生物表面活性剂课件

生物表面活性剂生物表面活性剂Introduction

Biosurfactants(amphiphiliccompounds)(synthesizedbymicroorganisms)hydrophobic(nonpolar)hydrophilic(polar)thatconferabilitytoaccumulatebetweenfluidphasessuchasoil/waterorair/water,reducingthesurfaceandinterfacialtensionsandformingemulsions.household、industryandagriculturemono-,oligo-orpolysaccharides(多糖）,peptides（缩氨酸）orproteinssaturated,unsaturatedandhydroxylatedfattyacidsorfattyalcoholsIntroductionBiosurfactant生物表面活性剂课件生物表面活性剂课件生物表面活性剂课件生物表面活性剂课件生物表面活性剂课件生物表面活性剂课件PropertiesSurfaceandinterfaceactivitybiodegradability(bioremediation).emulsifying

anddemulsifyingabilityantimicrobialactivityPropertiesSurfaceandinterfacSurfaceandinterfaceactivity

Ingeneral,biosurfactantsaremoreeffectiveandefficientandtheirCMC(criticalmicelleconcentration)isabout10-40timeslowerthanchemicalsurfactants,i.e.,lesssurfactantisnecessarytogetamaximaldecreaseonST.

Agoodsurfactantcanlowersurfacetension(ST)ofwaterfrom72to35mN/mandtheinterfacialtension(IT)water/hexadecane（十六烷）from40to1mN/m.SurfaceandinterfaceactivityThebiosurfactantsaccumulateattheinterfacebetweentwoimmisciblefluidsorbetweenafluidandasolid..(figure1)Byreducingsurface(liquid-air)andinterfacial(liquid-liquid)tensiontheyreducetherepulsiveforcesbetweentwodissimilarphasesandallowthesetwophasestomixandinteractmoreeasilyThebiosurfactantsaccumulateBiosurfactantactivitiesdependontheconcentrationofthesurface-activecompoundsuntilthecriticalmicelleconcentration(CMC)isobtained.AtconcentrationsabovetheCMC,biosurfactantmoleculesassociatetoformmicelles,bilayersandvesicles(Figure2).TheCMCiscommonlyusedtomeasuretheefficiencyofsurfactant.EfficientbiosurfactantshavealowCMC,whichmeansthatlessbiosurfactantisrequiredtodecreasethesurfacetension.Biosurfactantactivitiesdepe

Thebiosurfactanteffectivenessisdeterminedbymeasuringitsabilitytochangesurfaceandinterfacialtensions,stabilizationofemulsionsandbystudyingitshydrophilic-lipophilicbalance(HLB).EmulsifierswithlowHLBarelipophilicandstabilizewater-in-oilemulsification,whereasemulsifierswithhighHLBhavetheoppositeeffectandconferbetterwatersolubility

Lowtoxicity

Forexample:AbiosurfactantfromP.aeruginosa（绿脓假单胞菌）（wascomparedwithasyntheticsurfactant(MarlonA-350)widelyusedinindustryintermsoftoxicityandmutagenicproperties.Bothassaysindicatedthehighertoxicityandmutageniceffectofthechemical-derivedsurfactantwhereasbiosurfactantwasconsideredslightlytonon-toxicandnon-mutagenic.lowornon-toxicproductsandtherefore,appropriateforpharmaceutical,cosmeticandfooduses.LowtoxicityForexample:AEmulsionformingandemulsionbreaking

Anemulsionisaheterogeneoussystem,consistingofatleastoneimmiscibleliquidintimatelydispersedinanotherintheformofdroplets,whosediameteringeneralexceeds0.1µm.Emulsionshaveaninternalordispersedandanexternalorcontinuousphase,sotherearegenerallytwotypes:oil-in-water(o/w)orwater-in-oil(w/o)emulsions.

Suchsystemspossessaminimalstability,whichmaybeaccentuatedbyadditivessuchassurface-activeagents(surfactants).Thus,stableemulsionscanbeproducedwithalifespanofmonthsandyears.Biosurfactantsmaystabilize(emulsifiers)ordestabilize(de-emulsifiers)theemulsion.High-molecular-massbiosurfactantsareingeneralbetteremulsifiersthanlow-molecular-massbiosurfactants.EmulsionformingandemulsionAntimicrobialactivity

Asignificativereductiononthemycoflora（真菌群）presentinstoredgrainsofcorn,peanutsandcottonseedswasobservedatiturinconcentrationof50-100ppm).Inactivationofenvelopedvirussuchasherpes（疱疹）andretrovirus（逆转录酶病毒）wasobservedwith80mMofsurfactin（脂肽）.

Severalbiosurfactantshaveshownantimicrobialactionagainstbacteria,fungi（真菌）,algae（藻类）andviruses.

Thelipopeptideiturin（脂肽伊枯草菌素）fromB.subtilis（枯草芽孢杆菌）showedpotentantifungalactivity.

AntimicrobialactivityAProduction

Biosurfactantsdonotcompeteeconomicallywithsyntheticsurfactants.Toreduceproductioncosts,othercarbonsources,suchasoliveoil（橄榄油），milleffluent（工厂废水）,whey（乳清）fromcheesemaking,andcassavaflourwater（木薯粉水）,usedvegetableoils,molasses（糖浆）(by-product).

Biosurfactantshavebeensynthesizedbyvariousresearchersusingdifferentmicroorganismsandcarbonsources.Thecarbonsourcesusedforbiosurfactantproductionarehydrocarbons,

carbohydrates,andvegetableoils.ProductionBiosurfactanProductionmethodsNaturalbiologicalextractmethod、Microorganismfermentationmethod、EnzymecatalyticmethodPurificationmethodsPrecipitationmethod、Extractionmethod、Superfilteringmethod、Foamseparationmethod、Adsorptionmethod、Columnchromatographymethod、Thinlayerchromatographymethod、Highperformanceliquidchromatographymethod、Liquidsurfaceadsorptionenrichmentmethod、Liquidmembraneseparationmethod.ProductionmethodsFig.2.Structureoffourdifferentrhamnolipidsproducedby

P.aeruginosa.Fig.2.Structureoffourd生物表面活性剂课件FactorsAffectingBiosurfactant

ProductionEffectofCarbonSourceonBiosurfactantsProduction

carbohydratehydrocarbonvegetableoilsFactorsAffectingBiosurfactanEffectofSupportMaterialandRelationshipwithWater

Supportmaterialforimmobilizedenzymeaffectsthe

watercontentintheproximityoftheenzymeandthe

partitioningofreactantsand/orproductsinthereaction

mixture.Sincethermalstabilityiscloselyrelatedtothe

amountofwaterinclosevicinityoftheenzymesmolecule.Theidealcarriershouldnotretainwaterthan

necessarytoreducetheriskofenzymedenaturation（变性）.

Immobilizationonhydrophilicsupportsoftenleads

toalossoflipase（脂肪酶）activityastheenzymeundergoesa

conformational（构象）changetoaformofreducedactivity.

Thesesupportmaterialsmayalsoreducehydrophobic

substratesolubilityinhydrophilicregions,thereby

reducingthe

accessibilityofsubstratetotheactivesites.EffectofSupportMaterialandEffectofEnvironmentalFactorsonBiosurfactantsProduction

pHtemperatureagitation（搅拌）speedoxygenavailabilityRhamnolipidproductioninpseudomonassp（假单胞菌）wasitsmaximumatapHrangefrom

6to

6.5and

decreasedsharplyabovepH7.

Inaddition,surfacetensionandCMCsofabiosurfactantproduct

remainedstableoverawiderangeofpHvalues,whereasemulsificationhadanarrowerpHrange.EffectofEnvironmentalFactor

AthermophilicBacillussp（芽孢杆菌）grewandproducedbiosurfactantattemperatureabove40℃.Heattreatmentofsomebiosurfactantscausednoappreciablechangeinbiosurfactantproperties,suchastheloweringofthesurfacetensionandinterfacialtensionandtheemulsificationefficiency,allofthatremainedstableafterautoclaving（高压灭菌）at120℃for15min.

AnincreaseinagitationspeedresultinthereductionofbiosurfactantyieldduetotheeffectofshearinNocardia（土壤丝菌属）.Onotherhand,inyeast,biosurfactantproductionincreaseswhentheagitationandaerationratesareincreased.

Saltconcentrationalsoaffectedbiosurfactantproductiondependingonitseffectsoncellularactivity.Some

biosurfactantproducts,however,werenotaffectedby

saltconcentrationsupto10%(wt/vol),althoughslight

reductionintheCMCsweredetected.AthermophilicBacillusspamodifieddrop-collapsetechniqueforsurfactantquantitationandscreeningofbiosurfactantproducingmicroorganismsQualitativedrop-collapsetestAdropofwaterappliedtoahydrophobicsurfaceintheabsenceofsurfactantswillformabead,asshowninFig.1(A).Thebeadforms

becausethepolarwatermoleculesarerepelledfromthehydrophobicsurface.Incontrast,ifthewaterdropletcontainssurfactant,theforceorinterfacialtensionbetweenthewaterdropandthehydrophobicsurfaceisreduced,whichresultsinthespreadingofthewaterdropoverthehydrophobicsurface(Fig.1,B).Theamountofsurfactantrequiredtocausedrop-collapseisdependentontheabilityofthesurfactanttoreducesurfaceandinterfacialtension.Themorepotentthesurfactant,thesmallerthequantitythatcanbedetected.

(A)Watercontrol(nosurfactant),(B)1000mg/Lrhamnolipid.amodifieddrop-collapsetechsurfactantquantitationbythedrop-collapseQuantitativedrop-collapsemethod:(A)Watercontrol,(B)25mg/Lrhamnolipid,(C)50mg/Lrhamnolipid,(D)75mg/Lrhamnolipidand(E)100mg/Lrhamnolipid.Inthiscase,asthesurfactantconcentrationincreased,thediameterofthesampledropincreased.surfactantquantitationbytheQuantitativeresultsfortwosurfactants,rhamnolipidandSDS,arepresentedasstandardcurvesinFig.2.Alinearcorrelationwasfoundbetweentherhamnolipidconcentrationandthedropdiameter,intherangeof0to100mg/L,withanr2=of0.997(Fig.2A).ForSDS(Fig.2B),concentrationsbetween0and2400mg/Lwerelinearlycorrelatedwithdropdiameter(r2=50.989).Fig.2.Thequantitativedrop-collapsemethod.Thefigureshowstheresultsobtainedwithtwodifferentsurfactants:(A)P.aeruginosaIGB83withaCMCof27mg/Land(B)SDSwithaCMCof1845mg/L.Eachpointrepresentsthemeanandstandarddeviationoffivereplicatesfromexperimentsthatwerecarriedoutintriplicate.Quantitativeresultsfortwo

PotentialCommercial

Applications

Mostsurfactantsarechemicallysynthesized.Nevertheless,inrecentyears,muchattentionhasbeendirectedtowardbiosurfactantsduetotheirbroad-rangefunctionalpropertiesandthediversesyntheticcapabilitiesofmicrobes.Mostimportantistheirenvironmentalacceptability,becausetheyarereadilybiodegradableandhavelowertoxicitythansyntheticsurfactants.Anumberofapplicationsof

biosurfactantshavebeenenvisaged.MEOR、FoodIndustry、CosmeticIndustry、MedicinalUse、Soil

BioremediationPotentialCommercialApplicatBiosurfactantsinMicrobialEnhancedOilRecovery(MEOR)

Fig.Mechanismofenhancedoilrecoverybybiosurfactants.theoilistrappedintheporesbycapillary

pressure.

Biosurfactantsreduceinterfacialtensionbetweenoil/waterandoil/rock.Thisreducesthecapillaryforcespreventingoilfrommovingthroughrockpores.Biosurfactantscanalsobindtightlytotheoil-waterinterfaceandformemulsion.Thisstabilizesthedesorbedoilinwaterandallowsremovalofoilalongwiththeinjectionwater.

BiosurfactantsinMicrobialETheApplicationofBiosurfactantsforSoil

BioremediationThebiologicalremediationprocesscanbeperformed(i)insitu(ii)inapreparedbed(

iii)inaslurryreactorsystemInsituprocessesareusuallyaccomplishedbyadditionofmicrobialnutrientstothesoil,whichallowsconsiderablegrowthofsoilmicrobialindigenouspopulation.Thusincreasedmicrobialbiomassinthesoil.(fig1)TheApplicationofBiosurfacta生物表面活性剂课件Figure3Mechanismofbiosurfactantactivityinmetal-contaminatedsoilduetotheloweringoftheinterfacialtension.Figure3MechanismofbiosurfConclusion

Advantage:

higherbiodegradability,betterenvironmentalcompatibility,higherfoaming,highselectivityandhighspecificactivityatextremetemperature,pHandsalinity.

Therethedemandofbiosurfactantsisincreasingworldwideinrecentyears.However,biosurfactantsdonoteconomicallycompetewithchemicallysynthesizedsurfactants.That’swhythereisagreatscopeforfurtherresearchtofindamoreeconomicalproductionprocessandtechnology.ConclusionAdvantage:higherThankYouThankYou

结束语谢谢大家聆听！！！35

结束语谢谢大家聆听！！！35生物表面活性剂生物表面活性剂Introduction

Biosurfactants(amphiphiliccompounds)(synthesizedbymicroorganisms)hydrophobic(nonpolar)hydrophilic(polar)thatconferabilitytoaccumulatebetweenfluidphasessuchasoil/waterorair/water,reducingthesurfaceandinterfacialtensionsandformingemulsions.household、industryandagriculturemono-,oligo-orpolysaccharides(多糖）,peptides（缩氨酸）orproteinssaturated,unsaturatedandhydroxylatedfattyacidsorfattyalcoholsIntroductionBiosurfactant生物表面活性剂课件生物表面活性剂课件生物表面活性剂课件生物表面活性剂课件生物表面活性剂课件生物表面活性剂课件PropertiesSurfaceandinterfaceactivitybiodegradability(bioremediation).emulsifying

anddemulsifyingabilityantimicrobialactivityPropertiesSurfaceandinterfacSurfaceandinterfaceactivity

Ingeneral,biosurfactantsaremoreeffectiveandefficientandtheirCMC(criticalmicelleconcentration)isabout10-40timeslowerthanchemicalsurfactants,i.e.,lesssurfactantisnecessarytogetamaximaldecreaseonST.

Agoodsurfactantcanlowersurfacetension(ST)ofwaterfrom72to35mN/mandtheinterfacialtension(IT)water/hexadecane（十六烷）from40to1mN/m.SurfaceandinterfaceactivityThebiosurfactantsaccumulateattheinterfacebetweentwoimmisciblefluidsorbetweenafluidandasolid..(figure1)Byreducingsurface(liquid-air)andinterfacial(liquid-liquid)tensiontheyreducetherepulsiveforcesbetweentwodissimilarphasesandallowthesetwophasestomixandinteractmoreeasilyThebiosurfactantsaccumulateBiosurfactantactivitiesdependontheconcentrationofthesurface-activecompoundsuntilthecriticalmicelleconcentration(CMC)isobtained.AtconcentrationsabovetheCMC,biosurfactantmoleculesassociatetoformmicelles,bilayersandvesicles(Figure2).TheCMCiscommonlyusedtomeasuretheefficiencyofsurfactant.EfficientbiosurfactantshavealowCMC,whichmeansthatlessbiosurfactantisrequiredtodecreasethesurfacetension.Biosurfactantactivitiesdepe

Thebiosurfactanteffectivenessisdeterminedbymeasuringitsabilitytochangesurfaceandinterfacialtensions,stabilizationofemulsionsandbystudyingitshydrophilic-lipophilicbalance(HLB).EmulsifierswithlowHLBarelipophilicandstabilizewater-in-oilemulsification,whereasemulsifierswithhighHLBhavetheoppositeeffectandconferbetterwatersolubility

Lowtoxicity

Forexample:AbiosurfactantfromP.aeruginosa（绿脓假单胞菌）（wascomparedwithasyntheticsurfactant(MarlonA-350)widelyusedinindustryintermsoftoxicityandmutagenicproperties.Bothassaysindicatedthehighertoxicityandmutageniceffectofthechemical-derivedsurfactantwhereasbiosurfactantwasconsideredslightlytonon-toxicandnon-mutagenic.lowornon-toxicproductsandtherefore,appropriateforpharmaceutical,cosmeticandfooduses.LowtoxicityForexample:AEmulsionformingandemulsionbreaking

Anemulsionisaheterogeneoussystem,consistingofatleastoneimmiscibleliquidintimatelydispersedinanotherintheformofdroplets,whosediameteringeneralexceeds0.1µm.Emulsionshaveaninternalordispersedandanexternalorcontinuousphase,sotherearegenerallytwotypes:oil-in-water(o/w)orwater-in-oil(w/o)emulsions.

Suchsystemspossessaminimalstability,whichmaybeaccentuatedbyadditivessuchassurface-activeagents(surfactants).Thus,stableemulsionscanbeproducedwithalifespanofmonthsandyears.Biosurfactantsmaystabilize(emulsifiers)ordestabilize(de-emulsifiers)theemulsion.High-molecular-massbiosurfactantsareingeneralbetteremulsifiersthanlow-molecular-massbiosurfactants.EmulsionformingandemulsionAntimicrobialactivity

Asignificativereductiononthemycoflora（真菌群）presentinstoredgrainsofcorn,peanutsandcottonseedswasobservedatiturinconcentrationof50-100ppm).Inactivationofenvelopedvirussuchasherpes（疱疹）andretrovirus（逆转录酶病毒）wasobservedwith80mMofsurfactin（脂肽）.

Severalbiosurfactantshaveshownantimicrobialactionagainstbacteria,fungi（真菌）,algae（藻类）andviruses.

Thelipopeptideiturin（脂肽伊枯草菌素）fromB.subtilis（枯草芽孢杆菌）showedpotentantifungalactivity.

AntimicrobialactivityAProduction

Biosurfactantsdonotcompeteeconomicallywithsyntheticsurfactants.Toreduceproductioncosts,othercarbonsources,suchasoliveoil（橄榄油），milleffluent（工厂废水）,whey（乳清）fromcheesemaking,andcassavaflourwater（木薯粉水）,usedvegetableoils,molasses（糖浆）(by-product).

Biosurfactantshavebeensynthesizedbyvariousresearchersusingdifferentmicroorganismsandcarbonsources.Thecarbonsourcesusedforbiosurfactantproductionarehydrocarbons,

carbohydrates,andvegetableoils.ProductionBiosurfactanProductionmethodsNaturalbiologicalextractmethod、Microorganismfermentationmethod、EnzymecatalyticmethodPurificationmethodsPrecipitationmethod、Extractionmethod、Superfilteringmethod、Foamseparationmethod、Adsorptionmethod、Columnchromatographymethod、Thinlayerchromatographymethod、Highperformanceliquidchromatographymethod、Liquidsurfaceadsorptionenrichmentmethod、Liquidmembraneseparationmethod.ProductionmethodsFig.2.Structureoffourdifferentrhamnolipidsproducedby

P.aeruginosa.Fig.2.Structureoffourd生物表面活性剂课件FactorsAffectingBiosurfactant

ProductionEffectofCarbonSourceonBiosurfactantsProduction

carbohydratehydrocarbonvegetableoilsFactorsAffectingBiosurfactanEffectofSupportMaterialandRelationshipwithWater

Supportmaterialforimmobilizedenzymeaffectsthe

watercontentintheproximityoftheenzymeandthe

partitioningofreactantsand/orproductsinthereaction

mixture.Sincethermalstabilityiscloselyrelatedtothe

amountofwaterinclosevicinityoftheenzymesmolecule.Theidealcarriershouldnotretainwaterthan

necessarytoreducetheriskofenzymedenaturation（变性）.

Immobilizationonhydrophilicsupportsoftenleads

toalossoflipase（脂肪酶）activityastheenzymeundergoesa

conformational（构象）changetoaformofreducedactivity.

Thesesupportmaterialsmayalsoreducehydrophobic

substratesolubilityinhydrophilicregions,thereby

reducingthe

accessibilityofsubstratetotheactivesites.EffectofSupportMaterialandEffectofEnvironmentalFactorsonBiosurfactantsProduction

pHtemperatureagitation（搅拌）speedoxygenavailabilityRhamnolipidproductioninpseudomonassp（假单胞菌）wasitsmaximumatapHrangefrom

6to

6.5and

decreasedsharplyabovepH7.

Inaddition,surfacetensionandCMCsofabiosurfactantproduct

remainedstableoverawiderangeofpHvalues,whereasemulsificationhadanarrowerpHrange.EffectofEnvironmentalFactor

AthermophilicBacillussp（芽孢杆菌）grewandproducedbiosurfactantattemperatureabove40℃.Heattreatmentofsomebiosurfactantscausednoappreciablechangeinbiosurfactantproperties,suchastheloweringofthesurfacetensionandinterfacialtensionandtheemulsificationefficiency,allofthatremainedstableafterautoclaving（高压灭菌）at120℃for15min.

AnincreaseinagitationspeedresultinthereductionofbiosurfactantyieldduetotheeffectofshearinNocardia（土壤丝菌属）.Onotherhand,inyeast,biosurfactantproductionincreaseswhentheagitationandaerationratesareincreased.

Saltconcentrationalsoaffectedbiosurfactantproductiondependingonitseffectsoncellularactivity.Some

biosurfactantproducts,however,werenotaffectedby

saltconcentrationsupto10%(wt/vol),althoughslight

reductionintheCMCsweredetected.AthermophilicBacillusspamodifieddrop-collapsetechniqueforsurfactantquantitationandscreeningofbiosurfactantproducingmicroorganismsQualitativedrop-collapsetestAdropofwaterappliedtoahydrophobicsurfaceintheabsenceofsurfactantswillformabead,asshowninFig.1(A).Thebeadforms

becausethepolarwatermoleculesarerepelledfromthehydrophobicsurface.Incontrast,ifthewaterdropletcontainssurfactant,theforceorinterfacialtensionbetweenthewaterdropandthehydrophobicsurfaceisreduced,whichresultsinthespreadingofthewaterdropoverthehydrophobicsurface(Fig.1,B).Theamountofsurfactantrequiredtocausedrop-collapseisdependentontheabilityofthesurfactanttoreducesurfaceandinterfacialtension.Themorepotentthesurfactant,thesmallerthequantitythatcanbedetected.

(A)Watercontrol(nosurfactant),(B)1000mg/Lrhamnolipid.amodifieddrop-collapsetechsurfactantquantitationbythedrop-collapseQuantitativedrop-collapsemethod:(A)Watercontrol,(B)25mg/Lrhamnolipid,(C)50mg/Lrhamnolipid,(D)75mg/Lrhamnolipidand(E)100mg/Lrhamnolipid.Inthiscase,asthesurfactantconcentrationincreased,thediameterofthesampledropincreased.surfactantquantitationbytheQuantitativeresultsfortwosurfactants,rhamnolipidandSDS,arepresentedasstandardcurvesinFig.2.Alinearcorrelationwasfoundbetweentherhamnolipidconcentrationandthedropdiameter,intherangeof0to100mg/L,withanr2=of0.997(Fig.2A).ForSDS(Fig.2B),concentrationsbetween0and2400mg/Lwerelinearlycorrelatedwithdropdiameter(r2=50.989).Fig.2.Thequantitativedrop-collapsemethod.Thefigureshowstheresultsobtainedwithtwodifferentsurfactants:(A)P.aeruginosaIGB83withaCMCof27mg/Land(B)SDSwithaCMCof1845mg/L.Eachpointrepresentsthemea