L_半胱氨酸浓度对氧化还原电位和生物产氢过程的影响_英文_.docx

ChineseJournalofChemicalEngineering,18(4)681—686(2010)InfluenceofL-CysteineConcentrationonOxidation-reductionPotentialandBiohydrogenProduction*CHENHuoqing(陈火晴)1,2,MAXiaoxuan(马晓轩)1,2,**,FANDaidi(范代娣)1,2,**,LUOYan’e(骆艳娥)1,2,GAOPengfei(高鹏飞)1,2andYANGChanyuan(杨婵媛)1,21ShaanxiKeyLaboratoryofDegradableBiomedicalMaterials,SchoolofChemicalEngineering,NorthwestUni-versity,Xi’an710069,China2ShaanxiRDCenterofBiomaterialsandFermentationEngineering,SchoolofChemicalandEngineering,NorthwestUniversity,Xi’an710069,ChinaAbstractTheeffectsofL-cysteineconcentrationonbiohydrogenproductionbyEnterobacteriumBacteriumM580wereinvestigatedinbatchcultivation.TheexperimentalresultsshowedthatL-cysteinecouldenhancethecellgrowth,hydrogenproductionrateandhydrogenyieldwhenitsconcentrationwaslessthan500mg·L?1,whileithadnegativeeffectswhenitsconcentrationwashigherthan500mg·L?1.Thehydrogenproductionwasthehighest[1.29mol·mol?1(H2/glucose)]when300mg·L?1L-cysteinewasaddedintotheculture,andtheyieldwas9.4%higherthanthatinthecontrol.Theoxidation-reductionpotential(ORP),whichwasinfluencedbyL-cysteine,alsoaffectedhydrogenproduction.TheORPvalueswereintherange?300mVto?150mVwhentheL-cysteinecon-centrationwashigherthan500mg·L?1.AlthoughtheORPinthisrangewasfavorableforhydrogenproduction,itwasnotsuitableforthebiomassgrowth.Hence,lesshydrogenwasproduced.WhentheL-cysteineconcentrationwaslowerthan500mg·L?1,theORPwasmoresuitableforbothbiomassgrowthandhydrogenproduction.Inaddi-tion,atleast91%glucosewasconsumedwhenL-cysteinewasaddedtotheculturemedia,comparedtothe97.37%consumptionwithoutL-cysteineadded.Keywordsanaerobicfermentation,biohydrogen,L-cysteine,ORP1INTRODUCTIONORPatanoptimallevelforhydrogenproduction[9-11].Furthermore,L-cysteinemayaffectthecellgrowthbecauseofitsuniquestructureandassociationwithsomebacterialproteins[12,13].FewresearcheshavefocusedonL-cysteineandORP,whichmayplayimportantrolesinbiohydrogenproduction.Theobjectiveofthisstudyistoinvesti-gatetheinfluenceofL-cysteineandORPonbiohy-drogenproduction.Fossilfu