What mushrooms eat
By the type of nutrition, mushrooms are divided into symbionts and saprotrophs . Symbionts parasitize living organisms. And saprotrophs include most of the mold and cap fungi, yeast. Saprotrophic fungi form a constantly lengthening mycelium every day. Due to its rapid growth and structural features, the mycelium is closely associated with the substrate, which is partially digested by secreted enzymes outside the body of the fungus, and then absorbed into the cells of the fungus as food.
Based on the fact that mushrooms are devoid of chlorophyll, they are completely dependent on the availability of a source of organic food, which is already completely ready for consumption.
The bulk of mushrooms for their nutrition uses organic matter of dead organisms, as well as plant residues, rotting roots, decaying forest litter, etc. The work done by fungi to decompose organic matter is of great benefit to forestry as it increases the rate at which dry leaves, twigs and dead trees are destroyed that would litter the forest.
Fungi develop wherever there is plant debris, such as fallen leaves, old wood, animal remains, and provoke their decomposition and mineralization, as well as the formation of humus. So, fungi are decomposers (destroyers), like bacteria and other microorganisms.
Fungi differ greatly in their ability to absorb various organic compounds. Some can consume only simple carbohydrates, alcohols, organic acids (sugar mushrooms), others are able to secrete hydrolytic enzymes that decompose starch, proteins, cellulose, chitin and grow on substrates containing these substances.
Parasitic fungi
The life of these fungi is carried out at the expense of other organisms, incl. mature trees. Such fungi can invade randomly formed cracks or get inside trees in the form of spores carried by insects eating in the bark. Sapwood beetles are considered the main carriers of spores. If we examine them in detail under a microscope, then hyphae are located on the fragments of the external skeleton of these insects, as well as on the shell of their testicles. As a result of the penetration of the mycelium of parasitic fungi into the vessels of plants, fibrous seals of a whitish color are formed in the tissues of the "host", as a result of which it quickly fades and dies.
However, it is worth noting the existence of fungi that parasitize other fungi. A striking example of this is Boletus parasiticus, which can develop exclusively on fungi belonging to the genus Scleroderma (pseudo-raincoats). At the same time, there is no clear distinction between these development systems. For example, certain groups of parasitic fungi, as a result of certain circumstances, may become absolute saprophytes. Examples of such fungi are tinder fungi, as well as the usual autumn honey fungus, which in a very short period of time can consume the resources of the "host" and kill him, after his dying off, he uses already dead tissues for his life.