The evaluation of the viability of the bacterial cells in dormant (long-stored) cultures Azospirillum brasilense and the renewal of their reproduction in the presence of the protein WGA, a component of root exudates of the host plant, were studied. It was found that for 3.5 years the number of viable A. brasilense cells the culture retained sufficient to resume growth in fresh medium. Azospirilla also not lose viability when persisted under stress conditions. Protein WGA (wheat germ agglutinin) stimulated the reactivation of growth A.