Bacteria with the ability to grow on nitrogen-free media and with nitrogenase activity under aerobic or microaerobic
conditions were isolated from sugarcane roots collected from four different agricultural locations in Granada
(Spain). Isolates were Gram negative rods and were identified as Azotobacter chroococcum and Azospirillum
brasilense. Our results suggest that Azotobacter isolates do not have a particular affinity for sugarcane rhizospheres
and that, on the contrary, Azospirillum isolates show specific association and perhaps endophytic colonization of
sugarcane. However, obligate endophytes (Gluconacetobacter diazotrophicus) were not found in the apoplastic
fluid of the stems and macerates extracts of sugarcane tissues with the procedure applied. Population of this
microorganism might be in low number in the Spanish sugarcane varieties studied which is also discussed.