DynamicEnergyBudgettheory动态能量预算理论

会计学1DynamicEnergyBudgettheory动态能量预算理论EmpiricalspecialcasesofDEB11.1yearauthormodelyearauthormodel1780Lavoisiermultipleregressionofheatagainstmineralfluxes1950Emersoncuberootgrowthofbacterialcolonies1825GompertzSurvivalprobabilityforaging1951Huggett&Widdasfoetalgrowth1889Arrheniustemperaturedependenceofphysiologicalrates1951Weibullsurvivalprobabilityforaging1891Huxleyallometricgrowthofbodyparts1955Bestdiffusionlimitationofuptake1902HenriMichaelis--Mentenkinetics1957Smithembryonicrespiration1905Blackmanbilinearfunctionalresponse1959Leudeking&Piretmicrobialproductformation1910HillCooperativebinding1959Hollinghyperbolicfunctionalresponse1920PüttervonBertalanffygrowthofindividuals1962Marr&Pirtmaintenanceinyieldsofbiomass1927Pearllogisticpopulationgrowth1973Droopreserve(cellquota)dynamics1928Fisher&TippittWeibullaging1974Rahn&Arwaterlossinbirdeggs1932Kleiberrespirationscaleswithbodyweight3/41975Hungatedigestion1932Mayneordcuberootgrowthoftumours1977Beer&AndersondevelopmentofsalmonidembryosDEBtheoryisaxiomatic,basedonmechanismsnotmeanttoglueempiricalmodelsSincemanyempiricalmodelsturnouttobespecialcasesofDEBtheorythedatabehindthesemodelssupportDEBtheoryThismakesDEBtheoryverywelltestedagainstdata第1页/共23页Empiricalpatterns:stylisedfactsFeeding

Duringstarvation,organismsareabletoreproduce,growandsurviveforsometimeAtabundantfood,thefeedingrateisatsomemaximum,independentoffooddensityGrowth

ManyspeciescontinuetogrowafterreproductionhasstartedGrowthofisomorphicorganismsatabundantfoodiswelldescribedbythevonBertalanffyFordifferentconstantfoodlevelstheinversevonBertalanffygrowthrateincreaseslinearlywithultimatelengthThevonBertalanffygrowthrateofdifferentspeciesdecreasesalmostlinearlywiththemaximumbodylengthFetusesincreaseinweightapproximatelyproportionaltocubedtimeReproduction

Reproductionincreaseswithsizeintra-specifically,butdecreaseswithsizeinter-specificallyRespiration

AnimaleggsandplantseedsinitiallyhardlyuseO2TheuseofO2increaseswithdecreasingmassinembryosandincreaseswithmassinjuvenilesandadultsTheuseofO2scalesapproximatelywithbodyweightraisedtoapowercloseto0.75Animalsshowatransientincreaseinmetabolicrateafteringestingfood(heatincrementoffeeding)Stoichiometry

Thechemicalcompositionoforganismsdependsonthenutritionalstatus(starvedvswell-fed)ThechemicalcompositionoforganismsgrowingatconstantfooddensitybecomesconstantEnergy

Dissipatingheatisaweightedsumof3massflows:CO2,O2andN-wasteFromSousaetal2008Phil.Trans.R.Soc.Lond.B

363:2453-2464第2页/共23页Empiricalpatterns111.1aFromSousaetal2008Phil.Trans.R.Soc.Lond.B

363:2453-2464第3页/共23页Empiricalpatterns211.1bFromSousaetal2008Phil.Trans.R.Soc.Lond.B

363:2453-2464第4页/共23页Topologicalalternatives11.1cFromLika&Kooijman2011J.SeaRes66:381-391第5页/共23页Testofproperties11.1dFromLika&Kooijman2011J.SeaRes,66:381-391第6页/共23页ApplicationsofDEBtheory11.1ebioproduction:agronomy,aquaculture,fisheriespestcontrolbiotechnology,sewagetreatment,biodegradation(eco)toxicology,pharmacologymedicine:cancerbiology,obesity,nutritionbiologyglobalchange:biogeochemicalclimatemodelingconservationbiology;biodiversityeconomy;sustainabledevelopmentFundamentalknowledgeofmetabolicorganisationhasmanypracticalapplications第7页/共23页InnovationsbyDEBtheory11.1fUnifiesalllifeonearth(bacteria,protoctists,fungi/animals,plants)LinkslevelsoforganisationExplainsbodysizescalingrelationshipsDealswithenergeticandstoichiometricconstraintsIndividualsthatfollowDEBrulescanmergesmoothly intoasymbiosisthatagainfollowsDEBrulesMethodfordeterminingentropyoflivingbiomassBiomasscompositiondependsongrowthrateProductformationhas3degreesoffreedomExplainsindirectcalorimetryExplainshowyieldofbiomassdependsongrowthrateQuantitativepredictionshavemanypracticalapplications第8页/共23页DEBtheoryrevealsunexpectedlinks11.1gLength,mmO2consumption,μl/h1/yield,mmolglucose/mgcells1/specgrowthrate,1/hDaphniaStreptococcusrespirationlengthinindividualanimals&yieldgrowthinpopofprokaryotes

havealotincommon,asrevealedbyDEBtheoryReserveplaysanimportantroleinbothrelationships,butyouneedDEBtheorytoseewhyandhow第9页/共23页Weirdworldatsmallscale11.2aAlmostalltransformationsincellsareenzymemediatedClassicenzymekinetics:basedonchemicalkinetics(industrialenzymes)

diffusion/convectionlawofmassaction:transformationrateproductofconc.ofsubstrateslargernumberofmoleculesconstantreactorvolumeProblematicapplicationincellularmetabolism:

definitionofconcentration(compartments,movingorganelles)transportmechanisms(proteinswithaddresslabels,targetting,allocation)crowding(presenceofmanymacro-moleculesthatdonotpartakeintransformation)intrinsicstochasticityduetosmallnumbersofmoleculesliquidcrystallinepropertiessurfacearea-volumerelationships:membrane-cytoplasm;polymer-liquidconnectivity(manymetabolitesareenergysubstrate&buildingblock;dilutionbygrowth)Alternativeapproach:reconstructionoftransformationkineticsonthebasisofcellularinput/outputkinetics第10页/共23页Diffusioncannotoccurincells11.2b第11页/共23页Self-ionizationofwaterincells11.2cAcellofvolume0.25mm3andpH7at25°Chasm=14protonsN=8109watermoleculesconfidenceintervalsofpH95,90,80,60%pHcellvolume,m3modifiedBesselfunction7第12页/共23页Crowdingaffectstransport11.2dcytoskeletalpolymersribosomesnucleicacidsproteins第13页/共23页ATPgeneration&use11.2e5106ATPmoleculesinbacterialcellenoughfor2sofbiosyntheticworkOnlyusedifenergygenerating&energydemandingtransformationsareatdifferentsite/timeIfADP/ATPratiovaries,thenratesofgeneration&usevaries,butnotnecessarilytheratesoftransformationstheydriveProcessesthatarenotmuchfasterthancellcycle,shouldbelinkedtolargeslowpoolsofmetabolites,nottosmallfastpoolsDEBtheoryusesreserveaslargeslowpoolfordrivingmetabolism第14页/共23页Classicenergetics

11.3Anabolism:syntheticpathwaysCatabolism:degradationpathwaysDuality:compoundsassourceforenergyandbuildingblocksInDEB:fromfoodtoreserve;fromreservetostructureFrom:Mader,S.S.1993Biology,WCBThisdecompositionoccursatseveralplacesinDEBs第15页/共23页Classicenergetics

11.3aFrom:Duve,C.de1984Aguidedtourofthelivingcell,Sci.Am.Lib.,NewYorkheterotrophautotrophTheclassicconceptonmetabolicregulationfocussesonATPgenerationanduse.TheapplicationofthisconceptinDEBtheoryisproblematic.第16页/共23页StaticEnergyBudgets11.3bFrom:Brafield,A.E.andLlewellyn,M.J.1982Animalenergetics,Blackie,GlasgowCenergyfromfoodPproduction(growth)FenergyinfaecesUenergyinurineRheatNumbers:kJin28dBasicdifferencewithdynamicbudgets:Productionisquantifiedasenergyfixedinnewtissue,notasenergyallocatedtogrowth:excludesoverheadsHeatincludesoverheadsofgrowth,reproductionandotherprocesses,itdoesnotquantifymaintenancecosts第17页/共23页StaticvsDynamicBudgets11.4

Netproductionmodelstime-dependentstaticmodelsnodempingbyreserveAssimilationmodelsdynamicsbynaturereservedampsfoodfluctuations第18页/共23页StaticEnergyBudgets(SEBs)11.4aDifferenceswithDEBsoverheadsinterpretationofrespirationinterpretationofurinationmetabolicmemorylifecycleperspectivechangeinstatesgrossingestedfaecesurineapparentassimilatedgrossmetabolisednetmetabolisedspecdynamicactionworkmaintenancesomaticmaintenanceactivitythermoregulationproductiongrowthproductsreproduction第19页/共23页Productionmodel11.4cfoodfaecesassimilationfeedingdefecationmaintenanceoffspringreproductionreservestructuregrowth第20页/共23页Productionmodels11.4dnoaccommodationforembryonicstage;requireadditionalstatevariables(nofoodintake,stillmaintenancecostsandgrowt