Isolation of a High Efficient Nitrobacteria Union

A nitrobacteria union called A2-6-3 which uses ammonia nitrogen as the only energy and has efficient nitrification was isolated from substrate sludge of Xihu Lake in Wuhan by the separation of most probable number and solid plate.16S rDNA identification of A2-6-3 showed that the union included Nitrobacter,Nitrospira and Rhodopseudonomas,with Nitrospira as the main bacteria.Study on nitrification rates and stability of subculture of A2-6-3 found that it can transform ammonia nitrogen into nitrate nitrogen,with average nitrification rates as 4.02 mg/(L.d) and the maximum nitrification rates as 13.99 mg/(L.d).Besides that the composition and nitrification rates of A2-6-3 keep stability after subculture.