华中农业大学微生物英文版课件9.ppt

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1、Chapter9MicrobialEcologyMicrobialecology=?EnvironmentalmicrobiologyThetermmicrobialecologyisnowusedinageneralwaytodescribethepresenceanddistributionsofmicroorganisms.Microbialecologyisthethestudyofthebehaviorandactivitiesofmicroorganismsintheirnatura

2、lenvironments.Environmentalmicrobiology,incomparison,relatesprimarilytoall-overmicrobialprocessesthatoccurinasoil,waterorfood,asexamples.Itisnotconcernedwiththeparticularmicroenvironmentwherethemicroorganismsactuallyarefunctioning,butwiththebroader-s

3、caleeffectsofmicrobialpresenceandactivities.9.1Microorganismsinnatureecosystem9.2Microbialpopulationinteractions9.3Biogeochemicalcycles9.4Plant-microbeinteractions9.5BioremediationChapter9MicrobialEcology9.1Microorganismsinnatureecosystem1.Microorgan

4、ismsandmicroenvironment2.TerrestrialEnvironments3.FreshwaterEnvironments4.MarineEnvironments9.1.1MicroorganismsandmicroenvironmentpopulationsguildscommunitiesecosystemMetabolicallyrelatedpopulationsconstitutegroupingscalledguilds.Setsofguildsconducti

5、ngcomplementaryphysiologicalprocessesinteracttoformmicrobialcommunities.Inamicrobialecosystemindividualcellsgrowtoformpopulations.Community3Microbialcommunitiestheninteractwithcommunitiesofmacroorganismstodefinetheentireecosystem.Thedistributionofmic

6、roorganismsinnatureecosystemdependsontheresources(nutrients)availableandonthegrowthconditions.Temperature,pH,wateravailability,light,oxygenofahabitatdefinethenicheforeachparticularmicroorganism.Soilparticlesarenothomogeneousintermsoftheiroxygenconten

7、t.Theouterzonesofasmallsoilparticlemaybefullyoxic,whereasthecenter,onlyaveryshortdistanceaway,canremaincompletelyanoxic.Asoilaggregatecomposedofmineralandorganiccomponents,showingthatlocalizationofsoilmicrobes.Veryfewmicroorganismsarefoundfreeintheso

8、ilsolution;mostofthemoccurasmicrocoloniesattachedtothesoilparticles.9.1.2.TerrestrialEnvironmentsProportionofdifferentsoilmicroorganismsinsoilMicrobialnumberandbiomassincultivatedfieldsoil（15cm）MicrobesNumbers/gBiomass(g/m3）Bacteria108160Fungi105200A