Microbiology and potential application of aerobic denitrification: a review

Abstract:

In recent years, aerobic denitrification researches focused on three fields: isolation and performance of aerobic denitrification strains, potential applications of aerobic denitrification microorganisms, and aerobic denitrifying mechanism. Aerobic denitrification strains are widely distributed in several environments. Functional species were mostly selected from Pseudomonas sp., Alcaligenes sp. and Paracoccus sp. In lab-scale tests, some aerobic denitrification microorganisms showed excellent psychrotolerant or haloduric property, and other strains had great potential on biodegradation of toxicant, or N2O emission reduction. Mechanism result of aerobic denitrification indicated that the competitiveness of nitrate was weaker than oxygen as an electron acceptor, whereas denitrification process could still occur as an assistant electron transport pathway to prevent the overload of NAD(P)H. Therefore, nitrate and oxygen could simultaneously participate in metabolism of microorganisms. However, researches on mechanisms and practical bioaugmentation of aerobic denitrification microorganisms are still insufficient, and more researches and process tests should be carried out in the future.

Key words:Aerobic denitrification, Nitrogen removal, psychrotolerant denitrification, N2O emission reduction, mechanism research