Enhanced heterotrophic nitrification and aerobic denitrification performance of Glutamicibacter arilaitensis EM-H8 with different carbon sources

Different carbon sources for Glutamicibacter arilaitensis EM-H8 were evaluated for ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N) and nitrite nitrogen (NO2--N) removal. Strain EM-H8 could rapidly remove NH4+-N, NO3--N and NO2--N. The highest removal rates measured for different forms of nitrogen with different carbon sources were 5.94 mg/L/h for NH4+-N with sodium citrate, 4.25 mg/L/h for NO3--N with sodium succinate, and 3.88 mg/L/h for NO2--N with sucrose. The Nitrogen balance showed that strain EM-H8 could convert 77.88% of the initial nitrogen into nitrogenous gas when NO2--N was selected as the sole nitrogen source. The presence of NH4+-N increased the removal rate of NO2--N from 3.88 to 4.02 mg/L/h. In an enzyme assay, ammonia monooxygenase, nitrate reductase and nitrite oxidoreductase were detected at 0.209, 0.314, and 0.025 U/mg protein, respectively. These results demonstrate that strain EM-H8 performs well for nitrogen removal, and shows excellent potential for simple and efficient removal of NO2--N from wastewater.