The most effective way of selection for microorganisms-destructors of xenobiotics is the isolation of microbes from soils, long term contaminated with pesticides or industrial wastes. In this research, a technological scheme was developed for the process of obtaining a microbial consortium involved in the degradation of herbicide trifluralin, using iron (II, III) oxide (Fe3O4 or magnetite) nanoparticles and zero-valent iron Fe(0) nanoparticles. Regulating the acidity of medium for accumulation culture, it is possible to control the development of a microbial consortium to the predominance of bacterial or fungal cultures. Depending on the acidity of the medium, trifluralin promoted an increase in the number of bacteria and a sharp increase in the number of micromycetes. A consequent increase in the concentration of trifluralin in the medium for accumulation culture has led to a reduction (depletion) in the species diversity of bacteria and micromycetes. An addition of Fe3O4 and Fe(0) nanoparticles to the medium restored the species diversity of these microorganisms. With every increase in the trifluralin concentration in the medium with acidity of pH 5.0, a gradual decrease in the number of bacteria occured, but the additon of Fe(0) nanoparticles contributed to an increase in their numbers. The magnetite and zero-valent iron nanoparticles stimulated the growth and reproduction of micromycetes on the initial etapes of development of the consortium, when trifluralin concentration range was 100-200 mg/L. Then, when the concentration of trifluralin was increased to 300-400 mg/L, the number of micromycetes did not depend on the acidity of medium, or on the presence of nanoparticles.