土壤氨氧化微生物对重金属胁迫的响应机制研究

项目名称： 土壤氨氧化微生物对重金属胁迫的响应机制研究

项目编号： No.41201523

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 地理学

项目作者： 刘玉荣

作者单位： 中国科学院生态环境研究中心

项目金额： 25万元

中文摘要： 土壤中重金属的累积会影响土壤微生物的群落结构和功能。氨氧化微生物是土壤N素循环的重要驱动者，但其对重金属胁迫的响应机制尚不清楚。以往的研究主要是基于室内短期培养实验基础上探讨重金属对氨氧化细菌(AOB)和氨氧化古菌(AOA)群落组成和丰度的影响，忽略了土壤中某些氨氧化微生物类群对重金属的敏感性、耐受性以及污染土壤自身的恢复力，从而可能没有合理地评估重金属对土壤微生物的毒性效应。因此，本项目拟以长期重金属Cu和Ni污染的试验田土壤为研究对象，结合短期室内培养实验，研究氨氧化微生物的功能和群落是如何响应重金属的胁迫，从而建立相关参数的剂量-效应关系。在此基础上，通过耐性和恢复力测试试验研究污染土壤氨氧化微生物功能和群落变化动力学，以明确其作用过程和机理。研究的结果将有助于进一步明确土壤氨氧化微生物的生态特性，为农田土壤生态保护和质量评价提供更为准确、合理的依据。

中文关键词： 土壤；重金属；微生物群落；微生物转化；毒性效应

英文摘要： The accumulation of heavy metal in soil will impact the microbial community structure and function. Ammonia-oxidizers are important driver of N cycle in soil, and their responsive mechanism to heavy metal still remains unclear. Many studies have been conducted on the effects of heavy metal on the abundance and community composition of ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) based on short-term incubation experiments, which could neglect the sensitivity, resistance and resilience of the ammonia oxidizer groups to the stress of heavy metal. These could lead to an unreasonable evaluation of the toxic effect of heavy metal on soil microorganism. Therefore, the aim of this study is to examine the responses of function and community of ammonia-oxidizers to the stress of heavy metal, basing on the long-term Cu and Ni contaminated fields together with the short-term exposure experiments. The obtained relative parameters will be fitted a dose-response with the concentrations of heavy metal. Then, the dynamic change of the function and community of ammonia-oxidizers in the contaminated soils will be measured using the tests of resistance and resilience, so that understand the process and mechanism of the changes. The results of this study will be helpful to further understand the ecological

英文关键词： soil；heavy metal；microbial community；microbial transformation；toxic effect