Screening of quinoline-degradation bacteria and their biodegradation capability at low temperature
低温喹啉降解菌的筛选及降解性能

One strain of psychrophilic bacteria (named as WS-5) which biodegrades quinoline efficiently and grows at a high speed was domesticated and screened from activated sludge of a petrochemical industry sewage treatment plant in Jilin. Strain WS-5 was able to utilize quinoline as a sole source of carbon, nitrogen and energy. It was identified as Pseudomonas putida which combined the morphology and physiological biochemical characteristics with the comparative analysis of 16S rDNA sequence. The experimental results under different conditions show that the optimal conditions for the degradation of quinoline of strain WS-5 were as follows: the amount inoculation of 15%; the pH value of 8~10; and the shaker rotary speed of 100 r/min. Under the best biodegradation conditions, the degradation rate of quinoline of 200 mg/L reached 85.3% during the period of 132 hours. Quinoline, whose initial concentrations of 50, 100, 200 and 300 mg/L, was completely biodegraded by Strain WS-5, in the time of 36, 72, 192 and 262 h, respectively. This research will provide technical guidance for treating quinoline sewage at low temperature in the future.