[Screening and denitrification characteristics of a heterotrophic nitrification-aerobic denitrifier bacteria].

A heterotrophic nitrification-aerobic denitrifier bacteria CPZ24 was isolated form the livestock wastewater by way of the limiting dilution combined with the chromogenic medium screening methods. This bacterium was Gram positive, rod. The colonies of the strain were orange-red.It was identified as Rhodococuus pyridinivorans according to its morphological and physiological properties and the analysis of its 16S rDNA gene. Studied on its function of heterotrophic nitrification and aerobic denitrification,the results show that all NH4+ -N is removed and the removal rate of TN is 98.70% in heterotrophic nitrification; the removal rate of NO3- -N by this strain is 66.74% and the removal rate of TN is 64.27%. This high effective microorganisms with nitrogen removed is able to realize simultaneous nitrification and denitrification. It can perform the whole process of bacteria denitrification independently.