細菌的細胞壁結(jié)構(gòu)主講老師：徐單單ThesizeandmorphologyofbacteriaGuangdongFoodandDrugVocationalCollege廣東食品藥品職業(yè)學院細胞壁結(jié)構(gòu)01Thecellwallstructureofbacteria01細胞壁的結(jié)構(gòu)Thecellwallstructureofbacteria

（1）外觀形態(tài)：外層、無色透明、堅韌、有彈性、網(wǎng)狀結(jié)構(gòu)。細胞壁的觀察方法：革蘭染色法，1884年由丹麥醫(yī)生革蘭首次發(fā)明，是最經(jīng)典的細菌鑒別染色法Observationmethodofcellwall:Gramstainingmethod,firstinventedbyDanishdoctorGramin1884,isthemostclassicbacterialidentificationstainingmethod細胞壁的結(jié)構(gòu)（1）Appearance：Outerlayer,colorlessandtransparent,tough,

elastic,withameshstructure。Thecellwallstructureofbacteria圖1.丹麥醫(yī)生革蘭

Figure1.DanishdoctorGram依革蘭染色法結(jié)果不同細菌分為兩類：AccordingtotheresultsofGramstaining,differentbacteriaaredividedintotwocategories革蘭陽性菌(G+)

革蘭染色藍紫色Grampositivebacteria(G+)

Gramstainingbluepurple革蘭陰性菌(G-)

革蘭染色紅色Gramnegativebacteria(G-)

Gramstainingred圖2.G+菌與G-菌的染色

Figure2.StainingofG+bacteriaandG-bacteriaG+菌G-菌細胞壁的結(jié)構(gòu)Thecellwallstructureofbacteria

(2)細胞壁成分與結(jié)構(gòu)(2)Compositionandstructureofcellwall共有成分—肽聚糖，G＋菌層多，G-菌層少Commoncomponents-peptidoglycan,withmoreG+bacteriallayerandlessG-bacteriallayer特有成分—G＋菌，磷壁酸；G-菌，外膜Uniquecomponent--G+,bacterialphosphatewallacid;G-,OutermembraneofGram圖4.G+菌肽聚糖單層結(jié)構(gòu)示意圖Figure4.SchematicdiagramofG+peptidoglycanmonolayerstructure四肽側(cè)鏈Tetrapeptidesidechain五肽交聯(lián)橋Pentapeptidecross-linkingbridgeGMGMGM聚糖骨架PolysaccharideskeletonGMGMGMGMGMGMGMGMGMG+菌肽聚糖單層結(jié)構(gòu)三維立體ThreedimensionalstructureofG+peptidoglycanmonolayerG+菌的肽聚糖PeptidoglycanofG+bacteriaGN-乙酰葡萄糖胺MN-乙酰胞壁酸N-acetylmuramicacidMN-acetylglucosamineN-acetylmuramicacidGN-乙酰葡萄糖胺MN-乙酰胞壁酸聚糖骨架四肽側(cè)鏈PolysaccharideskeletonTetrapeptidesidechainN-acetylmuramicacidMN-acetylglucosamineG②G-菌肽聚糖peptidoglycan圖5.G-肽菌聚糖單體Figure5.G-polysaccharidemonomerMGMGMGMGMGMGMGMGMG聚糖骨架Polysaccharideskeleton四肽側(cè)鏈TetrapeptidesidechainG-菌肽聚糖單層結(jié)構(gòu)二維平面TwodimensionalplaneofG-peptidoglycanmonolayerstructure聚糖骨架Polysaccharideskeleton四肽側(cè)鏈Tetrapeptidesidechain結(jié)構(gòu)StructureG-

菌的肽聚糖PeptidoglycanofG-bacteria圖6.G-菌肽聚糖單層結(jié)構(gòu)示意圖Figure6.SchematicdiagramofG-peptidoglycanmonolayerstructureG+菌肽聚糖特點StructuralcharacteristicsofG+peptidoglycan層數(shù)：最多達50層Numberoflayers:upto50layers厚：15～80nmThickness:15-80nm含量高：占壁干重50%～80%Highcontent:accountingfor50%to80%ofthewalldryweight致密、堅韌的三維立體結(jié)構(gòu)Weakened(ornon-toxic)vaccineG-菌肽聚糖特點StructuralcharacteristicsofG-peptidoglycan層數(shù)：1～3層Layers:1-3layers?。?0～15nmThickness:10-15nm含量低：占壁干重5%～15%Lowcontent:5%to15%ofwalldryweight疏松的二維平面結(jié)構(gòu)Loosetwo-dimensionalplanarstructure肽聚糖結(jié)構(gòu)特點Structuralcharacteristicsofpeptidoglycan肽聚糖(可達50層)肽聚糖(1～3層)peptidoglycan(upto50floors)peptidoglycan(only1-3floors)G+bacteriaG-bacteria圖7.G+菌與G-菌肽聚糖結(jié)構(gòu)特點Figure7.StructuralcharacteristicsofG+andG-peptidoglycanG+菌G-菌圖8.抗生素作用于細菌細胞壁，導致細菌裂解死亡Figure8.Antibioticsactonbacterialcellwalls,causingbacteriallysisanddeath圖9.青霉素作用前、后的葡萄球菌Figure9.Staphylococcusaureusbeforeandafterpenicillinaction桿菌肽作用點青霉素作用點溶菌酶作用點GMGMGMGMGMGMGMGMGMGMGMGMLysozymetargetsPenicillintargetsBacitracintargets圖10.藥物作用靶點Figure10.drugtarget聚糖骨架Polysaccharideskeleton四肽側(cè)鏈Tetrapeptidesidechain五肽交聯(lián)橋Pentapeptidebridge結(jié)構(gòu)StructureG+菌的肽聚糖PeptidoglycanofG+bacteria對溶菌酶、磷霉素等抗生素敏感Sensitivetoantibioticssuchaslysozymeandphosphomycin對桿菌肽、萬古霉素等抗生素敏感Sensitivetoantibioticssuchasbacteriocinsandvancomycin對青霉素、頭孢霉素等抗生素敏感Sensitivetoantibioticssuchaspenicillinandcephalosporin目標檢測TargetdetectionG+菌與G-菌的細胞壁（）。Whatistheunitfordescribingthesizeofbacteria（）A.都含有肽聚糖A.

AllcontainpeptidoglycanB.

都含有脂多糖B.

AllcontainlipopolysaccharidesC.結(jié)構(gòu)都十分致密堅韌

C.ThestructureisverydenseandtoughA.都含有肽聚糖A.

Allcontainpeptidoglycan小結(jié)：以