简介：

简介：

简介：MutantstrainsofGOl12andBM302withahigh2-keto-L-gulonicacid(2KLG)transformationrateinducedbyionbeamimplantationwereseparatelyandcombinatoriallycom-paredwiththeoriginalstrainsGO29andBM80tostudythemutageniceffectsofionbeamimplan-tation.BoththesoleGO112andmixedBM302:GO112demonstratedimprovedSNDHactivityand2KLGyieldcomparedtotheoriginalstrains.ThemutantcombinationsofBM302:GO112showedalongerstationaryphaseandhigherbiomassthanBM80:GO29.ThemutantBM302exhibitedastrongercapacitytomaintainastablepHenvironmentatmixedfermentationwithGluconobacteroxydans(G.oxydans)for2KLGtransformationandfacilitatedthegrowthofG.oxydanscomparedwiththeoriginalstrainBM80.ThepromotivecapacitytoL-sorbosonedehy-drogenase(L-SNDH)fromthesupernateofBM302was1.6-foldhigherthanthatofBM80.GenesencodedSNDHinGO29andGOl12wereamplifiedandsequenced,andmutationsincludingthreetransitions(CG→TA,CG→TA,GC→AT)andonetransversion(AT→TA)wereconfirmedfromGO29toGO112.ThecorrespondingaminoacidwaschangedasLeu→Phe,Arg→GlnandAsn→Lys.