Positive and negative aspects of denitrification in Rhizobium-legume associations.

Although denitrification by Rhizobium is well documented, the implication of the process for both free-living cells and the Rhizobium-legume symbiosis is still unclear. Several findings suggest possible positive implications, while others highlight possible detrimental effects of this pathway on nitrogen fixaction as well as on the environment. The present paper is an attempt to emphasize that in order to fully benefit from rhizobial activities in agricultural ecosystems, it is necessary to understand the denitrification process in detail.