The nitrogen removal characterization of a cold-adapted bacterium: Bacillus simplex H-b

The removal efficacy of biological nitrogen removal process is inhibited by low temperatures. Herein, a psychrotrophic bacterium strain, Bacillus simplex H-b, was isolated and identified with the potential to conduct heterotrophic nitrification and aerobic denitrification in the temperature range from 5 to 37 degrees C. At 10 degrees C, the removal efficiencies of initial nitrate-N (63 mg/L), nitrite-N (10 mg/L) and ammonium-N (60 mg/L) were 67.29%, 78.69% and 82.16%, with the maximum removal rate of 0.56, 0.18 and 0.74 mg/L/h, respectively. Additionally, both the accumulation level of ATP (adenosine triphosphate) and the formation of extracellular polymeric substances was found to increase with the decrease of temperature from 37 degrees C to 10 degrees C, indicating strain H-b might resist low temperature stress through its cellular extreme environment resistant mechanism and further suggesting the newly isolated strain could serve as a promising candidate for nitrogen contaminated wastewater treatment, especially under low-temperature condition.

Automated summary

The psychrotrophic bacterium strain Bacillus simplex H-b showed potential for biological nitrogen removal process at low temperatures, demonstrating high removal efficiencies for nitrate-N, nitrite-N, and ammonium-N at 10 degrees C. Additionally, the strain was found to resist low temperature stress through its cellular extreme environment resistant mechanism. This newly isolated strain could be a promising candidate for nitrogen contaminated wastewater treatment, especially in low-temperature conditions.