Denitrification process of root nodule endophyte .

To examine the characteristic of denitrification in , a symbiotic nitrogen-fixing microbe associated with non-leguminous plants, and its role as a NO source or sink, root nodule endophyte was isolated using sectioning method, which was then purely cultured to investigate the denitrification process under NO addition. The results showed that after addition of NO to the medium under anaerobic condition, the concentration of NO decreased with time, while the concentrations of NO and NO initially increased and then decreased over time. Key denitrification genes and nitrogenase gene were detected at 26 h, 54 h and 98 h during incubation. Abundances of these genes significantly differed among each other, and their dynamics were asynchronous. Redundancy analysis of the effect of NO, NO, NO concentrations on abundances of denitrification genes and nitrogenase gene indicated that 81.9% of the total variation in gene abundances could be explained by the first two axes. had a denitrifying activity under anaerobic condition, with denitrification genes, including nitrous oxide reductase gene (), being identified. Our results suggested that possessed a complete denitrification pathway and the ability of NO reduction under anaerobic condition.