EN
Development of microbiology and ecology allow us to better understand the importance of microorganisms, both prokaryote and eukaryote, in forming interpendence with other organisms. Microorganisms play important role not only in the decomposition of organic matter and cycling of nutrient but also create specific systems such as rhizosphere, mycorrhiza or phylosphere. Strong correlations exist among populations of microorganisms in a given ecosystem. The interactions are conditioned by the root or leaf exudates as well as the presence of the secondary metabolites, synthesized by microorganisms in the environment. Thanks to interactions between microorganisms and plants the environmental homeostasis that guaranty the maintenance of health of given biotope might be observed.