Quinoline biodegradation characteristics of a new quinoline-degrading strain, Pseudomonas citronellolis PY1

BACKGROUND Quinoline exerts inhibitory effects on microorganisms in the biological process. However, microbial degradation of quinoline is feasible, and bacteria with quinoline-degrading ability have gained increasing attention, making it possible to improve the bioremediation performance of wastewater. Therefore, this article focused on the quinoline removal performance of a new strain Pseudomonas citronellolis PY1. RESULTS The optimal conditions of strain PY1 for quinoline removal are incubation temperature 30 degrees C, dissolved oxygen (DO) 4.69 mg/L and pH 7.0-9.0. For strain PY1, complete removal of quinoline could be achieved within 18 h. Zinc ions (Zn2+) have less toxicity to PY1 than cadmium ions (Cd2+), and efficient removal of quinoline occurs within 50 mg/L Zn2+ and 30 mg/L Cd2+. Through high-performance liquid chromatography mass spectrometry (HPLC-MS) analysis, five major intermediates were identified in the quinoline biodegradation process. On the basis of these intermediates and gas detection, strain PY1 is suggested to degrade quinoline through the typical 8-hydroxy coumarin pathway. CONCLUSION Strain PY1 could utilize quinoline as the sole carbon and nitrogen source for growth, and show superior quinoline biodegradation performance, as indicated by simultaneous biomass growth and high chemical oxygen demand (COD) removal accompanied with quinoline removal. All the results provide a theoretical base for treating actual wastewater containing quinoline. (c) 2020 Society of Chemical Industry