Heterotrophic nitrogen removal by a newly-isolated microorganism, Oligella sp. XS68

A new bacterium capable of heterotrophic nitrogen removal was isolated and identified as Oligella sp. XS68. The strain exhibited efficient heterotrophic nitrogen removal capabilities, with a low accumulation of nitrification products. Single-factor experiments indicated that efficient nitrogen removal and growth of the strain XS68 occurred with sodium succinate as the carbon source, C/N ratio 15, pH 6.0–9.0, temperature 30–37 °C, and shaking speed 160–200 rpm. The removal efficiency of ammonium nitrogen could achieve 98 % within 96 h when the initial nitrogen concentration was 421.3 mg L-1. These findings demonstrate that XS68 is a promising candidate for nitrogen removal in wastewater treatments.