Pseudomonas fluorescens 2P24: A root beneficial bacterium with an excellent ability to remove multiple nitrogen sources

Abstract

The nitrogen removal capacity of the root-associated beneficial bacterium Pseudomonas fluorescens 2P24 was investigated in synthetic wastewater and actual wastewater. The results revealed that strain 2P24 removed 97.63 % of ammonium and 100 % of nitrate and nitrite within 48 h when ammonium, nitrate, or nitrite served as the sole nitrogen source (initial concentrations of 100 mg/L). At an ammonium to nitrate to nitrite ratio of 1:1:1, ammonium, nitrate, and nitrite were all removed with efficiencies exceeding 98 %. In addition, strain 2P24 exhibited high nitrogen removal performance in actual wastewater, removing 79.52 % of ammonium and 100 % of nitrate from unsterilized domestic sewage in 10 h. Moreover, regardless of whether the strain was grown in the presence of a sole nitrogen source or mixed nitrogen sources, there was no hazardous nitrite accumulation after 48 h of cultivation. Collectively, the findings indicated that strain 2P24 has potential applications as a standby bacterium for the biological treatment of wastewater.