第四章原核微生物—细菌和古生菌.

第4章原核生物:细菌和古生菌Procaryotes:BacteriaandArchaeaAMicrobiologyCoursebyBoCHEN(e-mail:[e-mail])内容1.原核细胞结构概览2.细菌外部结构与功能3.细菌内部结构与功能4.细菌形状、排列和大小5.细菌鉴定与分类6.特殊的原核微生物类群7.细菌的应用CONTENTS1.SurveyofProcaryoticCellStructure2.BacterialExternalStructure3.BacterialInternalStructure4.BacterialShapes,Arrangements,andSizes5.BacterialIdentificationandClassification6.UnusualProcaryoticGroups7.ApplicationsofBacteriaSECTION4BacterialShapes,ArrangementsandSizes（第四节细菌的形态、排列和大小）BacterialShapesandArrangements(细菌形状和排列)基本形态：•球菌Cocci•杆菌Bacilli•螺旋菌Spirilla1.Cocci(球菌)•Spherical:cocci,coccus•Measurement:diameter,μm•a:coccus(单球菌)•b:diplococcus(双球菌)•c:streptococcus(链球菌)•d:tetrad(四联球菌)•e:sarcina(八叠球菌)•f:staphylococcus(葡萄球菌)Diplococci双球菌Arrangementofcocciresultingfromdifferentplanesofcelldivision(细胞分裂).球菌的形成细菌繁殖方式：无性繁殖(二分裂繁殖)(微球菌thesmallerones)(葡萄球菌thelargerones)2.Bacilli(杆菌)•Bacilli,bacillus•Straightrods•Length×widthμmSingleRod(Bacillus单杆菌)ScanningelectronmicrographofPseudomonasaeruginosa铜绿假单胞菌Streptobacillusarrangement(链杆菌)3.Spirilla(螺旋菌)•Helicallycurvedrods•Spirilla,spirillum•Length×width,μm(弧线两端点直线距离!)SpiralFormsNotethecomparisonofspirillaandspirochetes弧菌螺菌螺旋体直径较小，较硬，多有致病性直径较大，较软，多无致病性螺旋菌分为ElectronMicrographofVibriocholerae,aVibrioVibriocholerae:Gram-negative,facultativelyanaerobic,curved(vibrio-shaped),rodprokaryote;causesAsiaticcholera.霍乱弧菌ScanningelectronmicrographofLeptospirainterrogans问号钩端螺旋体特殊形态丝状：Actinomyces(放线菌)ElectronmicrographofClostridiumbotulinum肉毒梭菌梭状EndosporestainofClostridiumtetani破伤风梭菌双歧杆菌Bifidobacteria分叉状形态汇总：Bacterialshapesandarrangements名称反映形态•肺炎链球菌•金黄色葡萄球菌•嗜热链球菌•保加利亚乳杆菌•嗜酸乳杆菌•霍乱弧菌•双歧杆菌多形性(pleomorphism)•Cellsofthesamespecieshavedifferentshapesunderdifferentenvironmentconditionstosomeextent.•同一种细菌的细胞在不同环境条件下可能具有一定程度的不同形态•细菌鉴定：需要在特定条件下培养和鉴定TheDimensionsofBacteria(细菌大小)Measurement:Cocciindiameter;Bacilliinlength×width;Spirillainlength×width(!)SECTION5BacterialIdentificationandClassification(第五节细菌的鉴定和分类)5.1MethodsinBacterialIdentification(细菌鉴定方法)1.MicroscopicmorphologyCell:shape,size,Gramstain,endospore,capsule,granule,etc.2.MacroscopicmorphologyColony:size,shape,texture,pigment,speedofgrowth,etc.3.Physiological/biochemicalcharacteristicssugarfermentation,proteinandpolysaccharidedigestion,productionofgas4.Chemicalcomponentspeptidesincellwall,lipidsinmembrane5.Serologicalanalysisantigen-antibodyreaction,immunereaction6.GeneticandmolecularanalysisG+C%,geneticprobe,DNAsequencing,rRNAanalysis5.1MethodsinBacterialIdentification(细菌鉴定方法)1.微观形态：细胞：形状，大小，革兰氏染色，芽孢，荚膜，储藏性颗粒2.宏观形态：菌落：大小，形状，质地，色素，生长速度3.生理/生化特征：糖发酵，蛋白质降解，多糖降解，气体产生4.化学组分：细胞壁的肽类，细胞膜的脂类5.血清学分析：抗原抗体反应，免疫反应6.基因或分子生物学分析：G+C%，核酸探针，DNA测序，rRNA分析参考(核酸杂交)Sequenceanalysis(序列分析)ofrRNA.E.coli(bacteria)andMethanococcusvannielii(甲烷球菌,archaea)参考5.2ClassificationSystemsinProcaryotes(细菌的分类系统)•《伯杰氏系统细菌学手册》(Bergey’sManualofSystematicBacteriology)•是细菌分类鉴定的主要工具书。1923年问世，最初由美国宾夕法尼亚大学D.Bergeyandcolleagues为细菌鉴定而编写，已发行第九版•第八版以前叫《伯杰氏鉴定细菌学手册》(Bergey’sManualofDeterminativeBacteriology)二分法：以鉴定芽孢杆菌为例选项有：二选一/三选一5.3Concepts(重要概念)•Species(种)isapopulationofcellswithsimilarcharacteristics.•Species以下的概念：•Strain(菌株)isagroupofcellsallderivedfromasinglecellofthesamespecies.e.g.pigmentedandnonpigmentedstrainsofSeratiamarcescens(粘质沙雷氏菌)flagellatedandnonflagellatedstrainsofPseudomonasfluorescens(荧光假单胞菌)•Type(型)Serotype(血清型):differentantigenmakeup(反映相同种的表面分子的多样性，如沙门氏菌内毒素的多样性)Pathotype(致病型):differentsusceptibilityinpathogenicity(跟表面特殊结构物质有无有关，如荚膜、菌毛)SECTION6UnusualProcaryoticGroups(第六节特殊的原核微生物类群)6.1Actinomycetes(放线菌)6.2Archaea(古生菌)6.1Actinomycetes-FilamentousBacteria放线菌—丝状细菌•菌落呈放线状(放射状、线状)而得名•细胞呈丝状，原核细胞，丝状细菌•产生抗生素卡特利链霉菌产黄色素放线菌皮疽诺卡氏菌细黄链霉菌蓝色链霉菌菌落呈放线状Thecrosssectionofanactinomycete(放线菌)colonyshowingthesubstratemycelium(基质菌丝)andaerialmycelium(气生菌丝)withchainsofconidiospores(分生孢子)Chainofconidiospores(分生孢子链)Aerialmycelium(气生菌丝)Agarsurface(培养基表面)Substratemycelium(基质菌丝)显微镜下看菌落由分支状菌丝组成细胞为丝状细胞，原核细胞，丝状细菌，多核，G+菌丝分类及繁殖方式（孢子繁殖—分生孢子）嗜热放线菌链霉菌的孢子堆放线菌的属•Streptomyces(链霉菌属)•Nocardia(诺卡氏菌属)•Actinomyces(放线菌属)•Micromonospora(小单胞菌属)•Streptosporangium(链孢囊菌属)•Actinoplanes(游动放线菌属)链霉菌属是放线菌代表性属链霉菌是放线菌（丝状细菌）而不是霉菌（丝状真菌）•Streptomyces(链霉菌属)produceover1000antibiotics(抗生素):streptomycin(链霉素),kanamycin(卡那霉素),mitomycin(丝裂霉素)•Morethan100antibioticshavebeenusedinmedicineandagriculture(医学和农业上有超过100种抗生素在实际应用)Actinomycetes(放线菌)Antibiotics(抗生素)Antibiotics(抗生素)AlexanderFleming(1881-1955)发现青霉素•Thestreptomycetesarealargegroupoffilamentous,grampositivebacteriathatformsporesattheendofaerialfilaments.•TheyhavethehighestGCpercentageintheDNAbasecompositionofanybacteriaknown.•ManyclinicallyimportantantibioticshavecomefromStreptomycetesspecies.代表性属：链霉菌属(Streptomyces)•AlkalineandneutralsoilsaremorefavorableforthedevelopmentofStreptomycesthanareacidsoils.•Streptomycesrequirealowerwaterpotentialforgrowththanmanyothersoilbacteria.•链霉菌属是一大群丝状细菌，G+，在气生菌丝末端形成分生孢子•DNA碱基组成GC含量在已知细菌中最高•许多医学重要的抗生素来自链霉菌属•碱性和中性土壤比酸性土壤更有利于链霉菌属的生长•比其它土壤细菌要求更低的水活性代表性属：链霉菌属(Streptomyces)放线菌与霉菌的区别•放线菌菌落形态与霉菌相似，但为原核细胞，菌落、菌丝都比霉菌的小。霉菌为真核细胞。•区别：放线菌—丝状细菌霉菌—丝状真菌放线菌（原核细胞，菌落较小）霉菌（真核细胞，菌落较大）Aspergillusniger(黑曲霉