原核生物的主要类群

2024/8/131原核生物简要介绍1原核生物的生理多样性2原核生物的分类InBergey'sManualthegroupsofprokaryotesareformedbasedoneasily-observedcharacteristicssuchasGramstain,morphology(rods,cocci,etc),andondistinguishingphysiologicalfeatures(e.g.anoxygenicphotosynthesis,methanogenesis，etc.).Nowadays,ofcourse,thepoliticallycorrectwaytogrouporganisms,especiallyprokaryotes,isonageneticbasis,i.e.,bycomparisonofthenucleotidesequencesofthesmallsubunitribosomalRNAthatiscontainedinallcellularorganisms.2024/8/132一、古细菌1ssrRNA分类：嗜泉古菌界、广域古菌界、初生古菌界2生理性状分类：产甲烷菌、极端嗜盐菌、极端嗜热菌2024/8/133（一）产甲烷菌1特殊的代谢方式2Methanococcusjannischii（詹氏产甲烷菌）2024/8/134（二）极端嗜盐菌1细菌紫膜质（一种集光色素）利用其把光能转化为ATP2Halobacteriumsalinarium（嗜盐盐杆菌）2024/8/135（三）极端嗜热菌1高温低pH环境（一般需要S元素）2Sulfolobus（硫化叶菌是第一个被发现的极端嗜热菌）3Sulfolobusacidocaldarius(嗜酸热硫化叶菌）图示L-R：横切面的电子显微照片；细胞黏附在硫晶体上的荧光显微照片2024/8/136二、Bacteria（真细菌）

PhylogenetictreeofBacteria2024/8/137Photosynthetic

purpleandgreenbacteria1细菌光合作用（不产生氧气、利用叶绿素a、只有一种光合系统、细菌光合作用的电子受体不是水而是比水氧化还原电位低的物质如氢气等）2紫细菌和硫细菌形态多样Purplesulferbacteria

Greensulferbacteria

2024/8/138Cyanobacteria（蓝细菌）1蓝细菌的形态

蓝细菌大多为球状或丝状，单个营养细胞具有双层细胞壁，壁外有称为鞘的粘质层，细胞膜下有类囊体，藻胆蛋白就附在类囊体上。蓝细菌细胞内有气泡，气泡可以保持细胞浮在上层水上，丝状蓝细菌内产生特殊异形孢来固定氮气。2蓝细菌的行动

蓝细菌以滑行或者旋转进行活动。3蓝细菌的生殖

球状蓝细菌以二分分裂生殖，子细胞再分裂形成一个群落，丝状蓝细菌通过裂殖为断殖体进行繁殖。4蓝细菌的生态

蓝细菌是光合自养细菌，在地球上分布广阔，自热带直到两极都有，普遍生长在淡水、海水和土壤内。5固氮蓝细菌

大多蓝细菌都可以固氮，主要的固氮蓝细菌大都属于念珠蓝细菌科和伪歧蓝细菌科。2024/8/139常见的蓝细菌L-R：丝状的颤蓝细菌，念珠蓝细菌，鱼腥蓝细菌（异形孢）2024/8/1310Spirochetes（螺旋体）螺旋体的形态和运动螺旋体菌体细长螺旋状，以中轴丝或内鞭毛运动图示L-R：（1）内膜和外鞘的内生鞭毛（2）Borreliaburgdorferi（布氏疏螺旋体）（3）Treponemapallidum(梅毒病菌）2024/8/1311Spirilla（螺旋菌）1.螺旋菌的基本介绍螺旋菌是一类革兰氏阴性的好气异养菌，卷曲或螺旋状，代谢方式是发酵而不是呼吸，有坚硬的细胞壁以极生鞭毛运动2.已发现的两种人类致病菌Cymylobacterjejuni(引发细菌性腹泻）Helicobacterpylorti(引发消化性溃疡）2024/8/1312Myxobacteria（粘细菌）1.粘细菌的基本介绍

粘菌是一类滑行细菌其原生质聚集在一起形成多细胞的子实体，子实体发育产生孢子进行繁殖。有的粘菌的粘孢子在子实体顶端还形成称为孢囊的二级结构。2.Stigmatellaaurantiaca

（橙色标桩粘细菌）2024/8/1313Lithotrophy（无机营养菌）1.Lithotrophy,atypeofmetabolismthatrequiresinorganiccompoundsassourcesofenergy。2.Themostimportantlithotrophicbacteriaarethenitrifyingbacteria（硝化细菌）.3.Mostlithotrophicbacteriaareautotrophs（自养生物）,and,insomecases,theymayplayanimportantroleinprimaryproductionoforganicmaterialinnature.2024/8/1314Pseudomonadsandtheirrelatives1.假单胞菌是一类革兰氏阴性细菌有着严格的呼吸代谢模式。2.许多假单胞菌和大肠菌在形态与生境上类似，但也有一些区别，假单孢菌以极生鞭毛运动，大肠菌以缘毛运动，假单胞菌不发酵糖，大肠菌发酵葡萄糖等。3.L-R电子显微照片，负染色；扫描电镜照片；革兰氏染色2024/8/13154.Afewrelativesofthepseudomonadsarepathogensofanimals,i.e.,theagentsofwhoopingcough(百日咳),Bordetellapertussis,Legionaires‘pneumonia,Legionellapneumophilia,gonorrhea(淋病)Neisseriagonorrhoeae,andbacterialmeningitis(脑膜炎),Neisseriameningitidis.2024/8/1316Entertics（肠细菌）1.EntericbacteriaareGram-negativerodswithfacultativeanaerobicmetabolism（兼性厌氧代谢）thatliveintheintestinaltractsofanimals.2.E.coliisthemoststudiedofallorganismsinbiologybecauseofitsoccurrence,andtheeaseandspeedof

growingthebacteriainthelaboratory.2024/8/1317Vibrios（弧菌）1.Vibrios(whichhaveacurvedrodmorphologyorcommashape)areverycommonbacteriainaquatic（水生）environments.2.ThegenusVibriocontainsanimportantpathogenofhumans,Vibriocholerae（霍乱弧菌）,thecauseofAsiaticcholera（亚洲霍乱）.2024/8/1318弧菌菌体只有一个弯曲，呈弧状或逗点状。弧菌属(Vibrio)广泛分布于自然界，尤以水中为多，有100多种。主要致病菌为霍乱弧菌和副溶血弧菌（致病性嗜盐菌）。前者引起霍乱；后者引起食物中毒。2024/8/1319Nitrogen-fixingorganisms1.Membersareunifiedonlyonthebasisoftheirmetabolicabilityto“fix”nitrogen.2.典型示例是根瘤菌刺激豆科植物生成根瘤并共生固氮。3.Cyanobacteria（蓝细菌，旧称蓝绿藻或蓝藻）arelikewiseveryimportantinnitrogenfixation.Cyanobacteriaprovidefixednitrogen,inadditiontofixedcarbon,fortheirsymbioticpartnerswhichmakeuplichens（地衣）.

4.Besidesnitrogenfixation,bacteriaplayotheressentialrolesintheprocessesofthenitrogen

cycle.2024/8/1320Thepyogeniccocci（脓球菌）Thepyogeniccocciaresphericalbacteriawhichcausevarioussuppurative(pus-producing)infectionsinanimals.IncludedaretheGram-positivecocciStaphylococcusaureus,StreptococcuspyogenesandStreptococcuspneumoniae,andtheGram-negativecocciNeisseriagonorrhoeaeandN.meningitidis.2024/8/1321Lacticacidbacteria（乳酸菌）LacticacidbacteriaareGram-positive,nonsporeformingrodsandcocciwhichproducelacticacidasasoleormajorendproductoffermentation.Theyareimportantinthefoodindustryasfermentationorganismsintheproductionofcheese,yogurt（酸奶）,buttermilk（奶油）,sourcream,pickles（泡菜）,sauerkraut（酸菜）,sausage（香肠）andotherfoods.ImportantgeneraareStreptococcus（链球菌属）andLactobacillus（乳杆菌属）.Somespeciesarenormalflora（菌群）ofthehumanbody(foundintheoralcavity,GItractandvagina);somestreptococciarepathogensofhumans(seepyogeniccocciabove).Certainorallacticacidbacteriaareresponsiblefortheformationofdentalplaqueandtheinitiationofdentalcaries(cavities).2024/8/1322Endospore-formingbacteria1.Endospore-formingbacteriaproduceauniquerestingcellcalledanendospore.TheyareGram-positiveandusuallyrod-shaped.ThetwoimportantgeneraareBacillus

（芽孢杆菌属）andClostridium（梭状芽孢杆菌属）.2.Stuctureofendospore（芽孢外壁，芽孢外被，皮层，内壁，DNA)2024/8/13233.Theendosporeiscryptobiotic(潜生的，exhibitsnosignsoflife)andisremarkablyresistanttoenvironmentalstresssuchasheat(boiling),acid,irradiation（辐射）,chemicalsanddisinfectants（消毒剂）.4.Somesporeformersarepathogensofanimals,usuallyduetotheproductionofpowerfultoxins.Bacillusanthracis（炭疽杆菌）causesanthrax（炭疽病）,adiseaseofdomesticanimals(cattle,sheep,etc.)whichmaybetransmittedtohumans.Clostridiumbotulinum（肉毒梭状芽孢杆菌）causesbotulism（肉毒中毒）,aformoffoodpoisoning.Clostridiumtetani

（破伤风梭状芽孢杆菌）istheagentoftetanus（破伤风）.2024/8/1324Actinomycetesandrelatedbacteria1.Actinomycetes（放线菌）andrelatedbacteriaarealargegroupofGram-positivebacteriathatusuallygrowbyfilamentformation2.Actinomycetesarethemainproducersofantibioticsinindustrialsettings,beingthesourceofmosttetracyclines(四环素）,macrolides（大环内酯）(e.g.Erythromycin红霉素),andaminoglycosides（氨基糖苷类抗生素）(e.g.Streptomycin链霉素,gentamicin庆大霉素,etc.).

2024/8/1325Rickettsiasandchlamydiae

立克次氏体和衣原体1.RickettsiasandchlamydiaearetwounrelatedgroupsofBacteriathatareobligatein