原核生物的主要類群

2024/8/131原核生物簡(jiǎn)要介紹1原核生物的生理多樣性2原核生物的分類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、古細(xì)菌1ssrRNA分類：嗜泉古菌界、廣域古菌界、初生古菌界2生理性狀分類：產(chǎn)甲烷菌、極端嗜鹽菌、極端嗜熱菌2024/8/133（一）產(chǎn)甲烷菌1特殊的代謝方式2Methanococcusjannischii（詹氏產(chǎn)甲烷菌）2024/8/134（二）極端嗜鹽菌1細(xì)菌紫膜質(zhì)（一種集光色素）利用其把光能轉(zhuǎn)化為ATP2Halobacteriumsalinarium（嗜鹽鹽桿菌）2024/8/135（三）極端嗜熱菌1高溫低pH環(huán)境（一般需要S元素）2Sulfolobus（硫化葉菌是第一個(gè)被發(fā)現(xiàn)的極端嗜熱菌）3Sulfolobusacidocaldarius(嗜酸熱硫化葉菌）圖示L-R：橫切面的電子顯微照片；細(xì)胞黏附在硫晶體上的熒光顯微照片2024/8/136二、Bacteria（真細(xì)菌）

PhylogenetictreeofBacteria2024/8/137Photosynthetic

purpleandgreenbacteria1細(xì)菌光合作用（不產(chǎn)生氧氣、利用葉綠素a、只有一種光合系統(tǒng)、細(xì)菌光合作用的電子受體不是水而是比水氧化還原電位低的物質(zhì)如氫氣等）2紫細(xì)菌和硫細(xì)菌形態(tài)多樣Purplesulferbacteria

Greensulferbacteria

2024/8/138Cyanobacteria（藍(lán)細(xì)菌）1藍(lán)細(xì)菌的形態(tài)

藍(lán)細(xì)菌大多為球狀或絲狀，單個(gè)營(yíng)養(yǎng)細(xì)胞具有雙層細(xì)胞壁，壁外有稱為鞘的粘質(zhì)層，細(xì)胞膜下有類囊體，藻膽蛋白就附在類囊體上。藍(lán)細(xì)菌細(xì)胞內(nèi)有氣泡，氣泡可以保持細(xì)胞浮在上層水上，絲狀藍(lán)細(xì)菌內(nèi)產(chǎn)生特殊異形孢來固定氮?dú)狻?藍(lán)細(xì)菌的行動(dòng)

藍(lán)細(xì)菌以滑行或者旋轉(zhuǎn)進(jìn)行活動(dòng)。3藍(lán)細(xì)菌的生殖

球狀藍(lán)細(xì)菌以二分分裂生殖，子細(xì)胞再分裂形成一個(gè)群落，絲狀藍(lán)細(xì)菌通過裂殖為斷殖體進(jìn)行繁殖。4藍(lán)細(xì)菌的生態(tài)

藍(lán)細(xì)菌是光合自養(yǎng)細(xì)菌，在地球上分布廣闊，自熱帶直到兩極都有，普遍生長(zhǎng)在淡水、海水和土壤內(nèi)。5固氮藍(lán)細(xì)菌

大多藍(lán)細(xì)菌都可以固氮，主要的固氮藍(lán)細(xì)菌大都屬于念珠藍(lán)細(xì)菌科和偽歧藍(lán)細(xì)菌科。2024/8/139常見的藍(lán)細(xì)菌L-R：絲狀的顫藍(lán)細(xì)菌，念珠藍(lán)細(xì)菌，魚腥藍(lán)細(xì)菌（異形孢）2024/8/1310Spirochetes（螺旋體）螺旋體的形態(tài)和運(yùn)動(dòng)螺旋體菌體細(xì)長(zhǎng)螺旋狀，以中軸絲或內(nèi)鞭毛運(yùn)動(dòng)圖示L-R：（1）內(nèi)膜和外鞘的內(nèi)生鞭毛（2）Borreliaburgdorferi（布氏疏螺旋體）（3）Treponemapallidum(梅毒病菌）2024/8/1311Spirilla（螺旋菌）1.螺旋菌的基本介紹螺旋菌是一類革蘭氏陰性的好氣異養(yǎng)菌，卷曲或螺旋狀，代謝方式是發(fā)酵而不是呼吸，有堅(jiān)硬的細(xì)胞壁以極生鞭毛運(yùn)動(dòng)2.已發(fā)現(xiàn)的兩種人類致病菌Cymylobacterjejuni(引發(fā)細(xì)菌性腹瀉）Helicobacterpylorti(引發(fā)消化性潰瘍）2024/8/1312Myxobacteria（粘細(xì)菌）1.粘細(xì)菌的基本介紹

粘菌是一類滑行細(xì)菌其原生質(zhì)聚集在一起形成多細(xì)胞的子實(shí)體，子實(shí)體發(fā)育產(chǎn)生孢子進(jìn)行繁殖。有的粘菌的粘孢子在子實(shí)體頂端還形成稱為孢囊的二級(jí)結(jié)構(gòu)。2.Stigmatellaaurantiaca

（橙色標(biāo)樁粘細(xì)菌）2024/8/1313Lithotrophy（無機(jī)營(yíng)養(yǎng)菌）1.Lithotrophy,atypeofmetabolismthatrequiresinorganiccompoundsassourcesofenergy。2.Themostimportantlithotrophicbacteriaarethenitrifyingbacteria（硝化細(xì)菌）.3.Mostlithotrophicbacteriaareautotrophs（自養(yǎng)生物）,and,insomecases,theymayplayanimportantroleinprimaryproductionoforganicmaterialinnature.2024/8/1314Pseudomonadsandtheirrelatives1.假單胞菌是一類革蘭氏陰性細(xì)菌有著嚴(yán)格的呼吸代謝模式。2.許多假單胞菌和大腸菌在形態(tài)與生境上類似，但也有一些區(qū)別，假單孢菌以極生鞭毛運(yùn)動(dòng)，大腸菌以緣毛運(yùn)動(dòng)，假單胞菌不發(fā)酵糖，大腸菌發(fā)酵葡萄糖等。3.L-R電子顯微照片，負(fù)染色；掃描電鏡照片；革蘭氏染色2024/8/13154.Afewrelativesofthepseudomonadsarepathogensofanimals,i.e.,theagentsofwhoopingcough(百日咳),Bordetellapertussis,Legionaires‘pneumonia,Legionellapneumophilia,gonorrhea(淋病)Neisseriagonorrhoeae,andbacterialmeningitis(腦膜炎),Neisseriameningitidis.2024/8/1316Entertics（腸細(xì)菌）1.EntericbacteriaareGram-negativerodswithfacultativeanaerobicmetabolism（兼性厭氧代謝）thatliveintheintestinaltractsofanimals.2.E.coliisthemoststudiedofallorganismsinbiologybecauseofitsoccurrence,andtheeaseandspeedof

growingthebacteriainthelaboratory.2024/8/1317Vibrios（弧菌）1.Vibrios(whichhaveacurvedrodmorphologyorcommashape)areverycommonbacteriainaquatic（水生）environments.2.ThegenusVibriocontainsanimportantpathogenofhumans,Vibriocholerae（霍亂弧菌）,thecauseofAsiaticcholera（亞洲霍亂）.2024/8/1318弧菌菌體只有一個(gè)彎曲，呈弧狀或逗點(diǎn)狀?；【鷮?Vibrio)廣泛分布于自然界，尤以水中為多，有100多種。主要致病菌為霍亂弧菌和副溶血弧菌（致病性嗜鹽菌）。前者引起霍亂；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（藍(lán)細(xì)菌，舊稱藍(lán)綠藻或藍(lán)藻）arelikewiseveryimportantinnitrogenfixation.Cyanobacteriaprovidefixednitrogen,inadditiontofixedcarbon,fortheirsymbioticpartnerswhichmakeuplichens（地衣）.

4.Besidesnitrogenfixation,bacteriaplayotheressentialrolesintheprocessesofthenitrogen

cycle.2024/8/1320Thepyogeniccocci（膿球菌）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（香腸）andotherfoods.ImportantgeneraareStreptococcus（鏈球菌屬）andLactobacillus（乳桿菌屬）.Somespeciesarenormalflora（菌群）ofthehumanbody(foundintheoralcavity,GItractandvagina);somestreptococciarepathogensofhumans(seepyogeniccocciabove).Certainorallacticacidbacteriaareresponsiblefortheformationofdentalplaqueandtheinitiationofdentalcaries(cavities).2024/8/1322Endospore-formingbacteria1.Endospore-formingbacteriaproduceauniquerestingcellcalledanendospore.TheyareGram-positiveandusuallyrod-shaped.ThetwoimportantgeneraareBacillus

（芽孢桿菌屬）andClostridium（梭狀芽孢桿菌屬）.2.Stuctureofendospore（芽孢外壁，芽孢外被，皮層，內(nèi)壁，DNA)2024/8/13233.Theendosporeiscryptobiotic(潛生的，exhibitsnosignsoflife)andisremarkablyresistanttoenvironmentalstresssuchasheat(boiling),acid,irradiation（輻射）,chemicalsanddisinfectants（消毒劑）.4.Somesporeformersarepathogensofanimals,usuallyduetotheproductionofpowerfultoxins.Bacillusanthracis（炭疽桿菌）causesanthrax（炭疽?。?adiseaseofdomesticanimals(cattle,sheep,etc.)whichmaybetransmittedtohumans.Clostridiumbotulinum（肉毒梭狀芽孢桿菌）causesbotulism（肉毒中毒）,aformoffoodpoisoning.Clostridiumtetani

（破傷風(fēng)梭狀芽孢桿菌）istheagentoftetanus（破傷風(fēng)）.2024/8/1324Actinomycetesandrelatedbacteria1.Actinomycetes（放線菌）andrelatedbacteriaarealargegroupofGram-positivebacteriathatusuallygrowbyfilamentformation2.Actinomycetesarethemainproducersofantibioticsinindustrialsettings,beingthesourceofmosttetracyclines(四環(huán)素）,macrolides（大環(huán)內(nèi)酯）(e.g.Erythromycin紅霉素),andaminoglycosides（氨基糖苷類抗生素）(e.g.Streptomycin鏈霉素,gentamicin慶大霉素,etc.).

2024/8/1325Rickettsiasandchlamydiae

立克次氏體和衣原體1.RickettsiasandchlamydiaearetwounrelatedgroupsofBacteriathatareobligatein