摘要
Ourobjectiveistosolvethelactosemalabsorptionandintoleranceofhumanbeingsbycombiningmlcro-ecologypathwithgeneticengineeringtechnique.PlasmidpMG36ewasusedtocloneandexpressaβ-galactosidasegenefromL.delbrueckiibulgaricusstrain1.1480intheLactococcuslactissubsp,cremorisMG1363andLactococcuslactissubsp.lactisIL1403.TherecombinantplasmidwaspreservedandproliferatedinEscherichiacoli(E.coli)JM109,andtransformedintoMG1363and1L1403byelectroporation.Theproteinexpressionwasstudied.(1)Thebifidobacteriumculturemedium(BBL)wassuitableforthegrowthofthestrain1.1480.(2)With13aminoacidsattheN-terminusfromthevector,β-galactosidasefusionprotein(whichretainedtheenzymeactivity)couldbesuccessfullyexpressedinE.coliJM109,MG1363andIL1403,buttheexpressionquantitywaslargerintheformerthaninthelattertwo.(3)TheSDsequencedesignedcouldbesuccessfullyrecognizedbyboththeE.coliandtheLactococcuslactis,buttheexpressionlevelofthenon-fusionβ-galac-tosidaseproteinwaslowerthanthatofthefusionproteininthesamehost.Theβ-galactosidasegeneticallyengineeredE.coliJM109isausefultooltoproducethisenzymeinvitro.Thesignalpeptideoftheusp45proteinfromtheLactococcuslactiscanbeaddedbeforethepromotersequencetopromoteβ-galactosidasesecretionfromLactococcuslactis.Thepotentialapplicationoftheβ-galactosidasegeneticallyengineeredMG1363andIL1403tocurethelactosemalabsorptionandlactoseintoleranceinbothhealthfoodandmedicineispromising。
出版日期
2004年04月14日（中国期刊网平台首次上网日期，不代表论文的发表时间）
