Chapter 6 微生物的生长与控制 Microbial Growth and Control AHNU
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ContentsDetection Method2Growth Curve3Main Factors Impact Microbial GrowthCultivation of MicrobesN5Control the Harmful Microbes
Contents 1 2 3 4 Main Factors Impact Microbial Growth Detection Method Growth Curve Cultivation of Microbes 5 Control the Harmful Microbes
1Detection MethodRBSORBANCE0.04Measuring the biomass(生物量）(1) Direct method:dry mass weighingRBSORBRNCE0.21(2) Indirect method:turbidimetry;PhotocellTubeofLampordetectorPhysiological indexbacterialsuspensionFigure7.37TurbidityandMicrobialMassMeasurement
1 Detection Method ● Measuring the biomass (生物量) (1) Direct method: dry mass weighing (2) Indirect method: turbidimetry; Physiological index
Countering cell numbervergass(1) Direct method:Vital stainingCnamberholdingbacteria(2) Indirect method:Plate colony counting for:Anaerobe (discuss late)aerobic bacteria(b)MembranefileedanWatersamolplcedinpatMembraneedthrocontaiiteronaIneubationnamoaneprfitersupport(0.45 um)mediunfor24hours
• ● Countering cell number • (1) Direct method: • Vital staining • (2) Indirect method: • Plate colony counting for: • Anaerobe (discuss late) • aerobic bacteria
Pour plate technique/倾注平板法The original sample is dluted several times1.0ml1.0ml1.0ml1.0mlParentcellsOrigindl9ml.09mIH.09miHo9mlHO(10-dlution)(10-dilution)(1o-diution)sarmple(10diluticng1.0ml1.0mlSomeofthe diutions (oftenthemostdilute)aremixedwithwarmagarandpouredontotheplateslsolatedcellsgrowintocoloniesonthesurface(appearround)andwithinthemedium(appearlens-shaped).TheisolatedcoloniesCanbecountedorusedtoestablishpurecultures.Figure 7.25 Pour-PlateTechnique
• Pour plate technique/倾注平板法
Figure6.16Methods of(a)Thepourplatemethod(b)Thespreadplatemethodpreparingplatesforplatecounts.1.0or0.1ml0.1mlHow do pour plates and spreadplates differ?InoculateInoculateplateemptyplatecontainingsolidmediumBacterialdilutionAddmeltednutrientagarSpreadinoculumoversurtaceevenlySwirltomixColaniesColoniesgrowgrowinandonlyonsurfaceonsolidifiedofmediummedium
2Growth Curve2.1 Synchronous growth/同步生长(1) Environmental condition induction method(2)Mechanical screening/机械筛选法
2.1 Synchronous growth/ 同步生长 (1) Environmental condition induction method (2) Mechanical screening/机械筛选法 2 Growth Curve
膜洗脱法Helmstetter-CummigsS
Helmstetter-Cummigs 膜洗脱法
Flaskinoculated+Samplestakenatequallyspacedintervals(0.1ml)300min420min480min540min60min120min180min240min360min600min0.1ml500mlSampleisdiluted inliquidagarmediumand pouredorspreadoversurfaceofsolidifiedmediumPlatesareincubatedNonecoloniesarecountedNumberofO'37132345801352301colonies(CFU)per0.1mlTotal cellO"5,00015,00035.00065.000115,000225,000400,000675,0001,150.000populationinflaskZeroCFUsonlymeans thattoofewcellsarepresenttobeassayed
• 2.2 Typical growth curve for single-celled microorganisms
: 2.2.1 Lag phase When microorganisms are introduced intofresh culture medium, usually no immediateincrease in cell number occurs. This period iscalled the lag phaseStationaryphaseaaExponential (log)phateDeathphaseLagphaseTime
• 2.2.1 Lag phase • When microorganisms are introduced into fresh culture medium, usually no immediate increase in cell number occurs. This period is called the lag phase