Sugars. EDTA and trypsin were tested for their effect in preventing aggregation of Azospirillum brasilense Cd cell suspension grown on malate as a C-source. d-Fructose (25-30 mM) strongly inhibited cell aggregation at various pH levels (5.0-8.4). Treatment of malate-grown cells with 20 mM d-fructose for 7.5 min. or with maize root extracts, significantly promoted the subsequent adsorption of Azospirillum cells to maize roots. No enhancement of adsorption could be observed when roots had been treated with d-fructose. The highest cell adsorption to roots was obtained with Azospirillum grown on d-fructose as C-source in combination with cells that had been exposed to root extract.