Soil fungi are an extremely active group, takes an important part in the processes of ecology and formation of soil. Their enzymes contribute to the decomposition of various materials into the soil and converting a portion of the recycled materials in the components of their body. They are the main destroyers of plant residues. This is primarily due to the reaction of acidic plant substrates, which favors the growth and development of fungi. If there were no fungi in nature, the entire surface of the Earth would shortly be coated with plant residues. As part of the plant, residue mass is dominated by plant cell wall materials, i.e. cellular tissue, cellulose, hemicelluloses and lignin – complex compounds, which include Carbon. Therefore, fungi play a very significant role in the Carbon cycle. Soil microscopic fungi are involved not only in the cycle of Carbon, but also – of Nitrogen. Remains of plants and animals, containing Nitrogen, fall into the soil and are destroyed by bacteria, actinomycetes and fungi. In the soil fall also specific substances such as feathers, hooves and horns of animals, remains of their scalp, chitin shells of insects and other animals. On them, specific complexes of fungi are developing, eventually leading to its complete degradation. There is a fungus that is confined to the soil soaked with oil, and often develops on kerosene, diesel fuel, and various lubricants (kerosene fungus) [1, 2].  Fungi promote destructuration of soil, thus improve and increase aeration and water supply. It is believed that the formation and destruction of humus is also associated with the activity of soil fungi in the course of their life and, after the death of the mycelium, substances that may be involved in the synthesis of humus are abundantly allocated into the environment. Some soil fungi are capable of decomposing humus, of using it as the unique source of Carbon and Nitrogen. Fungi are actively involved in the conversion of insoluble Phosphorus in the soluble and therefore available to higher plants.  Microscopic fungi stood at the origins of the development of biological means of protecting plants from pests, diseases and weeds, there are kinds of soil fungi that form substances that stimulate plant growth. Fungi are organisms heterogeneous in their needs to the sources of Carbon nutrition.  The aim of our study was to investigate the growth, development and antifungal activity of micromycetes grown on media with different concentrations of glucose and trifluralin.  The antimicrobial properties of the tested micromycetes were determined by using method of agar blocks (Egorov, 2004) [3].  As test-cultures were used: Fusarium solani; Fusarium oxysporum; Fusarium gibbosum. Studies have been conducted to determine the growth of filamentous fungi on agar and liquid medium Czapek with different concentrations of glucose. It was found that all 50 strains of studied micromycetes are able to grow on poor media with minimal glucose 10 g/l, on the medium without glucose, 28 strains had weak growth of the mycelium, and 22 strains of filamentous fungi do not grow. Investigation of antifungal activity of exometabolites of strains depending on the concentration of glucose in the medium showed that antagonism against phytopathogenic decreases gradually but remains even in variants without glucose. Experiments with herbicide trifluralin showed that even at a concentration in the nutrient medium of  500 mg/l fungi are growing, some harder than on Czapek medium without glucose. This suggests that the fungi use this herbicide as a source of carbon and the antifungal activity of metabolites of these strains is at the level of the data obtained in the control group.  Thus, it is shown that the fungi can grow and develop in the most stressful situations, using all accessible sources of carbon.