Characteristics and Mechanisms of Simultaneous Organic and Inorganic Nitrogen Removal by a Robust Bacterium <em>Pseudomonas stutzeri </em>H3

The discharge of organic and inorganic nitrogenous pollutants in wastewater leads to eutrophication and disrupts the ecological balance. Therefore, the pressing need for an effective treatment method has become increasingly evident. A robust bacterium Pseudomonas stutzeri H3 capable of simultaneous organic and inorganic nitrogen removal was isolated from the activated sludge in the coking wastewater treatment system. Strain H3 achieved above 90% of ammonium nitrogen and quinoline removal, exhibiting excellent simultaneous nitrogen removal capabilities compared with other nitrogen removal bacteria such as Halomonas sp. and Acinetobacter sp. The outstanding nitrogen removal efficiencies in the presence of quinoline and different inorganic nitrogen sources further confirmed the simultaneous organic and inorganic nitrogen removal capability of strain H3. The whole genome sequencing and nitrogen metabolic intermediates determination of strain H3 were performed to elucidate the gene function annotations, nitrogen removal function genes, and nitrogen metabolic pathways. The findings provide a promising pathway to treat the organic and inorganic nitrogenous pollutants in wastewater.