Without mushrooms, life on Earth cannot be imagined. They are key organisms in the process of converting complex organic substances into simple elements. Without their presence, organic waste would accumulate at a dizzying rate, and our planet would resemble a huge dump. Mushrooms in nature form an important group of living organisms. Not only the species that form the fruiting bodies, but also hardly visible micromycetes, are involved in the proper functioning of the ecosystem. Many of them live in symbiosis with roots, supporting living trees that provide a refuge for birds or insects, others are significant decompositors of wood. Their main task is to provide a circulation of substances and minerals in nature. Fungi, like animals including humans, do not produce the necessary organic compounds themselves for the construction of their bodies, so they have to accept ready-made substances. Complex chains of polysaccharides are fungi with their enzymes able to decompose into simple sugars – a part of their nutrition. They maintain a balance because at the same rate as the waste in nature is able to transform it into simple elements. Solid and durable wood turns by them into soft and flexible. It takes a few years to become a part of forest humus, which provides valuable substances to various plants and animals. Spores of the mushrooms are omnipresent. Under suitable weather conditions, it is only a matter of time when they start to destroy the non-living mass that is found around us. Also, many unnecessary waste ending in landfills (such as wood and paper products, plant waste, food residues, or even petroleum products) contain substances that are suitable for decomposition by the fungi. It happens, but we cannot perceive this relatively slow process in a short period of time. Therefore, we do not realize how beneficial the mushrooms are for us and the environment.