红树根际微生物介导硫循环驱动重金属高效修复的生态学机制研究

微生物的介导作用对硫和重金属偶联的代谢循环与迁移至关重要。我们对红树根际耦合镉的研究发现红树林对镉的固定、吸收和吸附等效率可能依赖于微生物驱动的硫循环。结合现有报道我们提出假设：硫代谢菌对实现红树林湿地中重金属污染的高效修复具有关键作用。本项目拟针对典型重金属污染的红树林湿地，利用宏基因组手段测定微生物群落结构多样性，同时通过FTRs技术拟合硫循环动力学模型，根据两者反馈关系，认识红树林根际微生物群落及硫循环对重金属污染修复的偶联作用，并进行相应功能菌分析与分离鉴定。通过模拟重金属污染的根际微环境与目标菌株反接种，揭示目标菌株与根系偶联作用下的硫循环对重金属在根土界面形态赋存与代谢的影响，实证目标菌株对重金属的高效修复作用与应用潜力。本项目的顺利开展可阐明硫代谢菌驱动硫循环实现重金属高效修复的生态学机制，且为受污染红树林的保护与修复提供科学的理论依据与实践基础。

The mediation of microorganism play a major role in the coupled metabolic cycle of sulphur and heavy metals. Our preliminary studies about the coupling between rhizosphere and cadmium showed that immobilization, absorption and adsorption efficiency of Cd may rely on S cycle driven by microorganism in the mangrove. Meanwhile, we incorporate previous reports and conjecture that sulphur bacteria may play a critical role in ecological remediation of mangrove ecosystem with heavy metals contamination. Firstly, assess the diversity of microorganism by metagenomics method and fit sulphur cycling dynamical model by FTRs technology in the typical heavy metals contamination mangrove sediment; then according to the feedback of the two，uncover the coupling effect of microbial communities and sulphur cycle on the heavy metals in mangrove rhizosphere, and analyze and identify the relevant functional bacteria. Simulate the microenvironment of the rhizosphere sediments with heavy metals pollution, inoculate the target strains in the sediment, and then demonstrate the effects of sulpher metabolism on the occurrence form, transformation and metabolism of heavy metals under the coupling between microorganism and roots in plant-soil interface. It is the final purpose to reveal the high-efficiency remediation effect of sulphur bacteria on heavy metals pollution and their utilization potentiality. This project will illuminate the ecological mechanism of sulphur bacteria regulating surlfur cycle and realizing high-efficiency remediation of heavy metals, and then provide scientific theory or practice foundation for the protection and remediation of polluted mangrove.