The Study Of Ammonia-oxidizing Bacteria From Sediments In Bohai Sea

Nitrogen is one of the basic elements for essential life activities. Various forms ofnitrogen exist in the biogeochemical cycling. Ocean nitrogen cycle plays an important role.Nitrification is a microbial facilitated process of the oxidation of ammonia to nitrate via nitrite.AmoA gene was widely used in the studies of Ammonia-Oxidizing Bacteria diversity. Tounderstand the composition and structure of Ammonia-Oxidizing Bacteria communities insedimentary environment of Bohai Sea, the diversity of amoA gene from the sediments ofBohai Sea was investigated by using a PCR-based gene cloning approach, combining thePrincipal Coordinates Analysis. A total of563amoA gene clones were obtained from6sampling stations. Restriction analysis of cloned amoA sequences obtained a total of49Operational Taxonomic Units (OTUs) from all samples. The number of OTUs in each stationwas ranged from15to18, which shows a low diversity of AOB in Bohai. The levels ofidentity of the amoA sequences to their best-match known sequences retrieved from theGenBank database varied from97%to100%. Molecular phylogenetic analysis of amoAsequences, being assigned into5Clusters(Clusters I-V), retrieved from the Gulf of Finland,estuary system, sediment of deep-sea、eurotrophic freshwater and coral reef and Jiaozhou Bay.The AOB are Nitrosomonas and Nitrosospira, the latter being the main AOB in B001、B005and B011station. Cluster Environment, Jackknife Cluster and Principal Coordinates Analysis(PCoA) indicated that the Ammonia-Oxidizing Bacteria communities of B001were unique.The Canonical Correspondence Analysis indicated that multi-environment factors, mainlysediment porewater concentration of NH4+-N controlled the community structure ofAmmonia-Oxidizing Bacteria.