参考文稿课件-,culture and metabolism

LectureNutrition,LaboratoryCultureandMetabolismofMicroorganismsCHAPTER4BROCKBIOLOGYOFZhao ,ChenSchoolofLifeScienceandShanghaiJiaoTongWhatdoesacellneedtobeasuccessfulchemicalmachine?ThecellneedsenergyChemicalThecellneedsbuildingmaterialsPrecursorsforGrowthfactorsShanghaiJiaoTongI.NutritionandCultureofAkeyfeatureofcellsistheirabilitytodirectchemicalreactionsandorganizemoleculesintospecificstructures:metabolism.Metabolicreactionsareeitherenergyreleasing,calledcatabolicreactions,orenergycalledanabolicreactions.ShanghaiJiaoTongMicrobialManyprokaryotesrequireanorganiccompoundascarbonsource.Someprokaryotesareautotrophs自养型,useCO2asCsource.Atypicalbacterialcellisabout12%nitrogen(bydryNitrogenisanimportantelementinproteins,nucleicacids,andseveralotherconstituentsinthecell.ShanghaiJiaoTongOtherMacronutrients:Phosphorus磷isrequiredforsynthesisofnucleicacidsandphospholipids.Sulfur硫isrequiredinaminoacidscysteineandandpresentinanumberofvitaminsandcoenzymePotassium钾requiredbyenzymesincludingthoseinproteinnucleicacidsandisalsorequiredfortheactivityofCalcium钙:stabilizecellwallandplaysakeyroleintheheatstabilityofendosporesIsnotessentialforthegrowthofmanySodium钠requiredbysomeorganismsItsneedsreflectsthehabitatoftheIronPlaysamajorroleincellularrespiration,beingakeycomponentofthecytochromesandiron-sulfurproteinsinvolvedinelectrontransport.在细胞的呼吸中有重要作用,是电子传递链中细胞色素和铁硫蛋白Micronutrients(traceElements)微量元Theyaremetals,manyofwhichplayastructuralroleinvariousenzymes.ShanghaiJiaoTongGrowthFactors生长因子Areorganiccompoundsthatarerequiredinverysmallamountsandonlybysomecells.Includevitamins,aminoacids,purines,andShanghaiJiaoTongNutritionalrequirementsofdifferentDifferentmicroorganismscanhavevastlydifferentnutritionalrequirementsbecausetheyhavedifferentbiosyntheticcapacitiesE.coli:capableofsynthesizingallorganiccompoundsitLeuconostocmesenteroidesneedmanyexternallyprovidedorganiccompounds-extremelyfastidious(nutritionallyShanghaiJiaoTongCulturemedia培养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.纯培养Solidculturemedia:culturemediapreparedinasemisolidformbytheadditionofagellingagenttoliquidmedia.固体培养基ShanghaiJiaoTongAsepticTechnique无菌（操作）技theseriesofstepsusedtopreventcontaminationduringmanipulationsofculturesandsterileculturemedia无菌操作在培养基消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钯钯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电子供体-theoxidizedH22e-Electronacceptor电子受体-thereducedhalfreaction-reduction(electron1/2O2+2e-+2H+RedoxreactioninvolvedelectronsbeingbyanelectrondonorandbeingacceptedbyanH2+1/2O2ShanghaiJiaoTongReductionpotentialE0E0’-tendencyto eoxidizedortoereduced被氧化或被还原的趋势Thispotentialismeasuredelectricallyinvolts(V)inreferencetoastandardsubstance-ShanghaiJiaoTongRedoxcouple氧还Thesamemoleculecanbeeitherelectrondonororacceptordependingonwhatothermoleculestheyreactwith,inotherwordsdependingthedifferenceofreductionpotentialbetweenreactants.同一个分子与不同物质反应Whenwritingaredoxcouple,theoxidizedformisalwaysplacedontheleft,eg.2H+/H2or1/2O2/H2OShanghaiJiaoTongTheElectronWhowilldonateelectrons?WhowillacceptThereducedsubstanceofaredoxcouplewhosereductionpotentialismorenegativedonateselectronstotheoxidizedformofaredoxcouplewhosepotentialismorepositiveTheoxidizedformofaredoxcouplewhosereductionpotentialismorepositiveacceptselectronsfromthereducedsubstanceoftheredoxcouplewhosereductionpotentialmorenegative ShanghaiJiaoTongTheelectrontowerRedoxcouplesfromthestrongestreductantsatthetoptothestrongestoxidantsatthebottom.ElectrondonorenergyWhydoeseverybodyneedoxygen?Whydoesadoctoroftengiveweakpatientsglucose?Howcanabacterialcellsurviveunderanoxicconditions?ShanghaiJiaoTongNADasaRedoxElectronPrimaryelectrondonorelectroncarrierterminalelectronacceptorInthecell,thetransferofelectronsinanredoxreactionfromdonortoacceptorusuallyinvolvesoneormoreintermediatesreferredtoascarriers.Whensuchcarriersareused,werefertotheinitialdonorastheprimaryelectrondonorandtothefinalacceptorastheterminalelectronacceptor.细胞中电子由供体到受体的转移时通常包括了一些中间物(载体初的受体为初级电子供体,最后的受体为最终电子受体ShanghaiJiaoTongTwogeneralclassesofelectronDiffusiblecarriersFreelydiffusiblecarriersincludethecoenzymesnicoti