一株邻苯二甲酸二丁酯降解菌的筛选及其降解特性

Screening and characterization of a dibutyl phthalate-degrading bacterium

摘要:

【目的】从自然环境中筛选邻苯二甲酸二丁酯(Dibutyl phthalate，DBP)降解能力较强的微生物，并研究其降解特性和代谢途径。【方法】从杭州市河道污水出口的淤泥中筛选到DBP降解菌ZJUTW，对其进行形态、生理生化特征、16S rRNA基因序列分析，考察该菌株对DBP的降解特性，并用GC-MS分析降解中间产物。【结果】该菌株经鉴定为Arthrobacter sp.，降解DBP的最适温度和最适pH值分别为30 °C和7.0?8.0，可降解多种邻苯二甲酸酯类化合物；当DBP浓度为800 mg/L时，半衰期为10.47 h；菌株的休止细胞(OD600=1.2)可在20 h内将1 200 mg/L的DBP完全降解。利用GC-MS进行中间产物分析，该菌株可通过酯交换方式起始DBP的降解。【结论】Arthrobacter sp. ZJUTW对DBP有较强的降解能力和较高的耐受性，具有潜在的应用前景。

Abstract:

[Objective] To screen efficient dibutyl phthalate-degrading bacterium from the environment. [Methods] A bacterial strain ZJUTW that could degrade dibutyl phthalate was isolated from sludge of river of Hangzhou city, and identified by morphological, physiological characteristics and the analysis of 16S rRNA gene sequence. Its dibutyl phthalate-degrading characteristics were studied. [Results] Strain ZJUTW was identified as Arthrobacter sp. The optimal temperature was 30 °C and optimal pH between 7.0 and 8.0. The degradation was best fitted by first-order kinetic equation and the half-life was 10.47 h at 800 mg/L dibutyl phthalate of initial concentration. Dibutyl phthalate of 1 200 mg/L could be completely degraded by the resting cell (OD600=1.2) in 20 h. GC-MS analysis of the metabolites revealed that initial step of dibutyl phthalate degradation was transesterification. [Conclusion] Based on the high-tolerance ability and high removal rate of the isolated Arthrobacter sp. ZJUTW, this strain has a potential for remediation of hazardous phthalates.