假单胞菌JX165及其完整细胞对硝基苯的好氧降解

摘要

The aerobic degradation characteristics and mechanism of nitrobenzene by Pseudomonas sp.JX165 and its intact cells were investigated and analyzed. The results indicated that, during the course of degradation, 2-aminophenol and aniline were first produced by reduction, then the degradation was completed by different oxidation pathway; at high concentration (more than 200 mg/L) and high shaking speed (more than 200 r/min), a more refractory azobenzene would be produced;the JX165 cells induced by nitrobenzene contain degrading enzymes for nitrobenzene, aniline,2-aminophenol and catechol, and all were inducible, with kinetic parameters: Km(nitrobenzene)=34.12mg/L, Vmax(nitrobenzene)= 3.01mg/L×min; Km(2-aminophenol)=43.49mg/L, Vmax(2-aminophenol)=2.56 mg/(L×min); Km(catechol)=51.03mg/L, Vmax(catechol)=1.32 mg/(L×min); and Km(aniline)=57.15mg/L, Vmax(aniline)=0.79mg/(L×min) respectively.%利用Pseudomonas sp. JX165及其完整细胞考察了硝基苯的好氧降解特性,并对其降解机理进行了分析.结果表明,菌株JX165对硝基苯的好氧降解过程,首先还原产生2-氨基酚和苯胺,再经不同的氧化途径彻底降解;在高浓度(＞200mg/L)及高转速(＞200r/min)下,菌株JX165对硝基苯的降解过程会产生更难以降解的偶氮苯类化合物;经硝基苯诱导的JX165细胞中含有硝基苯、2-氨基酚、苯胺及邻苯二酚降解酶,且它们均为诱导酶,其动力学参数分别为Km(硝基苯)=34.12mg/L,Vmax(硝基苯)=3.01mg/(L×min);Km(2-氨基酚)=43.49mg/L,Vmax(2-氨基酚) =2.56mg/(L×min);Km(邻苯二酚)=51.03mg/L,Vmax(邻苯二酚)=1.32mg/(L×min);Km(苯胺)=57.15mg/L,Vmax(苯胺)=0.79mg/(L×min).