大学考研 食品专业 双语课件_Lecture_2

Lecture2AnOverviewofMicrobialLifeSchoolofLifeScienceandTechnologyShanghaiJiaoTongUniversity真核生物具有细胞核及细胞器Eukaryoticcells真核Algae藻类Fungi真菌Molds丝状真菌YeastsProtozoa原生生物ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityNon-cellularlifeforms:virus病毒Asinglevirusparticleisabout65nmindiameter.ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityNucleoid:aggregatedDNA/bacterialchromosomeintheprokaryoticcell类核：用于描述原核细胞中聚集在一起的DNA2.2ArrangementofDNAinMicrobialCells:BacterialNucleoidBygentlylysingthecells,thehighlycompactednucleoidwillemergeintact.采用极轻微小心的细胞裂解方法，就可以得到一团完整展开的类核DNA。(Arrowspointtoedgeofstrands).ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityBacteriacontainonelongcircularDNA-chromosome.细菌的类核包含一条环状的DNA(染色体)TheDNAcanbe1mmlongThecellisusually2-3µmlongTheDNAinboththeopencircleandsupercoiledchromosomeispresentinacovalentlyclosedform.超螺旋Thedouble-strandedDNAinE.colichromosomecontainsover50supercoileddomains.超螺旋域ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityNucleusvs.Nucleoid细胞核与拟核Ineukaryotes,DNAispresentinlinearmoleculeswithinthenucleus,packagedandorganizedinchromosomes.Genomesizesvarygreatlyrangingfromviruseswiththesmallesttoalgaeandvertebratespossessingthegreatestamount.病毒基因组最小,藻类、脊椎动物最大ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversity2.3TreeofLifeEvolutionisthechangeinalineofdescentovertimeleadingtonewspeciesorvarieties.进化Evolutionaryrelationshipsbetweenlifeformsarethesubjectofphylogeny.系统发生学Phylogeneticrelationshipscanbededucedbycomparingsequencesofcertainmacromolecules(ribosomalRNAs).RibosomalRNAgenesequencingandphylogeny.(a)Cells,eitherfromapurecultureorfromanenvironmentalsample,arebrokenopen;(b)thegene-encodingribosomalRNAisisolated,andmanyidenticalcopiesmadebypolymerasechainreaction(PCR)(c)Thegeneissequenced(d)thesequencesobtainedarealignedinacomputer.（e)AnalgorithmmakesatreethatshowsthedifferencesinrRNAsequencebetweentheorganismsanalyzed.对比不同生物之间rRNA的差异,可得到描述其两两差异的树状结构.ThreeDomainsofLifeCellularevolutionasdeducedfromribosomalRNAsequencing.threedomainsoforganisms:thebacteriaandtheArchaea,cellsofwhichareprokaryotic,andtheEukarya(eukaryotes).三域:细菌,古生菌与真核生物.ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityPhylogenetictreeoflifeasdefinedbycomparativeribosomalRNAsequencing.threedomainsoforganisms:thebacteriaandtheArchaea,cellsofwhichareprokaryotic,andtheEukarya(eukaryotes).三域:细菌,古生菌与真核生物.PARTIIMicrobialDiversity2.4PhysiologicalDiversityofMicroorganisms微生物的生理多样性p.28ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityAllcellsneedcarbonandenergysources.Chemoorganotrophsobtaintheirenergyfromtheoxidationoforganiccompounds.化能有机营养型.Chemolithotrophsobtaintheirenergyfromtheoxidationofinorganiccompounds.化能无机营养型Phototrophscontainpigmentsthatallowthemtouselightasanenergysource.光能营养型ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityAutotrophsandheterotrophsAutotrophsuseCO2astheircarbonsource,whereasheterotrophsuseorganiccarbon.自养型生物以CO2为碳源,异养型生物以有机碳为碳源.Dependonthecarbonsource.ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversity2.5ProkaryoticDiversitySeverallineagesarepresentinthedomainsBacteriaandArchaea,andanenormousdiversityofcellmorphologiesandphysiologiesarerepresentedthere.细胞形态及生理的多样性ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityMicrobialcells:BacteriaPathogensSoils,water,animalintestine,etcDifferentenergysources,carbonsources,oxygendemandsDetailedphylogeneticstreeofBacteria产液菌属栖热袍菌属无硫绿细菌异常球菌螺旋体绿硫细菌浮霉状菌属蓝细菌变形杆菌革兰氏阳性细菌Proteobacteria:thelargestdivision(calledaphylum门)ofBacteria.变形杆菌ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityCyanobacteria蓝细菌TheCyanobacteriaarephylogeneticrelativesofgram-positivebacteriaandareoxygenicphototrophs.Filamentouscyanobacteria丝状蓝细菌ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityMicrobialcells:ArchaeaManyareextremephiles,anerobic•Boiling-hotspring•Freezing-Antarcticocean•Radioactivewastes•Salty,acidic,alkalinesoilsorwaterTheycanbefoundalmostanywhereonearthTherearetwolineagesofArchaea,theEuryarchaeotaandtheCrenarchaeota.古生菌有广古生菌界与泉古生菌界.ShanghaiJiaoTongUniversityShanghaiJiaoTongUniversityMoldsMushroomsFungiYeastsSlimemoldsAlgaeProtozoa2.6EukaryoticMicroorganismsCellsofalgaeandfungihavecellwalls,whereastheprotozoadonot.Fungiareheterotrophiceukaryoticmicroorganisms.Theyarenonphotosyntheticandtypicallyformreproductivespores.真菌为异养真核生物,非光合,一般可形成繁殖的孢子.Algaearephototrophiceukaryotesthatcontainphotosyntheticpigmentswithinchloroplast藻类是光合真核生物,在其叶绿体中有光合色素.Protozoaareanimallikeprotistsexhibitingheterotrophicnutritionandtheycanbedefinedasusuallymotileeukaryo