假单胞菌ZWL73降解4-氯硝基苯的代谢途径研究

氯代硝基芳香烃是一类环境中难以降解的有毒污染物。一株高效分解4-氯硝基苯的假单胞菌分离于4-氯硝基苯污染土壤, 可以完全降解4-氯硝基苯, 并以之为C源、N源生长。为阐明其降解4-氯硝基苯的代谢途径, 通过对以底物生长的降解菌的酶学分析, 检测到其还原降解的两个关键酶即初始酶硝基还原酶和苯环开环酶2-氨基-5-氯酚1, 6-双加氧酶的活性; 结合其它检测如培养液中降解产物分析、相关底物生长实验结果, 确定了其降解途径是通过部分还原途径。

Identification of Metabolic Pathways of 4-Chloronitrobenzene Degradation by Pseudomonas Strain ZWL73

Chloro- and nitro- substituted aromatics are toxic and persistent in the environment. Pseudomonas putida ZWL73, isolated from 4-chloronitrobenzene (4CNB) polluted soil, can grow on 4CNB as carbon and nitrogen sources. Enzymatic analyses were carried out in order to illuminate the degradation pathway. Two key enzymatic acivities were found to be invovled in the degradation: the nitroreductase activity that catalyzing the first step and the ring-cleavage dioxygenase activity leading the substrate to be mineralized. The degradation was therefore decided to process through a partial reductive pathway together with the proofs of the results of degradation intermediates test and growth substrate test.