球形红细菌厌氧降解2,4-二硝基甲苯（英文）

Anaerobic biodegradation of 2,4-dinitrotoluene by Rhodobacter sphaeroides

摘要:

【目的】研究不同环境条件对2,4-二硝基甲苯(2,4-DNT)生物降解的影响。【方法】采用光合细菌球形红细菌在温度为30 °C的光照培养箱中厌氧降解2,4-DNT，并用高效液相色谱仪测定其浓度。【结果】去除2,4-DNT的最佳条件是初始浓度40 mg/L、初始pH 7.0和接种量15%。另外，2,4-DNT在菌体延滞期被细胞吸收,然后在指数期作为碳源被降解。2,4-DNT的去除率在72 h达到98.8%。从液相色谱图中观察到有2种中间代谢产物，但在120 h内产物被逐渐降解。2,4-DNT的去除动力学符合一级速率模型。【结论】不同条件下2,4-DNT的去除率表明球形红细菌能有效降解2,4-DNT。

Abstract:

[Objective] To investigate the biodegradation of 2,4-dinitrotoluene (2,4-DNT) under various environmental conditions by Rhodobacter sphaeroides. [Methods] 2,4-DNT was anaerobically biodegraded under 30 °C in illumination incubator using photosynthetic bacterium Rhodobacter sphaeroides. The concentration of 2,4-DNT in liquid medium were detected by HPLC. [Results] Optimum conditions for the removal of 2,4-DNT were initial concentration of 40 mg/L, initial pH 7.0 and inoculation quantity of 15%. In addition, 2,4-DNT could be absorbed by the cells in lag phase, then degraded as carbon source in exponential phase. The removal rate of 2,4-DNT achieved 98.8% at 72 h. Using HPLC, two different intermediate metabolites were also observed, however, these decreased gradually within 120 h. Furthermore, the removal kinetics of 2,4-DNT corresponded with the first-order rate model. [Conclusion] The removal rate of 2,4-DNT under different conditions indicated that Rhodobacter sphaeroides is efficient in biodegrading 2,4-DNT.