資源描述：
《微生物發(fā)酵畢業(yè)論文》由會員上傳分享，免費在線閱讀，更多相關(guān)內(nèi)容在學術(shù)論文-天天文庫。
1、微生物發(fā)酵畢業(yè)論文題目:白色鏈霉菌PL3-6菌株產(chǎn)聚賴氨酸發(fā)酵條件研究專業(yè)：生物工程III摘要ε-聚賴氨酸(ε-Poly-L-Lysine)是由微生物發(fā)酵合成的一種由賴氨酸單體通過ε-酞胺鍵形成的多膚。ε-PL具有優(yōu)良的抑菌作用，對革蘭氏陽性菌和陰性菌、酵母和一些病毒都有抑制作用，而且兼有水溶性好、熱穩(wěn)定性高等特點。采用正交實驗對篩選的一株白色鏈霉菌StreptomycesalbulusPL3-6發(fā)酵產(chǎn)ε-聚賴氨酸(ε-PL)的培養(yǎng)基成分進行了優(yōu)化。結(jié)果表明，該菌株產(chǎn)ε-PL的優(yōu)化培養(yǎng)基為:葡萄糖3.0g·L-1、酵母粉0
2、.5g·L-1、(NH4)2SO41.2g·L-1、KH2PO40.20g·L-1、K2HPO40.12g·L-1、MgSO4·7H2O0.05g·L-1、FeSO4·7H2O0.003g·L-1、ZnSO4·7H2O0.008g·L-1。在優(yōu)化培養(yǎng)基下，ε-PL搖瓶產(chǎn)量達到4.05g·L-1，比優(yōu)化前提高了25%。采用D152弱酸性陽離子交換樹脂(H型)對發(fā)酵法生產(chǎn)的ε-聚賴氨酸進行了分離提取。參考文獻設(shè)計了合理的工藝流程。離心分離發(fā)酵(pH3.2)，調(diào)節(jié)濾液的pH值到8.5，過濾除去沉淀。濾液通過D152離子交換柱(H
3、型)，用水和0.2N醋酸洗滌，用0.1N的鹽酸洗脫。用1N的NaOH調(diào)節(jié)洗脫液的pH值到6.5，加入活性炭脫色后濃縮到小體積。加入乙醇和乙醚的混合物(體積比2:1)后，析出白色晶體。關(guān)鍵詞：ε-聚賴氨酸白色鏈霉菌發(fā)酵條件提取離子交換IIIAbstractε-Poly-L-Lysineiscomprisedoflysinelinkedbyamidebondthroughmicrobialfermentation.IthasexcellentantibacterialactivityagainstGram-positivean
4、dGram-negativebacteria,yeastandsomekindsofviruses.Inadditionalε-Poly-L-Lysineissolubleandattractiveheatstable.ThefermentationmediumofStreptomycesalbulusproducingε-poly-L-Lysinewasoptimizedbyorthogonalexperiments.Theoptimalmediumconsistedof3.0g·L-1glucose,0.5g·L-1y
5、eastextract,1.2g·L-1(NH4)2SO4，0.20g·L-1KH2PO4,0.12g·L-1K2HPO4,0.05g·L-1MgSO4·7H2O,0.003g·L-1FeSO4·7H2Oand0.008g·L-1ZnSO4·7H2O.Theyieldofε-PLreached4.05g·L-1withoptimalmedium,whichincreased25%comparedtoinitialmedium.Theseparationandextractionofε-Poly-L-Lysinefromfe
6、rmentationliquidbyusingweakacidanion-exchangeresinD152.Theculturebroth(pH3.2)wasfilteredandthefiltratewasadjustedtopH8.5.Then,theprecipitateformedwasremovedbyfiltration.Thefiltratewasappliedonacolumnofweakacidanion-exchangeresinD152(H+-from)andwashedwith0.2Nacetic
7、acidandwater,successively.Thesubstancewaselutedwith0.1Nhydrochloricacid.Theeluatewasneutralizedwith1Nsodiumhydroxideanddecolorizedwithactivecharcoal,andthenevaporatedtoasmallvolume.Thesubstancewasprecipitatedasawhitepowderbyadditionofanethanolandether(2:1)mixture.
8、Keywords:ε-Poly-L-Lysine;Streptomycesalbulus;fermentcondition;extractionionexchangeresinsIII目次1引言………………………………………………………………………………11.1ε-聚賴氨酸………………………………………
