河流沉积物氮循环主要微生物的生态特征

Ecological characteristics of nitrogen cycling microbes in river sediments

摘要:

微生物驱动的氮循环过程是全球生物地球化学循环的重要组成部分，由于人类活动的影响，氮循环负荷加剧，氮素的生态平衡和微生物的功能特征也相应地受到干扰。河流生态系统是陆地与海洋联系的纽带，因人类活动过量活性氮的输入导致水体富营养化，明显影响着河流的生态功能以及河口沿岸海洋生态系统的平衡。富含微生物的沉积物对氮素的转化和去除起着至关重要的作用。本文主要介绍河流沉积物氮循环主要功能微生物，包括氨氧化细菌、氨氧化古菌、亚硝酸盐氧化菌、反硝化细菌和厌氧氨氧化细菌的群落特征和生态功能，总结氮相关营养盐、溶氧和季节变化等环境因子，以及河道控制管理措施和污水处理厂扰动等条件下氮循环过程主要功能类群的生态特征和响应关系。指出还需深入全面地研究河流沉积物生态系统氮循环过程的驱动机制和微生物的贡献效率，加强城市河流沉积物微生物功能作用的研究及河道生物修复技术的开发。

Abstract:

Nitrogen is one of the most important substances on global biogeochemical processes which are driven by microorganisms. Due to anthropogenic disturbance in recent years, the nitrogen flux has increased and therefore disturbed the balance of nitrogen cycle and the community characteristics of functional microbes. Excessive activated nitrogen discharged into water body has lead to eutrophication which impairs the ecological function of river and coastal zone adjacent to estuary. The nitrogen transformation and removal by microorganism plays a vital role in improving river ecosystem, which is connecting link between terrestrial and marine ecosystems. This review focuses on ecological functions and community patterns of ammonia-oxidizing prokaryotes, nitrite-oxidizing bacteria, denitrifying bacteria and anaerobic ammonia oxidation bacteria in river sediment. Characteristics of community response to different environmental factors (e.g. ammonia, nitrate, dissolved oxygen, salinity and seasonal change), river management practices and effluent from wastewater treatment plant are reviewed. Further approach to a better understanding on ecological function of nitrogen cycling microbes in river ecosystem are suggested, including contribution of microbes to nitrogen cycle in urban rivers and development of bioremediation technology.