Abstract:The discovery of nitrite-dependent anaerobic methane oxidation (N-DAMO) process, mediated by functional microorganisms, gives us a new understanding of the natural carbon and nitrogen cycle. This process can simultaneously reduce methane and nitrogen pollution. The reaction mechanism of N-DAMO process and the physiological and biochemical characteristics of the functional bacteria Candidatus Methylomirabilis oxyfera (M. oxyfera) were systematically introduced in this paper. The molecular and microbiological methods for the study of the functional bacteria were overviewed. This paper summarized and analyzed the research reports of M. oxyfera bacteria in different natural habitats. The potential effects of macro environmental factors such as average precipitation, annual average temperature, different natural areas and growth factors, like carbon source, nitrogen source, pH and oxygen content on the structure of functional bacteria community were revealed. The future research direction of the functional bacteria is proposed, which is expected to clarify the N-DAMO process and the ecological function of the functional bacteria in carbon and nitrogen cycle.