一株好氧反硝化菌的鉴定及脱氮特性研究

1276北京市科技专项(Z161100005016034)资助收稿日期:20171120;修回日期:20171227;网络出版日期:20181022北京大学学报(自然科学版)第54卷第6期2018年11月ActaScientiarumNaturaliumUniversitatisPekinensis,Vol.54,No.6(Nov.2018)doi:10.13209/j.0479-8023.2018.071一株好氧反硝化菌的鉴定及脱氮特性研究李雪1刘思彤2陈倩2,†1.兰州城市学院化学与环境工程学院,兰州730070;2.北京大学环境工程系,北京市新型污水深度处理工程技术研究中心,北京100871;†通信作者,E-mail:qianchen@pku.edu.cn摘要以筛选分离得到的好氧反硝化菌HG-7为研究对象,经过16SrRNA同源性分析,初步鉴定该菌株为假单胞菌属(Pseudomonassp.)。对菌株HG-7反硝化功能基因的扩增结果表明,菌体HG-7内存在好氧反硝化功能基因napA和nirK,证实该细菌为好氧反硝化细菌。对菌株的脱氮特性和影响因素的研究表明,以硝酸盐氮为氮源时,菌株的最适碳源为乙酸钠和丁二酸钠,最佳C/N比为6~10,最适宜的温度范围为26~30℃。在上述条件下,菌株HG-7的好氧反硝化活性较高,48小时内对100mg/L硝酸盐氮的去除率可达98%,且在反应过程中亚硝酸盐氮积累量较低。以亚硝酸氮为唯一氮源时,低浓度条件下可实现100%的氮素去除率;高浓度条件下,脱氮速率则受到明显的抑制,对91.4mg/L的亚硝酸盐氮氮去除率约为40%。因此,将该菌株应用于废水的脱氮处理,可实现氮素的有效去除,具有潜在的应用价值。关键词好氧反硝化菌;鉴定;脱氮特性中图分类号X172IdentificationofanAerobicDenitrifierandItsDenitrificationCharacteristicsLIXue1,LIUSitong2,CHENQian2,†1.SchoolofChemistryandEnvironmentalEngineering,LanzhouCityUniversity,Lanzhou730070;2.BeijingEngineeringResearchCenterofAdvancedWastewaterTreatment,DepartmentofEnvironmentalEngineering,PekingUniversity,Beijing100871;†Correspondingauthor,E-mail:qianchen@pku.edu.cnAbstractStrainHG-7wasidentifiedasPseudomonassp.through16srRNAgenesequenceanalysis.TheaerobicdenitrificationabilityofstrainHG-7wasfurtherprovedbytheexistenceofthenapAandnirKgenes.FurtherstudiesshowedthattheoptimalcarbonresourcesforstrainHG-7weresodiumacetateandsodiumsuccinate,theoptimalC/Nratiowas610,andthesuitabletemperaturewas2630℃.Atthiscondition,withaninitialnitratenitrogenof100mg/L,98%ofnitratecouldberemovedin48hoursandtheamountofnitriteaccumulationwasverysmall.Moreover,withnitriteasthesolenitrogensource,100%ofnitritecouldberemovedatlowernitriteconcentration.Butthenitritenitrogenremovalratewasabout40%whenthenitriteconcentrationincreasedto91.4mg/L,indicatingthathighnitriteconcentrationwasharmfulforaerobicdenitrificationbystrainHG-7.ThestrainHG-7hasgreatpotentialtobeusedforbiologicalnitrogenremoval,whichwasparticularlysignificantforactualwastewatertreatmentpro