一株降解对氯硝基苯的Comamonas sp.CNB1的分离鉴定及其降解特性

Characterization of p-chloronitrobenzene-degrading Comamonas sp. CNB1 and its Degradation of p-chloronitrobenzene

从处理某化工厂污水的活性污泥中分离到一株降解对氯硝基苯的细菌CNB1菌株。经过对其形态特征、生理生化、以及 1 6SrDNA序列分析 ,该菌株初步鉴定为Comamonassp .,进一步研究表明 ,该菌株能够以对氯硝基苯为唯一碳源、氮源和能源生长。生长过程中 ,氯离子释放同步于对氯硝基苯降解 ,且氯离子的释放量与对氯硝基苯的降解量相当。该细菌利用对氯硝基苯生长的最适生长温度和pH分别为 2 8℃和 9 0。测定了降解途径中相关酶的活性 ,表明初始降解过程是由对氯硝基苯还原酶催化的硝基还原反应 ,芳环的裂解是由 2_氨基苯酚 1 。

A bacterial strain that degrades p _chloronitrobenzene was isolated from activated sludge of wastewater treatment plant treating wastewater from a chemical factory producing chloronitroenzene. This strain was identified as Comamonas sp. CNB1 based on its morphology, physiological, biochemical properties and 16S rDNA sequence analysis. Results indicated that strain CNB1 took p _chloronitrobenzene as sole carbon, nitrogen and energy resources. During cultivation, chloride anion was released simultaneously and stoichemically to p _chloronitrobenzene degradation. The optimal pH and temperature for cell growth and for p _chloronitrobenzene degradation was 9 0 and 28℃, respectively. Enzymatic analysis showed that initial reactions of p _chloronitrobenzene degradation with Comamonas sp. CNB1 were catalyzed by p _chloronitrobenzene nitroreductase and 2_aminophenol 1,6_dioxygenase.