Research progress in the characteristics and pathways of carbon and nitrogen metabolism of aerobic denitrifying bacteria

Abstract:

The discovery of aerobic denitrification has broken the traditional cognition that the denitrification only occurs under strictly anaerobic conditions. The aerobic denitrification provides a new way for biological denitrification and becomes a research hotspot in recent years. Carbon source can provide energy and electron donors for aerobic denitrification. The metabolism of carbon sources directly influences the nitrogen removal efficiency of aerobic denitrifying bacteria. Therefore, it is necessary to clarify the metabolic mechanism of carbon sources during aerobic denitrification. In this review, we summarized the known aerobic denitrifying bacteria and elaborated their metabolism pathways for nitrate and nitrite. Further, we systematically compared the mechanisms of different aerobic denitrifying bacteria in metabolizing carbon and nitrogen sources and comprehensively analyzed the effects of carbon metabolism differences on aerobic denitrification. Finally, we prospected the future research directions. With this review, we aim to deeply understand the mechanism of aerobic denitrifying bacteria in simultaneous removal of carbon and nitrogen and to provide a theoretical basis for improving the efficiencies of biological method for removing nitrogen and carbon from wastewater.

Key words:aerobic denitrifying bacteria;carbon metabolism;nitrogen metabolism;mechanism;pathway