Reductie van ammoniak- en methaanemissie via het voerspoor : onderzoek naar de wisselwerking tussen de excretie van Totaal Ammoniakaal Stikstof (TAN) en de emissie van enterisch methaan (CH4) op de Koeien&Kansen praktijkbedrijven in de periode 2010-2013
Spek, J.W. ; Klop, A. ; Šebek, L.B. - \ 2017
Wageningen : Wageningen UR Livestock Research (Rapport / Koeien en kansen nr. 79) - 19
ammoniakemissie - methaan - emissiereductie - rundveevoeding - ammonia emission - methane - emission reduction - cattle feeding
Assessing methane emission from dairy cows : modeling and experimental approaches on rumen microbial metabolism
Lingen, Henk J. - \ 2017
Wageningen University. Promotor(en): W.H. Hendriks, co-promotor(en): J. Dijkstra; A. Bannink; C.M. Plugge. - Wageningen : Wageningen University - ISBN 9789463431590 - 207
dairy cows - methane - emission - microbial degradation - rumen metabolism - rumen fermentation - models - fatty acids - biochemical pathways - animal nutrition - nutrition physiology - melkkoeien - methaan - emissie - microbiële afbraak - pensmetabolisme - pensfermentatie - modellen - vetzuren - biochemische omzettingen - diervoeding - voedingsfysiologie
Methane (CH4) is a greenhouse gas (GHG) with a global warming potential of 28 CO2 equivalents. The livestock sector was estimated to emit 7.1 gigatonnes of CO2 equivalents, which is approximately 14.5% of total global anthropogenic GHG emissions. Enteric CH4 production is the main source of GHG emissions from dairy cattle, representing 46% of the global GHG emissions in dairy supply chains. Dairy production has great value in view of the ability of ruminants to effectively turn human inedible biomass into human edible food and to produce food from non-arable land. Consequently, there is an urgent need to develop strategies to decrease dairy cattle enteric CH4 emission. Evaluation of these strategies requires meticulous quantification and increased understanding of anaerobic fermentation and methanogenesis in the rumen ecosystem. The overall aim of this PhD research was, therefore, to quantitatively evaluate enteric CH4 emission from dairy cows as affected by feeding and rumen microbial metabolism.
A meta-analysis was performed to quantify relationships between enteric CH4 yield (per unit of feed and unit of milk) and milk FA profile in dairy cattle and to develop equations to predict CH4 yield based on milk FA profile of cows fed a wide variety of diets. Various milk FA concentrations were significantly or tended to be positively or negatively related to CH4 yield per unit of feed or milk. Mixed model multiple regression resulted in various milk FA included in optimal equations to predict CH4 yield per unit of feed and per unit of milk. These regression equations indicated a moderate potential for using milk FA profile to predict CH4 yield.
For the development of a mechanistic model of CH4 production in the rumen, the thermodynamic control of pH2 on reaction rates of specific fermentation pathways, NADH oxidation and methanogenesis was theoretically explored. This control was determined using the thermodynamic potential factor (FT), which is a dimensionless factor that corrects a predicted kinetic reaction rate for the thermodynamic control exerted. The thermodynamic feasibility of these microbial conversions showed that the control of pH2 on individual VFA produced and associated yield of H2 and CH4 cannot be explained without considering NADH oxidation, with a considerable effect of pH.
For obtaining experimental support of the conclusions drawn from the theoretical exploration, diurnal patterns of gaseous and dissolved metabolite concentrations in the bovine rumen, H2 and CH4 emitted, and the rumen microbiota were monitored. In addition, the effect of dietary inclusion of linseed oil on these patterns was assessed. An in vivo experiment with rumen cannulated dairy cows was performed to study the anaerobic metabolism and the microbiota composition in the rumen. A 100-fold increase in pH2 in the rumen headspace was observed at 0.5 h after feeding, followed by a decline. Qualitatively similar patterns after feeding were observed for H2 and CH4 emission, ethanol and lactate concentrations, and propionate molar proportion, whereas an opposite pattern was seen for acetate molar proportion. Associated with these patterns, a temporal biphasic change in the microbial composition was observed as based on 16S ribosomal RNA with certain taxa specifically associated with each phase. Bacterial concentrations were affected by time and increased by linseed oil supplementation. Archaeal concentrations tended to be affected by time and were not affected by diet, despite linseed oil supplementation tending to decrease the partial pressure and emission of CH4 and tending to increase propionate molar proportion. The various diurnal profiles that were monitored support the key role of the NAD+ to NADH ratio in rumen fermentation and the importance of diurnal dynamics when understanding VFA, H2 and CH4 production.
A dynamic mechanistic model was developed, in which the thermodynamic control of pH2 on VFA fermentation pathways, and methanogenesis in the bovine rumen are incorporated. The model represents substrate degradation, microbial fermentation and methanogenesis in the rumen, with the type of VFA formed to be controlled by the NAD+ to NADH ratio, which in turn is controlled by pH2. Feed composition and feed intake rate representing a twice daily feeding regime were used as model input. The model predicted a marked peak in pH2 after feeding that rapidly declined in time. This peak in pH2 caused a decrease in NAD+ to NADH ratio followed by an increased propionate molar proportion at the expense of acetate molar proportion. In response to feeding, the model predicted a sudden increase and a steady decrease in CH4 production in time. The pattern of CH4 emission rate followed the patterns of pH2 and H2 emission rate, but its magnitude of increase in response to feeding was less pronounced. A global sensitivity analysis indicated the parameter that determines the NADH oxidation rate to explain the most substantial part of the variation of predicted daily CH4 emission. The modeling effort provides the integration of more detailed knowledge than accomplished in previous rumen fermentation models and enables assessment of diurnal dynamics of rumen metabolic pathways yielding VFA, H2 and CH4.
For assessing the general value of the research reported in this thesis, the potential for predicting enteric CH4 emission from dairy cattle based on milk FA profile was discussed in the light of published studies and compared with empirical modeling of enteric CH4 based on feed input. Moreover, the concept of NAD-controlled fermentation was considered in a more general perspective by comparing the rumen ecosystem with bioreactor systems. Furthermore, the feasibility of the developed models as an alternative for IPCC tiered approaches was explored. In conclusion, the research reported in this thesis contributes to an increased understanding of rumen fermentation and microbial metabolism, and has provides a basis to further improve prediction models of enteric CH4 emissions from dairy cattle.
Browse species from Ethiopia: role in methane reduction and nematode control in goats
Mengistu, Genet F. - \ 2017
Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Wilbert Pellikaan. - Wageningen : Wageningen University - ISBN 9789462579767 - 130
goats - browsing - nematode control - methane - anthelmintic properties - browse plants - ethiopia - geiten - afgrazen - nematodenbestrijding - methaan - wormdrijvende eigenschappen - graasplanten - ethiopië
The aim of the research reported in this thesis was to evaluate browse species collected from Ethiopia for preference by goats, and for their in vitro anthelmintic and methane (CH4) reduction properties. During the conduct of the studies observations were made warranting a further aim, to compare in vitro fermentation patterns of browse species using inocula from goats and cows kept on identical dietary regime.
The preference of browse species using dry matter intake (DMI) as a proxy and in combination with polyethylene glycol (PEG), relationships between browse species intake and chemical composition were determined in Chapter 2. Air-dried leaves of Acacia etbaica, Cadaba farinosa, Capparis tomentosa, Dichrostachys cinerea, Dodonaea angustifolia, Euclea racemosa, Maerua angolensis, Maytenus senegalensis, Rhus natalensis and Senna singueana were used. Two cafeteria trials, each lasting 10 days were conducted using goats receiving a daily ration of grass hay and wheat bran, without (trial 1) or with (trial 2) the inclusion of PEG. Preference measured as the first 10 min browse DMI differed significantly among browse species and with PEG (P<0.0001). Browse with higher tannin content, D. cinerea, R. natalensis and A. etbaica were the most preferred species regardless of PEG presence. Preference appeared to be based on digestible fibre fraction, hemicellulose rather than tannin levels in the browse species.
Extracts of the 10 browse species were evaluated for their anthelmintic activity against Haemonchus contortus (Chapter 3). The larval exsheathment inhibition assay (LEIA) was applied using H. contortus third stage larvae (L3) in a dose dependent manner with extract concentrations of 0, 150, 300, 600, 1200 µg/ml phosphate buffered saline (PBS). The role of polyphenols in the inhibition against L3 was evaluated using polyvinylpolypyrrolidone (PVPP). All browse extracts significantly (P<0.0001) inhibited larval exsheathment in a dose dependent manner with the dose required to inhibit 50% of the L3 (EC50) being highest in C. farinosa and lowest in E. racemosa and M. senegalensis. Polyvinylpolypyrrolidone treated A. etbaica, C. tomentosa, M. angolensis, R. natalensis and D. cinerea were different (P<0.001) from the control (only PBS), indicating that larval inhibition was largely due to non-phenolic compounds. Absence of significant differences between PVPP treated E. racemosa, M. senegalensis, D. angustifolia and S. singueana, and control suggest that inhibition was mostly attributable to tannins and other polyphenols. Browse species anthelmintic property against H. contortus L3 was due to the presence of phenolic and non-phenolic compounds.
In vitro gas production (GP), CH4, volatile fatty acids (VFA) and in vitro organic matter digestibility (IVOMD) of the 10 browse species were determined using PEG 6000 in Chapter 4. Proanthocyanidins (PA) were quantified using a modified HCl-butanol method and PA composition was determined by UPLC-DAD, with detection of other polyphenols by UPLC-ESI-MS/MS. Substrates were inoculated in buffered goat rumen fluid with or without PEG 6000 for 72 h to measure GP with head space gas sample measurements taken at 0, 3, 6, 9, 12, 24, 30, 48, 54, and 72 h for CH4. At the end of incubation, VFA, ammonia (NH3) and IVOMD were determined. Increased (P<0.0001) GP, CH4 and total VFA were observed after PEG addition indicating PA were mainly involved in reducing methanogenesis and to a lower extent also overall fermentability. Prodelphinidins were the major explaining factors for this reduction but other polyphenols like quercetin, myricetin and kaempferol were also involved in CH4 reduction. The effect of PEG addition on IVOMD was variable among browse and could be due to artefacts from the tannin-PEG complexes in the incubation residue. Proanthocyanidins were mainly responsible for the reduced in vitro fermentative activities with possible minor effects of other phenolic and non-phenolic components.
Due to unusual fermentation patterns observed in Chapter 4, a comparison was made between goat and cow inocula on in vitro gas and CH4 production and kinetics parameters as well as VFA production in Chapter 5. Leaves of A. etbaica, C. tomentosa, D. cinerea, R. natalensis, freeze-dried maize and grass silage, and a concentrate were inoculated for 72 h to measure GP, in buffered inocula from goats and cows kept on an identical feeding regime. During incubation, headspace gas samples were obtained at 0, 3, 6, 9, 24, 30, 48, 54, and 72 h, and analysed for CH4 with VFA determined at the end of incubation. A triphasic and monophasic modified Michaelis-Menten equation was fitted to the cumulative GP and CH4 curves, respectively. Total GP and CH4 (P<0.0001), half-time for asymptotic (P<0.012) and rate (P<0.0001) of GP were higher for goat inoculum. The total VFA were higher (P<0.0001) in goats and the proportion of individual VFA differed significantly (P<0.002) between animal species. Differences between goat and cow inocula were attributable to variation in the activity and composition of the microbial population, and differences were more pronounced for fermentation of browse species than grass and maize silages.
A synthesis of the results from the four research chapters is provided in the general discussion (Chapter 6). The present work highlights the browse species characteristics which can be strategically exploited in goat production systems to improve health and feed utilization efficiency.
Assessing the case for sequential cropping to produce low ILUC risk biomethane : final report
Peters, Daan ; Zabeti, Masoud ; Kühner, Ann-Kathri ; Spöttle, Matthias ; Werf, Wopke van der; Stomph, Jan - \ 2016
Utrecht : ECOFYS Netherlands - 39
methane - biofuels - sequential cropping - farmers' associations - biogas - ancillary enterprises - farm management - agricultural energy production - transport - biobased economy - fuel crops - biomass production - methaan - biobrandstoffen - estafetteteelt - boerenorganisaties - biogas - nevenactiviteiten - agrarische bedrijfsvoering - energieproductie in de landbouw - transport - biobased economy - brandstofgewassen - biomassa productie
In recent years and especially since the COP - 21 climate agreement reached in Paris last year, efforts to mitigate climate change accelerate. All sectors need to contribute in order to achieve the well below 2 degree climate target. The agricultural sector is relevant for climate change in various ways. Like the agricultural sector, the transport sector is also responsible for significant greenhouse gas emissions. Advanced biofuels and biogas produced from wastes and residues can play an increasingly important role in the transport mix. In Italy, 600 Italian farmers are organised in the Italian Biogas Council (Consorzio Italiano Biogas e Gassificazione, CIB). Some years ago, CIB members developed a concept that they coined Biogasdoneright. In collaboration with various research institutes they seeked for a way to combine biogas feedstock production with crop production for food and feed as a way to generate additional income in a sustainable manner. The core of the Biogasdoneright concept is that farmers apply sequential cropping by growing a winter cover crop on land that was previously fallow during winter time, while maintaining the main crop production during summer time as previously. Multiple claims can be made about Biogasdoneright, for example related to the large potential role for biogas in our future energy system. This project focussed on the most relevant claims related to the use of biomethane in transport, with a focus on sustainability aspects.
Rekenregels voor de enterische methaan-emissie op het melkveebedrijf en reductie van de methaan-emissie via mesthandling, het handelings-perspectief van het voerspoor inzichtelijk maken met de Kringloopwijzer
S̆ebek, L.B. ; Mosquera, J. ; Bannink, A. - \ 2016
Wageningen : Wageningen Livestock Research (Livestock Research rapport 976) - 65
methaan - emissie - dierlijke meststoffen - emissiereductie - melkveehouderij - methane - emission - animal manures - emission reduction - dairy farming
Methaanemissie uit mest : schatters voor biochemisch methaan potentieel (BMP) en methaanconversiefactor (MCF)
Groenestein, C.M. ; Mosquera, J. ; Melse, R.W. - \ 2016
Wageningen : Wageningen Livestock Research (Livestock Research rapport 961) - 28
mest - methaan - emissie - broeikasgassen - dierhouderij - manures - methane - emission - greenhouse gases - animal husbandry
This report presents the results of a desk study performed to determine and justify the use of new BMP and MCF values for cattle, pig and poultry manure under Dutch conditions.
Towards improving the manure management chain
Hou, Yong - \ 2016
Wageningen University. Promotor(en): Oene Oenema, co-promotor(en): Gerard Velthof. - Wageningen : Wageningen University - ISBN 9789462579620 - 215
manures - manure treatment - livestock - excretion - nitrogen - mitigation - methane - european union - mest - mestverwerking - vee - excretie - stikstof - mitigatie - methaan - europese unie
Animal manures are major sources of nutrients and organic matter, to be used to fertilize crops and improve soil quality. However, when not properly managed, these manures release considerable amounts of ammonia (NH3), nitrous oxide (N2O) and methane (CH4) into the air, and nitrogen (N) and phosphorus (P) to water bodies, which create a range of unwanted environment impacts. Nutrient losses from manure depend on the management activities and techniques used at different stages of the whole manure management chain, from animal feeding up to manure application to land. The trade-offs and co-benefits of emission mitigation measures and manure treatment technologies are as yet poorly understood, especially when taking the whole manure management chain into account. Moreover, the effects of combinations of measures and technologies have not been well analyzed, and analyses at national scales are lacking. The overall objective of this PhD thesis research is (i) to enhance the quantitative insight into the effects of emission mitigation measures and treatment technologies on emissions of NH3, N2O and CH4, and the recovery of N and P from animal manure in the whole management chain, and (ii) to explore the effects of combinations of measures and technologies to mitigate these emissions and to increase the N and P recovery.
In Chapter 2, methodologies for estimating N excretion factors for the main animal categories in member states of the European Union (EU) were reviewed. In Chapter 3, a transparent and uniform methodology for estimating annual feed use and N excretion per animal category for all countries of the EU-27 was developed, based on the energy and protein requirements of the animals and statistics of feed use and composition, animal number and productivity. In Chapter 4, firstly the impacts of a suite of NH3 mitigation measures on emissions of NH3, N2O and CH4 at individual stages of the manure management chain were analyzed by means of a meta-analysis of published data. Secondly, the overall impacts of alternative combinations of mitigation measures on emissions from the whole chain were evaluated through scenario analysis. Chapter 5 reports on an integrated assessment of the effects of manure treatment on NH3, N2O and CH4 emissions from manure management chains in EU-27 at the national level for 2010, using the model MITERRA-Europe. Whole-chain effects of implementing twelve treatment technologies in EU-27 on emissions and N and P recovery were further explored through scenario analyses. Chapter 6 reports on a survey conducted under various stakeholder groups with expertise in the domain of manure treatment in four European countries that have regions of high animal density. The survey addressed questions related to i) which factors facilitate and hinder the implementation of treatment technologies in practice, ii) which technologies have the most potential for successful adoption, and iii) how farm characteristics and the scale of the treatment operation affect priorities for adoption. The main conclusions of this PhD thesis are as follows:
In EU-27, the amounts of N and P in manure are as large as or larger than the total amounts of fertilizer N and P used annually. However, there is a huge spatial variation in manure production. Nutrient excretion factors per animal category also vary between countries, as a result of variations in feed use and animal productivity. Clearly, for accurate inventories of national emission there is a need for estimating nutrient excretion using country-specific feed use data.
Increasing the effectiveness of measures to mitigate NH3 and GHG emissions from animal manure requires proper combination of measures in the manure management chain. Lowering the dietary protein content in animal feed is an effective measure to reduce NH3 emissions and other N emissions at all stages of the manure management chain. Other measures may reduce emissions of a specific gas or emissions source, by which there is a risk of unwanted trade-offs in the manure management chain. Joint adoption of these measures with low-N feeding strategies and slurry acidification can greatly decrease the risk of pollution swapping.
Implementation of manure treatment is on average still limited in EU-27. Effects of manure treatment on NH3 and GHG emissions are therefore relatively small at EU level. Increasing the implementation of treatment technologies, including acidification, incineration and thermal drying, or optimized combinations of treatment technologies, can significantly contribute to achieving NH3 and GHG emission targets of EU environmental policies. Implementation of manure treatment technologies provides opportunities to improve the use of plant nutrients in manures, because of the release of manure products with different N/P ratios. Applying acidification technology and optimized combination of NH3 emission mitigation measures increase the N recovery from animal manure, and can decrease the demand of mineral fertilizers. However, some technologies decrease the N and P recovery and/or decrease the availability of the N and P in manure products to plants.
Implementation of manure treatment in practice is forced by the pressure from EU environmental regulations, and is hindered by financial barriers. To encourage the adoption of manure treatment, policies must be economically appealing to attract new adopters (farmers and industries). Long-term financial support schemes (e.g. subsidies) seem to be necessary, especially with the current low prices for fossil fuels. Outreach strategies are required to convey the knowledge to stakeholders from both the supply and the demand side, with respect to the economic, technical and environmental aspects of manure treatment technologies.
Referentieraming van emissies naar lucht uit de landbouw tot 2030 : achtergronddocument bij de Nationale Energieverkenning 2015, met emissies van ammoniak, methaan, lachgas, stikstofoxide en fijnstof uit de landbouw tot 2030
Velthof, G.L. ; Bruggen, C. van; Groenestein, C.M. ; Huijsmans, J.F.M. ; Luesink, H.H. ; Sluis, S.M. van der; Kolk, J.W.H. van der; Oude Voshaar, S.V. ; Vonk, J. ; Schijndel, M.W. van - \ 2016
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2746) - 75
luchtverontreiniging - ammoniakemissie - methaan - distikstofmonoxide - stikstofoxide - fijn stof - landbouw - nederland - air pollution - ammonia emission - methane - nitrous oxide - nitric oxide - particulate matter - agriculture - netherlands
Methodology for estimating emissions from agriculture in the Netherlands. : Calculations of CH4, NH3, N2O, NOx, PM10, PM2.5 and CO2 with the National Emission Model for Agriculture (NEMA)
Vonk, J. ; Bannink, A. ; Bruggen, C. van; Groenestein, C.M. ; Huijsmans, J.F.M. ; Kolk, J.W.H. van der; Luesink, H.H. ; Oude Voshaar, S.V. ; Sluis, S.M. ; Velthof, G.L. - \ 2016
Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 53) - 164
air pollutants, greenhouse gases, livestock, crops, animal housing, manure storage, manure application, inorganic fertilizer, enteric fermentation, manure management, agricultural soils, liming, NIR, CRF, IIR, NFR - landbouw - gewassen - landbouwgronden - vee - huisvesting, dieren - dierlijke meststoffen - rundveemest - mestverwerking - begrazing - broeikasgassen - luchtverontreinigende stoffen - emissie - ammoniakemissie - kooldioxide - methaan - anorganische meststoffen - fermentatie - bekalking - nederland - compost - rioolslib - teelt - oogstresten - rijp worden - agriculture - crops - agricultural soils - livestock - animal housing - animal manures - cattle manure - manure treatment - grazing - greenhouse gases - air pollutants - emission - ammonia emission - carbon dioxide - methane - inorganic fertilizers - fermentation - liming - netherlands - composts - sewage sludge - cultivation - crop residues - ripening
The National Emission Model for Agriculture (NEMA) is used to calculate emissions to air from agricultural activities in the Netherlands on a national scale. Emissions of ammonia (NH3) and other N-compounds (NOx and N2O) from animal housing, manure storage, manure application and grazing are assessed using a Total Ammoniacal Nitrogen (TAN) flow model. Furthermore, emissions from application of inorganic N-fertilizer, compost and sewage sludge, cultivation of organic soils, crop residues, and ripening of crops are calculated. NEMA is also used to estimate emissions of methane (CH4) from enteric fermentation and manure management, particulate matter (PM) from manure management and agricultural soils, and carbon dioxide
(CO2) from liming. Emissions are calculated in accordance with international guidance criteria and reported in an annual Informative Inventory Report (IIR; for air pollutants) and National Inventory Report (NIR; for greenhouse gases). This methodology report describes the outline and backgrounds of the emission
calculations with NEMA
Biotechnological removal of H2S and thiols from sour gas streams under haloalkaline conditions
Roman, P. - \ 2016
Wageningen University. Promotor(en): Albert Janssen, co-promotor(en): Martijn Bijmans. - Wageningen : Wageningen University - ISBN 9789462577336 - 193
desulfurization - biogas - bioreactors - methane - sulfides - oxidation - ontzwaveling - biogas - bioreactoren - methaan - sulfiden - oxidatie
Biological removal of H2S from sour gas streams became popular in recent years because of high process efficiency and low operational costs. To expand the scope of these processes to gas streams containing volatile organosulfur compounds, like thiols, it is necessary to provide new insights into their impact on overall biodesulfurization process. In the current thesis multidisciplinary investigations are performed, such as investigations of inhibitory effects of organic sulfur compounds on sulfide-oxidizing biomass by biochemical and enzyme studies; modelling of the process performance and biological pathways; preparation of analytical tools for measuring unstable sulfur compounds under the process conditions; following the microbial dynamics. The research described in this thesis increases the understanding of the underlying processes occurring in biological gas desulfurization systems when organosulfur compounds are present in the feed gas and provides solutions how to cope with these compounds in full-scale gas biodesulfurization installations.
Evaluatie van methaanemissieberekeningen en -metingen in de veehouderij
Groenestein, C.M. ; Mosquera Losada, J. - \ 2015
Wettelijke Onderzoekstaken Natuur & Milieu (WOt-technical report 54) - 46
veehouderij - mest - methaan - emissie - meting - berekening - varkens - livestock farming - manures - methane - emission - measurement - calculation - pigs
Wageningen UR Livestock Research heeft een deskstudie uitgevoerd om te analyseren waarom berekende en
gemeten methaanemissies verschillen en doet aanbevelingen voor nader onderzoek. Het blijkt dat zowel aan
de kant van de meetwaarden als aan de kant van de berekeningen vragen kunnen worden gesteld. De
aanbevelingen betreffen een nadere beschouwing van mestsamenstelling (met name organische stof (OS),
de fractie van de organische stof die afbreekbaar is (Bo) en het deel van de afbreekbare fractie die
daadwerkelijk wordt afgebroken tot CH4 (MCF)) met in achtneming van Nederlandse omstandigheden.
Tevens wordt geadviseerd te bestuderen wat de oorzaak kan zijn van de grote variatie in gemeten
methaanemissie met oog voor de leeftijd van de mest, effect van ammoniakemissie-reducerende
maatregelen, mestmanagement en enterische methaanemissie door varkens
Exploring the ecophysiology of anaerobic communities of methanotrophic archaea and sulfate-reducing bacteria
Timmers, P.H.A. - \ 2015
Wageningen University. Promotor(en): Fons Stams, co-promotor(en): Caroline Plugge. - Wageningen : Wageningen University - ISBN 9789462575820 - 181
sulfate reducing bacteria - methane - oxidation - anaerobic conditions - sulfates - marine sediments - microbial physiology - sulfaat reducerende bacteriën - methaan - oxidatie - anaërobe omstandigheden - sulfaten - mariene sedimenten - microbiële fysiologie
Anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) is a widespread occurring process in anoxic marine sediments. The process is performed by ANaerobic MEthane oxidizing archaea (ANME) and associated sulfate reducing bacteria (SRB). The ANME presumably oxidize methane through reverse methanogenesis. The associated SRB were thought to reduce sulfate using an interspecies electron carrier (IEC) derived from AOM. The product of methane oxidation that is transferred to the SRB is either a less reduced compound that acts as IEC or electrons are transferred directly (through nanowires or pili) or indirectly (through extracellular quinones). However, recent evidence emerged that ANME could perform both methane oxidation and sulfate reduction to produce sulfur, where the SRB disproportionate the produced sulfur. Little is known on the physiology and ecology of these ANME and associated SRB. The main reasons for this are the difficulties in lab cultivation and to perform in situ studies.
Anaerobic methane oxidation is a process that is at the border of what is energetically possible for sustaining life, which makes it hard to cultivate the responsible organisms. Estimates of the Gibbs free energy yields are between -18 and -35 kJ mol-1 and growth rates between 1.1 and 7.5 months, depending on the environment. AOM therefore operates close to thermodynamic equilibrium and is highly dependent on substrate and product concentrations. In chapter 2, we obtained faster growth rates at elevated methane partial pressure as compared to ambient pressure. The increase in partial pressure increased the solubility of methane and thus the energy yield for the organisms. In chapter 6, we showed higher AOM activity and growth of ANME under thermodynamically favorable sulfate and sulfide concentrations. The problems in studying the process in situ in complex environments comes from difficulties in differentiation of reversible processes. In most studies, methane oxidation is monitored by labelled CO2 formation from labelled methane. Methanogens can perform trace methane oxidation (TMO)during net methanogenesis, which also results in the production of labelled CO2 from labelled methane. When AOM becomes less favorable, the anaerobic back flux of AOM becomes significant, leading to the production of measurable amounts of methane. In chapter 2 and chapter 3, we were able to differentiate between AOM and TMO in long-term incubations.
Another challenge is related to the detection of ANME in complex environments. The phylogenetic distance between and within ANME clades is large. In chapter 5, we discussed the difficulties in primer and probe design for selective detection of ANME without targeting closely related methanogens. Furthermore, it is not known if even more ANME species and clades have yet to be discovered that are not detected with the primers and probes used thus far. In chapter 3, we found indications that besides ANME-2a/b, ANME-2d archaea were also able to perform AOM coupled to sulfate reduction in freshwater conditions. The finding of ANME-2a/b in freshwater shows that ANME archaea are ubiquitously distributed and not only occur in marine sediments. In chapter 6, we confirmed that different ANME clades show niche separation based on the presence of methane and different sulfate and sulfide concentrations. In chapter 2, we obtained indications that ANME-2c grows at high methane partial pressure. More research on the ecophysiology could help in understanding occurrence and activity of ANME in different environments.
Many different SRB have been found so far to form close associations with ANME. Most fall within the Desulfosarcina/Desulfococcus (DSS) clade and only for two enrichment cultures the dominant partner of ANME-2a/b was determined to belong to a specific group with the DSS named SEEP-SRB1. In chapter 2, we found more evidence that a group outside the DSS clade, SEEP-SRB2, could also associate with ANME-2a/b and that Eel-1 members are not directly involved in AOM. In chapter 4, we enriched for SRB within the DSS clade on alternative substrates besides methane, but we were unable to show that these are involved in AOM. Therefore, more research on the sulfate-reducing partner is needed to understand the metabolic interactions between ANME and SRB.
Oogstmoment snijmais beïnvloedt methaanuitstoot : Later oogsten mais verlaagt methaanuitstoot zonder negatieve bijeffecten
Bannink, A. ; Hatew, B. ; Dijkstra, J. - \ 2015
Veeteelt 2015 (2015)Oktober. - ISSN 0168-7565 - p. 34 - 35.
landbouw en milieu - oogsttijdstip - droge stof - maïs - ruwvoer (forage) - methaan - emissiereductie - duurzame landbouw - broeikasgassen - agriculture and environment - harvesting date - dry matter - maize - forage - methane - emission reduction - sustainable agriculture - greenhouse gases
Wageningse diervoedingonderzoekers keken naar de gevolgen van het oogstmoment van mais op de methaanemissie. De conclusie is dat per procent drogestoftoename van snĳmais in maisrĳke rantsoenen de methaanvorming per kilogram meetmelk met 1,5 procent wordt verlaagd.
Anaerobic oxidation of methane : evaluation of alternative conditions
Suarez Zuluaga, D.A. - \ 2015
Wageningen University. Promotor(en): Cees Buisman, co-promotor(en): Jan Weijma. - Wageningen : Wageningen University - ISBN 9789462574823 - 131
microorganisms - methane - oxidation - sulfates - reduction - bioreactors - micro-organismen - methaan - oxidatie - sulfaten - reductie - bioreactoren
Microorganisms capable of performing anaerobic oxidation of methane (AOM) coupled to sulphate reduction have high doubling times which make their enrichment difficult. However, due to higher energy gain, they might be rapidly enriched using alternative electron acceptors. In chapter 2, it was shown that up to 50 times higher conversion rates were obtained with thiosulphate when compared to sulphate. However, it was also presented that thiosulphate was not be exclusively used by microorganisms that reduce it, but that it was also disproportionated into sulphate and sulphide (Chapter 2).
In Chapter 3, a 5 litre membrane bioreactor was fed not only with methane and sulphate but also with acetate and thiosulphate. As previous experiments using these additional substrates had allowed to obtain either faster conversion rates or enrichment of methanotrophic microorganisms; it was expected that AOM rates in the reactor would increase relatively fast. However, the microorganisms that were enriched were not AOM related. They microbial community that showed the highest activity rates in the reactor was comprised by thiosulphate disproportionated bacteria and green sulphur bacteria. The former disproportionated thiosulphate into sulphate and sulphide while the latter converted the sulphide into elemental sulphur.
Chapter 4, unlike the previous chapters, focused on studying the occurrence of AOM in a fresh water ecosystem. Such system was located next to a natural gas source which captured methane for domestic purposes. It was presented how, with the different electron acceptors added, AOM and trace methane oxidation occurred. However, net AOM was only measured in the presence of sulphate as electron acceptor. Furthermore, the microorganisms that were enriched in the presence of methane and sulphate were also detected.
There are several hypotheses which attempted to explain the AOM coupled to sulphate reduction. One of them indicates that it is a process that involves two microorganisms working in a syntrophic relationship. The first microorganism would convert the methane into carbon dioxide and pass the electrons to the second one. Consequently, the second microorganism would convert the sulphate into hydrogen sulphide. In such a structure, the way that electrons are released by the conversion performed by the first microorganism is unknown. It is possible, that electrons are not transfer via electron shuttles or chemical compounds, but that they are transferred directly from one microorganism to the other. A methodology which could be used to determine if the AOM consortia uses direct electron transfer mechanisms was evaluated in Chapter 5. Different kinds of granular biomass were used for this evaluation and, the granule types that would potentially be capable of using direct electron transfer mechanisms were detected.
Minder gasvormige emissies op melkveebedrijf : praktijkervaringen met voer- en diermanagement als sturing voor methaan en ammoniak
Sebek, L.B. ; Goselink, R.M.A. ; Evers, A.G. ; Vrolijk, M. ; Haan, M.H.A. de - \ 2015
Wageningen : Wageningen UR Livestock Research (Rapport / Koeien & Kansen nr. 75) - 32
broeikasgassen - melkveehouderij - ammoniakemissie - emissie - reductie - methaan - greenhouse gases - dairy farming - ammonia emission - emission - reduction - methane
Dit rapport beschrijft wat het voor de melkveehouder betekent om reductiemaatregelen voor methaan in de bedrijfsvoering te implementeren. Het gaat om de beleving en de praktijkervaring van de 16 Koeien & Kansen deelnemers en hun bedrijfsadviseurs. De effectiviteit van de toegepaste maatregelen is in een ander Koeien & Kansen rapport beschreven (Goselink, 2015). De beschreven maatregelen zijn gericht op de reductie van de on farm emissie van het broeikasgas methaan in wisselwerking met de maatregelen om de emissie van ammoniak te verminderen. De bruikbaarheid voor de brede praktijk van de in Koeien & Kansen toegepaste reductiemaatregelen is onderzocht. Aangevuld met een omgevingsanalyse geeft dat een beeld van wat de Nederlandse melkveehouder nodig heeft om actief aan de slag te gaan met de reductie van de gasvormige emissies methaan en ammoniak.
Minder gasvormige emissies: onbekend maakt onbemind
Sebek, L.B. ; Goselink, R.M.A. - \ 2015
Nieuwsbrief Koeien & Kansen (2015)41. - p. 3 - 3ov.
melkveehouderij - broeikasgassen - emissiereductie - ammoniakemissie - methaan - dairy farming - greenhouse gases - emission reduction - ammonia emission - methane
Kosteneffectief sturen via voer- en diermanagement op minder methaan en ammoniak is goed mogelijk. Dat blijkt uit 4 jaar onderzoek in Koeien & Kansen. De Nederlandse praktijk hoort deze positieve boodschap echter (nog) niet. Er is weinig afiniteit met ‘gasvormige emissies’. Ammoniak heeft de aandacht dankzij Natura2000, NB-vergunningen en de PAS, maar broeikasgassen zijn voor het Nederlandse melkveebedrijf nog ‘ver van mijn bed’.
Effecten reducerende technieken op emissies bij biologisch gehouden pluimvee : deskstudie
Ellen, H.H. ; Ogink, N.W.M. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 811)
pluimveehouderij - biologische landbouw - emissiereductie - ammoniakemissie - fijn stof - stankemissie - methaan - mestverwerking - dierenwelzijn - pluimvee - dierlijke productie - huisvesting, dieren - diergezondheid - poultry farming - organic farming - emission reduction - ammonia emission - particulate matter - odour emission - methane - manure treatment - animal welfare - poultry - animal production - animal housing - animal health
De eisen die worden gesteld aan de biologische houderij van pluimvee hebben mogelijk een effect op de emissies van ammoniak (NH3), geur, fijnstof (PM10), methaan (CH4) en lachgas (N2O). Op basis van beschikbare kennis is een inschatting gemaakt van dit effect. Daarna is aangegeven of emissie reducerende systemen zoals toegepast in de reguliere houderij, een vergelijkbaar effect hebben in de biologische houderij. Bij de systemen is ook aangegeven of ze, eventueel met een kleine aanpassing in de beschrijving, toegepast kunnen worden bij biologisch gehouden pluimvee.
Effect van snijmaissilage als strooiselmateriaal in vleeskuikenstallen op de emissies van ammoniak, geur en fijnstof
Harn, J. van; Nijeboer, G.M. ; Ogink, N.W.M. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 845) - 49
emissie - ammoniak - stankemissie - fijn stof - methaan - distikstofmonoxide - vleeskuikens - huisvesting van kippen - pluimveehouderij - maïskuilvoer - emissiereductie - luchtkwaliteit - duurzame veehouderij - emission - ammonia - odour emission - particulate matter - methane - nitrous oxide - broilers - chicken housing - poultry farming - maize silage - emission reduction - air quality - sustainable animal husbandry
This report describes the results of emission measurements of ammonia, odour, PM10, methane and nitrous oxide from broiler houses bedded with white wood shavings (=control), fresh silage maize or pre-dried silage maize.
Methaanproductie bij witvleeskalveren
Gerrits, W.J.J. ; Dijkstra, J. ; Bannink, A. - \ 2014
Wageningen : Wageningen UR Livestock Research (Rapport 813) - 15
vleeskalveren - methaan - emissie - kunstmelk - diervoedering - nederland - veal calves - methane - emission - filled milk - animal feeding - netherlands
De methaanemissie uit (deels) met kunstmelk gevoerde Nederlandse witvleeskalveren is veel lager dan de door IPCC gehanteerde defaultwaarden aangeven. Aanbevolen wordt om de methaanconversiefactor, Ym (de fractie van de bruto energieopname met voer die emitteert als methaanenergie) meer dan te halveren. Tevens wordt aanbevolen om de jaarlijkse methaanemissie door witvleeskalveren vast te stellen met een aparte waarde van 0,003 voor de gevoerde kunstmelk en een waarde van 0,055 voor gevoerde ruw- en krachtvoeders, uitgaande van de jaarlijkse rantsoenberekeningen volgens gestandaardiseerde methode door het CBS.
Greenhouse gas emissions in The Netherlands 1990-2012; National inventory report 2014
Coenen, P.W.H.G. ; Maas, C.W.M. ; Zijlema, P.J. ; Arets, E.J.M.M. ; Baas, K. ; Berghe, A.C.W.M. van den; Biesebeek, J.D. te; Nijkamp, M.M. ; Huis, E.P. - \ 2014
Bilthoven : RIVM - 278
broeikasgassen - emissie - kooldioxide - methaan - inventarisaties - nederland - greenhouse gases - emission - carbon dioxide - methane - inventories - netherlands
Total greenhouse gas emissions from the Netherlands in 2012 decreased by approximately 1.7 per cent, compared with 2011 emissions. This decrease is mainly the result of decreased fuel combustion in the Energy sector (increased electricity import) and in road transport. In 2012, total direct greenhouse gas emissions (excluding emissions from LULUCF – land use, land use change and forestry) in the Netherlands amounted to 191.7 Tg CO2 eq. This is approximately 10 per cent below the emissions in the base year (213.2 Tg CO2 eq.). The 51% reduction in the non-CO2 emissions in this period is counterbalanced by 4 per cent increase in CO2 emissions since 1990.This report documents the Netherlands’ 2014 annual submission of its greenhouse gas emissions inventory in accordance with the guidelines provided by the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the European Union’s Greenhouse Gas Monitoring Mechanism.The report comprises explanations of observed trends in emissions; a description of an assessment of key sources and their uncertainty; documentation of methods, data sources and emission factors applied; and a description of the quality assurance system and the verification activities performed on the data.Keywords: greenhouse gases, emissions, trends, methodology, climate.