Abundance Of Aquatic Ammonia-oxidizing Archaea And Relationship With Water Quality

Ammonia oxidation, as the first step in nitrification, is considered to be the rate-limiting step. It was thought to be solely mediated by a few bacterial groups,ammonia-oxidizing bacteria.Till several recent studies have proved that ammonia-oxidizing archaea are also involved in this process and may play a much more significant role in nitrification which breakthroughs the limitations of ammonia oxidizer community research.Abundance of ammonia-oxidizing archaea of fresh water and sediment samples collected in November2011with different nutrient loading were detected based on quantification of amoA gene, including South Lake,Sanjiao lake,Nantaizi Lake,Caidian Lake,Houguan Lake,Liangzi Lake,Shizikou reservoir and Malone reservoir. Data were analyzed to study the relationship between ammonia-oxidizing archaea and environmental factors.The results showed amoA copies covered from7.80×104to1.34×106per liter in water samples while from4.64×104～3.19×105per gram in sediment samples. The highest copies was found in sitel of South Lake and the lowest in site2of Houguan Lake of water samples.As to sediment samples the highest copies was also found in sitel of South Lake but the lowest in Liangzi Lake. Correlation analysis showed that the abundance of ammonia-oxidizing archaea of water samples was positively correlated with total nitrogen and ammonia but in sediment samples positively correlated with total nitrogen.