biofilms

Oil and petroleum products are a signifi cant source of environmental pollution, leading to the accumulation of hydrocarbons in the soil profi le. They contaminate groundwater, disrupt natural soil biochemical processes, interact with mineral compounds – thereby reducing their bioavailability to plants – and cause the poisoning and death of living organisms. The study of hydrocarbon-oxidizing microorganisms is of considerable practical importance due to their ability to degrade hydrocarbons.

The bacteria Azospirillum brasilense, used as biofertilizers, have a signifi cant positive eff ect on the growth and development of plants. The genome of the strain A. brasilense Sp7 is represented by a chromosome and numerous plasmids with molecular weight of 90, 115, and over 300 MDa. Genomic rearrangements that cause changes in the “plasmid profi le” can contribute to the formation of subpopulations or phenotypic variants in a bacterial population. There is little data on the role of such rearrangements in the adaptation of A.

Azospirillum bacteria are engaged in associative interactions with a wide range of plants. In this type of interaction, there formed no specialized structures like nodules, which are characteristic of the legume-Rhizobium symbiosis. The formation of biofilms by Azospirillum on the plant root surface can be important for the successful functioning of plant-microbe associations. Scarce data exist on the role of cell surface protein structures in the formation and stabilization of Azospirillum biofilms. It is known that as compared to A.