主养草鱼池塘中氨氧化古菌的多样性和种群分布

为了解淡水养殖池塘环境中氨氧化古菌的多样性和种群分布,本研究以荆州地区风生水起生态农场的主养草鱼(Ctenopharyngodon idellus)池塘为研究对象,采集不同养殖区的典型的沉积物样品和水样,利用AOA氨单加氧酶(amoA)基因通用引物(amoAF/amoAR)扩增amoA基因,构建amoA基因克隆文库。从每个克隆文库中随机挑选阳性克隆子进行测序、比对,利用MEGA和MOTHUR软件构建amoA基因系统发育树和可操作分类单元(OTU)分析。结果显示:主养草鱼池塘水体和沉积物中AOA存在着差异,且沉积物中AOA种类数和多样性都更为丰富。从三个采样区域的沉积物和水体共325个AOA amoA基因阳性克隆中得到24个OTU(基于3%差异度),其中水体克隆文库中得到13个OTU,沉积物克隆文库中得到18个OTU。OTU01、OTU02、OTU05、OTU07、OTU11、OTU13、OTU16是沉积物和水体中共有的OTU,并且OTU01、OTU02是养殖池塘中的优势类群,分别占克隆子的47.38%和21.84%。系统发育分析表明,AOA主要隶属于Nitrososphaera sister group、Nitrososphaera cluster、Nitrosopumilus cluster,并且OTU01、OTU02均属于Nitrososphaera sister group。主养草鱼池塘沉积物和水体中的AOA存在差异,且在沉积物中更为丰富,主要类群为Nitrososphaera sister。

Diversity and distribution of ammonia-oxidizing archaea in Ctenopharyngodon idellus aquaculture pond

Ammonia-oxidizing archaea(AOA)plays an important role in nitrogen cycling mediated by microorganisms and widely distributed.In this study,we studied AOA diversity and distribution in ponds culturing Ctenopharyngodon idellus in Jingzhou,Hubei province.Sediment and water samples were collected and DNA were extracted with DNA-extracting kits.Ammonia monooxygenase(amoA)gene was amplified using universal primers(amoAF/amoAR),cloned and sequenced.The phylogenetic tree was constructed with MEGA and analysed with MOTHUR.The results showed that AOA were different in the water and sediment.The richness and diversity of AOA were more abundant in the sediment.A total of 24 OTUs from 325 AOA amoA positive clones were detected,in which 13 OTUs belonged to the water clone libraries,and 18 belonged to the sediment clone libraries.Seven OTUs(OTU01,OTU02,OTU05,OTU07,OTU11,OTU13 and OTU16)were found to exist in both the water and sediment samples.OTU01 and OTU02 were the dominant groups in this aquaculture pond and accounted for 47.38%and 21.84%of the total clones sequenced,respectively.Phylogenetic analysis showed that the 24 OTUs mainly belonged to Nitrososphaera sister group,Nitrososphaera cluster and Nitrosopumilus cluster,and OTU01 and OTU02 both belonged to Nitrososphaera sister group.Thus Nitrososphaera sister group were the dominant AOA species/cluster in the C.idellus aquaculture ponds.