ABSTRACT
A heterotrophic nitrifier, named Bacillus sp. LY, was newly isolated from a membrane bioreactor (MBR). Bacillus sp. LY could utilize the organic carbon as the source of assimilation when it grew on glucose and ammonium chloride medium companying the formation of oxidized-nitrogen. It also could denitrify nitrate while nitrification. After 24 days incubation, the removal efficiencies of the COD and TN by Bacillus sp. LY were 71.7% and 61.2%, respectively. The phylogenetic analysis of Bacillus sp. LY was performed and the phylogenetic tree of Bacillus sp. LY and the neighbouring nitrifiers was given. Bacillus sp. LY could become a new bacterial resource for heterotrophic nitrification and might play a bioremediation role for nutrient removal.