Microbiology has been changing and revising the phylogeny and classification of fungi for many years, starting from the 19th century. The objects of research are really unusual and will be studied for a long time.
Mushrooms that grow all their lives, like plants, but crawl and devour other organisms - is this possible? Yes, modern studies of the ultrastructure of the cell, its biochemistry and physiological characteristics allow us to conclude that the intermediate position of fungi possessing signs of animals and plants.
Sign | Mushrooms | Animals | Plants |
The number of nuclei in the cell | Many, rarely one | One | One |
Cell wall | Present and may contain chitin, cellulose, chitosan, glucan | Not | Present and contain cellulose |
The final product of nitrogen metabolism | Urea (urea) | Urea (urea) | Asparagine, Glutamine |
Carbohydrates (spare parts) | Glycogen, sugar alcohols | Glycogen | Starch |
Lifestyle | Attached and free | Free | Attached |
How mushrooms became a separate kingdom
In the time of Karl Linnaeus (early 18th century), mushrooms were considered plants. In the twentieth century (in the 40s) B. M. Kozopolyansky proposed to split the plant kingdom into kingdoms:
- Schizophytes Schizophyta (nodules) - bacteria were referred to them.
- Nomophytes Nomophyta (real plants) are the main representatives of the flora.
- Mycophytes Mycophyta (mushrooms and slugs).
In the 50s of the twentieth century, changes continued in the systematics of fungi: in microbiology, and more precisely in the relevant literature, publications appeared that analyzed the evolution of cellular microstructures. Based on this material, Whittaker created in 1969 his own system of the world, where all living things can be distributed across 5 kingdoms. One of them was reserved for mushrooms.
A. L. Takhtadzhyan (works of 1973 and 1976) insisted on four kingdoms in the organic world, and the fourth was given to mushrooms. Both scientists had the highest authority in the scientific community. The question of a separate kingdom for mushrooms has been resolved. But then this taxon also began to "creep".
Mushrooms of mysterious origin
The group of mushrooms is interesting in that their historical development (phylogeny) is heterogeneous.
As they recently turned out, they differ in biochemical composition, the structure of cell membranes and the genome. Since the end of the twentieth century (1998), three trunks of fungi have been distinguished evolutionarily different from each other. Each corresponds to a separate class (Cavallier-Smith):
- The simplest.
- Chromists.
- Fungi.
Protozoa and Chromists belong to the lower mushrooms, the Fungi class belongs to the higher ones.
Higher and lower - what is the difference
A mushroom of any rank is represented by mycelium (mycelium). Mycelium of the lower fungi is non-cellular, that is, not divided by partitions into small sectors. Higher fungi have septa (septa), but they are not continuous, but have openings, so the contents of protoplasm can move from sector to sector.
Another difference between lower and higher mushrooms is the impossibility of forming large and dense fruiting bodies. In primitive non-cellular fungi (or mushroom-like organisms), no one has yet found fruiting bodies. This does not detract from their nutritional function - small soil animals eat microscopic mycelium very willingly.
Mushroom-like monsters
In the classification of fungi in microbiology, the kingdom of Fungi is always considered, and the other two kingdoms (Protozoa and Chromists) are sometimes not mentioned at all. This is because Protozoa are more mushroom-like organisms than fungi.
They are unique in that they are capable of independent amoeboid movement. Their body is a multinuclear extensive protoplast (plasmodium not forming hyphae), and in the development cycle there is a flagellum moving stage.
Chromists are also very unusual. The kingdom unites a rather motley group of organisms related to algae (brown, golden, diatom, etc.), and organisms like fungi.
Mushroom-like chromists secondarily lose their color, are equipped with flagella, and instead of chitin, the cell walls may contain cellulose. Often there are no cell walls at all. Then the body of the fungus is represented by protoplast, that is, it is surrounded only by a membrane. By origin, they are close to algae (yellow-green).
More on Protozoa
The Kingdom of Protozoa (Protozoa) contains departments:
- Myxomycetes (Myxomycota)
- Plasmodiophoromycetes (Plasmodiophoromycota)
- Dictyosteliomycetes (Dictyosteliomycota)
Representatives of the Myxomycota department are also called mucus. They combine the features inherent in both mushrooms and animals. They can crawl along the substrate like amoebas, passively absorb nutrients throughout the surface, or actively capture and digest bacteria. React to light or food congestion. Usually live on forest soils, rotting wood.
But they multiply like mushrooms by spores. There is also a sexual process. The sizes of the mucus can be microscopic, but they grow all their lives. Some mucus membranes, for example, fuligo, grow up to several tens of centimeters.
Amazing chromists
The Kingdom of the Chromists unites the departments of:
- Hypochitriomycetes (Hyphochytriomycota).
- Oomycetes (Oomycot).
- Labyrinthulomycetes (Labyrinthulomycota).
Among the Chromists, one can consider the maze as an example. These are small marine mushroom-like creatures. The body of the “fungus” is plasmodium, which is covered from above by a mesh of ectoplasm mucosa, dressed with a membrane. The mesh facilitates attachment to the substrate or movement towards the food source. It even protects against drying out if plasmodium creep out on land.
Reproduction, as in most fungi, is carried out using spores, but under certain conditions the sexual process is activated. In marine food chains, labyrinths are given an honorable place - they feed on amoeba, plankton species, small crustaceans. Labyrinths, along with bacteria, successfully colonize inorganic debris - glass, glass wool, plastic. Secondary debris colonizers can already be, for example, sea acorns.
About real mushrooms
In the understanding of man, real mushrooms are first of all macromycetes. The fruiting bodies of macromycetes are so valuable as food objects that a separate industry has emerged in the industry - the cultivation of mushrooms in specially created conditions.
The kingdom of Fungi (Fungi, Mycota) is divided into four divisions. Among them:
- Chitridiomycetes (Chytridiomycota).
- Zygomycetes (Zygomycota).
- Ascomycetes (Ascomycota).
- Basidiomycetes (Basidiomycota).
Of these, the first two departments include representatives of lower fungi (micromycetes), and the second two - higher (mainly macromycetes). Micromycetes cannot be seen with the naked eye. Rarely in the life cycle arise mobile flagellar stages. Among the representatives are many parasites. Macromycetes include representatives that form fruiting bodies. This is mainly tinder fungi and hat mushrooms.
Sometimes deuteromycetes (Deuteromycóta) are indicated as the fifth division. In the construction of the classification of fungi, microbiology attaches great importance to methods of reproduction. Representatives of deuteromycetes are called imperfect mushrooms. The reason is that they completely lost the ability to reproduce sexually.
Yeast - Unicellular Mushrooms
According to the modern classification of fungi, microbiology refers the yeast to the kingdom of Fungi, the Ascomycetes department. These are higher fungi, despite the fact that their body is unicellular. The ancestors of the yeast were multicellular, but the evolutionary direction of their development shifted towards the loss of mycelium.
A distinctive feature of the department is bilayer cell membranes. They have macromycetes, and molds, and yeast. Yeast shells contain polysaccharides glucans and mannans.
Yeast - a class of mushrooms Hemiascomycetes (Hemiascomycetes), order Saccharomycetales. There is an opinion that yeast is a group of organisms that does not have its own taxon. It includes representatives of the Ascomycetes and Basidiomycetes departments.
Yeast multiplies by budding, less often by dividing the cell in half, and under adverse conditions, the sexual process is possible. Part of the yeast forms spores, which allows them to be divided into two large groups - sporogenous and asporogenic.
Mold mushrooms
It is found in almost all large taxa. There are higher and lower molds: unlike lower fungi, in higher mold micromycetes the mycelium is divided by partitions into fragments (cells). They feed by isolating enzymes on the substrate, which decompose substances into simple components. For example, molds and yeasts can be found on the same piece of bread, but the substances they consume will be different. Yeast feeds on sugar, and proteins and fats are the food substrate for molds.
Mildew is found in all taxonomic groups of the kingdom of Fungi:
- Chitridiomycetes. A representative of Synchytrium endobioticum is a potato parasite that causes rotting of tubers.
- Zygomycetes. The representative of mucor - saprophyte (settles on an inanimate substrate), causes bread mold.
- Ascomycetes. The representative of black mold is saprophyte, which is used for the industrial extraction of citric acid. The strongest allergen in humans causes a disease such as aspergillosis. Penicillas used to make cheeses and antibiotics are also included here.
- Basidiomycetes. Cause cereal diseases (rust and smut parasites).
There are molds even in the kingdom of the Chromists, among the oomycetes:
- Phytophthora, a parasite that causes rot of tomatoes and potatoes.
- Plasmopara (Plasmopara viticola) parasitizes on vines and fruits. The disease of the plant is powdery mildew.
Thus, mushrooms remain one of the most poorly studied groups of organic nature. Modern methods for studying microstructures and cell biochemistry make it possible to make new discoveries, on the basis of which the classification of fungi continues to change.