[Characteristic and prospects of heterotrophic nitrification]

Nitrification is a key step in the global nitrogen cycle. Classically, nitrifying bacteria are chemoautotroph. Recently, bacteria that have the ability of heterotrophic nitrification have been intensively studied as potential microorganisms that may be used to overcomeproblems inherent in the conventional method. This review gives a broad overview of the current status of heterotrophic nitrification including the heterotrophic species which nitrify actively, optimal condition for nitrification, heterotrophic nitrification pathway, enzymatic system and isolation methods. Also, the promising prospects of heterotrophic nitrification are especially introduced.