Methane, together with carbon dioxide and nitrous oxide, is a greenhouse gas and its concentration in atmosphere have been increasing since the 19th century due to anthropogenic activities. Methane is of concern since it is a much more powerful greenhouse gas than CO2 with a high global warming potential (GWP) of 21–25timesmorethanCO2 and it accounts for about 20% of global warming. But methane is also a source of energy that can be produced by anaerobic tretament of residues and recovered and used as Clean energery – so here we have methane to market.
So, for mitigation strategies of methane emissions and also strategies that focus on the use of methane as a energy source, we need to know: the sources of methane as well as the microorganisms involved in methanogenesis.
and this biological process occurs under anaerobic condition during the degradation of organic matter Methanogenic archaea depend on bacteria for generation of their substrates. Complex polímeres are hidrolized to mónumers, which are fermented to organic acids and hydrogen, acetate – the substrates of methanogenenic archaea. By removing hydrogen, methanogens allow the microorganisms involved in fermentation to function optimally and support the complete oxidation of substrates - Methanogens are classified according their subtrates for methane production. from the ruminal environment as a terminal step of carbohydrate fermentation Methanogenesis actually refers to a multi-step process that is catalyzed by different groups of prokaryotes: Group 1 (hydrolytic) : breakdown complex polymers into monomers (sugars, amino acids) Group 2 (Fermentative) : breakdown products are converted into organic acids Group 3 (Acidogenic) : converts organic acids into H2, CO2, and Acetate Group 4 (Methanogens) : convert CO2, H2 and acetate to CH4 and sometimes CO2 For the conversion of a typical polysaccharide to methane - as many as 5 major physiological groups of prokaryotes may be involved. As a group, methanogens can convert at least ten substrates to methane. Only two genera of methanogens can convert acetate to methane, and this is a very significant ecological process - high competition between sulfate-reducers and methanogens for acetate.
Including those used for agriculture activitivities.
And this Figure shows that And this activity is the most important contributor to methane emission, accounting for 54%, followed by 29% from energy sector and 18% from waste sector. Regarding sources of methane, this figure shows that agriculture is the most important sector, followed by energy sector and waste. This trend has been observed since 1990. In 2010, emissions of methane from agriculture accounted for 54%, against 29% from energy sector and 18% from waste sector.
Regarding agriculture, enteric fermentation is the major contributor with 53% of methane emission followed by rice cultivation and manure management.This trend has been observed since 1990. Enteric fermentation with contribution of deiri and beed káttle, as well as sheep and goats. Brazil is the second largest contributer, behind China. Ric field: methane emission mainly from flooded rice Dairy – deiri Káttle´sheep – ship, golt - the top emitting countries are the U.S., Germany, India, China, France, Russia, Turkey, and Brazil.
in Brazil, agriculture is also the major source of methane, accounting for 45%. Enteric fermentation is the major contributor, followed by rice cultivation and manure management. Brazil is the largest beef exporter in the world
Another source of greenhouse gas in Brazil is originated by the use of vinasse, the liquid waste of ethanol, as fertilizer to sugar cane fields. This use is responsible for the emission of methane
Mitigation strategies for enteric fermentation are needed, since methane is not only a GHG but also a waste of fed energy for the animal. Large numer of MA are in the ruminal liquid and most of them are hydrogenotrophic methanogens.
by limitation of substrate availability ( mainly H 2 ) – knowledegment of associations with other organisms (rumen protozoa) is important Abatement strategies are often limited by the diet fed, the management conditions, physiological state and use of the animal, as well as government regulations No matter what the lipid form used for supplementation, it is important to consider the ruminant species and the diet being examined, as methane reductions can vary depending on the feed components present (see Table 1) . Further, lipid inclusion can affect palatability, intake, animal performance, and milk components, all of which can have implications for practical on-farm use [57, 67]. Finally, the majority of in vivo experiments conducted to investigate lipids as methane abatement strategies are short-term, making it nearly impossible to draw conclusions about long-term repressive effects. Therefore, long-term supplementation experiments need to be conducted to thoroughly gauge the efficacy of lipid supplementation as an abatement strategy. The search for strategies to reduce methane from enteric fermentation of ruminants is ongoing since quite some time as methane not only represents a greenhouse gas but also a loss of feed energy to the animal. - Strategies to mitigate enteric methanogenesis can be distinguished into direct or indirect effects. While direct strategies affect the methanogenic activity or the proliferation of methanogens, indirect strategies rather limit the supply of substrates for the methanogens often by inhibiting other ruminal microbes and therewith the fermentative activity in the rumen.
Other strategies that focus to increase feed conversion eff to produce meat and milk However, no matter what MS used, researches have shown…
In rice fields is produced... Ant its emission to atmosphere occurs through
Hydrogenotrophic methanogen is the main source of CH4
About structure and function of methanogens and methanotrophic and the mechanisms of methane turnover in rice fields and methanotrophs communities will be beneficial for understanding the microbial ecology of methane to control the methane turnover in rice soils.
Anaerobic reactors are operated to promote methanogenesis
Have been studied
Studies are recent
No matter the configuration of the reactor studied, we can find all the methanogic archaea kinds, not only the hydrogenotrophi ones. There is no input of energy to decrease temperature
Acidogenic biorreactor is operated to maximize
Tercer Seminario regional agricultura y cambio climático: nuevas tecnologías en la mitigación y adaptación de la agricultura al cambio climático Arqueas metanógenas en al mitigación del cambio climático en la agricultura Flávia Talarico Saia Chemistry Institute, Universidade Estadual Paulista Júlio de Mesquita Filho – UNESP, Araraquara, SP, Brazil Email: firstname.lastname@example.org 1
l on climate change (IPCC), 2007 Intergovernmental pane METHAN 19th century anthropogenic E CH4 as a source of energy Anaerobic treatment of waste Methane concentration in the atmosphere CH4 as a greenhouse gas CH4 Recovered and used Methane has global warmingFonte: NASA/Goddardas clean energy Space Flight Center potential (GWP) 21-25 times more than CO2 Methane accounts for about 20% Methane to Market of global warming 2
• Mitigation strategies for methane emissions • Use of methane as a energy source •• Sources of methane emission Sources of methane emission •• Methanogenic microorganisms Methanogenic microorganisms 3
THEY ARE THE ONLY MICROORGANISMS KNOWN THAT PRODUCE METHANE
Methanogenesis: The Process Anaerobic condition 1 multi-step process carried out by differentgroups of microorganisms 1. Hydrolytic Bacteria 2 2. Fermentative Bacteria 3. Acetogenic Bacteria 4. Methanogenic Archaea 3Hydrogenotrophic Acetoclastic Methilotrophic Methilotrophic H2, formate Acetate Methanol MethanolMethanobrevibacter Methanosaeta Methanosarcina• It is important for carbon cycle since methanogenesis prevents a build-up of organic matter,allowing the other microorganisms to support the oxidation of substrates 5
Hydroeletric Rice fields wetlands Landfill WHERE ARE METHANOGENIC ARCHAEA ? Methanogens are ubiquitous in anoxic environmentsAnaerobic digesters Livestock - cattle Termites 6
Agriculture - source of methaneMajor sources of methane emissions:• Agriculture : In 2010 accounted for 53% of global methane emission• Energy: oil and natural gas systems• Waste: solid waste and wastewater treatment Yusulf et al. (2012) Renewable and Sustainable Energy Reviews 7
Agriculture sectors • Manure: stored or treated in liquid system - Top emmiting counties: U.S., Germany, India, China, France, Russia, Turkey and Brazil.Yusulf et al. (2012) Renewable and Sustenaible Energy Reviews 8
Agriculture - CH4 emissions Agriculture sectors in Brazil glogster.com Largest beef exporter in the world novotempo.com Manure Management 7% Landfills 10% greencleanguide.com Wastewater Agriculture Treatmentaccounting for 45% of 7% CH4 emission 10 10
Vinasse – liquid waste from ethanol Sugarcane Sugarcane Ethanol Ethanol Vinasse Vinasse Vinasse has been used as fertilizer to sugarcane fields •Emission of methane during storage of vinasse • Emission of N2O from soil Brazil is the largest producer of sugarcane ethanol in the world and immense volume Brazil is the largest producer of sugarcane ethanol in the world and immense volume of vinasse is generated ––10L vinasse/L ethanol of vinasse is generated 10L vinasse/L ethanol In 2006/2007, 190 billions of liters of vinasse were produced In 2006/2007, 190 billions of liters of vinasse were produced 11Rego e Hernández (2006); Oliveira (2011); Carmo et al., 2012
Brazilian authorities announced that the country will target a reduction in its GHG between 36.1 and 38.9% from projected 2020 levels.The Intergovernmental Panel on Climate Change - IPCC (2007) 12
Mitigation Strategies: Enteric Fermentation • CH4 is not only GHG but it is also a waste of fed energy for the animal •Large number of MA are in the ruminal liquid: 107 to 109 cells/mL (Kamra, 2005). Hydrogenotrophic methanogens: Methanobacteriales, Methanomicrobiales, Methanosarcinales have been foundMethanobrevibacter smithii Methanobacterium formicicum Methanosarcina barkeri 13 microbewiki
Enteric Fermentation – mitigation strategies (MS) to methane emission MS target the methanogens of the rumen directly or indirectly • Diet Composition: use of easy degradable carbohydrate – reduce pH in the rumen – decreases MA. However, accumulation of organic acids can occur, leading to subacute ruminal acidosis (SARA) and disruption of the rumen microbiota (Plaizier et al., 2008). • Lipids: Fatty acids and oils (Johnson and Johnson, 1995; Hook et al., 2010). - inhibition of protozoa which supply methanogens with hydrogen - Increase the production of propionic acid - it is not used for methanogens - Binding to the cell membrane of methanogens and interrupting membrane transport • Defaunation: decrease the number of protozoa by the use of copper, sulphate, acids, (Hook et al., 2010) • Vaccines: target methanogens directly (Wedlock et al., 2010) 14Hook et al. (2010)
Enteric Fermentation – mitigation strategies (MS) to methane emission • Other strategies: selection of high quality grasses, increase grain level and increasing feed conversion efficiency to produce meat and milk Researches have shown: Researches have shown: ••MS are limited by the diet feed, the management conditions, physiological MS are limited by the diet feed, the management conditions, physiological condition, use of the animal, and government laws. condition, use of the animal, and government laws. ••Long-term experiments in vivo need to be done to implement MS Long-term experiments in vivo need to be done to implement MS •• Economic viability of the producer needs to be addressed Economic viability of the producer needs to be addressedBrazil: diversty of methahogens related with diet – hay proportions ( Neves et al., 2010) improvement of meat production related with sugarcane feeding in dry season (Primavesi et al., 2003) 15Hook et al. (2010); Yusuf et al., 2012
Rice fields CH4 is produced by anaerobic degradation of organic matter that occurs in soil and also in roots CH4 oxidation by methanotrophic bacteria Anaerobic CH4 oxidation www1.ethz.ch MS = net methane emission 16Phillipot et al. (2009), Dubey (2005)
••Acetoclastic but mainly hydrogenotrofic methanogens Acetoclastic but mainly hydrogenotrofic methanogens Methanolinea Methanobacterium kanagiense Methanoculleus chikugoensis Sakai et al., 2012 Kitamura et al., 2011 Dianou et al., 2011••Methanotrophic bacteria Methanotrophic bacteria Methylomonas koyamae sp Adachi et al 2001 Methylosinus Ogiso et al., 2011 17
Mitigation Strategies: Rice field • Mitigation strategies include: - reduction of methane production; increasing methane oxidation, lowering methane transport through the plant ••Selection of cultivars with low exudation rates Selection of cultivars with low exudation rates •• To keep the soil as dry as possible in the off- rice season : : adverse environmental To keep the soil as dry as possible in the off- rice season adverse environmental condition for methanogenesis condition for methanogenesis ••Use of fertilizer: ammonium nitrate and sulphate instead of urea Use of fertilizer: ammonium nitrate and sulphate instead of ureaCurrent information is insufficient for the development of technologyand strategy for reduction in methane emission To improve the knowldgement of methanogens and Phillipot et al. (2009), methanotrophic bacteria in soil and in roots Dubey (2005) 18
Mitigation Strategy: anaerobic treatment of manure and vinasse Aim: to apply anaerobic technology to Aim: to apply anaerobic technology to PRODUCE METHANE for BIOENERGY PRODUCE METHANE for BIOENERGY PURPOSES PURPOSES Land applications (N, K, P) pathogenic microorganisms Methane has a high energy value (ΔHo= 816 kJ/mol or 102 kJ/e- eq) that can be captured through combustion and used for space heating or eletricity 19
• Studies have been carried out to better understand the anaerobicprocess in order to control the process and achieve optimum biogas yiel Configuration of reactors Support medium UASB Polyhurethane foam HAIB • Effect of inhibitory substances: ammounium, salt content, sulphate, temperature Lettinga (1980) 20 Foresti et al. (1995)
Microorganisms – biodigestors treating manure slurries• Methanosarcinaceae and Methanobacteriales are predominant in anaerobic reactors treating different kinds of manure• Due to high levels of ammonium, pointig out the importance of hydrogenotrophic methanogenesis (Netmman et al., 2010) Methanomicrobium Methanobrevibacter Methanosarcina 21
Microorganisms – biodigestors treating vinasse• Acetoclastic and hydrogenothrophic methanogens Methanomicrobium sp Methanosaeta Methanosarcina microbewiki Araújo et al. (2003) bacmap.wishartlab.com••Termophilic process ––vinasse is produced at high temperatures (80-900C) Termophilic process vinasse is produced at high temperatures (80-900C)Souza et al. (1992); Viana (2006); Ribas (2006) Souza et al. (1992); Viana (2006); Ribas (2006) - sludge stable among harvests - It is necessary to decrease temperature - process is faster than mesophilic 22
Hydrogen and methane production Use of two -stage bioreactors to produce hydrogen and methane Vinasse Acidogenic Acidogenic Methanogenic Methanogenic reactor reactor reactor reactor H2 and acids production Consumption of acids and production of methanePeixoto et al. (2012) 23
Conclusions Emissions of methane from agriculture activities are a Emissions of methane from agriculture activities are aworlwide problem, mainly regarding enteric fermentation, rice worlwide problem, mainly regarding enteric fermentation, ricefield and manure managment field and manure managment In Brazil: contribution of vinasse used as fertilizer In Brazil: contribution of vinasse used as fertilizer Studies have shown that there are mitigation strategies, however a better understanding of the microorganisms, the factors affecting symbiotic relation with other microbial population and their environment, also long term expriments are needed to implement MS 24
Brazil• Studies focused on microbial diversity: Amazon and Pantanal 25