Nitrogen Removal Characteristics and Application by a Novel Cold-Resistant Bacterium

Area of Science:

• Environmental Microbiology
• Wastewater Treatment Technologies

Background:

• Biological nitrogen removal is crucial for wastewater treatment but is often inhibited at low temperatures.
• Reduced microbial activity and impaired metabolic processes hinder nitrogen removal in cold conditions.

Purpose of the Study:

• To isolate and characterize a cold-resistant bacterium for efficient biological nitrogen removal.
• To evaluate the performance of the novel bacterium under various low-temperature conditions.

Main Methods:

• Isolation and identification of a cold-resistant bacterium, Acinetobacter pragensis FX1.
• Assessment of nitrogen removal efficiency at different temperatures (5-30 °C).
• Metabolic activity analysis at 5 °C and nitrogen balance studies.

Main Results:

• Acinetobacter pragensis FX1 demonstrated efficient nitrogen removal (NH4+-N, NO3--N, NO2--N) at 10 °C, reaching up to 99.39% removal.
• The bacterium remained metabolically active at 5 °C, indicating excellent cold-resistant capability.
• Nitrogen assimilation was identified as the primary pathway, minimizing greenhouse gas (N2O) production.

Conclusions:

• Acinetobacter pragensis FX1 is a promising candidate for enhancing biological nitrogen removal in cold-region wastewater treatment.
• The bacterium's cold shock response and fatty acid biosynthesis genes contribute to its cold tolerance.
• Bioaugmentation with FX1 improved nutrient removal, highlighting its potential for practical applications.