26316.微生物轉化法產(chǎn)γ氨基丁酸

1、江南大學碩士學位論文微生物轉化法產(chǎn)γ氨基丁酸姓名：楊帆申請學位級別：碩士專業(yè)：生物化工指導教師：徐巖李江華20080601AbstractAbstract7arninobutyricacid(GABA)iSanonproteinaminoacidthatiSwidelydistributedinnatureGABAinthebrainandspinalcordofmammalswithavarietyofeffectsinthecent

2、ralnervoussystemasinhibitoryneurotransmitterfunction，GABAisagoodmedicaldrugsandrawmaterialsforhealthcareGABAplayedapoultryheatstressandgrowthpromotingeffectInthispapertheEcoli(AS1505)whichhashighactivityofglutamatedecarb

3、oxylaseastheoriginalitystrainThestraintransforillLglutamicacidaSsubstratetoGABAAseriesofschemewereusedinordretoachievehighyield，hi曲concentrationandhighproductivityofGABAproduction即1emainelementsofthisthesisareaSfollows：1

4、CompositionsofculturemediumandcultureconditionswerestudiedtoimprovequantityofGlutamicaciddecarboxylase(GAD)producedbyAS1505liquidcultureTheoptimizedmediumandconditionswereaSfollows：glucose10％，tryptone3O％，NaClO3％，K2HP043H

5、2001％(w／v)，MgS047H20002％(w／v)，Lglutarnicacid001％(w／v)，COrnsteepliquor15％(w／v)，biotin30ttg。L一，bran4％(w／v)，initialpH70，37℃，liquidvolume25mL／250mLbaffledflaSk，for20hoursTheactivityofGADwas1290unitsofeachmilliliterbrothunder

6、theseconditions2TheconditionsoftransformationfromL—glutamicacidtOGABA，includingtemperature，pH，buffersystem，strainconcentrationsubstrateconcentrationandreusetimesofstrainwereoptimized：temperature37℃，pH46，Na2HP04一citricaci

7、dastheoptimizedbuffersystem，theratioofvolumeoffermentationbrothtotransformationbroth2：1defmed鶴optimizedstrainconcentration，substratcconcentration03molL～，reusewithinthreetimes3Undertheglucoselimitedcondition，thegrowthofGA

8、DproducercouldbesupposedbyMonodequationwithtmax=O543h1andKs=O102gLqinthecontinuouscultureprocess111emaximumyieldofbiomassandGADproductwere％=0434gg～，respectivelyThemaximumdilutionrateWasDm=045h～111emaximumbiomassyieldandt

9、heGADyieldare1785g(Lh)～and11934U。(LhmL)一，respectively4n地effectsofpH，ventilationvolume，stirringspeedandfedbatchoncultureprocessandtransformationwereinvestigatedin5LfermentorWhenpHwascontrolledat70，theventilationvolume，sti

10、rringspeed，totalconcentrationofglucoseinculturemediunlandinitialglucoseconcentrationwere15vvm，600印鷗3083gL～and107gL～，respectively1kresidualglucosesolutionasfedbatchbeganfeedingsteadilyafterculturefor2h111efedbatchWaSended

11、after5handthebiomassreachedthehighestvaluearound181gLqafterculturefor1lhFinally，60gL～GABAWasobtainedfrom882gL～Lglutamicacidaftertransformationfor16ll，conversionlevelreachs100％Keywords：7aminobutyricacid，Ecoil，Optimization