沉水植物及叶面附生菌群对邻苯二甲酸酯（PAEs）污染水体的修复机制研究

Phthalate acid esters (PAEs), especially di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP), were frequently detected in various water samples in China. Submerged macrophytes and the foliage epiphytic microorganism are found to have ability in removing PAEs from the water column, therefore greatly affect the environmental fate of the pollution. Biodegradation and biotransformation are supposed to be dominant in removal of PAEs. In this research, eight speices of common native submerged macrophytes are selected for the tests. Mechanisms involving in biodegradation and biotransformation of DBP and DEHP by these plants are to be investigated under aseptic conditions. Related enzymes in the biodegradation will be determined. Contribution of biodegradation and biotransformation to the removal by plants will be also calculated. The resulting metabolites of DBP and DEHP should determined by C-14 isotops addition and analyses, together with the analyses using GC-MS. Meanwhile, epiphytic microorganism of those plants are to be investigated in their contribution in removing DBP and DEHP from water column. Mechanisms involving in the biodegradation and biotransformation will be also tested, and the resulting products shall be also determined. Bacteria and fungi in the epiphytes responsible for the biodegradation and biotransformation are to be identified according to the analyses of comparable variation in community compositions using RFLP based on 16S rRNA and 18S rRNA, respectively. This research will be greatly beneficial to the application of submerged plants and their epiphytic microorganism to the phytoremediation of water ecosystems polluted by PAEs.

邻苯二甲酸酯(phthalic acid esters, PAEs)是水体中常见的内分泌干扰物, 目前我国水体受PAEs污染极为严重。沉水植物及叶面附生菌群能去除该类污染物，生物降解转化可能是主要途径。研究沉水植物及附生菌群对水体中常见的PAEs （邻苯二甲酸二正丁酯（DBP）和邻苯二甲酸二异辛酯（DEHP））的降解转化，对阐明该类污染物的环境归趋有重要意义。本研究采用常见的8种沉水植物，以无菌苗为材料研究其对DBP和DEHP的降解转化机制和效率，确定有关的降解酶类，并通过C-14同位素技术结合GC-MS和LC-MS检测鉴定降解转化产物。同时，研究附生菌群对DBP和DEHP的降解转化机制和效率，鉴定产物，后通过基于16S rRNA和18S rRNA RFLP技术分析附生细菌和附生真菌群落多样性并鉴定主要降解菌种类，本研究结果可水体中该类污染物的植物修复应用提供理论依据。