Abstract: Denitrifying bacteria are a diverse functional group with the members from almost all phylogenetic bacterial groups. Therefore, their denitrification capability cannot be easily detected by relying on taxonomic affinities identified by 16S rRNA gene probes. As an alternative approach, functional genes are applied to investigate the denitrifying organisms in the environment. In this review, we introduced the genetic basis of denitrification, the main molecular tools for exploring denitrifying bacteria, recent researches of denitrifying bacterial communities in different environments, the problems unresolved, and future developments in this field. Up to now, though the links between community structure and function are not yet established, the study of the ecology of denitrifying bacteria would provide fundamental data to apply denitrifying bacteria in solving environment problems.

Key words: Geostatistics, CIS, Organic matter, Available nitrogen, Available phosphorus, Available potassium