嗜热真菌Thermomyceslanuginosus耐热木聚糖酶性质及应用研究

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1、中国农业大学博士学位论文嗜热真菌Thermomyceslanuginosus耐热木聚糖酶性质及应用研究姓名：李秀婷申请学位级别：博士专业：食品科学指导教师：李里特;江正强20040601中国农业大学博十学位论文AbstmctAbstractXylanasecanhydrolyze13-1，4lgJycosidiclinkagesofthexylanbackbonetoproduceshortchainxylo‘oligosacchridesofvariouslengths．Hence．endo-G-xylanaseisthecruc

2、ialenzymecomponentsofmicrobialxylanolyticenzymesystems．Microbialxylanaseshaveattractedconsiderableresearchinterestinrecentyearsbecausetheirpotentialapplicationinthefood,animalfeed,paperandpulpindustries．Inthepresentdissertation，athermostablexylanasofromThermomyceslanug

3、inosusCBS288．54wereinvestigated．TheeffectsofdifferentfactorsOnxylanaseproduction印ZlanuginosusCBS288,54inshakeflaskconditionEightimprovedxylanaseproducingstrainswerescreenedbyshakena咄cultivationaftersporesofThermomyceslanuginosusCBS288．54weretreatedwithUV-irradiationand

4、ethyl-methanesulfonate．CultivationconditionsofthethermophilicfungusThermomyceslanuginosusCBS288．54·M18forthermostablexylanaseproductionwel"einvestigated．Corn-cobxylan(water·insoluble)wasfoundtobethebestinducerandcarbonSOUl'Ce．Tryptone+yeastextractWaSthebestnitrogensoum

5、es．TheoptimaltemperatureandtheinitialpHoftheculturesforxylanaseproductionwe[e50"CandpH7．0，respectively．Thehighestxylanaseactivityof1,834u／mLwasachievedundertheseoptimalconditions．Theeffectsofdifferent扣ctorsonxylanaseproductionbyT．1anuginosusCBS288．54-M18undersolidstate

6、culture(ssc)ThecultivationconditionsfortheproductionofthermostablexylanasefromThermomyceslanuginosusCBS288．54-M18undersolidstateculture(ssc)weTcinvestigated．Theeffectsofcarbonandnitrogensources，carbonSOUlVⅪtomineralsolutionratio，fermentationtemperatureandinitialpHofcul

7、tureonenzymeproductionwerestudied．Resultsshowedthat,byusingwheatbranandoomcubattheratioof8：2asthecarbonsonrce)yeastextractandtryptoneattheratioof1：1asthenitrogensource．amountofxylanaseproducedbythecultureincreased200％comparedtothosewithoutoptimizedcarbonandnitrogensour

8、ces．TheoptimalcarbonsourcetomineralsolutionratioandtheinitialpHofculturesforenzymeproductionwas1：3andpH7．0，respective