復合誘變檸檬酸菌種的選育及發(fā)酵條件和培養(yǎng)基的優(yōu)化.pdf

1、天津大學碩士學位論文復合誘變檸檬酸菌種的選育及發(fā)酵條件和培養(yǎng)基的優(yōu)化姓名：李文友申請學位級別：碩士專業(yè)：生物工程指導教師：趙學明李榮杰20070801ABST尉記TAspergillusnigerC0827isahighcitricacidproducingstrainwhichhasverystablecitricacidproduction，transformationratioandfermentationtime，etcButc

2、omparingwiththeforeignproductionlevelthecitricacidleveloffermentationisstilllowInthispaper，strainforproducingcitricacidisbreedingbycompositemutation(theultravioletandDES)，inordertaisethecitricacidproduction，transformatio

3、nratioandsingleproductionunitofcitricacid，optimizationtheprocessofcitricacidfermentationofobtainednewstrain，mlfiUindustrialtestofthenewstrain1Byoptimizationofculturemediumofexistingproductionstrainincludingthecarbonsourc

4、e，nitrogensourceandtheconcentrationofmincralsalts，thecompositionofculturemediumoffermentationofstartstrainiSfixedonandoptimizationof，fermentationconditions2Theeffectsofthreedifferentmutagens(uv，DES，UVDES)onthecitricacidp

5、roducingstrainAspergillusnigerwerestudiedItwasdemonstratedthattheeffectofcompositemutation(theultravioletandDES)wasmoreefficient3Ahi曲citricacidproducingstrainwasobtainedthroughaseriesofscreeninginflasksinordertotrainthes

6、trainbyusinganindicatormethodforscreeninginthehighcitricacidconcentrationandhi曲concentrationofdextrosemediumByoptimizingtheculturemedium(carbonsource，nitrogensource，mineralsalts，etc)，theopticalmediumWaSobtained，andoptimi

7、zationoffermentationconditionsBytestingthegeneticstability，itWaSshowedthatthenewstrainwasstableinthespecialityofheredity，andconfirmedthecurvesofthegrowthandfermentationprocess4Comparingtheperformanceofthestaltstrainandhi

8、。ghproducingstrainthroughindustrialteston300m3fermentationtankatdifferentinitialconcentrationofdextrose，itWaSdemonstratedthatthenewstrainGSY085wasmoresuitableforthefermentationlevelatinitialconcentration17％ofdextrosecomp