Characteristics of selected molecular methods used in identification and assessment of genetic diversity of bacteria belonging to the genus Azotobacter

Modern molecular techniques have greatly increased our knowledge concerning phylogenetic and functional diversity of microorganisms inhabiting the soil environment. Soil ecosys-tem is relatively complex with a high level of microbiologically diversity. The application of traditional culture-based techniques dose not reflect the total diversity of microbial community in-habiting in soil environment. On the other hand commonly used molecular methods allow for quick and accurate identification and evaluation of the genetic diversity of microorganisms in-habiting this environment. Free-living bacteria belonging to the genus Azotobacter commonly occurring in soil. Azotobacter spp. are the subject of many studies conducted both in Poland and in the world. The interest in these bacteria is largely related to their properties very useful for agriculture. Owing to their capability of fixing atmospheric nitrogen and making it available to plants and production of plant growth promotion and fungicidal substances, they are used in the production of soil bacterial inoculants. In addition, these bacteria are an excellent indicator of soil fertil-ity, which is why they are often used as test microorganisms in many studies. The paper presents an overview of molecular mi-crobiological techniques used to identify and evaluate the genetic diversity of Azotobacter spp. in studies conducted both in Poland and across the world. The ITS PCR, PCR-RFLP methods and 16S rRNA gene amplification are used to identify bacteria of the ge-nus Azotobacter, and PCR MP, RAPD PCR and ARDRA are used to assess the genetic diversity of these microorganisms.