Characterization of a novel salt-tolerant strain Sphingopyxis sp. CY-10 capable of heterotrophic nitrification and aerobic denitrification. (August 2022) - Chen, Peipei
Graphical abstract: Highlights: A Sphingopyxis sp. strain with HN-AD function was firstly isolated. The HN-AD pathway followed NH4 + -N → NH2 OH → NO2 – -N → NO → N2 O → N2 . A maximum nitrogen removal rate of 6.25 mg/(L·h) was realized at 5% salinity. The high-salt tolerance mechanism of strain CY-10 was revealed. Abstract: A novel heterotrophic nitrification and aerobic denitrification (HN-AD) strain CY-10 was isolated and identified as Sphingopyxis sp. When ammonium, nitrate or nitrite was used as the sole nitrogen source (300 mg/L), the maximum nitrogen removal efficiency of strain CY-10 were 100%, 91.1% and 68.5%, respectively. The optimal salinity for ammonia nitrogen removal by strain CY-10 was in the range of 0–5%. At the salinity of 5%, a maximum nitrogen removal rate of 6.25 mg/(L·h) was realized. Metabonomics data showed that the metabolic levels of sucrose and D-tagatose increased significantly at 5% salinity condition, enabling the strain to regulate osmotic pressure and survive in high-salt environments. Functional genes were successfully amplified by quantitative PCR, and HN-AD pathway of strain CY-10 followed NH4 + -N → NH2 OH → NO2 – -N → NO → N2 O → N2 . These findings show that strain CY-10 has great potential in nitrogen removal treatment of saline wastewater.