简介:ToobtainthermotolerantmutantsofG.oxydans,whichcanenhancethetransformationrateofL-sorboseto2-Keto-L-gulonate(2-KLG)at33℃inatwo-stepprocessofvitaminCmanufacture,ionbeamwasusedasamutationsource.GluconobacteroxydansGOandBacillusmegateriumB0wereusedinthisstudy.TheoriginalstrainGluconobacteroxydansGOwasmutatedbytheheavyionimplantationfacilityattheInstituteofPlasmaPhysics,ChineseAcademyofSciences.SeveralmutantsincludingGluconobacteroxydansGI13wereisolatedandcoculturedwithBacillusmegateriumB0at33℃inshakingflasks.TheaveragetransformationrateofthenewmixedstrainGI13-B0inpergram-moleculereached94.4%aftersevenpassagesinshakingflasks,whichwasincreasedby7%whencomparedwiththeoriginalmixedstrainG0-B0(GluconobacteroxydansG0andBacillusmegateriumB0).Moreover,thetransformationrateofI13B0wasstableat94%attemperaturesrangingfrom25℃to33℃,whichwouldbeofmuchvalueinreducingenergyconsumptioninthemanufactureofL-ascorbicacid,especiallyintheseasonofsummer.Toclarifysomemechanismofthemutation,thespecificactivitiesofL-sorbosedehydrogenaseinbothG0andGI13wereestimated.
简介:Thepreliminarydesignofamulti-barrelspelletinjectorwithcyclerefrigeratorasanadvancedplasma-fuellingtoolforHL-2Atokamakhasbeenproposed.Thedesignaimsatprecisetemperaturecontrol,easyoperation.withhighreliabilityandhighflexibility.GM-cyclerefrigeratorandpipe-gunStructurehavebeenemployedtoproduce25pelletsin25gunbarrelssimultaneouslyandthedesignaims.havebeenaccomplished.Primedesignprinciple,engineeringparameters,structureandlayoutofthecryostatcomponentsaswellascalculationofheatloadforthecryostatarepresented.
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