喹啉降解菌的分离鉴定及在柴油脱氮中的应用

喹啉是一种有毒、难生物降解的有机氮化合物, 通过以喹啉为唯一氮源, 富集培养筛选出19 种能降解喹啉的菌株, 通过喹啉降解实验筛选出降解喹啉较好的HY9 菌株作为实验菌株, 喹啉降解曲线和细胞生长曲线测定表明, 菌株生长和喹啉的降解是同步的, 并且在50 ～ 70 h , 菌株的生长和降解达到最佳状态。研究了葡萄糖和初始喹啉体积对菌株降解喹啉的影响, 确定碳源是葡萄糖, 喹啉体积分数为1.4 mL/ L。正交实验确定了温度为35 ℃、pH 值为7.0、培养时间为4 d 和摇床转速为125 r/ min, 并且温度对细胞生长的影响最大, 其次是摇床转速、pH 值, 培养时间对其影响最小。柴油脱碱氮的初步实验表明, 脱除率为13 %, 比较低, 可能是油水混溶性不好所致, 设法提高油水混溶性是提高柴油碱氮脱除率的关键。

Isolation Characterization and Diesel Oil Denitrogen of Quinoline - Degrading Bacterium

Quinoline is poisonous organic compound and not easy to be biodegraded. Nineteen bacterial strains were screened out by enrichment culture to decompose quinoline as sole nitrogen source. By the quinoline-degrading test, HY9 is the best quinoline-degrading bacterium as experimental strain. The curves of degration and growth of quinoline-degrading show that the growth of HY9 strain and degradation of quinoline are concurrent, optimal time is 50～70 hours, which is stable stage. Effects of glucose and the volume of initial quinoline on degradation of quinoline were studied. The optimal carbon source is glucose and volume fraction of quinoline is 1.4 mL/L. By orthogonal test determination, the optimal conditions are as following: temperature is 35 ℃, pH is 7.0, time of culture is 4 days, 125 r/min rotation speed of mechanical shaker. Temperature is the key factor for the growth of cell, then is rotation speed and pH, time of culture is the unimportance factor. The initial test of denitrification indicates that the denitrification percent for diesel oil is only 13%. Low denitrogen rate is probably because that the mixing of oil and water is not perfect, efficient mixing of oil and water is important for the enhancement of denitrogen rate for diesel oil.