鏈霉菌Z18木聚糖酶XYN-1的純化和性質.pdf

1、中國農業(yè)大學碩士學位論文鏈霉菌Z18木聚糖酶XYN1的純化和性質姓名：翟倩申請學位級別：碩士專業(yè)：食品生物技術指導教師：江正強20061101AbstractMicrobialxylenaseespeciallyxylenaseproducedactinomyceteshaveattractedconsiderableresearchinterestinrecentyearsbecausetheirpotentialapplicatio

2、ninthefoodanimalfeedpaperandpulpindustriesTheconclusionsarcasfollows：1Theproductionofxylanase，cellulase，proteaseandthesubunitsofthesupcTllatantprodneedbythreeactinomyceteswe坤cⅫmparedForindustries，itrequireshighxyhnase，lo

3、wcellulaseandprotease，thenStreptomycesspZ18wastObetheresearchaetinomycete2Fermentationconditionsofxylanaseproductionbys位aillofStreptomycesspZ18werestudied15％insolublecorncobxylanproducedthehighestxylanaseOptimumpHandtemp

4、eratureforxylanaseproductionbyStreptomycesspZ18we∞pH55end30“(2，respectivelyHighestxylanaseactivityof755U／mLwasachievedintheseventhdayNativePAGEandzymogramanalysisofculturesupernatantbyStreptomycesZIgusingdifferentxylausa

5、sinducershowedthatStreptomycesZ18producedthreexyhnasesandthexylanaseof22kDaWasthemainprotein3ThexylanaseWaspun矗edbyammoniumsulfateprecipitationandSephacfylS300gelfiltrationchromatographyAccordingtotheNterminalsequenceana

6、lysesofthe10andnoacidresidueoftheXYNItheXYN1Was90％homologous謝ItIGXYN4TheoptimaltemperatureandpHforxylanaseactivityWas60“(2andpH70，respectivelyPHstabilityofxylanaseactivityofXYNlWasbetweenpH50～8O：temperaturestabilityofxyl

7、anaseactivityofXYN—lWas45“CMostofmentalionsandotherreagentstimulatedthexylanaseXYN1activitymxylanaseXYN一1exhibitedhigtIspecificitytowardsdifferentxylansandlowornOactivityWasseenwiththeothersubstratestested5Thehydrolysism

8、echanismsofXYN—lseemedtobesimilarwhenthesubstrateswerebirchwcodxyl∞andbeechwoodxylanWhenthereactolltimeWasincreasedXYNIaccumulatedxylobioseandxylolriose，thexyloteWaoseandxylopentoseincreasedinthebeginningthendeclinedlate

9、rTherewasnoxylosefrombeginningtoendSOXYN1WassuitableforproductionofxylooligosaccharidesFromtimeCOUI“Seofhydrolysisofcomcobpowderas160U／100mLxylenaseWasadded，thehydrolysisrateofcorncobwas13撕at24hTheresultsindicatethexylan