Abstract:
A quinoline-degrading strain, C2, which could completely degrade 250 mg/L of quinoline within 24 h, was isolated from coking wastewater. Strain C2 was identified as Ochrobactrum sp. on the basis of 16S rDNA sequence analysis According to 16S rDNA gene sequence analysis, Strain C2 was identified as Ochrobactrum sp. Strain C2 could utilize quinoline as the sole carbon sources and nitrogen sources to grow and degrade quinoline well under acidic conditions. The optimum inoculum concentration, temperature and shaking speed for quinoline degradation were 10%, 30 °C and 150 r/min, respectively. The degradation of quinoline at low concentration by the strain followed the first-order kinetic model. The growth process of strain C2 was more consistent with the Haldane model than the Monod model, and the kinetic parameters were: Vmax = 0.08 h-1, Ks = 131.5 mg/L, Ki = 183.1 mg/L. Compared with suspended strains, strain C2 immobilized by sodium alginate had better degradation efficiency of quinoline and COD. The metabolic pathway of quinoline by Strain C2 was tentatively proposed, quinoline was firstly converted into 2(1H) quinolone, then the benzene ring was opened with the action of catechol 1,2-dioxygenase and subsequently transformed into benzaldehyde, 2-pentanone, hydroxyphenyl propionic acid and others.
摘要:
一种喹啉降解菌株,C2可以在24h内完全降解250mg/L的喹啉,从焦化废水中分离出来。菌株C2被鉴定为苍白杆菌属。根据16SrDNA基因序列分析,菌株C2被鉴定为苍白杆菌属。菌株C2可以利用喹啉作为唯一的碳源和氮源,在酸性条件下生长和降解喹啉。最佳接种物浓度,喹啉降解温度和振荡速度为10%,30°C和150r/min,分别。该菌株在低浓度下对喹啉的降解遵循一级动力学模型。菌株C2的生长过程比Monod模型更符合Haldane模型,动力学参数为:Vmax=0.08h-1,Ks=131.5mg/L,Ki=183.1mg/L与悬浮菌株相比,海藻酸钠固定化菌株C2对喹啉和COD有较好的降解效果。初步提出了菌株C2对喹啉的代谢途径,首先将喹啉转化为2(1H)喹诺酮,然后在邻苯二酚1,2-双加氧酶的作用下打开苯环,然后转化为苯甲醛,2-戊酮,羟苯基丙酸和其他。