonstrated that the protein retained its biological activity. Moreover, anti-FimH156 antisera were able to inhibit in vitro binding of E. coli to mannosylated bovine serum albumin. In a first vaccination experiment, FimH156 was administered intramuscularly as a water-in-oil emulsion to specific pathogen free broiler chicks. A predisposing infection with the Newcastle disease virus strain Lasota was administered 3 weeks later, followed 3 days later by an aerosol challenge with the virulent APEC strain CH2. A good anti-FimH156 immunoglobulin (Ig)G immune response was detected in serum, but no protective effects of FimH156 against APEC were seen. In a second experiment, SPF chicks were vaccinated intramuscularly or intranasally with FimH156. Booster vaccinations were administered 20 days later. While the intramuscular immunization yielded a strong IgG response in the serum and trachea, no significant IgA response could be detected in tracheal washes. Intranasal immunization did not yield a significant IgG or IgA response in serum and trachea. No protective effects of the FimH156 could be detected, confirming the results of the first experiment. Thus, although the FimH156 induced a strong immune response, it was unable to protect chickens against APEC.
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Affiliation(s)
- Fréderic Vandemaele
- Laboratory of Physiology and Immunology of Domestic Animals, Faculty of Applied Bioscience and Engineering, Catholic University Leuven, Kasteelpark Arenberg 30, 3001, Leuven, Belgium.
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