假单胞菌JX165及其完整细胞对硝基苯的好氧降解

 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K_m(硝基苯)=34.12mg/L,V_{max(硝基苯)}=3.01mg/(L.min);K_{m(2氨基酚)}=43.49mg/L,V_{max(2氨基酚)}s =2.56mg/-L-min-;K_{m(邻苯二酚)}51.03mg/L,_{Vmax(邻苯二酚)}=1.32mg/_(L-min);K_{m（苯胺）}=57.15mg/L,V_max(苯胺)=0.79mg/(L.min)

Aerobic degradation of nitrobenzene by Pseudomonas sp. JX165 and its intact cells.

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.