Katsy Elena I. RussiaSaratovInstitute of Biochemistry and Physiology of Plants and Microorganisms of the Russian Academy of Sciences, 410049, Russia, Saratov, Entuziastov Avenue, 13ei_katsy@mail.ru Author's articles On the Contribution of Cell Aggregation and Extracellular DNA to Biofilm Formation and Stabilization in Azospirillum brasilense Bacteria