学姐微生物课件growth

1、Lecture5bMicrobialIV.EnvironmentalEffectsMicrobialLecture5bMicrobialIV.EnvironmentalEffectsMicrobialOsmolarity/WaterEnvironmentalfactorsaffecting bacterial growthOsmolarity/WaterEnvironmentalfactorsaffecting bacterial growth5.10Effect of Temperature 5.10.1CardinaltemperaturesMinimum temperaturetempe

2、rature below which growth no longer Optimum5.10Effect of Temperature 5.10.1CardinaltemperaturesMinimum temperaturetemperature below which growth no longer Optimum temperaturetemperature at which growth is most um temperature最高生长温temperature above which growth is Cardinaltemperatures基本温Cardinaltemper

3、aturesaregenerallycharacteristiceachtypeanismbutCardinaltemperatures基本温Cardinaltemperaturesaregenerallycharacteristiceachtypeanismbutarenotyastheycanbemodifiedslightlybyotherfactorstheenvironment;inparticular,bythecom the growth medium.itionCardinaltemperaturesandCardinaltemperaturesandthemolecularc

4、onsequen the cell基本温度与分子活性的关系FigTheoptimumtemperatureTheoptimumtemperatureisalwaysnearerntheFig5.10.2Temperatureclassesanisms Psychrophile嗜冷Psychrotrophs/冷菌/兼性嗜冷Mesophile嗜温Thermophile嗜5.10.2Temperatureclassesanisms Psychrophile嗜冷Psychrotrophs/冷菌/兼性嗜冷Mesophile嗜温Thermophile嗜热ivepsychrophile嗜热Psychroph

5、iles:growthwellat0Hyperthermophiles:havehavPsychThermopoptiman80Candof1Psychrophiles:growthwellat0Hyperthermophiles:havehavPsychThermopoptiman80Candof1psych growthoptima higher.The113C.Theyusuallydonotarothough haveatemperaroundbelow ubetn55andC,and Fig.6.17 5.12 Microbial growthigh 5.11Microbialgro

6、w t5.12 Microbial growthigh 5.11Microbialgrow tAsmallsuperheatedboilingspringAsmallsuperheatedboilingspringin YellowstoneNationalPark.spring have a temperature 12C above the boiling po . The mineral de itsconsistsmainlyofsilica andsulfur.Micro anisms tcan grow in it are hyperthermophiles.Thermophili

7、cprocaryotes en reported growing in Thermophilicprocaryotes en reported growing in Evidence has been presented reproduce at 113 C.t these microbes can grow vebe 5.12.1MolecularbasisgrowingatextremeMolecularadap ionsofenzymestoCold-active enzymes are more flexible due to higher portionofhelixandlessa

8、mountof-sheet耐冷的Heatresistantenzymes:moresaltbridgesand5.12.1MolecularbasisgrowingatextremeMolecularadap ionsofenzymestoCold-active enzymes are more flexible due to higher portionofhelixandlessamountof-sheet耐冷的Heatresistantenzymes:moresaltbridgesanddenselypackederior(comparedtheirmesophile区域-helixpr

9、ovides -helixprovides 多弹-sheet causes morerigidity带来更多刚More-helixesMore-helixesorestructure,whichiscoldMoreMore-sheetsresultinamorerigid structure, which is less cold active2. MolecularionsofcellmembranesextremeCold-resistantcellshavemoreunsaturatedfatty2. MolecularionsofcellmembranesextremeCold-res

10、istantcellshavemoreunsaturatedfatty(morederlowtemperatures)thermophileshavesrichinsaturatedfatty(membranesremainstableandfunctionalatLifeplantoilcontainsmorefattyacids,thusremaininliquideesolidatthetemperatures,whileanimaltemperatures生活经验:植物油因有3.Hyperthermophiles(Archaea)3.Hyperthermophiles(Archaea)

11、havemembraneasmonolayer,whichisresistanttopeelingIndustrialapplicationofIndustrialHigherLowerTaqDNApolymeraseandIndustrialapplicationofIndustrialHigherLowerTaqDNApolymeraseandRepetitivemeltingand95oC-52oC-SomeanismhasapHrangewithinwhichgrowthsibleandusuallyhasawell-definedpHoptimum.SomeanismhasapHra

12、ngewithinwhichgrowthsibleandusuallyhasawell-definedpHoptimum.anismsshowagrowthpHrangeof2-3.MostnaturalenvironmentshavepHvaluesnand9,anismswithhisrangemostcommon.自然界pH范围一般是5-9适应这一5.13 Microbial GrowtLowand High pHExtreme alkaliphiles have growthoptimaatpH10orExtreme alkaliphiles have growthoptimaatpH

13、10orhigherAlkaliphiles prefer the growth optimumpHrangeof8.5to11.5Neutrophilesgrowthoptimum pH betn pH 5.5 and 8.0Acidophiles have their growth optimum betnpH0and5.5;Optimal growth pH represents the pH of the extracellularenvironmentonly最适生长pH指的racellularOptimal growth pH represents the pH of the ex

14、tracellularenvironmentonly最适生长pH指的racellularpHmustremainnearneutralityordertopreventdestructionofacid-oralkali-在中性附近he cell.细胞内pH值一般保Inextremeacidophilesorextremealkaliphiles,racellularpHmayvarybyseveralits嗜酸/碱菌的胞内pH可能偏中性几ernalCellpH胞内pHWateractivity:aw,isaratioofthereoftheairWateractivity:aw,isarat

15、ioofthereoftheairinequilibriumsubstanceorsolutiontothevaporpre pure water. 水分活度reOsmosis: water diffuses from a region of high waterconcentration(lowsoluteconcentration)to a region of lower water concentration (highersolute渗透作hesof5.14OsmoticEffectsonGrowth 渗透压影响 Halophiles: Etanisms: tolerateaw ofe

16、nvironmentgenerallyabsenceofaddedsoluteFigure6. of microEffectofsodiumionconcentrationongrowth Halophiles: Etanisms: tolerateaw ofenvironmentgenerallyabsenceofaddedsoluteFigure6. of microEffectofsodiumionconcentrationongrowth Osmophilesabletoliveinenvironmentshighin Osmophilesabletoliveinenvironment

17、shighin Xerophilesabletogrowinverydryenvironments (made dry by lack of water) 耐旱生物Aerobes好氧Strict Aerobes专性好氧Microaerophiles微好氧ive Aerobes好氧Strict Aerobes专性好氧Microaerophiles微好氧ive aerobes兼性厌氧Anaerobes厌氧Aerotolerant anaerobes耐氧的厌氧Obligate (strict) anaerobes专性厌氧5.15Oxygenandmicrobial(a)(b)(d(e)Aerotol

18、erantanaerobesthroughoutthetube.However,growthdisgroawnobetter(a)(b)(d(e)Aerotolerantanaerobesthroughoutthetube.However,growthdisgroawnobetternearthesurfacebecauseae theanismscanonlycanbacteria are InoculatedeachA small amount ofagarhasbeen added to keep the liquid fromis added as aredoxindicator: p

19、ink when oxidized and colorless when Q1:WhichQ1:Whichone(s)cangrow presence of oxygen?Q2:Q2:DotheyreallyuseoxygenQ3:WhichQ3:Whichone(s)canabsenceofTypeofWithoxygenWithout+-+ -+TypeofWithoxygenWithout+-+ -+ +Typesofbacteriainrelationto5.16ToxicformsofOxygeninitsnormalgroundeisreferredtoas5.16Toxicfor

20、msofOxygeninitsnormalgroundeisreferredtoasoxygen3O2).Onemajorformoftoxicoxygenissingletoxygen(1O2),higher energy form of oxygen. Carotenoids can convert singletoxygentonontoxicforms.单线态氧因有高能量而性Superoxideanion(O -),hydrogenperoxide(H O ),2hydroxylradical(OHareby-productsduringthereduction of O2 to H2

21、O in respiration.超氧阴离子,过氧化氢,羟基Toxicformsofoxygenproducedduringthe reduction of O2Toxicformsofoxygenproducedduringthe reduction of O2 to H2O in respiration.Figure:06-Figure:06-DetoxificationbyAerobesandiveaerobesgenerallycontainsuperoxide dismutase and catalase, although a few obligate aerobeslackcat

22、alase.TheabsenceofsuperoxideAerobesandiveaerobesgenerallycontainsuperoxide dismutase and catalase, although a few obligate aerobeslackcatalase.Theabsenceofsuperoxidedismutasein obligate anaerobes may be the reason why oxygen is toxic to酶Someaerotolerantchaslacticacidbacteria,superoxidedismutase,butt

23、heyuseprotein-freeMn2+tocarryouttheionofO - toH andO 2基InsomeArchaea,superoxidedismutaseisabsentbutaenzyme,superoxidee,ispresentandisresponsiblesuperoxideremoval.一些古生菌以过氧化物还原酶来替代AheavyloopfulAheavyloopfulofcellsfromanagarculturewasmixedonaslidedrop30%hydrogenperoxide.Theimmediateappearanceofbubblesisindicativeof the presence of catalase. The bubbles are O2 pr