Zhang Xiaohui, Liu Lincong, Zhang Siping, Pan Yan, Li Jing, Pan Hongwei, Xu Shiguo, Luo Feng
Research Center of Bioenergy and Bioremediation, College of Resource and Environment, Southwest University, Chongqing 400715, China.
Institute of Environment and Ecology, Shandong Normal University, 88 Wenhua Donglu, Jinan, Shandong 250014, China.
Biomed Res Int. 2016;2016:5178697. doi: 10.1155/2016/5178697. Epub 2016 Dec 19.
The biodegradation characteristics of dimethyl phthalate (DMP) by three freshwater unicellular organisms were investigated in this study. The findings revealed that all the organisms were capable of metabolizing DMP; among them, sp. PCC7822 achieved the highest degradation efficiency. Lower concentration of DMP supported the growth of the Cyanobacteria; however, with the increase of DMP concentration growth of Cyanobacteria was inhibited remarkably. Phthalic acid (PA) was detected to be an intermediate degradation product of DMP and accumulated in the culture solution. The optimal initial pH value for the degradation was detected to be 9.0, which mitigated the decrease of pH resulting from the production of PA. The optimum temperature for DMP degradation of the three species of organisms is 30°C. After 72 hours' incubation, no more than 11.8% of the residual of DMP aggregated in Cyanobacteria cells while majority of DMP remained in the medium. Moreover, esterase was induced by DMP and the activity kept increasing during the degradation process. This suggested that esterase could assist in the degradation of DMP.
本研究考察了三种淡水单细胞生物对邻苯二甲酸二甲酯（DMP）的生物降解特性。研究结果表明，所有生物均能够代谢DMP；其中，sp. PCC7822的降解效率最高。较低浓度的DMP对蓝细菌的生长有促进作用；然而，随着DMP浓度的增加，蓝细菌的生长受到显著抑制。检测到邻苯二甲酸（PA）是DMP的中间降解产物，并在培养液中积累。检测发现降解的最佳初始pH值为9.0，这减轻了因PA产生导致的pH值下降。三种生物降解DMP的最适温度为30℃。培养72小时后，蓝细菌细胞内聚集的DMP残留量不超过11.8%，而大部分DMP仍留在培养基中。此外，DMP可诱导酯酶产生，且在降解过程中酯酶活性持续增加。这表明酯酶有助于DMP的降解。
