LectureNutrition,LaboratoryCultureandMetabolismofMicroorganismsCHAPTER4BROCKBIOLOGYOFZhao ,ChenSchoolofLifeScienceandShanghaiJiaoTongWhatdoesacellneedtobeasuccessfulchemicalmachine?ThecellneedsenergyChemicalThecellneedsbuildingmaterialsPrecursorsforGrowthfactorsShanghaiJiaoTongI.NutritionandCultureofAkeyfeatureofcellsistheirabilitytodirectchemicalreactionsandorganizemoleculesintospecificstructures:metabolism.Metabolicreactionsareeitherenergyreleasing,calledcatabolicreactions,orenergycalledanabolicreactions.ShanghaiJiaoTongMicrobialManyprokaryotesrequireanorganiccompoundascarbonsource.Someprokaryotesareautotrophs自養型,useCO2asCsource.Atypicalbacterialcellisabout12%nitrogen(bydryNitrogenisanimportantelementinproteins,nucleicacids,andseveralotherconstituentsinthecell.ShanghaiJiaoTongOtherMacronutrients:Phosphorus磷isrequiredforsynthesisofnucleicacidsandphospholipids.Sulfur硫isrequiredinaminoacidscysteineandandpresentinanumberofvitaminsandcoenzymePotassium鉀requiredbyenzymesincludingthoseinproteinnucleicacidsandisalsorequiredfortheactivityofCalcium鈣:stabilizecellwallandplaysakeyroleintheheatstabilityofendosporesIsnotessentialforthegrowthofmanySodium鈉requiredbysomeorganismsItsneedsreflectsthehabitatoftheIronPlaysamajorroleincellularrespiration,beingakeycomponentofthecytochromesandiron-sulfurproteinsinvolvedinelectrontransport.在細胞的呼吸中有重要作用,是電子傳遞鏈中細胞色素和鐵硫蛋白Micronutrients(traceElements)微量元Theyaremetals,manyofwhichplayastructuralroleinvariousenzymes.ShanghaiJiaoTongGrowthFactors生長因子Areorganiccompoundsthatarerequiredinverysmallamountsandonlybysomecells.Includevitamins,aminoacids,purines,andShanghaiJiaoTongNutritionalrequirementsofdifferentDifferentmicroorganismscanhavevastlydifferentnutritionalrequirementsbecausetheyhavedifferentbiosyntheticcapacitiesE.coli:capableofsynthesizingallorganiccompoundsitLeuconostocmesenteroidesneedmanyexternallyprovidedorganiccompounds-extremelyfastidious(nutritionallyShanghaiJiaoTongCulturemedia培養Culturemediaarethenutrientsolutionsusedtogrowmicroorganismsinthelaboratory.Chemicallydefined(theexactchemicalcompositionisSyntheticmediaMinimalmediaBasalmediaComplexmediaNaturalmediaShanghaiJiaoTongPrepare1LLBMedium(Luria-BertaniPerBacto-ShanghaiJiaoTongPDAMedium(PotatoDextroseAutoclave200gramsofslicedpotatoin1000mLoftapwater.Filterthroughahankerchief.Totheturbidfiltrateadd20gramsofglucoseand10gramsofagar.Addwatertomake1litertotalvolume.AutoclavePDAslantsgivegoodgrowthofmostfungi,Agrobacterium,Nocardia,andmanyShanghaiJiaoTongSSWMedium(SyntheticSeawaterMgSO4.7H2O..........5.0g

CaCl2.2 Thismediumisexcellentforgrowingmostbacteriafromtheoceans.ShanghaiJiaoTongTwomostimportantnutritionalChemicalLightCarbonsource碳源OrganicInorganicCO2orShanghaiJiaoTongLaboratoryCultureofPureCultureaculturecontainingonlyasinglekindofmicroorganism.純培養Solidculturemedia:culturemediapreparedinasemisolidformbytheadditionofagellingagenttoliquidmedia.固體培養基ShanghaiJiaoTongAsepticTechnique無菌（操作）技theseriesofstepsusedtopreventcontaminationduringmanipulationsofculturesandsterileculturemedia無菌操作在培養基消ShanghaiJiaoTong(e)Afterremovingsampleonloop,thetubeisreflamedand(e)Afterremovingsampleonloop,thetubeisreflamedandthesampletransferredtoasterilemedium.(c)Tipoftubeisrunthe(a)Loopisheateduntilred-hotandcooledinair (b)Tubeis(d)(d)Sampleisonsterile(f)Thetubeisrecapped.LoopisreheatedbeforebeingtakenoutofMethodMethodofmakingastreakplatetoobtainpure(a)(a)Loopissterilized,andthenaloopfulofinoculumisremovedfromtube.(b)Streakismadeoverasterileagarplate,spreadingouttheorganisms.Followingtheinitialstreak,subsequentstreaksaremadeatanglestoit,theloopbeingresterilizedbetweenstreaks.MethodofPureCulturefromsoil:ShanghaiJiaoTongMethodofPureCulture:StreakoveranagarCultureanaerobic鈀鈀II.EnergeticsandEnergy-abilitytodoChemicalenergy-energyreleasedwhenorganicorinorganiccompoundsareoxidizedkilocalorie(kcal)-the tyofheatenergynecessarytoraisethetemperatureof1kgofwater1oC=4.184kJShanghaiJiaoTongFreeenergyG自由能-theenergyreleasedthatissuitabletodousefulworkFreeenergyofformationG0f-theenergyyieldorenergyrequiredfortheformationofagivenmoleculefromitsconstituentelementsShanghaiJiaoTongEnergyFlowofelectronsfromdonor(Glucose)throughcarrierstoacceptor(O2)produceenergyforcellsHighenergycompounds(ATP)saveenergyinaformreadyforusebycellsasifabatteryfortheelectriccarShanghaiJiaoTongIII.Oxidation-reductionandenergy-richcompoundsOxidation-removalofanelectronorelectronsfromaReduction-additionofanelectronorelectronstoaredoxreactionswithtransferofhydrogenatomoneShanghaiJiaoTongEletrondonorsandElectrondonor電子供體-theoxidizedH22e-Electronacceptor電子受體-thereducedhalfreaction-reduction(electron1/2O2+2e-+2H+RedoxreactioninvolvedelectronsbeingbyanelectrondonorandbeingacceptedbyanH2+1/2O2ShanghaiJiaoTongReductionpotentialE0E0’-tendencyto eoxidizedortoereduced被氧化或被還原的趨勢Thispotentialismeasuredelectricallyinvolts(V)inreferencetoastandardsubstance-ShanghaiJiaoTongRedoxcouple氧還Thesamemoleculecanbeeitherelectrondonororacceptordependingonwhatothermoleculestheyreactwith,inotherwordsdependingthedifferenceofreductionpotentialbetweenreactants.同一個分子與不同物質反應Whenwritingaredoxcouple,theoxidizedformisalwaysplacedontheleft,eg.2H+/H2or1/2O2/H2OShanghaiJiaoTongTheElectronWhowilldonateelectrons?WhowillacceptThereducedsubstanceofaredoxcouplewhosereductionpotentialismorenegativedonateselectronstotheoxidizedformofaredoxcouplewhosepotentialismorepositiveTheoxidizedformofaredoxcouplewhosereductionpotentialismorepositiveacceptselectronsfromthereducedsubstanceoftheredoxcouplewhosereductionpotentialmorenegative ShanghaiJiaoTongTheelectrontowerRedoxcouplesfromthestrongestreductantsatthetoptothestrongestoxidantsatthebottom.ElectrondonorenergyWhydoeseverybodyneedoxygen?Whydoesadoctoroftengiveweakpatientsglucose?Howcanabacterialcellsurviveunderanoxicconditions?ShanghaiJiaoTongNADasaRedoxElectronPrimaryelectrondonorelectroncarrierterminalelectronacceptorInthecell,thetransferofelectronsinanredoxreactionfromdonortoacceptorusuallyinvolvesoneormoreintermediatesreferredtoascarriers.Whensuchcarriersareused,werefertotheinitialdonorastheprimaryelectrondonorandtothefinalacceptorastheterminalelectronacceptor.細胞中電子由供體到受體的轉移時通常包括了一些中間物(載體初的受體為初級電子供體,最后的受體為最終電子受體ShanghaiJiaoTongTwogeneralclassesofelectronDiffusiblecarriersFreelydiffusiblecarriersincludethecoenzymesnicoti