芽孢桿菌產(chǎn)β-甘露聚糖酶的純化及其穩(wěn)定性研究.pdf

1、天津大學(xué)碩士學(xué)位論文芽孢桿菌產(chǎn)β甘露聚糖酶的純化及其穩(wěn)定性研究姓名：劉躍申請學(xué)位級(jí)別：碩士專業(yè)：化學(xué)工程指導(dǎo)教師：齊崴20080501ABSTRACTpMannanaseisanimponanthemicellulase，whichiswidelyusedandusuallyproducedbymicrobialfennentationmethodInthisthesis，6rstly，thefennentationmediumwass

2、implifiedandoptimized，andthepuri6edenzymewasobtainedbysepa眥ingandpuri母ingThen，thecirculardichroismandthepredictionofproteinsecond習(xí)ⅡystnlcturewereemployedininVeStigatingthesmJcturesandstabilizationofp’mannanaseFinally，the

3、stabili妙ofspray—d巧ingproductwasimprovedbyaddingstabilizerandoptimizingoperatingparametersThemainresults、Ⅳereshownasfollowing：Theni仃ogensources，carbonsourcesandin6rganicsaltsofthefermentationmediumwerescreenedandoptimized

4、，thesimpli行edfementationmedium、vasdete徹inedTheunitenzymeactivi哆costof行nalfermentativesolutiondeceasedabout63％comparingwiththatbeforeoptimization，whichsuggestedthatthebenefitwaslargelyincreasedMeanwhile，thepigmentandimpur

5、i夠contentsofthefe徹entatiVesolutionwereobviouslylowerthanthatbeforeoptimization，whichisbeneficialtothesubsequentenzymerefiningThep—mannanaseofelec協(xié)ophoreticpuri夠wasprepared仔omcmdeenzymeby鋤moniumsulfateprecipitation，UF，DEA

6、E一52sepharose，SephadexG100，andhydroxyapatitechromatographyThemolecularweightofpmannanaseestimatedmrou曲GECisconsistcntwiththatthrou曲SDSPAGE，whichisabout39I(DaFoursequenceanalysismethods—APSSP2，SSPR04，PSIPREDandPHDwereused

7、topredicttheseconda巧structureandsomepropertiesofpmannanasebasedonitsaminoacidsequenceTheresultsindicatedthepIofBmannanasewas5505andthemoIecularweightwas380054Thehydrophobici夠curVeandtitrationcurvewerealsopredicted甲ll‘‘●一

8、lnrougnmVestlgatmgchangesmseconda拶structureandenzymeactivityofp。mannanaseatdifferenttemperatureandpHbyfarUVcirculardichroism，theeffectsofseconda巧stllJctureonenzymestabilizationwerepreIiminarilystudiedTheseconda叫stmcturer