邻苯二甲酸二丁酯降解菌株的筛选鉴定及其降解特性研究

Isolation and Identification of Dibutyl Phthalate-degrading Strain and Its Degradation Characteristics

摘要:

从四川省雅安市使用过地膜的蔬菜田地的土壤中筛选得到一株以邻苯二甲酸二丁酯（DBP）为唯一碳源和能源生长的高效降解菌株JF，经形态学、生理生化特征和16S rDNA序列分析，该菌株被鉴定为枯草芽孢杆菌（Bacillus subtilis）。在LB培养基的动力学研究表明，菌株JF降解邻苯二甲酸二丁酯的过程满足一级动力学方程模型，在测试的底物（DBP）浓度、温度、pH范围内，DBP的半衰期为3.11~6.98 h，且该反应的速率受底物浓度和温度的影响较大，受pH值影响不大。菌株JF可降解DBP及其中间产物邻苯二甲酸，此外，菌株JF在72 h内对200 μg/mL的邻苯二甲酸二（2-乙基己）酯（DEHP）、邻苯二甲酸二辛酯（DOP）和邻苯二甲酸丁苄酯（BBP）降解率为90.10%、79.10%和76.30%。该研究为消除或减少环境、农产品中邻苯二甲酸酯残留提供了理论依据。

Abstract:

In this study, a high-efficiency degrading strain, JF, that utilized dibutyl phthalate (DBP) as the sole source of carbon and energy for growth was isolated from vegetable field soil in Ya’ an, Si Chuan province, where mulch film was used. The strain was identified as Bacillus subtilis based on morphology, physiological and biochemical features, and 16S rDNA sequence analysis. Study on growth dynamics of strain JF in LB medium showed that degradation of dibutyl phthalate conformed to a first-order kinetics equation model. Based on substrate concentration, temperature, and pH, the half-life of DBP was estimated to be between 3.11 and 6.98 h. Additionally, the reaction rate was greatly influenced by substrate concentration and temperature but was not largely affected by pH. The strain was able to degrade DBP as well as its intermediate product phthalic acid. Degradation rate of 200 μg/mL di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DOP), and butyl benzyl phthalate (BBP) in 72 h was 90.10%, 79.10% and 76.30%, respectively. This study could provide theoretical basis for the removal of pollutant phthalic acid ester from both, the environment and agricultural products.