产几丁质酶渤海丝状真菌alternaria tenuissima的筛选 鉴定及产酶研究

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1、天沾_范人学硕1:学位论文胞内儿丁质酶的最适pH同样为6.5，不同的是，在pH6.5?8.0之问，酶活性随pH升高而明显下降，pH8.0时，酶活性仅存6.60%，表明该酶不具有碱性酶的特性;此外，该酶仅在25?35°C范围内有较好的活性表现，最适反应温度为30°C，随着温度增加，酶活性下降，5(TC时酶活性仅保留15.1%的活性。6)菌种鉴定：对MTJ04-1-1菌株进行经典分类指标的观察结果表明，该菌具有链格孢菌的特性。将该菌株的ITS序列提交到Gen-Bank数椐库进行BLAST比对，结果表明：该菌株ITS序列与Mtcmariate

2、nuissima(GenBank:JF835819.1；EU816392.1)fllAlternariaalternate(EU807867.1)等相似度为99%。依掘形态学鉴定结果，结合菌种來源和优先原则，将该菌株鉴定为极细链格孢菌QAlternariatenuissimaMTJ04-1-1)。关键词：渤海丝状真菌；几丁质酶；筛选鉴定；18SrDNA-ITS序列；酶学特性人if帅范人学她I学位论义AbstractChitinisakindofstraigtchainmacromoleculepolymerizedbyN-acetylg

3、lucosaminegroupwhichislinkedbybeta-1,4-glycosidicbonds.Itiswidelyexistedbehindthecellulose.ChitinaseisakindofenzymewhichcanspecificallymadethechintinhydrolyzedtobeNacetylglucosamineoroligomerizationN-acetamidoglucose.Themarineenvironmentisrichinchitinwhichisthecomponento

4、fshrimpsandcrabs.Ifthesesubstancesarenottreated,couldbecometheorganicsourcesofpollution.Becauseofthisparticularoceanhabitat,soitispossibletoseparateandscreenchitinaseformingfungi.Inthispaper,achitinaseproducingstrainofmarine-derivedfungusMTJ04-1-1wasselectedoutof52isolat

5、esfromBohai-Baythroughtransparentcirclemethodandchitinaseactivityassay.Thenwiththefermentationconditionsoptimizationexperiment,withcarbonnitrogensource,initialpH,culturetemperature,trainingtime,thebottlefactorssuchasthedesignoforthogonaltest,theoptimalconditions,todeterm

6、inetheoptimalfermentationscheme.ThestrainwasidentifiedasAlternariatenuissimabasedonitsmorphologicalcharacteristicsand18SrDNA-ITSsequencing.AndtheMTJ04-1-1instrainschitinaseenzymologynatureofthestudy,theresultsareasfollows:a.ThroughtheCongored-chitinflattransparentcirclem

7、ethodandfermentedliquidchitinaseactivitydeterminationmethodtoproducechitinstrainsoftheenzymescreening,fromwhichaplantproductionwerechitinasevigorhigherMarinefungiMTJ04-1-1.b.Throughtheorthogonalexperiment,theoptimalconditionweredetermined.The107Sporesoffonguswereincubate

8、din500mlconicalflaskwith150mlliqudculturemediumunder150r/minfor3daysat26°C，theoptimalcarbonsourseandnit