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1、Chapter7MicrobialGrowthandGrowthcontrol7.1OverviewofCellGrowth7.2PopulationGrowth7.3MeasurementofGrowth7.4ContinuousCulture:TheChemostat7.5EffectofEnvironmentonGrowth7.6GrowthControl7.7ViralControl7.8FungalControl7.1OverviewofmicrobialgrowthThebacterialcellisasyntheticmachinethati
2、sabletoduplicateitself.Thesyntheticprocessesofbacterialcellgrowthinvolveasmanyas2000chemicalreactionsofawidevarietyoftypes.Someofthesereactionsinvolveenergytransformations.Otherreactionsinvolvebiosynthesisofsmallmolecules-thebuilding,blocksofmacromolecules-aswellasthevariouscofact
3、orsandcoenzymesneededforenzymaticreactions.BinaryFission6–1.MicrobialNutritionNutrientrequirementsNutritionaltypesofmicroorganismsUptakeofNutrientsbytheCellCultureMediumIsolationofPureCulturesMicroorganismsrequireabouttenelementsinlargequantities,becausetheyareusedtoconstructcarbo
4、hydrates,lipids,proteins,andnucleicacids.Severalotherelementsareneededinverysmallamountsandarepartsofenzymesandcofactors.Concepts:NutrientrequirementsMacronutrients95%ormoreofcelldryweightismadeupofafewmajorelements:carbon,oxygen,hydrogen,nitrogen,sulfur,phosphorus,potassium,calci
5、um,magnesiumandiron.Thefirstsix(C,H,O,N,PandS)arecomponentsofcarbonhadrates,lipids,proteinsandnucleicacidsTraceElementsMicrobesrequireverysmallamountsofothermineralelements,suchasiron,copper,molybdenum,andzinc;thesearereferredtoastraceelements.Mostareessentialforactivityofcertaine
6、nzymes,usuallyascofactors.GrowthFactorsAminoacidsareneededforproteinsynthesis,purinesandpyrimidinesfornucleicacidsynthesis.Vitaminsaresmallorganicmoleculesthatusuallymakeupallorpartenzymecofactors,andonlyverysmallamountsarerequiredforgrowth.(1)aminoacids,(2)purinesandpyrimidines,(
7、3)vitaminsMajornutritionaltypeSourcesofenergy,hydrogen/electrons,andcarbonRepresentativemicroorganismsPhotoautotroph(Photolithotroph)Lightenergy,inorganichydrogen/electron(H/e-)donor,CO2carbonsourceAlgae,Purpleandgreenbacteria,CyanobacteriaPhotoheterotroph(Photoorganotroph)Lighten
8、ergy,inorganicH/e-donor,Organicca