Conductive materials(CM)can improve methane production(MP)efficiency in many methanogenic systems.However,several types of CM exist,and there are uncertainties regarding whether they all improve MP efficiency to the s...Conductive materials(CM)can improve methane production(MP)efficiency in many methanogenic systems.However,several types of CM exist,and there are uncertainties regarding whether they all improve MP efficiency to the same extent and modulate microbial communities in a similar way.To investigate that,different microbial enrichments with and without activated carbon(AC),magnetite(Mag),and zeolites(Zeo)(at 0.5 g/L)were developed.MP profiles and microbial composition changes were compared among enrichments.The behavior of all enrichments was different,although the initial inoculum sludge was the same.Lag phase duration was lower in AC enrichment,while the complete conversion of butyrate to methane was faster in Mag enrichment.Syntrophomonas was the most abundant bacterial genus in all enrichments,but changes in the methanogenic community were evident.Acetoclastic methanogens were more diverse in Mag enrichment,with microorganisms assigned to Methanosarcina and Methanothrix gener1,but Methanothrix was the only acetoclastic methanogen in the other enrichments.On the other hand,different species of hydrogenotrophic methanogens prevailed in distinct enrichments.The metatranscriptomics results revealed that the dominant mechanism of interspecies electron transfer in the AC enrichment utilized hydrogen as the electron carrier,and no evidences of direct interspecies electron transfer(DIET)could be found.These results showed how different CM modulate microbial communities and affect MP efficiency through mechanisms that do not necessarily involve DIET or mediation via CM.展开更多
The well-known El Nio event, the abnormal increase of Equatorial sea surface temperature of the east Pacific Ocean exerts significant influence on the global-scale atmospheric circulation and climatical anomaly in var...The well-known El Nio event, the abnormal increase of Equatorial sea surface temperature of the east Pacific Ocean exerts significant influence on the global-scale atmospheric circulation and climatical anomaly in various areas. The El Nio events have been reported to result from an earlier-stage warm water accumulation in the west Pacific and the eastward transmission of Kelvin waves caused by the collapse of the SE trades, or rolated to the weakening of the trades led by decrease of SE Pacific high.展开更多
基金supported by the Portuguese Foundation for Science and Technology(FCT)under the scope of the strategic funding of UIDB/04469/2020 unit and by the CM4Methane project(Ref:PTDC/BTA-BTA/2249/2021,DOI 10.54499/PTDC/BTABTA/2249/2021)FCT and European Union(EU),through the Portuguese State Budget and the European Social Fund under the scope of Norte2020-Programa Operacional Regional do Norte,also funded the SFRH/BD/132003/2017 and COVID/BD/152431/2022 grants held by Cátia S.N.Braga.,and the SFRH/BD/147271/2019 grant held by João C.Sequeira.M.SaloméDuarte acknowledges FCT for the Junior Research contract obtained under the scope of the Scientific Stimulus Employment 2022(ref:2022.06569.CEECIND/CP1718/CT0004,doi:https://doi.org/10.54499/2022.06569.CEECIND/CP1718/CT0004)PhD M.Fernando R.Pereira and PhD O.SaloméG.Soares from the Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials,Faculty of Engineering(University of Porto),for providing the AC used in this study.
文摘Conductive materials(CM)can improve methane production(MP)efficiency in many methanogenic systems.However,several types of CM exist,and there are uncertainties regarding whether they all improve MP efficiency to the same extent and modulate microbial communities in a similar way.To investigate that,different microbial enrichments with and without activated carbon(AC),magnetite(Mag),and zeolites(Zeo)(at 0.5 g/L)were developed.MP profiles and microbial composition changes were compared among enrichments.The behavior of all enrichments was different,although the initial inoculum sludge was the same.Lag phase duration was lower in AC enrichment,while the complete conversion of butyrate to methane was faster in Mag enrichment.Syntrophomonas was the most abundant bacterial genus in all enrichments,but changes in the methanogenic community were evident.Acetoclastic methanogens were more diverse in Mag enrichment,with microorganisms assigned to Methanosarcina and Methanothrix gener1,but Methanothrix was the only acetoclastic methanogen in the other enrichments.On the other hand,different species of hydrogenotrophic methanogens prevailed in distinct enrichments.The metatranscriptomics results revealed that the dominant mechanism of interspecies electron transfer in the AC enrichment utilized hydrogen as the electron carrier,and no evidences of direct interspecies electron transfer(DIET)could be found.These results showed how different CM modulate microbial communities and affect MP efficiency through mechanisms that do not necessarily involve DIET or mediation via CM.
文摘The well-known El Nio event, the abnormal increase of Equatorial sea surface temperature of the east Pacific Ocean exerts significant influence on the global-scale atmospheric circulation and climatical anomaly in various areas. The El Nio events have been reported to result from an earlier-stage warm water accumulation in the west Pacific and the eastward transmission of Kelvin waves caused by the collapse of the SE trades, or rolated to the weakening of the trades led by decrease of SE Pacific high.
