河道重金属微生物转移转化机制研究

Heavy metal pollution in river sediments is one of the major challenges currently facing China. In this research project, we will focus on Longjiang River of Guangxi province which previously happened huge environmental pollution accident of cadmium, explore mechanisms for cadmium microbial migration and transformation in river sediments, and pour attention into the bioremediation foundation of cadmium pollution in river sediments by iron reducing bacteria and sulfate reducing bacteria. The project will apply various analyzing measures to the river sediments of Longjiang River in large – scale, elucidate current situation and successional status of cadmium pollution in river sediments; by using tools such as metagenomics, metatranscriptomics and real-time PCR analysis of mRNA, metabolic pathways of microbial transformation and migration of cadmium will be determined; iron reducing bacteria and sulfate reducing bacteria will be applied in certain sediment and laboratory simulation environment, their microbial functional activities for the immobilization process of these heavy metals will be monitored, interaction mechanism between microorganism and heavy metals will be revealed. The results of this project may reveal important life phenomenon and interaction mechanism of river sediment microbes during its geochemical circulation and interaction process with heavy metal, have important meaning to the metal migration in biological geochemistry and environment geochemistry, and may provide theory foundation for microbial in situ remediation of heavy metal contamination in river sediments.

河道重金属污染是目前我国面临的重要环境问题之一。本课题将以发生重大镉污染事件的广西龙江河为研究对象，系统查清龙江河道底泥镉的微生物介导转移转化机制，并探索利用铁还原菌和硫酸盐还原菌对底泥镉污染开展修复的理论基础。课题将通过多种分析手段对整个龙江河道底泥进行大尺度长期跟踪，查清龙江河镉污染现状及镉的存在形态演替；通过宏基因组、宏转录组和mRNA的荧光定量PCR分析确定镉代谢相关的微生物群落及功能基因代谢网络；在典型河段引入外源铁还原菌和硫酸盐还原菌，结合实验室微环境模拟，探索修复环境下各不同形态重金属的长期稳定性及其与修复微生物的相互作用机制。研究成果将揭示河道底泥微生物群落在重金属胁迫下的重要生命现象和应激反应机制，对环境生物地球化学中重金属迁移具有重要意义，并构建河道重金属污染的微生物原位修复理论基础。

河道重金属迁移及其形态转移转化是学术界研究热点。本研究选题以发生重大镉污染事件的广西龙江河为研究对象，系统研究了龙江河道底泥镉的微生物介导转移转化机制，并探索了利用铁还原菌和硫酸盐还原菌对底泥镉污染开展修复的理论研究。课题对整个龙江河道底泥进行大尺度长期跟踪，查清了龙江河镉污染的现状及镉的存在形态演替；跟踪微生物介导的镉转移转化过程，确定了镉代谢相关的微生物群落及功能基因代谢网络；通过实验室微环境模拟，探索了修复环境下各不同形态重金属的长期稳定性及其与修复微生物的相互作用机制。研究成果对环境生物地球化学中重金属迁移具有重要意义，能够为我国重金属污染控制提供理论支撑。. 本研究项目已发表了论文8 篇（其中SCI 7篇，EI 1篇），申请专利 5项，获中国有色金属工业科学技术二等奖1项，培养研究生3名。依托本项目1人由中级晋升为副高级，1人由副级晋升为正高级。. 基于河道重金属微生物转移转化机制研究，已经形成相应的重金属污染微生物固化修复技术。在本研究获得的理论成果基础上申请了环保部公益基金项目，通过环保部公益基金将本研究所形成的修复理论成功进行了应用推广，在广西河池开展了3万平米的尾矿库修复示范，取的了理想的实验效果，顺利通过了环保部组织的专家验收。在本研究获得的理论成果基础上我们还将重金属污染微生物固化技术在河道重金属污染修复中进行推广。