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Pedersen L, Houe H, Rattenborg E, Nielsen LR. Semi-Quantitative Biosecurity Assessment Framework Targeting Prevention of the Introduction and Establishment of Salmonella Dublin in Dairy Cattle Herds. Animals (Basel) 2023; 13:2649. [PMID: 37627440 PMCID: PMC10451256 DOI: 10.3390/ani13162649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/12/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
An increasing average herd size and complexity in farm structures call for a higher level of biosecurity. It can reduce the risk of introducing and establishing pathogens with multiple-pathway and indirect spread mechanisms, such as Salmonella Dublin, a pathogen with an increasing occurrence in dairy cattle farms across different countries and continents. Therefore, this study aimed to use existing knowledge to develop a framework with a supporting tool allowing for a time-efficient, yet comprehensive, assessment of biosecurity measures that can help prevent the introduction and establishment of S. Dublin in dairy herds. Based on the literature review, a seven-step biosecurity assessment framework was developed and evaluated in collaboration with biosecurity experts. The resulting framework includes a weighted semi-quantitative assessment method with a scoring guide in an electronic supporting tool for 12 biosecurity sections assessed through on-farm observations and farmer interviews. The framework and tool provide a novel approach to comprehensively assess the overall (mainly external) on-farm biosecurity level by a trained biosecurity assessor. They can be used for systematic data collection in epidemiological studies on risk factors for the introduction and establishment of S. Dublin in dairy farms. Preliminary interrater reliability testing indicated moderate reliability between assessors with varying biosecurity skills.
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Affiliation(s)
- Lars Pedersen
- Department of Veterinary and Animal Sciences, Section for Animal Welfare and Disease Control, University of Copenhagen, 1870 Frederiksberg, Denmark; (H.H.); (L.R.N.)
- SEGES Innovation P/S, 8200 Aarhus, Denmark;
| | - Hans Houe
- Department of Veterinary and Animal Sciences, Section for Animal Welfare and Disease Control, University of Copenhagen, 1870 Frederiksberg, Denmark; (H.H.); (L.R.N.)
| | | | - Liza Rosenbaum Nielsen
- Department of Veterinary and Animal Sciences, Section for Animal Welfare and Disease Control, University of Copenhagen, 1870 Frederiksberg, Denmark; (H.H.); (L.R.N.)
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Carraturo F, Panico A, Giordano A, Libralato G, Aliberti F, Galdiero E, Guida M. Hygienic assessment of digestate from a high solids anaerobic co-digestion of sewage sludge with biowaste by testing Salmonella Typhimurium, Escherichia coli and SARS-CoV-2. ENVIRONMENTAL RESEARCH 2022; 206:112585. [PMID: 34922984 DOI: 10.1016/j.envres.2021.112585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/13/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
Anaerobic digestion is a consolidated technology to convert sewage sludge and other organic wastes into biogas and a nutrient-rich fertilizer (i.e. digestate). The origin of sewage sludge does not exclude the potential presence of pathogens (e.g. Salmonella spp. and SARS-CoV-2) in mature digestate that hence could represent a source of sanitary concerns when it is spread on soil for agriculture purpose. Therefore, an experimental study aimed at proving the sanitizing effect of a full scale thermophilic high solids anaerobic digestion process was conducted by monitoring the hygienic characteristics of mature digestate. Although Salmonella spp. was detected in the sewage sludge fed to the full scale plant, the anaerobic digestion treatment demonstrated sanitization capacity since the monitored pathogens were never found in the mature digestate over the entire duration of the monitoring survey. Furthermore, tests on the regrowth of Salmonella Typhimurium and Escherichia coli, artificially inoculated on mature digestate, were also conducted under both anaerobic and aerobic conditions with the aim to assess the effectiveness of mature digestate as microbial growth medium. Concentrations of Salmonella Typhimurium and Escherichia coli were drastically reduced after a short time of incubation under anaerobic process and the two microorganisms already resulted undetectable after 24-48 h, whereas, under aerobic conditions, two microorganisms' concentrations were stably high for longer than 10 days. The combination of no free oxygen, high temperature, anaerobic metabolites (e.g. total ammonium nitrogen, and volatile fatty acids) production, bacteria competition and lack of nutritional elements in mature digestate considerably reduced in 24-48 h the sanitary risks associated to accidently contaminated digestate. Furthermore, a SARS-CoV-2 monitoring survey on mature digestate during 13 months, resulted in the absence of the virus RNA in the analyzed digestate.
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Affiliation(s)
- Federica Carraturo
- Hygiene Laboratories, Department of Biology, University of Naples Federico II, Via Cinthia 21, I, 80126, Naples, Italy
| | - Antonio Panico
- Department of Engineering, University of Campania "Luigi Vanvitelli", Real Casa dell'Annunziata, via Roma 29, 81031, Aversa, CE, Italy.
| | - Andrea Giordano
- Acqua & Sole srl, Via Giulio Natta, 27010, Vellezzo Bellini, PV, Italy
| | - Giovanni Libralato
- Hygiene Laboratories, Department of Biology, University of Naples Federico II, Via Cinthia 21, I, 80126, Naples, Italy
| | - Francesco Aliberti
- Hygiene Laboratories, Department of Biology, University of Naples Federico II, Via Cinthia 21, I, 80126, Naples, Italy
| | - Emilia Galdiero
- Hygiene Laboratories, Department of Biology, University of Naples Federico II, Via Cinthia 21, I, 80126, Naples, Italy
| | - Marco Guida
- Hygiene Laboratories, Department of Biology, University of Naples Federico II, Via Cinthia 21, I, 80126, Naples, Italy
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Russell L, Whyte P, Zintl A, Gordon SV, Markey B, de Waal T, Nolan S, O'Flaherty V, Abram F, Richards K, Fenton O, Bolton D. The Survival of Salmonella Senftenberg, Escherichia coli O157:H7, Listeria monocytogenes, Enterococcus faecalis and Clostridium sporogenes in Sandy and Clay Loam Textured Soils When Applied in Bovine Slurry or Unpasteurised Digestate and the Run-Off Rate for a Test Bacterium, Listeria innocua, When Applied to Grass in Slurry and Digestate. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.806920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study investigated the survival of Salmonella Senftenberg, Escherichia coli O157:H7, Listeria monocytogenes, Enterococcus faecalis and Clostridium sporogenes in sandy and clay loam textured soils when applied in bovine slurry or unpasteurised digestate, using laboratory based inoculation studies. The run-off rate for a test bacterium, Listeria innocua, when applied to grass in slurry and digestate, was also examined using field studies. Bovine slurry and digestate were inoculated with the target bacteria to a final concentration of 106 log10 cfu/g or spores/g, thoroughly mixed into soil samples and incubated at 4°C or 14°C. Samples were removed periodically and the surviving cells enumerated using AOAC or equivalent methods. The loss of viability/culturability phase followed first order kinetics and T90 values ranged from 11.9 to 166.7 d at 4°C and from 6.0 to 156 d at 14°C. With the exception of E. coli O157:H7 and E. faecalis in sandy loam textured soil at 14°C (T90 values were significantly (P < 0.05) higher in slurry) the type of soil texture or application material (slurry or digestate) did not affect survival rates. In the field study, 12 grass covered micro-plots were prepared. L. innocua was applied in digestate and bovine slurry and rainfall was simulated at a target rate of ~11 mm per plot per h−1. Rainfall simulation (30 min) took place after 24, 48 h, 14 d and 30 d. Run-off samples were tested for the L. innocua strain using Brilliance Listeria agar supplemented with streptomycin sulphate (1,000 μg/ml) at 37°C for 48 h, as were soil samples after 30, 58, 86 and 112 d. Significantly (P < 0.05) lower counts were obtained in the run-off from digestate after 1, 2 and 30 d as compared to slurry. It was concluded that the type of organic fertiliser does not affect the bacterial survival rates in sandy and clay soils, with the exception of E. coli O157:H7 and E. faecalis in sandy loam textured soil at 14°C. Furthermore, bacteria may be retained better in the soil-digestate matrices during rainfall although additional research is required to further validate and provide the scientific basis for this observation.
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Lin M, Wang A, Ren L, Qiao W, Wandera SM, Dong R. Challenges of pathogen inactivation in animal manure through anaerobic digestion: a short review. Bioengineered 2022; 13:1149-1161. [PMID: 35258411 PMCID: PMC8805936 DOI: 10.1080/21655979.2021.2017717] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Animal manure is the main source of bioenergy production by anaerobic digestion (AD). However, the pathogenic bacteria in manure may pose a high risk to human health by contaminating the environment if not effectively inactivated during AD. Worldwide, more than 20,000 biogas plants are running for the treatment of animal manure. AD has been playing the important role in establishing a circular economy in the agricultural sector and may contribute to the United Nations sustainable development goal (UN SDG). Nevertheless, whether AD is a reliable approach for pathogens inactivation has been challenged. A comprehensive understanding of the coping mechanisms of pathogens with adverse conditions and the challenges of establishing the AD process to inactivate effectively pathogens are yet to be analyzed. In this review, the diversity and resistance of pathogens in animal manure are summarized. The efficiencies and the difficulties of their inactivations in AD are also analyzed. In particular, three forms of pathogens i.e. sporing-forming pathogens, viable but non-culturable (VBNC) pathogens, and persistent pathogens are discussed. The factors influencing the pathogens’ inactivation and AD efficiencies are analyzed. The trade-off between energy production and pathogens inactivation in an AD system was consequently pointed out. This review concluded that the development of anaerobic processes should meet the goals of high efficient bioenergy production and deep hygienization.
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Affiliation(s)
- Min Lin
- College of Engineering, China Agricultural University, Beijing, China
| | - Aijie Wang
- Key Laboratory of Environmental Biotechnology, Chinese Academy of Sciences, Beijing, China
| | - Lijuan Ren
- College of Engineering, China Agricultural University, Beijing, China
| | - Wei Qiao
- College of Engineering, China Agricultural University, Beijing, China
- Key Laboratory of Environmental Biotechnology, Chinese Academy of Sciences, Beijing, China
| | - Simon Mdondo Wandera
- Department of Civil, Construction & Environmental Engineering, Jomo Kenyatta University of Agriculture & Technology, Nairobi, Kenya
| | - Renjie Dong
- College of Engineering, China Agricultural University, Beijing, China
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Li M, Song G, Liu R, Huang X, Liu H. Inactivation and risk control of pathogenic microorganisms in municipal sludge treatment: A review. FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING 2022; 16:70. [PMID: 34608423 PMCID: PMC8482957 DOI: 10.1007/s11783-021-1504-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/28/2021] [Accepted: 07/12/2021] [Indexed: 05/05/2023]
Abstract
The rapid global spread of coronavirus disease 2019 (COVID-19) has promoted concern over human pathogens and their significant threats to public health security. The monitoring and control of human pathogens in public sanitation and health facilities are of great importance. Excessive sludge is an inevitable byproduct of sewage that contains human and animal feces in wastewater treatment plants (WWTPs). It is an important sink of different pollutants and pathogens, and the proper treatment and disposal of sludge are important to minimize potential risks to the environment and public health. However, there is a lack of comprehensive analysis of the diversity, exposure risks, assessment methods and inactivation techniques of pathogenic microorganisms in sludge. Based on this consideration, this review summarizes the control performance of pathogenic microorganisms such as enterovirus, Salmonella spp., and Escherichia coli by different sludge treatment technologies, including composting, anaerobic digestion, aerobic digestion, and microwave irradiation, and the mechanisms of pathogenic microorganism inactivation in sludge treatment processes are discussed. Additionally, this study reviews the diversity, detection methods, and exposure risks of pathogenic microorganisms in sludge. This review advances the quantitative assessment of pathogenic microorganism risks involved in sludge reuse and is practically valuable to optimize the treatment and disposal of sludge for pathogenic microorganism control.
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Affiliation(s)
- Mengtian Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Ge Song
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Ruiping Liu
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing, 100084 China
| | - Xia Huang
- School of Environment, Tsinghua University, Beijing, 100084 China
| | - Huijuan Liu
- Center for Water and Ecology, School of Environment, Tsinghua University, Beijing, 100084 China
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6
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Nag R, Auer A, Nolan S, Russell L, Markey BK, Whyte P, O'Flaherty V, Bolton D, Fenton O, Richards KG, Cummins E. Evaluation of pathogen concentration in anaerobic digestate using a predictive modelling approach (ADRISK). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 800:149574. [PMID: 34399337 DOI: 10.1016/j.scitotenv.2021.149574] [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: 06/14/2021] [Revised: 08/06/2021] [Accepted: 08/06/2021] [Indexed: 06/13/2023]
Abstract
Farmyard manure and slurry (FYM&S) is a valuable feedstock for anaerobic digestion (AD) plants. However, FYM&S may contain high concentrations of pathogens, and complete inactivation through the AD process is unlikely. Thus, following land application of digestate, pathogens may contaminate a range of environmental media posing a potential threat to public health. The present study aimed to combine primary laboratory data with literature-based secondary data to develop an Excel-based exposure assessment model (ADRISK) using a gamma generalised linear model to predict the final microorganism count in the digestate. This research examines the behaviour of a suite of pathogens (Cryptosporidium parvum, norovirus, Mycobacterium spp., Salmonella spp., Listeria monocytogenes, Clostridium spp., and pathogenic Escherichia coli) and indicators (total coliforms, E. coli, and enterococci) during mesophilic anaerobic digestion (M-AD) at 37 °C, pre/post-AD pasteurisation, and after a period of storage (with/without lime) for different feedstock proportions (slurry:food waste: 0:1, 1:3, 2:1, and 3:1). ADRISK tool simulations of faecal indicator bacteria levels across all scenarios show that the digestate can meet the EU standard without pasteurisation if the AD runs at 37 °C or a higher temperature with a higher C:N ratio (recipe 3) and a hydraulic retention time ≥ 7 days. The storage of digestate also reduced levels of microorganisms in the digestate. The Irish pasteurisation process (60 °C for 4 days), although more energy-intensive, is more effective than the EU pasteurisation (70 °C for 1 h) specification. Pre-AD pasteurisation was more effective for C. parvum, norovirus, Mycobacterium thermoresistibile. However, post-AD literature-based pasteurisation is most likely to assure the safety of the digestate. The information generated from this model can inform policy-makers regarding the optimal M-AD process parameters necessary to maximise the inactivation of microorganisms, ensuring adverse environmental impact is minimised, and public health is protected.
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Affiliation(s)
- Rajat Nag
- University College Dublin School of Biosystems and Food Engineering, Belfield, Dublin 4, Ireland.
| | - Agathe Auer
- University College Dublin School of Veterinary Medicine, Belfield, Dublin 4, Ireland.
| | - Stephen Nolan
- National University of Ireland Galway, School of Natural Sciences and Ryan Institute, University Road, Galway, Ireland.
| | - Lauren Russell
- University College Dublin School of Veterinary Medicine, Belfield, Dublin 4, Ireland; TEAGASC, Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland.
| | - Bryan K Markey
- University College Dublin School of Veterinary Medicine, Belfield, Dublin 4, Ireland.
| | - Paul Whyte
- University College Dublin School of Veterinary Medicine, Belfield, Dublin 4, Ireland.
| | - Vincent O'Flaherty
- National University of Ireland Galway, School of Natural Sciences and Ryan Institute, University Road, Galway, Ireland.
| | - Declan Bolton
- TEAGASC, Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland.
| | - Owen Fenton
- TEAGASC, Environment Research Centre, Johnstown Castle, County Wexford, Ireland.
| | - Karl G Richards
- TEAGASC, Environment Research Centre, Johnstown Castle, County Wexford, Ireland.
| | - Enda Cummins
- University College Dublin School of Biosystems and Food Engineering, Belfield, Dublin 4, Ireland.
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Conventional and Innovative Hygienization of Feedstock for Biogas Production: Resistance of Indicator Bacteria to Thermal Pasteurization, Pulsed Electric Field Treatment, and Anaerobic Digestion. ENERGIES 2021. [DOI: 10.3390/en14071938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Animal by-products (ABP) can be valorized via anaerobic digestion (AD) for biogas energy generation. The digestate issued from AD process is usually used to fertilize farming land for agricultural activities, which may cause potential sanitary risk to the environment. The European Union (EU) requires that certain ABP be thermally pasteurized in order to minimize this sanitary risk. This process is called hygienization, which can be replaced by alternative nonthermal technologies like pulsed electric field (PEF). In the present study, Enterococcus faecalis ATCC 19433 and Escherichia coli ATCC 25922 were used as indicator bacteria. Their resistance to thermal pasteurization and PEF treatment were characterized. Results show that Ent. faecalis and E. coli are reduced by 5 log10 in less than 1 min during thermal pasteurization at 70 °C. The critical electric field strength was estimated at 18 kV∙cm−1 for Ent. faecalis and 1 kV∙cm−1 for E. coli. “G+” bacteria Ent. faecalis are generally more resistant than “G−” bacteria E. coli. AD process also plays an important role in pathogens inactivation, whose performance depends on the microorganisms considered, digestion temperature, residence time, and type of feedstock. Thermophilic digestion is usually more efficient in pathogens removal than mesophilic digestion.
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Increased (Antibiotic-Resistant) Pathogen Indicator Organism Removal during (Hyper-)Thermophilic Anaerobic Digestion of Concentrated Black Water for Safe Nutrient Recovery. SUSTAINABILITY 2020. [DOI: 10.3390/su12229336] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Source separated toilet water is a valuable resource for energy and fertilizers as it has a high concentration of organics and nutrients, which can be reused in agriculture. Recovery of nutrients such as nitrogen, phosphorous, and potassium (NPK) decreases the dependency on energy-intensive processes or processes that rely on depleting natural resources. In new sanitation systems, concentrated black water (BW) is obtained by source-separated collection of toilet water. BW-derived products are often associated with safety issues, amongst which pathogens and antibiotic-resistant pathogens. This study presents results showing that thermophilic (55–60 °C) and hyperthermophilic (70 °C) anaerobic treatments had higher (antibiotic-resistant) culturable pathogen indicators removal than mesophilic anaerobic treatment. Hyperthermophilic and thermophilic anaerobic treatment successfully removed Escherichia coli and extended-spectrum β-lactamases producing E. coli from source-separated vacuum collected BW at retention times of 6–11 days and reached significantly higher removal rates than mesophilic (35 °C) anaerobic treatment (p < 0.05). The difference between thermophilic and hyperthermophilic treatment was insignificant, which justifies operation at 55 °C rather than 70 °C. This study is the first to quantify (antibiotic-resistant) E. coli in concentrated BW (10–40 gCOD/L) and to show that both thermophilic and hyperthermophilic anaerobic treatment can adequately remove these pathogen indicators.
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9
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Russell L, Whyte P, Zintl A, Gordon S, Markey B, de Waal T, Cummins E, Nolan S, O’Flaherty V, Abram F, Richards K, Fenton O, Bolton D. A Small Study of Bacterial Contamination of Anaerobic Digestion Materials and Survival in Different Feed Stocks. Bioengineering (Basel) 2020; 7:bioengineering7030116. [PMID: 32972002 PMCID: PMC7552645 DOI: 10.3390/bioengineering7030116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/10/2020] [Accepted: 09/20/2020] [Indexed: 01/01/2023] Open
Abstract
If pathogens are present in feedstock materials and survive in anaerobic digestion (AD) formulations at 37 °C, they may also survive the AD process to be disseminated in digestate spread on farmland as a fertilizer. The aim of this study was to investigate the prevalence of Salmonella spp., Escherichia coli O157, Listeria monocytogenes, Enterococcus faecalis and Clostridium spp. in AD feed and output materials and survival/growth in four formulations based on food waste, bovine slurry and/or grease-trap waste using International Organization for Standardization (ISO) or equivalent methods. The latter was undertaken in 100 mL Ramboldi tubes, incubated at 37 °C for 10 d with surviving cells enumerated periodically and the T90 values (time to achieve a 1 log reduction) calculated. The prevalence rates for Salmonella spp., Escherichia coli O157, Listeria monocytogenes, Enterococcus faecalis and Clostridium spp. were 3, 0, 5, 11 and 10/13 in food waste, 0, 0, 2, 3 and 2/3 in bovine slurry, 1, 0, 8, 7 and 8/8 in the mixing tank, 5, 1, 17, 18 and 17 /19 in raw digestate and 0, 0, 0, 2 and 2/2 in dried digestate, respectively. Depending on the formulation, T90 values ranged from 1.5 to 2.8 d, 1.6 to 2.8 d, 3.1 to 23.5 d, 2.2 to 6.6 d and 2.4 to 9.1 d for Salmonella Newport, Escherichia coli O157, Listeria monocytogenes, Enterococcus faecalis and Clostridium sporogenes, respectively. It was concluded that AD feed materials may be contaminated with a range of bacterial pathogens and L. monocytogenes may survive for extended periods in the test formulations incubated at 37 °C.
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Affiliation(s)
- Lauren Russell
- Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland;
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland; (P.W.); (A.Z.); (S.G.); (B.M.); (T.d.W.)
| | - Paul Whyte
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland; (P.W.); (A.Z.); (S.G.); (B.M.); (T.d.W.)
| | - Annetta Zintl
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland; (P.W.); (A.Z.); (S.G.); (B.M.); (T.d.W.)
| | - Stephen Gordon
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland; (P.W.); (A.Z.); (S.G.); (B.M.); (T.d.W.)
| | - Bryan Markey
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland; (P.W.); (A.Z.); (S.G.); (B.M.); (T.d.W.)
| | - Theo de Waal
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland; (P.W.); (A.Z.); (S.G.); (B.M.); (T.d.W.)
| | - Enda Cummins
- School of Biosystems and Food Engineering, University College Dublin, Belfield, Dublin 4, Ireland;
| | - Stephen Nolan
- School of Natural Sciences, National University of Ireland, Galway, Ireland; (S.N.); (V.O.); (F.A.)
| | - Vincent O’Flaherty
- School of Natural Sciences, National University of Ireland, Galway, Ireland; (S.N.); (V.O.); (F.A.)
| | - Florence Abram
- School of Natural Sciences, National University of Ireland, Galway, Ireland; (S.N.); (V.O.); (F.A.)
| | - Karl Richards
- Teagasc Environmental Research Centres, Johnstown Castle, Wexford, Ireland; (K.R.); (O.F.)
| | - Owen Fenton
- Teagasc Environmental Research Centres, Johnstown Castle, Wexford, Ireland; (K.R.); (O.F.)
| | - Declan Bolton
- Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland;
- Correspondence:
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Exploring Biogas and Biofertilizer Production from Abattoir Wastes in Nigeria Using a Multi-Criteria Assessment Approach. RECYCLING 2020. [DOI: 10.3390/recycling5030018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Management of waste streams from abattoirs is a major challenge in developing countries. Harnessing these wastes as resources for the production of biogas and biofertilizer could contribute to curbing the environmental menace and to addressing the problems of energy and food deficits in Nigeria. However, large scale uptake of the technology is faced with techno-socio-economic and the lack of data required for effective investment decisions. In this study, the potential use of waste generated in the north central region of Nigerian abattoirs, representing approximately 12% of the land and 6% of the population, were evaluated for suitability for biogas and biofertilizer production. Data acquired from the study sites were used for computational estimation and integrated into strengths, weaknesses, opportunities, and threats (SWOT) analysis to give a detailed overview of the prospects and the limiting factors. The study revealed that high investment costs and public subsidies for fossil fuels are the key limiting factors while the prospects of tapping into the unexploited carbon markets and multiple socio-economic and environmental benefits favors investment. Public supports in the form of national policy reforms leading to intervention programs are required for progress.
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11
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Combined Effects of Dewatering, Composting and Pelleting to Valorize and Delocalize Livestock Manure, Improving Agricultural Sustainability. AGRONOMY-BASEL 2020. [DOI: 10.3390/agronomy10050661] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
An agronomic strategy to mitigate climate change impact can be the build-up of soil organic carbon. Among agronomic management approaches, the administration of organic fertilizers like livestock manure represents an effective strategy to increase soil organic carbon. However, livestock manure usually contains a high amount of water, reducing its sustainable delocalization and impacting on greenhouse gas emissions and nutrient leaching. Furthermore, the possible presence of weed seeds and harmful microorganisms could reduce the agronomic value of the manure. To overcome these issues, the combined effects of dewatering, composting and pelleting were investigated on livestock manure to produce sustainable organic fertilizers. Our results showed that composting and pelleting can represent a feasible and sustainable solution to reduce the potential risks related to the presence of weed seeds and harmful bacteria, concentrating nutrients and allowing a sustainable valorization and delocalization of the livestock manure. In addition, the processed manures were assessed as fertilizers in the growing medium (GM), displaying an increase in water retention and nutrient availability and a decrease of GM temperature and weed seed emergences. However, further study is needed to validate, both in open field and greenhouse productions, the effects of the proposed fertilizers in real cropping systems.
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12
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Hupfauf S, Winkler A, Wagner AO, Podmirseg SM, Insam H. Biomethanation at 45 °C offers high process efficiency and supports hygienisation. BIORESOURCE TECHNOLOGY 2020; 300:122671. [PMID: 31901776 DOI: 10.1016/j.biortech.2019.122671] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/19/2019] [Accepted: 12/21/2019] [Indexed: 06/10/2023]
Abstract
The aim of this work was to prove a process temperature of 45 °C as a practical alternative to commonly applied mesophilic (37 °C) and thermophilic (55 °C) anaerobic digestion (AD). Regarding methane production, no differences were found between the three temperature regimes. However, the maximum possible loading rate at 45 °C exceeded that at 37 °C and 55 °C. Pathogen inactivation at 45 °C was higher than at 37 °C and similarly efficient as at 55 °C. At each process temperature, a unique microbial community established. In addition, the archaeome at 55 °C was dominated by hydrogenotrophs, while at 37 °C and 45 °C it was dominated by acetotrophs. For the investigated substrate mixture, liquid cattle manure with wheat straw as co-substrate, 45 °C turned out to be preferable for AD. For other substrates, these findings still need to be confirmed.
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Affiliation(s)
- Sebastian Hupfauf
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria.
| | - Anna Winkler
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria
| | - Andreas Otto Wagner
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria
| | - Sabine Marie Podmirseg
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria
| | - Heribert Insam
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria
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13
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Pathogen Reduction Potential in Anaerobic Digestion of Organic Fraction of Municipal Solid Waste and Food Waste. Molecules 2020; 25:molecules25020275. [PMID: 31936589 PMCID: PMC7024283 DOI: 10.3390/molecules25020275] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/31/2019] [Accepted: 01/03/2020] [Indexed: 11/23/2022] Open
Abstract
Anaerobic digestion (AD) is a commonly used method of processing waste. Regardless of the type of the used digestate (fertilizer, feedstock in case of solid-state fermentation, raw-material in case of thermal treatment) effective pathogen risk elimination, even in the case of high pathogen concentration is essential. An investigation of the survival time and inactivation rate of the Salmonella Senftenberg W775, Enterococcus spp., and Ascaris suum eggs during thermophilic anaerobic digestion performed on laboratory scale and confirmation of hygienization in full-scale operation were performed in this study. Except for sanitization efficiency, the AD process performance and stability were also verified based on determination of pH value, dry matter content, acidity, alkalinity, and content of fatty acids. The elimination of pathogen was met within 6.06 h, 5.5 h, and about 10 h for the Salmonella Senftenberg W775, Enterococcus spp., and Ascaris suum, respectively in the laboratory trials. The obtained results were confirmed in full-scale tests, using 1500 m3 Kompogas® reactors, operating in MBT Plant located in Poland. Sanitization of the digestate was achieved. Furthermore, the process was stable. The pH value, suspended solids, and ammonium content remained stable at 8.5, 35%, and 3.8 g/kg, respectively. The acetic acid content was noted between almost 0.8 and over 1.1 g/kg, while the concentration of propionic acid was noted at maximum level of about 100 mg/kg. The AD conditions could positively affect the pathogen elimination. Based on these results it can be found that anaerobic digestion under thermophilic conditions results in high sanitation efficiency.
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14
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Kirby M, Mirza M, Leigh T, Oldershaw L, Reilly M, Jeffery S. Destruction of Staphylococcus aureus and the impact of chlortetracycline on biomethane production during anaerobic digestion of chicken manure. Heliyon 2019; 5:e02749. [PMID: 31763470 PMCID: PMC6859293 DOI: 10.1016/j.heliyon.2019.e02749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/29/2019] [Accepted: 10/25/2019] [Indexed: 11/25/2022] Open
Abstract
Research was undertaken to ascertain the effect on biogas potential during the anaerobic digestion of chicken manure containing Staphylococcus aureus and chlortetracycline (antibiotic) from infected chicken flocks. S. aureus is a pathogenic bacteria in chicken flocks that is usually treated with the broad-spectrum antibiotic, chlortetracycline. Veterinary antibiotics are often prescribed in the poultry sector for on-farm use at the flock level to control disease; consequently, significant quantities of antibiotics are excreted from the bird into the manure. Subsequent anaerobic digestion of this chicken manure could lead to pathogens and antibiotics affecting the digestion process. Anaerobic digestion biochemical methane potential assays were completed at 35°C for 39 days, with some assays receiving S. aureus and some receiving S. aureus and chlortetracycline. No viable S. aureus cells were detected after Day 0 of the experiment. A further experiment utilising an order of magnitude greater concentration of S. aureus demonstrated a significant reduction (>400 fold) in S. aureus within 24 h when inoculated into anaerobic digestate, with no viable S. aureus cells detected by the end of 3 days. Furthermore, the efficacy of chlortetracycline was significantly reduced when applied to anaerobic digestate compared to water alone. Total biogas yields from chicken manure were significantly lowered by the addition of S. aureus, with and without chlortetracycline. However, there was no significant difference in methane yields between treatments. The cellulose control assays showed a lag phase in methane production after receiving chlortetracycline. In comparison, the absence of a lag phase when the antibiotic were added to chicken manure may have been due to the relatively high nitrogen content of the feedstock reducing the inhibition of chlortetracycline on methanogens. Therefore, this study demonstrates that the addition of S. aureus and chlortetracycline does not have a commercially relevant effect on the digestion of chicken manure.
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Affiliation(s)
- M.E. Kirby
- Agricultural Centre for Sustainable Energy Systems (ACSES), Animal Production, Welfare and Veterinary Sciences Department, Harper Adams University, Newport, Shropshire, TF10 8NB, United Kingdom
| | - M.W. Mirza
- Agricultural Centre for Sustainable Energy Systems (ACSES), Animal Production, Welfare and Veterinary Sciences Department, Harper Adams University, Newport, Shropshire, TF10 8NB, United Kingdom
| | - T. Leigh
- Princess Margaret Science Laboratories, Harper Adams University, Newport, Shropshire, TF10 8NB, United Kingdom
| | - L. Oldershaw
- Princess Margaret Science Laboratories, Harper Adams University, Newport, Shropshire, TF10 8NB, United Kingdom
| | - M. Reilly
- Agricultural Centre for Sustainable Energy Systems (ACSES), Animal Production, Welfare and Veterinary Sciences Department, Harper Adams University, Newport, Shropshire, TF10 8NB, United Kingdom
| | - S. Jeffery
- Crop and Environmental Sciences Department, Harper Adams University, Newport, Shropshire, TF10 8NB, United Kingdom
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15
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Zhao Q, Liu Y. Is anaerobic digestion a reliable barrier for deactivation of pathogens in biosludge? THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 668:893-902. [PMID: 30870755 PMCID: PMC7112049 DOI: 10.1016/j.scitotenv.2019.03.063] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/04/2019] [Accepted: 03/05/2019] [Indexed: 04/14/2023]
Abstract
As World Health Organization advocates, the global burden of sanitation related disease and access to safely managed sanitation and safely treated wastewater should be monitored strictly. However, the spread of pathogens through various agricultural applications or direct discharge of sewage sludge generated in municipal wastewater treatment plants poses a serious challenge on the environment and public health. Anaerobic digestion (AD), the principal method of stabilizing biosolids, can efficiently and largely deactivate viable pathogens, including parasite, virus, and the pathogens harboring antibiotic resistance genes. This review aims to provide a critical overview regarding the deactivation of sludge-associated pathogens by AD, through which a serious concern on the effectiveness and rationality of AD towards sludge pathogens control was raised. Meanwhile, the underlying deactivation mechanisms and affecting factors were all discussed, with the focus on pathogen-associated modeling, engineering design and technological aspects of AD. Lastly, a matric method incorporating the operating strategy of AD with the risk assessment was proposed for evaluating the reliability of AD-based pathogen deactivation, while the research agenda forward was also outlined.
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Affiliation(s)
- Qian Zhao
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, 1000 Fengming Road, Jinan 250101, China; Shandong Province Co-Innovation Center of Green Building, Jinan 250101, China; Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
| | - Yu Liu
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore.
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16
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Tsachidou B, Scheuren M, Gennen J, Debbaut V, Toussaint B, Hissler C, George I, Delfosse P. Biogas residues in substitution for chemical fertilizers: A comparative study on a grassland in the Walloon Region. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 666:212-225. [PMID: 30798232 DOI: 10.1016/j.scitotenv.2019.02.238] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 02/09/2019] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
To provide sufficient quantities of food and feed, farming systems have to overcome limiting factors such as the nutrient depletion of arable soils. Nitrogen being the main mineral element required for plant growth, has led to the extensive use of chemical fertilizers causing nitrogen pollution of the ecosystems. This field study investigates the use of biogas residues (BRs) as biofertilizers and their contribution to the mitigation of nitrate leaching in agricultural soils, while also demonstrating the polluting nature of chemical fertilizers. Nine different fertilization treatments classified in three schemes and two nitrogen doses were tested for three consecutive years on a grassland in the Walloon Region of Belgium. Residual soil mineral nitrogen, percentage contribution of treatments in residual nitrate and agronomic performance were assessed for each fertilization treatment. The results obtained showed significant differences on treatment and scheme level regarding nitrate accumulation in the soil, with chemical fertilizers posing the highest nitrate leaching risk. BRs did not cause nitrate accumulation in the soil, and were N rate and rainfall independent, while the chemical treatments indicated a cumulative tendency under high N rate and low precipitation. Forage yield did not demonstrate statistical differences on treatment and scheme level but varied with changing precipitation, while the maximum application rate suggested a plateau. Aboveground nitrogen content was significantly higher after the application of chemical fertilizers only in the first year, while all the chemical treatments indicated a dilution effect under elevated annual rainfall. Finally, the partial substitution of chemical fertilizers by raw digestate reduced the concentration of NO3- in the soil without having a negative impact on the yield and N content of the biomass. These results strongly advocate for the environmental benefits of BRs over chemical fertilizers and underline their suitability as biofertilizers and substitutes for chemical fertilizers in similar agricultural systems.
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Affiliation(s)
- Bella Tsachidou
- Luxembourg Institute of Science and Technology, ERIN, Belvaux, Luxembourg; Université Libre de Bruxelles, Laboratoire d'Ecologie des Systèmes Aquatiques, Bruxelles, Belgium.
| | - Marie Scheuren
- Université de Liège, Département des Sciences de la Vie, Faculté des Sciences, Liège, Belgium
| | | | - Vincent Debbaut
- Université de Liège, Département des Sciences de la Vie, Faculté des Sciences, Liège, Belgium
| | | | - Christophe Hissler
- Luxembourg Institute of Science and Technology, ERIN, Belvaux, Luxembourg
| | - Isabelle George
- Université Libre de Bruxelles, Laboratoire d'Ecologie des Systèmes Aquatiques, Bruxelles, Belgium
| | - Philippe Delfosse
- Luxembourg Institute of Science and Technology, ERIN, Belvaux, Luxembourg
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17
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Donat K, Eisenberg SWF, Einax E, Reinhold G, Zoche-Golob V. Reduction of viable Mycobacterium avium ssp. paratuberculosis in slurry subjected to anaerobic digestion in biogas plants. J Dairy Sci 2019; 102:6485-6494. [PMID: 31103291 DOI: 10.3168/jds.2018-15937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 03/21/2019] [Indexed: 11/19/2022]
Abstract
Cattle infected with Mycobacterium avium ssp. paratuberculosis (MAP) shed the bacterium in their feces. This may lead to considerable concentrations of MAP in slurry, which has been postulated to contribute to MAP transmission when this slurry is used as fertilizer. For other bacterial species, anaerobic digestion has been shown to reduce bacterial load and to increase the safety of organic waste. Therefore, the objective of this study was to investigate the effects of anaerobic digestion in biogas plants on MAP survival in slurry from 16 dairy farms with a history of MAP infection. Presence of MAP was determined using MAP culture and a commercial MAP IS900 quantitative PCR (qPCR) applied on untreated slurry samples, slurry samples after primary fermentation, and digestate. Unfermented slurry samples from most enrolled farms tested positive for MAP, via both culture and qPCR. After the fermentation process, MAP could no longer be cultured in most samples, with the exception of 2 samples from farms where high numbers of MAP-shedding cows were kept at the time of sampling. A Bayesian binomial model predicted a probability of 93% for a MAP-negative culture result after fermentation. In most samples, MAP DNA was still detectable when using the IS900 qPCR. The probability of a negative result in qPCR was estimated to be 27%. Results of this study indicate that subjecting MAP-positive slurry to anaerobic digestion in biogas plants leads to a reduction of viable MAP below the detection limit; however, MAP DNA remained detectable. It remains undetermined whether MAP DNA detected in fermentation products is a residue of MAP degradation or belongs to viable MAP below the detection limit or in a dormant state. In conclusion, subjecting MAP-positive slurry to anaerobic mesophilic digestion reduces viable MAP concentration below the detection limit. The use of digestion products as fertilizer on pasture and agricultural soils instead of untreated slurry may therefore reduce the risk of MAP transmission.
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Affiliation(s)
- K Donat
- Animal Health Service, Thuringian Animal Diseases Fund, 07745 Jena, Thuringia, Germany; Clinic for Obstetrics, Gynecology and Andrology of Large and Small Animals with Veterinary Ambulance, Justus Liebig University Giessen, 35392 Giessen, Germany.
| | - S W F Eisenberg
- Animal Disease Fund of Lower Saxony, 30169 Hanover, Lower Saxony, Germany
| | - E Einax
- Animal Health Service, Thuringian Animal Diseases Fund, 07745 Jena, Thuringia, Germany
| | - G Reinhold
- Thuringian State Institute for Agriculture, 07745 Jena, Thuringia, Germany
| | - V Zoche-Golob
- Animal Health Service, Thuringian Animal Diseases Fund, 07745 Jena, Thuringia, Germany
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18
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Nolan S, Waters NR, Brennan F, Auer A, Fenton O, Richards K, Bolton DJ, Pritchard L, O'Flaherty V, Abram F. Toward Assessing Farm-Based Anaerobic Digestate Public Health Risks: Comparative Investigation With Slurry, Effect of Pasteurization Treatments, and Use of Miniature Bioreactors as Proxies for Pathogen Spiking Trials. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2018. [DOI: 10.3389/fsufs.2018.00041] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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19
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Jiang Y, Dennehy C, Lawlor PG, Hu Z, Zhan X, Gardiner GE. Inactivation of enteric indicator bacteria and system stability during dry co-digestion of food waste and pig manure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 612:293-302. [PMID: 28850849 DOI: 10.1016/j.scitotenv.2017.08.214] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/08/2017] [Accepted: 08/20/2017] [Indexed: 06/07/2023]
Abstract
Provision of digestate with satisfactory biosafety is critical to land application of digestate and to the anaerobic digestion approach to treating manure and food waste (FW). No studies have been conducted on digestate biosafety in dry co-digestion systems. The aim of this study was to assess the inactivation efficiency and possible inactivation mechanism for three enteric indicator bacteria and the system stability during dry mesophilic anaerobic co-digestion of FW and pig manure (PM). The effects of two different inocula were examined at a rate of 50% based on volatile solids (VS): digestate taken from existing dry co-digestion digesters and dewatered anaerobic sludge from a local wastewater treatment plant. The FW/PM ratios of 50:50 and 75:25 on a VS basis were also assessed. The results showed that using digestate as the inoculum and a FW/PM ratio of 50:50 led to stable dry co-digestion, with the specific methane yield (SMY) of 252mL/gVSadded. Total volatile fatty acid (VFA) concentration was a significant inhibition factor for methane production during dry co-digestion (P<0.001). The data also showed that dry co-digestion of FW and PM effectively inactivated enteric indicator bacteria. E. coli and total coliforms counts decreased below the limit of detection (LOD, 102CFU/g) within 4-7days, with free VFA identified as a significant inactivation factor. Enterococci were more resistant but nonetheless the counts decreased below the LOD within 12days in the digestate inoculum systems and 26-31days in the sludge inoculum systems. The residence time was the most significant inactivation factor for enterococci, with the free VFA concentration playing a secondary role at high FW/PM ratio in the sludge inoculum system. In conclusion, digestate as inoculum and the FW/PM ratio of 50:50 were preferable operation conditions to realize system stability, methane production and enteric indicator bacteria inactivation.
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Affiliation(s)
- Yan Jiang
- Civil Engineering, College of Engineering & Informatics, National University of Ireland Galway, Ireland
| | - Conor Dennehy
- Civil Engineering, College of Engineering & Informatics, National University of Ireland Galway, Ireland
| | - Peadar G Lawlor
- Teagasc, Pig Development Department, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland
| | - Zhenhu Hu
- School of Civil Engineering, Hefei University of Technology, Hefei 230009, Anhui Province, China
| | - Xinmin Zhan
- Civil Engineering, College of Engineering & Informatics, National University of Ireland Galway, Ireland.
| | - Gillian E Gardiner
- Department of Science, Waterford Institute of Technology, Waterford, Ireland
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20
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Dennehy C, Lawlor PG, McCabe MS, Cormican P, Sheahan J, Jiang Y, Zhan X, Gardiner GE. Anaerobic co-digestion of pig manure and food waste; effects on digestate biosafety, dewaterability, and microbial community dynamics. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 71:532-541. [PMID: 29113838 DOI: 10.1016/j.wasman.2017.10.047] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/26/2017] [Accepted: 10/27/2017] [Indexed: 06/07/2023]
Abstract
This study assessed the effect of varying pig manure (PM)/food waste (FW) mixing ratio and hydraulic retention time (HRT) on methane yields, digestate dewaterability, enteric indicator bacteria and microbial communities during anaerobic co-digestion. Three 10 L digesters were operated at 39 °C, each with a PM/FW feedstock composition of 85%/15%, 63%/37% and 40%/60% (volatile solids basis). While the PM/FW ratio was different among reactors, the organic loading rate applied was equal, and increased stepwise with reducing HRT. The effects of three different HRTs were studied: 41, 29, and 21 days. Increasing the proportion of FW in the feedstock significantly increased methane yields, but had no significant effect on counts of enteric indicator bacteria in the digestate or specific resistance to filtration, suggesting that varying the PM/FW feedstock composition at the mixing ratios studied should not have major consequences for digestate disposal. Decreasing HRT significantly increased volumetric methane yields, increased digestate volatile solids concentrations and increased the proportion of particles >500 µm in the digestate, indicating that decreasing HRT to 21 days reduced methane conversion efficiency High throughput 16S rRNA sequencing data revealed that microbial communities were just slightly affected by changes in digester operating conditions. These results would provide information useful when optimizing the start-up and operation of biogas plants treating these substrates.
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Affiliation(s)
- C Dennehy
- Civil Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland
| | - P G Lawlor
- Teagasc Pig Development Department, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland
| | - M S McCabe
- Teagasc Animal and Bioscience Research Department, Animal and Grassland Research and Innovation Centre, Grange, Dunsany, Co. Meath, Ireland
| | - P Cormican
- Teagasc Animal and Bioscience Research Department, Animal and Grassland Research and Innovation Centre, Grange, Dunsany, Co. Meath, Ireland
| | - J Sheahan
- School of Mathematics, Statistics and Applied Mathematics, National University of Ireland, Galway, Ireland
| | - Y Jiang
- Civil Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland
| | - X Zhan
- Civil Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland.
| | - G E Gardiner
- Department of Science, Waterford Institute of Technology, Ireland
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21
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Costa A, Gusmara C, Gardoni D, Zaninelli M, Tambone F, Sala V, Guarino M. The effect of anaerobic digestion and storage on indicator microorganisms in swine and dairy manure. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:24135-24146. [PMID: 28884271 DOI: 10.1007/s11356-017-0011-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 08/22/2017] [Indexed: 06/07/2023]
Abstract
The aim of this experimental study was to evaluate the influence of anaerobic digestion and storage on indicator microorganisms in swine and dairy excreta. Samples were collected every 90 days for 15 months at eight farms, four pig, and four dairy farms, four of them having a biogas plant. Moreover, to evaluate storage effects on samples, 20 l of manure and slurry taken at each farm (digested manure only in farms with a biogas plant) were stored in a controlled climatic chamber at 18 °C, for 6 months. The bacterial load and the chemical-physical characteristics of excreta were evaluated at each sampling time, stored slurry, and manure were sampled and analyzed every 2 months. A high variability of the concentration of bacteria in the different excreta types was observed during the experiment, mainly depending on the type and time of treatment. No sample revealed either the presence of Escherichia coli O157:H7 or of Salmonella, usually linked to the temporary rearing of infected animals in facilities. Anaerobic digestion and storage affected in a significant way the reduction of indicator bacteria like lactobacilli, coliforms, and streptococci. Anaerobic digestion lowered coliforms in pig slurry (- 2.80 log, P < 0.05), streptococci in dairy manure (- 2.44 log, P < 0.001) and in pig slurry (- 1.43 log, P < 0.05), and lactobacilli in pig slurry (- 3.03 log, P < 0.05). Storage lowered coliforms and the other indicators counts, in particular in fresh wastes, while clostridia did not show a reduction in concentration.
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Affiliation(s)
- Annamaria Costa
- Department of Health, Animal Science and Food Safety, Faculty of Veterinary Medicine, University of Milan, via Celoria, 10, 20133, Milan, Italy.
| | - Claudia Gusmara
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Milan, via Celoria, 10, 20133, Milan, Italy
| | - Davide Gardoni
- Department of Health, Animal Science and Food Safety, Faculty of Veterinary Medicine, University of Milan, via Celoria, 10, 20133, Milan, Italy
| | - Mauro Zaninelli
- Department of Human Sciences and Quality of Life Promotion, Università Telematica San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Fulvia Tambone
- Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy, University of Milan, via Celoria, 2, 20133, Milan, Italy
| | - Vittorio Sala
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Milan, via Celoria, 10, 20133, Milan, Italy
| | - Marcella Guarino
- Department of Health, Animal Science and Food Safety, Faculty of Veterinary Medicine, University of Milan, via Celoria, 10, 20133, Milan, Italy
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22
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Gómez-Brandón M, Juárez MFD, Zangerle M, Insam H. Effects of digestate on soil chemical and microbiological properties: A comparative study with compost and vermicompost. JOURNAL OF HAZARDOUS MATERIALS 2016; 302:267-274. [PMID: 26476314 DOI: 10.1016/j.jhazmat.2015.09.067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/22/2015] [Accepted: 09/29/2015] [Indexed: 06/05/2023]
Abstract
Anaerobic digestion has become increasingly popular as an alternative for recycling wastes from different origins. Consequently, biogas residues, most of them with unknown chemical and biological composition, accrue in large quantities and their application into soil has become a widespread agricultural practise. The aim of this study was to evaluate the effects of digestate application on the chemical and microbiological properties of an arable soil in comparison with untreated manure, compost and vermicompost. Once in the soil matrix either the addition of compost or digestate led to an increased nitrification rate, relative to unamended and manure-treated soil, after 15 and 60 days of incubation. Faecal coliform and E. coli colony forming units (CFUs) were not detected in any of the amended soils after 60 days. The highest number of Clostridium perfringens CFUs was recorded in manure-amended soil at the beginning of the experiment and after 15 days; whilst after 60 days the lowest CFU number was registered in digestate-treated soil. Denaturing gradient gel electrophoresis patterns also showed that besides the treatment the date of sampling could have contributed to modifications in the soil ammonia-oxidising bacteria community, thereby indicating that the soil itself may influence the community diversity more strongly than the treatments.
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Affiliation(s)
- María Gómez-Brandón
- University of Innsbruck, Institute of Microbiology, Technikerstrasse 25d, 6020 Innsbruck, Austria.
| | | | - Matthias Zangerle
- University of Innsbruck, Institute of Microbiology, Technikerstrasse 25d, 6020 Innsbruck, Austria
| | - Heribert Insam
- University of Innsbruck, Institute of Microbiology, Technikerstrasse 25d, 6020 Innsbruck, Austria
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23
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Fröschle B, Messelhäusser U, Höller C, Lebuhn M. Fate of Clostridium botulinum
and incidence of pathogenic clostridia in biogas processes. J Appl Microbiol 2015. [DOI: 10.1111/jam.12909] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- B. Fröschle
- Department for Quality Assurance and Analytics; Bavarian State Research Center for Agriculture (LfL); Freising Germany
| | - U. Messelhäusser
- Bavarian Health and Food Safety Authority (LGL); Oberschleißheim Germany
| | - C. Höller
- Bavarian Health and Food Safety Authority (LGL); Oberschleißheim Germany
| | - M. Lebuhn
- Department for Quality Assurance and Analytics; Bavarian State Research Center for Agriculture (LfL); Freising Germany
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24
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Fröschle B, Heiermann M, Lebuhn M, Messelhäusser U, Plöchl M. Hygiene and Sanitation in Biogas Plants. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 151:63-99. [PMID: 26337844 DOI: 10.1007/978-3-319-21993-6_3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The increasing number of agricultural biogas plants and higher amounts of digestate spread on agricultural land arouse a considerable interest in the hygiene situation of digested products. This chapter reviews the current knowledge on sanitation during anaerobic digestion and the hygienic status of digestate concerning a multitude of pathogens potentially compromising the health of humans, animals and plants. Physical, chemical and biological parameters influencing the efficiency of sanitation in anaerobic digestion are considered. The degree of germ reduction depends particularly on the resistance of the pathogen of concern, the processing conditions, the feedstock composition and the diligence of the operation management. Most scientific studies facing sanitation in biogas plants have provided data ascertaining reduction of pathogens by the biogas process. Some pathogens, however, are able to persist virtually unaffected due to the ability to build resistant permanent forms. As compared to the feedstock, the sanitary status of the digestate is thus improved or in the worst case, the sanitary quality remains almost unchanged. According to this, the spreading of digestate on agricultural area in accordance to current rules and best practice recommendations is considered to impose no additional risk for the health of humans, animals and plants.
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Affiliation(s)
- Bianca Fröschle
- Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354, Freising, Germany,
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25
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Beneragama N, Moriya Y, Yamashiro T, Iwasaki M, Lateef SA, Ying C, Umetsu K. The survival of cefazolin-resistant bacteria in mesophilic co-digestion of dairy manure and waste milk. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2013; 31:843-848. [PMID: 23512952 DOI: 10.1177/0734242x13477717] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The use of cefazolin to treat mastitic cows leads to cefazolin residues in milk and manure. This is responsible for the high occurrence of cefazolin resistant bacteria (CRB) in waste and the environment. Anaerobic digestion is considered to have the potential to reduce antibiotic-resistant bacteria present in waste that results from concentrated animal feeding operations. Thus, the objective of this study was to investigate the survival of CRB and the digester performance in mesophilic co-digestion of dairy manure and waste milk. The experiment was carried out using three digester compositions: 100% slurry (slurry), 50% slurry + 50% manure (manure mixture) and 50% slurry + 45% manure + 5% waste milk (milk mixture) in batch digesters of 1 l with a working volume of 800 ml in triplicate at 37°C for 34 days. The daily biogas production in each digester, and methane (CH4) and carbon dioxide compositions in the gas were determined. The population densities of total culturable bacteria (TCB) and CRB were determined by plate counts on agar media at day 0, 10, 20 and 34 of digestion. Milk mixture produced the highest (P < 0.05) daily and cumulative total and CH4 gas. The maximum percentage reductions of TCB and CRB in manure and milk mixture was observed at day 20, the values being 96.2%, 96.0% and 99.8% and 99.8% respectively. Final volatile fatty acids (VFA) and pH values of the digesters confirmed the digester stability. Based on the findings, mesophilic anaerobic digestion can be considered a potent method to avoid the dissemination of CRB in nature.
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Affiliation(s)
- Nilmini Beneragama
- Department of Environmental Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
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Surendra KC, Takara D, Jasinski J, Khanal SK. Household anaerobic digester for bioenergy production in developing countries: opportunities and challenges. ENVIRONMENTAL TECHNOLOGY 2013; 34:1671-1689. [PMID: 24350427 DOI: 10.1080/09593330.2013.824012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Access to clean and affordable energy is vital for advancing development objectives, particularly in rural areas of developing countries. There are some three billion people in these regions, however, who lack consistent access to energy and rely on traditional solid fuels such as firewood, cattle manure, and crop residues for meeting cooking and heating needs. Excessive use of such highly polluting resources creates serious environmental, social and public health issues. In this context, household digesters (which convert readily available feedstocks such as cattle manure, human excreta, and crop residues into biogas) have the potential to play a significant role in supplying methane as a clean, renewable energy resource for remote geographies. In addition to bioenergy production, the slurry generated from anaerobic digestion is rich in nutrients and can improve the physical, chemical, and biological attributes of soil when applied to agricultural land. This type of approach has the potential to significantly reduce greenhouse gas emissions while simultaneously improving the quality of life. Despite a long history of research and innovation for the development and optimization of household digesters, little is known and has been reported for the application of these systems in decentralized communities. The primary purpose of this paper seeks to review the dearth of literature pertaining to small-scale anaerobic digesters in remote geographies and in regions where much of the world's population reside.
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Affiliation(s)
- K C Surendra
- Department of Molecular Biosciences and Bioengineering, University of Hawai 'i at Mānoa, 1955 East-West Road, Ag Sci 218, Honolulu, HI 96822, USA
| | - Devin Takara
- Department of Molecular Biosciences and Bioengineering, University of Hawai 'i at Mānoa, 1955 East-West Road, Ag Sci 218, Honolulu, HI 96822, USA
| | - Jonas Jasinski
- Department of Molecular Biosciences and Bioengineering, University of Hawai 'i at Mānoa, 1955 East-West Road, Ag Sci 218, Honolulu, HI 96822, USA
| | - Samir Kumar Khanal
- Department of Molecular Biosciences and Bioengineering, University of Hawai 'i at Mānoa, 1955 East-West Road, Ag Sci 218, Honolulu, HI 96822, USA
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Beneragama N, Iwasaki M, Lateef SA, Yamashiro T, Ihara I, Umetsu K. Survival of multidrug-resistant bacteria in thermophilic and mesophilic anaerobic co-digestion of dairy manure and waste milk. Anim Sci J 2012; 84:426-433. [PMID: 23607603 DOI: 10.1111/asj.12017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 08/14/2012] [Indexed: 11/28/2022]
Abstract
Anaerobic digestion is considered as a promising method to manage animal waste with antibiotic-resistant bacteria. Current research was conducted to investigate the survival of multidrug-resistant bacteria (MDRB) resistant to three groups of antibiotics: (i) cefazolin, neomycin, vancomycin, kanamycin (group 1); (ii) penicillin, oxytetracycline, ampicillin, streptomycin (group 2); and (iii) cefazolin, neomycin, vancomycin, kanamycin, penicillin, oxytetracycline, ampicillin, streptomycin (group 3), in anaerobic digestion of dairy manure and co-digestion of dairy manure and waste milk at 37°C and 55°C for 22 days, respectively. The population densities of three groups of MDRB on peptone, tryptone, yeast and glucose agar plates incubated at 30°C for 7 days before and after digestion showed 100% destruction in both digestates at thermophilic temperature. Overall reduction of more than 90% of three groups of MDRB was observed in mesophilic digestion with no significant differences (P > 0.05) between manure and milk mixture. Co-digestion of dairy manure and waste milk always produced significantly (P < 0.05) higher total gas and methane gas than digestion of manure alone at both temperatures. Gas production in each case was significantly (P < 0.05) higher in thermophilic digestion than in mesophilic digestion. The results demonstrate that thermophilic co-digestion of dairy manure and waste milk offers more benefits in terms of the environment and economy.
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Affiliation(s)
- Nilmini Beneragama
- Department of Environmental Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Masahiro Iwasaki
- Department of Environmental Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Suraju A Lateef
- Department of Environmental Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Takaki Yamashiro
- Department of Environmental Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Ikko Ihara
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Kazutaka Umetsu
- Department of Environmental Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
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Olsen JE, Hoegh-Andersen KH, Casadesús J, Thomsen LE. The importance of motility and chemotaxis for extra-animal survival of Salmonella enterica serovar Typhimurium and Dublin. J Appl Microbiol 2012; 113:560-8. [PMID: 22716502 DOI: 10.1111/j.1365-2672.2012.05363.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 06/18/2012] [Accepted: 06/18/2012] [Indexed: 11/27/2022]
Abstract
AIMS This study investigated the importance of flagella and motility of Salmonella enterica serovar Typhimurium and Dublin in models of extra-animal survival. METHODS AND RESULTS The study was performed using transposon mutants in flagella genes fliC and fljB and in chemotaxis genes cheA, cheB and cheR. Flagella and chemotaxis were found to be of minor importance for attachment to plant leaves, survival in liquid manure and interaction with the nematode C. elegans, while differences were observed between the fliC mutant and the wild-type strain of S. Dublin in interactions with amoebae. CONCLUSIONS The study shows that flagella and chemotaxis play a minor role in extra-animal survival of these two serovars of Salmonella under the conditions tested. SIGNIFICANCE AND IMPACT OF THE STUDY Extra-animal survival is important in the full infection cycle for zoonotic salmonellae. Such serovars are motile. Even though the current study was only based on the characterization of two serovars, it strongly suggests that motility and chemotaxis are of minor importance during the spread of Salmonella from one animal to the next through the external environment.
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Affiliation(s)
- J E Olsen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
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Franke-Whittle IH, Insam H. Treatment alternatives of slaughterhouse wastes, and their effect on the inactivation of different pathogens: a review. Crit Rev Microbiol 2012; 39:139-51. [PMID: 22694189 PMCID: PMC3622235 DOI: 10.3109/1040841x.2012.694410] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Slaughterhouse wastes are a potential reservoir of bacterial, viral, prion and parasitic pathogens, capable of infecting both animals and humans. A quick, cost effective and safe disposal method is thus essential in order to reduce the risk of disease following animal slaughter. Different methods for the disposal of such wastes exist, including composting, anaerobic digestion (AD), alkaline hydrolysis (AH), rendering, incineration and burning. Composting is a disposal method that allows a recycling of the slaughterhouse waste nutrients back into the earth. The high fat and protein content of slaughterhouse wastes mean however, that such wastes are an excellent substrate for AD processes, resulting in both the disposal of wastes, a recycling of nutrients (soil amendment with sludge), and in methane production. Concerns exist as to whether AD and composting processes can inactivate pathogens. In contrast, AH is capable of the inactivation of almost all known microorganisms. This review was conducted in order to compare three different methods of slaughterhouse waste disposal, as regards to their ability to inactivate various microbial pathogens. The intention was to investigate whether AD could be used for waste disposal (either alone, or in combination with another process) such that both energy can be obtained and potentially hazardous materials be disposed of.
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Ziemba C, Peccia J. Net energy production associated with pathogen inactivation during mesophilic and thermophilic anaerobic digestion of sewage sludge. WATER RESEARCH 2011; 45:4758-68. [PMID: 21764416 DOI: 10.1016/j.watres.2011.06.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 06/14/2011] [Accepted: 06/15/2011] [Indexed: 05/03/2023]
Abstract
The potential for anaerobic digester energy production must be balanced with the sustainability of reusing the resultant biosolids for land application. Mesophilic, thermophilic, temperature-phased, and high temperature (60 or 70 °C) batch pre-treatment digester configurations have been systematically evaluated for net energy production and pathogen inactivation potential. Energy input requirements and net energy production were modeled for each digester scheme. First-order inactivation rate coefficients for Escherichia coli, Enterococcus faecalis and bacteriophage MS-2 were measured at each digester temperature and full-scale pathogen inactivation performance was estimated for each indicator organism and each digester configuration. Inactivation rates were found to increase dramatically at temperatures above 55 °C. Modeling full-scale performance using retention times based on U.S. EPA time and temperature constraints predicts a 1-2 log inactivation in mesophilic treatment, and a 2-5 log inactivation in 50-55 °C thermophilic and temperature-phased treatments. Incorporating a 60 or 70 °C batch pre-treatment phase resulted in dramatically higher potency, achieving MS-2 inactivation of 14 and 16 logs respectively, and complete inactivation (over 100 log reduction) of E. coli and E. faecalis. For temperatures less than 70 °C, viability staining of thermally-treated E. coli showed significantly reduced inactivation relative to standard culture enumeration. Due to shorter residence times in thermophilic reactors, the net energy production for all digesters was similar (less than 20% difference) with the 60 or 70 °C batch treatment configurations producing the most net energy and the mesophilic treatment producing the least. Incorporating a 60 or 70 °C pre-treatment phase can dramatically increase pathogen inactivation performance without decreasing net energy capture from anaerobic digestion. Energy consumption is not a significant barrier against improving the pathogen quality of biosolids.
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Affiliation(s)
- Christopher Ziemba
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520, USA
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Cunault C, Pourcher AM, Burton CH. Using temperature and time criteria to control the effectiveness of continuous thermal sanitation of piggery effluent in terms of set microbial indicators. J Appl Microbiol 2011; 111:1492-504. [PMID: 21895897 DOI: 10.1111/j.1365-2672.2011.05144.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To determine the minimal conditions (temperature-time), necessary to achieve set sanitation targets for selected microbial indicators during the continuous thermal treatment of pig slurry. METHODS AND RESULTS The effectiveness of thermal treatment between 55 and 96°C was studied using Escherichia coli, enterococci, sulfite-reducing Clostridia (SRC), mesophilic culturable bacteria (MCB), F+-specific and somatic phages. Identification of SRC and MCB was performed using 16S rRNA gene analysis. Ten minutes at 70°C or 1 h at 60°C was sufficient to reduce the vegetative bacteria by 4-5 log(10), but it had little effect on somatic phages nor on spore formers, dominated by Clostridium sp. At 96°C, somatic phages were still detected, but there was a reduction of 3.1 log(10) for SRC and of 1.4 log(10) for MCB. At 96°C, Clostridium botulinum was identified among the thermotolerant MCB. CONCLUSION Only those hygienic risks relating to mesophilic vegetative bacteria can be totally eliminated from pig slurry treated at 60°C (60 min) or 70°C (<10 min). SIGNIFICANCE AND IMPACT OF THE STUDY Hygiene standards based on the removal of the indicators E. coli and enterococci can easily be met by treatment as low as 60°C (enabling, a low-cost treatment using heat recovery). However, even at 96°C, certain pathogens may persist.
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IWASAKI M, YAMASHIRO T, BENERAGAMA N, NISHIDA T, KIDA K, IHARA I, TAKAHASHI JI, UMETSU K. The effect of temperature on survival of pathogenic bacteria in biogas plants. Anim Sci J 2011; 82:707-12. [DOI: 10.1111/j.1740-0929.2011.00887.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Persistence of Mycobacterium avium subsp. paratuberculosis at a farm-scale biogas plant supplied with manure from paratuberculosis-affected dairy cattle. Appl Environ Microbiol 2011; 77:3115-9. [PMID: 21398476 DOI: 10.1128/aem.02407-10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, products from all steps of anaerobic digestion at a farm-scale biogas plant supplied with manure from paratuberculosis-affected dairy cattle were examined and quantified for the presence of the causal agent of paratuberculosis, Mycobacterium avium subsp. paratuberculosis, using culture and quantitative real-time PCR (qPCR). Viable M. avium subsp. paratuberculosis cells were detected using culture in fermentors for up to 2 months; the presence of M. avium subsp. paratuberculosis DNA (10(1) cells/g) was demonstrated in all anaerobic fermentors and digestate 16 months after initiation of work at a biogas plant, using IS900 qPCR. F57 qPCR was able to detect M. avium subsp. paratuberculosis DNA (10(2) cells/g) at up to 12 months. According to these results, a fermentation process that extended beyond 2 months removed all viable M. avium subsp. paratuberculosis cells and therefore rendered its product M. avium subsp. paratuberculosis free. However, M. avium subsp. paratuberculosis DNA was found during all the examined periods (more than 1 year), which could be explained by either residual DNA being released from dead cells or by the presence of viable cells whose amount was under the limit of cultivability. As the latter hypothesis cannot be excluded, the safety of the final products of digestion used for fertilization or animal bedding cannot be defined, and further investigation is necessary to confirm or refute this risk.
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Massé D, Gilbert Y, Topp E. Pathogen removal in farm-scale psychrophilic anaerobic digesters processing swine manure. BIORESOURCE TECHNOLOGY 2011; 102:641-646. [PMID: 20801022 DOI: 10.1016/j.biortech.2010.08.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 07/29/2010] [Accepted: 08/05/2010] [Indexed: 05/28/2023]
Abstract
This study assessed the efficiency of commercial-scale psychrophilic anaerobic digestion in sequencing batch reactors (PADSBRs) for pathogen removal from pig manure. The impact of treatment cycle length and of hydraulic flow regimes on pathogen removal efficiency was investigated. Two conventionally operated SBRs (BR1 and BR2) and two SBRs simultaneously fed during the draw step (BR3 and BR4) were monitored over a two-year period. PADSBRs significantly decreased the concentration of coliforms, Salmonella, Campylobacter spp., and Y. enterocolitica, respectively from about 10(6), 10(3) CFU g(-1), 10(3), and 10(4) CFU g(-1) to undetectable levels in most samples. Densities of the gram-positive Clostridium perfringens and Enterococcus spp. remained high (10(5) CFU g(-1)) in the digesters throughout treatment. The PADSBRs maintained the same level of pathogen removal when the treatment cycle length was reduced from 2 to 1 week. Mass balances on volatile fatty acids (VFAs) revealed short-circuits of inlet flow respectively averaging 6.3% and 6.4% for BR3 and BR4, significantly reducing the overall performance of these reactors regarding pathogens removal. The results obtained in this study show the ability of low temperature anaerobic digestion to remove or significantly reduce indicator and pathogen concentration from raw pig manure.
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Affiliation(s)
- Daniel Massé
- Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, 2000, College Street, Sherbrooke, QC, Canada J1M 0C8.
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Bagge E, Persson M, Johansson KE. Diversity of spore-forming bacteria in cattle manure, slaughterhouse waste and samples from biogas plants. J Appl Microbiol 2010; 109:1549-65. [PMID: 20629803 DOI: 10.1111/j.1365-2672.2010.04790.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS As biowaste intended for biogas production can contain pathogenic micro-organisms, the recommended treatment is pasteurization at 70°C for 60min. This reduces pathogens such as Salmonella spp., whereas spore-forming bacteria (Bacillus spp. and Clostridium spp.) survive. Most spore-forming bacteria are harmless, but some can cause diseases such as blackleg, botulism and anthrax. In this study, the effect of the biogas process on Bacillus spp. and Clostridium spp. was investigated. METHODS AND RESULTS We analysed 97 faecal samples, 20 slaughterhouse waste samples and 60 samples collected at different stages in the biogas process. Bacillus spp. and Clostridium spp. were quantified and subcultured. The isolates were identified by biochemical methods and by 16S rRNA gene sequencing. Phylogenetic trees were constructed from the sequences obtained from isolates from the samples. Clostridium botulinum/Clostridium spp. and Clostridium sordellii were found both before and after pasteurization, but not after digestion (AD). Some of the isolated strains probably represented new members of the genera Clostridium and Bacillus. CONCLUSION After digestion, the numbers of clostridia decreased, but none of the pathogenic bacteria did, whereas Bacillus spp. remained constant during the process. SIGNIFICANCE AND IMPACT OF THE STUDY Biogas is gaining in importance as an energy source and because the residues are used as fertilizers, we needed to study the prevalence of pathogenic bacteria in such material.
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Affiliation(s)
- E Bagge
- Department of Bacteriology, National Veterinary Institute, Uppsala, Sweden.
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Watcharasukarn M, Kaparaju P, Steyer JP, Krogfelt KA, Angelidaki I. Screening Escherichia coli, Enterococcus faecalis, and Clostridium perfringens as indicator organisms in evaluating pathogen-reducing capacity in biogas plants. MICROBIAL ECOLOGY 2009; 58:221-30. [PMID: 19259627 DOI: 10.1007/s00248-009-9497-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 02/02/2009] [Indexed: 05/15/2023]
Abstract
This study was conducted to identify an indicator organism(s) in evaluating the pathogen-reducing capacity of biogas plants. Fresh cow manure containing 10(4) to 10(5) colony forming unit (CFU) per milliliter of Escherichia coli and Enterococcus faecalis along with an inoculated Clostridium perfringens strain were exposed to 37 degrees C for 15 days, 55 degrees C for 48 h, and 70 degrees C for 24 h. C. perfringens was the most heat-resistant organism followed by E. faecalis, while E. coli was the most heat-sensitive organism. E. coli was reduced below detection limit at all temperatures with log(10) reductions of 4.94 (10 s), 4.37 (40 min), and 2.6 (5 days) at 70 degrees C, 55 degrees C, and 37 degrees C, respectively. Maximum log(10) reductions for E. faecalis were 1.77 at 70 degrees C (1 day), 1.7 at 55 degrees C (2 days) and 3.13 at 37 degrees C (15 days). For C. perfringens, maximum log(10) reduction at 37 degrees C was 1.35 log(10) units (15 days) compared to less than 1 unit at 55 and 70 degrees C. Modeling results showed that E. faecalis and C. perfringens had higher amount of heat-resistant fraction than E. coli. Thus, E. faecalis and C. perfringens can be used as indicator organisms to evaluate pathogen-reducing capacity in biogas plants at high temperatures of 55 degrees C and 70 degrees C while at 37 degrees C E. coli could also be included as indicator organism.
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Affiliation(s)
- Montira Watcharasukarn
- Department of Environmental Engineering, Technical University of Denmark, Building 115, 2800 Kgs. Lyngby, Denmark
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Arthurson V. Proper sanitization of sewage sludge: a critical issue for a sustainable society. Appl Environ Microbiol 2008; 74:5267-75. [PMID: 18606792 PMCID: PMC2546642 DOI: 10.1128/aem.00438-08] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Veronica Arthurson
- Department of Microbiology, Swedish University of Agricultural Sciences, Box 7025, 75007 Uppsala, Sweden.
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Côté C, Massé DI, Quessy S. Reduction of indicator and pathogenic microorganisms by psychrophilic anaerobic digestion in swine slurries. BIORESOURCE TECHNOLOGY 2006; 97:686-91. [PMID: 15979308 DOI: 10.1016/j.biortech.2005.03.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2003] [Revised: 03/11/2005] [Accepted: 03/11/2005] [Indexed: 05/03/2023]
Abstract
The objective of this study was to evaluate the efficiency of a low temperature anaerobic treatment to reduce viable populations of indicator microorganisms (total coliforms, Escherichia coli) and the presence of selected pathogens (Salmonella, Yersinia enterocolitica, Cryptosporidium and Giardia) in swine slurries from different sources. Experiments were carried out in 40 l Sequencing Batch Reactors (SBRs). Experimental results indicated that anaerobic digestion of swine manure slurry at 20 degrees C for 20 days in an intermittently fed SBR: (1) reduced indigenous populations of total coliforms by 97.94-100%; (2) reduced indigenous populations of E. coli by 99.67-100%; (3) resulted in undetectable levels of indigenous strains of Salmonella, Cryptosporidium, and Giardia. It can be considered as a promising method for reducing indigenous indicator and pathogenic microorganisms populations in liquid swine manure slurries.
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Affiliation(s)
- Caroline Côté
- Research and Development Institute for the Agri-environment, 3300 Sicotte, Saint-Hyacinthe, Que., Canada J2S 7B8.
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Bagge E, Sahlström L, Albihn A. The effect of hygienic treatment on the microbial flora of biowaste at biogas plants. WATER RESEARCH 2005; 39:4879-86. [PMID: 16297957 DOI: 10.1016/j.watres.2005.03.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2004] [Revised: 02/21/2005] [Accepted: 03/07/2005] [Indexed: 05/05/2023]
Abstract
In Sweden, full-scale, commercial biogas plants (BGP), which process low-risk animal waste, operate a separate pre-pasteurisation at 70 degrees C for 60 min as required by EEC regulation 1774/2002. The purpose of this study was to establish if, during pasteurisation and further processing and handling in full-scale BGPs, pathogens in biowaste could be sufficiently reduced to allow its use on arable land. Four BGPs were sampled on six occasions during 1 year. Sampling was performed from six locations during biogas production. The samples being analysed quantitatively to detect indicator bacteria (Escherichia coli, Enterococcus spp. and coliforms) and spore-forming bacteria (Clostridium spp. and Bacillus spp.) and qualitatively for bacterial pathogens (salmonella, listeria, campylobacter and VTEC O157). Salmonella was the most frequently isolated pathogen before pasteurisation In general, the treatment adequatly reduced both indicator and pathogenic bacteria. Spore-forming bacteria were not reduced. However, recontamination and regrowth of bacteria in biowaste was frequently noted after pasteurisation and digestion.
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Affiliation(s)
- Elisabeth Bagge
- Department of Bacteriology, National Veterinary Institute, S-751 89 Uppsala, Sweden.
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Boes J, Alban L, Bagger J, Møgelmose V, Baggesen DL, Olsen JE. Survival of Escherichia coli and Salmonella Typhimurium in slurry applied to clay soil on a Danish swine farm. Prev Vet Med 2005; 69:213-28. [PMID: 15907571 DOI: 10.1016/j.prevetmed.2005.02.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Revised: 12/30/2004] [Accepted: 02/07/2005] [Indexed: 10/25/2022]
Abstract
A pilot study was carried out on a Danish swine farm infected with multi-resistant Salmonella Typhimurium DT104 (MRDT104). We aimed to (1) investigate to which degree the decline of Escherichia coli and Salmonella in swine slurry applied to farmland depended on the application method; (2) estimate the survival times of E. coli and Salmonella in the soil surface following deposition of naturally contaminated pig slurry; and (3) simulate survival of Salmonella in different infection levels using E. coli data as input estimates. Slurry was deposited by four different methods: (1) hose applicator on black soil followed by ploughing and harrowing; (2) hose applicator on black soil followed only by harrowing; (3) hose applicator on a field with winter-wheat seedlings without further soil treatment; (4) slurry injector on a field with winter-wheat seedlings without further soil treatment. E. coli and Salmonella could not be detected at all in soil following treatment 1. Following the other treatments, E. coli was not detected in soil samples after day 21 and Salmonella was no longer detected after day 7. Simulation results showed that clinical (4 log CFU g(-1)) and sub-clinical Salmonella levels (2500 CFU g(-1)) would fall below the detection limit within 10 or 5 days, respectively. Analysis of samples from 62 Danish MRDT104-infected swineherds showed that nearly 75% of these herds had low levels of MRDT104 (< 10 CFU g(-1)) in their slurry. Our results show that ploughing and harrowing of soil amended with contaminated pig slurry was an effective means to reduce environmental exposure to E. coli and Salmonella on this clay-soil farm.
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Affiliation(s)
- J Boes
- The National Committee for Pig Production, Danish Bacon and Meat Council, Axeltorv 3, DK-1609 Copenhagen V, Denmark.
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Bigras-Poulin M, Ravel A, Bélanger D, Michel P. Development of agroenvironmental indicators to evaluate the hygienic pressure of livestock production on human health. Int J Hyg Environ Health 2004; 207:279-95. [PMID: 15330396 DOI: 10.1078/1438-4639-00290] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Infections by enteropathogenic microorganisms linked to agroenvironmental contamination represent a significant threat to urban and rural communities. To better characterize and manage this risk, it is necessary, not only to accurately describe enteric illnesses occurring over time or across regions, but also to correctly assess exposure attributable to this environmental pollution. New agroenvironmental hygienic pressure indicators (AHPIs) were developed to synthesise relevant data expressing this exposure. They were derived from a conceptual framework for developing sustainable agriculture indicators and specifically adapted for describing the microbial risk of water contamination by livestock operations. The proposed indicators include two components, and five attributes whose values are calculated at the livestock operation level from a set of available data related to the fields of microbiology, animal production, agronomy, hydrology, and meteorology. They are then aggregated at a higher geographical level to better express exposure of human populations to potential of water contamination by zoonotic enteropathogens. The indicators are calculated separately by zoonotic enteropathogens, and by water source (surface or groundwater). They take into account the various animal species within each livestock operation. When validated, the proposed indicators will allow decision-makers and public health officials to better manage crucial issues in the area of water safety and agriculture.
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Sahlström L. A review of survival of pathogenic bacteria in organic waste used in biogas plants. BIORESOURCE TECHNOLOGY 2003; 87:161-6. [PMID: 12765355 DOI: 10.1016/s0960-8524(02)00168-2] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Anaerobic digestion is one way of handling biowaste and generating energy in the form of methane (biogas). The digested residue may be used as fertiliser on agricultural land. Biowaste is known to contain pathogenic bacteria such as Salmonella and other microorganisms that may be a health risk for both people and animals. The biosecurity risk associated with using digested residue as fertiliser is hard to assess, but this risk cannot be neglected. It is of greatest importance that the treatment in the biogas plants (BGPs) minimise the survival of pathogens. Temperature is the most important factor when considering the reduction of pathogens in BGP, but there are also other factors involved. Different indicator bacteria are used to evaluate the hygienic treatment, but an indicator that is good enough to give an overall picture has not yet been found.
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Ugwuanyi JO, Harvey LM, McNeil B. Effect of process temperature, pH and suspended solids content upon pasteurization of a model agricultural waste during thermophilic aerobic digestion. J Appl Microbiol 1999; 87:387-95. [PMID: 10540241 DOI: 10.1046/j.1365-2672.1999.00831.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Thermophilic aerobic digestion(TAD), or liquid composting, is a versatile new process for the treatment and stabilization of high strength wastes of liquid or, perhaps more importantly, slurry consistency. The pattern of inactivation of various pathogenic and indicator organisms was studied using batch digestions under conditions that may be expected to be found in full-scale TAD processes. Rapid inactivation of test populations occurred within the first 10 min from the start of digestion. The inactivation rate was slightly lower when digestions were conducted below 60 degrees C. In some instances, a 'tail' was apparent, possibly indicating the survival of relatively resistant sub-populations particularly in the case of Serratia marcescens and Enterococcus faecalis, or of clumping or attachment of cells to particulate materials. The effect of pH on the inactivation of the test populations depended on the temperature of digestion, but varied with the test population. At 55 degrees C Escherichia coli was more sensitive to temperature effects at pH 7 than at pH 8, but was more sensitive at pH 8, 60 degrees C. The reverse was the case at 60 degrees C for Ent. faecalis. An increase in the solid content of the digesting waste caused a progressive increase in the protection of test organisms from thermal inactivation. Challenging a TAD process with test strains allows (via estimation of D-values) a quantification of the cidal effects of such processes, with a view to manipulating process variables to enhance such effects.
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Affiliation(s)
- J O Ugwuanyi
- Stathclyde Fermentation Centre, Department of Bioscience and Biotechnology, University of Strathclyde, Glasgow, UK
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Ponti C, Sonnleitner B, Fiechter A. Aerobic thermophilic treatment of sewage sludge at pilot plant scale. 2. Technical solutions and process design. J Biotechnol 1995; 38:183-92. [PMID: 7765809 DOI: 10.1016/0168-1656(94)00126-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The performance of the ATS process depends essentially on the oxygen transfer efficiency. Improvement of the mass transfer capacity of a bioreactor allowed to reduce the incubation time necessary to attain sludge stabilization. It is important to use equipment with a high aeration efficiency such as an injector aeration system. The ratio between the total oxygen consumption and the organic matter degradation (delta COD) ranged between 0.4 and 0.8 in the pilot plant, whereas 1.23 was found in completely mixed bioreactors (Bomio, 1990). No significant improvement of the bacterial degradation efficiency was attained with a specific power input exceeding 6-8 kW m-3. A mean residence time of less than 1 d allowed organic matter removals up to 40% with specific power consumption of 10 kWh kg-1 COD oxidized. The sludge hygienization is one of the objectives and benefits of the thermophilic treatment: not only temperature but also the total solids content were important factors affecting inactivation of pathogens. The inactivation rate was promoted by the increase of temperature, while the residual colony forming units decreased with reducing the total solids content of sewage sludge. It is concluded that continuous operation mode would not affect the quality of the hygienization but could display the high degradation potential of the aerobic system.
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Affiliation(s)
- C Ponti
- Institute of Biotechnology, Swiss Federal Institute of Technology, ETH Hönggerberg, Zürich
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Kearney TE, Larkin MJ, Levett PN. Metabolic activity of pathogenic bacteria during semicontinuous anaerobic digestion. Appl Environ Microbiol 1994; 60:3647-52. [PMID: 7986040 PMCID: PMC201868 DOI: 10.1128/aem.60.10.3647-3652.1994] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In natural environments such as anaerobic digesters, bacteria are frequently subjected to the stress of nutrient fluxes because of the continual changes in the flow of nutrients, and to survive, they must be capable of adapting readily to nutrient changes. In this study, the metabolic activities of Escherichia coli, Salmonella typhimurium, Yersinia enterocolitica, Listeria monocytogenes, and Campylobacter jejuni were studied within culture bags (Versapor-200 filters, 0.22-microns pore size) in laboratory anaerobic digesters. The metabolic activity of these bacteria was indicated by their adenylate energy charge (EC) ratios and their ability to incorporate [3H]thymidine, which was related to the respective changes in viable numbers within the culture bags during anaerobic digestion. Fluctuations in the adenylate EC ratios, the uptake of [3H]thymidine, and the viable numbers of E. coli, S. typhimurium, Y. enterocolitica, and L. monocytogenes cells were probably due to constant changes in the amount of available nutrients within the anaerobic digesters. The viability of S. typhimurium increased quickly after a fresh supply of nutrients was added to the system as indicated by the uptake of [3H]thymidine and an increase in the adenylate EC ratios. The viable numbers of E. coli, S. typhimurium, Y. enterocolitica, and L. monocytogenes organisms declined rapidly from 10(7) to 10(8) CFU/ml to 10(3) to 10(4) CFU/ml and remained at this level for an indefinite period. The decimal reduction time calculated during the period of exponential decline ranged from 0.8 to 1.2 days for these bacteria. C. jejuni had the greatest mean decimal reduction time value (3.6 days).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T E Kearney
- School of Biology and Biochemistry, Queen's University of Belfast, Northern Ireland, United Kingdom
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Kearney TE, Larkin MJ, Frost JP, Levett PN. Survival of pathogenic bacteria during mesophilic anaerobic digestion of animal waste. THE JOURNAL OF APPLIED BACTERIOLOGY 1993; 75:215-9. [PMID: 8244898 DOI: 10.1111/j.1365-2672.1993.tb02768.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The survival of pathogenic bacteria was investigated during the operation of a full-scale anaerobic digester which was fed daily and operated at 28 degrees C. The digester had a mean hydraulic retention time of 24 d. The viable numbers of Escherichia coli, Salmonella typhimurium, Yersinia enterocolitica, Listeria monocytogenes and Campylobacter jejuni were reduced during mesophilic anaerobic digestion. Escherichia coli had the smallest mean viable numbers at each stage of the digestion process. Its mean T90 value was 76.9 d. Yersinia enterocolitica was the least resistant to the anaerobic digester environment; its mean T90 value was 18.2 d. Campylobacter jejuni was the most resistant bacterium; its mean T90 value was 438.6 d. Regression analysis showed that there were no direct relationships between the slurry input and performance of the digester and the decline of pathogen numbers during the 140 d experimental period.
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Affiliation(s)
- T E Kearney
- School of Biology and Biochemistry, Queen's University of Belfast, Northern Ireland, UK
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Kearney TE, Larkin MJ, Levett PN. The effect of slurry storage and anaerobic digestion on survival of pathogenic bacteria. THE JOURNAL OF APPLIED BACTERIOLOGY 1993; 74:86-93. [PMID: 8420921 DOI: 10.1111/j.1365-2672.1993.tb03000.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The decline in viable numbers of Salmonella typhimurium, Yersinia enterocolitica and Listeria monocytogene in beef cattle slurry is temperature-dependent; they decline more rapidly at 17 degrees C than at 4 degrees C. Mesophilic anaerobic digestion caused an initial rapid decline in the viable numbers of Escherichia coli, Salm. typhimurium, Y. enterocolitica and L. monocytogenes. This was followed by a period in which the viable numbers were not reduced by 90%. The T90 values of E. coli, Salm. typhimurium and Y. enterocolitica ranged from 0.7 to 0.9 d during batch digestion and 1.1 to 2.5 d during semi-continuous digestion. Listeria monocytogenes had a significantly higher mean T90 value during semi-continuous digestion (35.7 d) than batch digestion (12.3 d). Anaerobic digestion had little effect in reducing the viable numbers of Campylobacter jejuni.
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Affiliation(s)
- T E Kearney
- School of Biology and Biochemistry, Queen's University of Belfast, Medical Biology Centre, Northern Ireland, UK
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Olsen JE. Studies on the reduction of pathogenic and indicator bacteria in liquid pig manure treated by sedimentation and anaerobic filter digestion for methane generation. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0269-7483(88)90023-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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