简介：Thesteady-stateelectricalconductivity,aswellasthedielectricpropertiesbetween2×10-4Hzand100kHz,andat1GHz,arereportedforureasecompressedpowdersamplesoflowhydration.Theresultsshowthatthelarge,lowfrequencydielectricdispersion,knownasα-dispersion,isduetothebuild-upofaspacechargeofprotonsatthesample-electrodeinterfaces.Asmallerdispersion,appearingathigherfrequencies,isconcludedtobeassociatedwithhinderedmotionsofthepeptideresiduesinthemolecularstructureofurease.Theextentofthesepolypeptidebackbonemotionsisshowntobestronglydependedontheextentofenzymehydration.Thisworkiscontributedtothede-velopmentofconductimetricbiosensors.

简介：INTRODUCTIONItisaninterestingresearchareausingureaseinhibitorstocurbureaseactivityinsoil,todecreasetherateofureahydrolysisandtoincreasetherecoveryofureanitrogen(Zhou,1984;Guan,1985).Fewstudieshavebeenconductedontherelationshipbetweentheeffectivenessoftheinhibitorsappliedtoriceandtheenvironmentalconditionsandits

简介：在这处理了纸从在福建的Changtai枇杷果园为土壤转化酶和urease是在土壤和活动参数的Cu内容之间的关系省。土壤转化酶活动和最大的反应速度(酶运动参数：V最大和V最大/Km)没与Cu集中有显著否定关联，但是Cu集中在转化酶K在在Cu和转化酶之间的反应上显示可逆竞争抑制的m,。土壤urease活动和最大的反应速度(V最大,V最大/Km)与Cu集中有显著否定关联，并且在这个方面，当土壤的生态的索引由Cu弄脏，他们能被使用。稍微可变的Km显示在Cu和土壤urease之间的非可逆的竞争抑制。Cuconcentration=在土壤的2.00mg·L−1是中等Cu污染水平的一口陈述语气。

简介：Inordertoinvestigatetheeffectsofmicroorganismsandtheirureaseactivitiesinmacrophyticrootzonesonpollutantremoval,foursmall-scaleplots(SSPs)ofvertical/reverse-verticalflowwetlandsweresetuptodetermine:a)therelationshipbetweentheabundanceofmicroorganismsintherootzonesandwaterpurificationefficiency;andb)therelationshipbetweenureaseactivitiesintherootzonesandpollutantremovalinaconstructedwetlandsystem.Totalnumbersofthemicrobialpopulation(bacteria,fungi,andactinomyces)alongwithureaseactivitiesinthemacrophyticrootzonesweredetermined.Inaddition,therelationshipsbetweenmicrobialpopulationsandureaseactivitiesaswellasthewastewaterpurificationefficienciesoftotalphosphorus(TP),totalKjeldahlnitrogen(TKN),biochemicaloxygendemandin5days(BOD5),andchemicaloxygendemand(COD)werealsoanalyzed.Theresultsshowedthattherewasahighlysignificantpositivecorrelation(r=0.9772,P＜0.01)betweenthenumberofbacteriaintherootzonesandBOD5removalefficiencyandasignificantnegativecorrelation(r=-0.9092,P＜0.05)betweenthenumberoffungiandtheremovalefficiencyofTKN.Meanwhile,therewasasignificantpositivecorrelation(r--0.8830,P＜0.05)betweenureaseactivitiesintherootzonesandtheremovalefficiencyofTKN.Thus,duringwastewatertreatmentinaconstructedwetlandsystem,microorganismandureaseactivitiesintherootzoneswereveryimportantfactors.

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简介：IndividualandcombinedeffectsofCu,Pb,ZnandCdonNmineralization,ureaseandphosphatasewereexaminedinaTypicUdicFerrisolinlaboratorybyemployinganduniformdesignandasinglefactordesign,SoilpollutioncausedbyheavymetalsinhibitedNmineralization(N0value)andureaseandphosphataseactivities.ThecombinedpollutionofmetalsalleviatedtheirtoxicitytoNmineralizationtosomeextentwhereasaggravatedthetoxicitytoureaseandphosphatase.Phosphorousapplicationcouldmitigatthetoxiceffectofheavymetalsonphosphataseactivities,whilealleviatingeffectofNapplicationonthetoxicityofheavymetalstoureasewasinconsistent.However,themitigatingeffectofthefertilizerswaslimitedinheavilypollutedsoils.

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