Ecological characteristics of nitrogen cycling microbes in river sediments

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.