unicellular organisms became known to man only with the advent of magnifying devices.However, to date they - the basis of the securities of genetic research for the accumulation of theoretical material on many issues of biochemistry, molecular biology, genetics.There are different unicellular organisms.Mushrooms - one of them.Not all, of course, but quite a significant part.This article will look at some representatives fall into the category of simple fungi and what qualities and characteristics they possess.
unicellular and multicellular fungi: general characteristics
from all five kingdoms of nature mushrooms - the most unusual.The thing is that to determine the taxonomic status of the plant or animal is quite simple.Bacteria and viruses are quite differently arranged, so with them at all errors can not be.
Only mushrooms - these are complex organisms that have for a long time did not belong to any particular kingdom.Originally, they were regarded as plants, just devoid of chlorophyll.Later studies showed that the decomposition products of urea is contained and the cell wall is composed largely of chitin.Thus digestion outer and many enzymes similar to that produced by mammalian organisms.
These symptoms clearly talked about supplies mushrooms to animals.In addition, it became known that the Department of unicellular fungi slime molds (slime) can move in the direction of food and light under certain conditions.This proves once again that these organisms and animals share a common ancestor.
All this has led to the fact that mushrooms are classified as a separate kingdom wildlife.A common feature for identification of steel:
- availability of multi-core single-celled or multicellular mycelium;
- hyphae - thin strands that can be intertwined, forming mycelium and fruiting body;
- heterotrophic way of eating;
- chitin in the cell wall;
- urea in the composition of the decay products of substances;
- lack plastids;
- reproduction by means of spores.
Total Today there are about 250 thousand species of these organisms.Most of them - single-celled fungi.
Classification of unicellular fungi
With this diversity there is a need in the classification.Therefore, it was systematized all single-celled fungi, examples of which can be reduced if we consider the complete classification.United
it today did not exist, so different authors, they are not the same.Thus, isolated four main groups.
- deuteromycetes - another name of imperfect fungi.Do not have a sexual mode of reproduction.Representatives sklerotium, Rhizoctonia, many species of Candida.
- Chytridiomycota - complex single-celled fungus mycelium which represented long branched structures containing multiple cores.Representatives olpidium, silhitrium, spizellomy, monoblefaridy and others.Most are aquatic or semi-aquatic lifestyle, being parasites of marine and freshwater plants and animals.
- Zygomycota - typical unicellular fungi, some representatives of the mycelium with a few weak walls.Representatives Mucor, trihomitsety, spinellusy, zoopagalisy and others.Among them are the inhabitants of the soil, and parasites of humans, animals and plants.
- Ascomycetes - most multicellular, but there are also single-celled fungi.Examples: yeasts, morels, truffles, lines, and other parmeliya.It got its name for the structural features of the dispute, which are called ascospores.Some representatives ceases during the life of the ability to sexual reproduction and include at deuteromycetes, ie imperfect fungi.
Each department has its own features and characteristics, and only the more species are very diverse.Interesting way of life, it is important to economic value.Furthermore, fungi play a major ecological role in nature.
avilable and lifestyle
Before answering the question: "Describe the role of the single-celled fungi in nature," should consider their particular structure and way of life.After all, this will depend on the significance they have for the environment of the organism, including those for humans.
Thus, the structural features of single-celled fungi.
- mycelium or not developed at all, or very weak.It may be represented by a single multi-core or single-core cell.
- most asexual reproduction, although for many characteristic of the sexual process.
- Water representatives have formed zoospores (hitridiomikota), which move freely in the water with the help of flagella.Ascomycetes have special organs spore bags, which mature ascospores.Their number does not exceed eight pieces.
- Some soil Zygomycetes form mycorrhiza with tree roots.
- imperfect fungi enter into a symbiosis with bacteria, creating healthy Kombucha.
general structure of almost all fungi, as well as the internal cellular structure is almost identical.It does not matter, it is the highest, or imperfect.Therefore, based on the classification is always the main feature - the way of reproduction.
Features lifestyle:
- vast majority - obligate or facultative parasites.
- Many have adapted to life in water or soil.
- Some representatives emits large amounts of enzymes to the environment, to prepare food for themselves.Even without branched mycelium, some organisms produce thin rhizoids, which are attached to the substrate, and capture (suction) food.
- Among zygomycetes have special representatives - zoopagalisy.It received its name for a predatory lifestyle.They grab adhesive hyphae insect larvae, nematodes and other protozoa and eat them, digesting the outside.
- during the life of many members (especially yeast) are able to produce valuable medicinal substances, enzymes, important chemical compounds.
Highlight common features for all lifestyles difficult, because the number of species is too big.Therefore it is better to dwell on the most frequent and important for a person.
process of reproduction
We have clarified that the main feature of the organism in question - it is a way of procreation.The reproduction of unicellular fungi can be carried out in three ways:
- sexually;
- vegetative;
- asexually.
consider all the options in more detail.
- Asexual reproduction involves the formation of spores within sporangia special formations.Thus, for example, is movable chytrid zoospores and at ascomycete - ascospores endogenous origin.Vegetative
- for unicellular budding involves representatives.That is, one cell buds and became an independent body.This occurs in yeast, which are generally considered to be the second single-celled fungi.
- sexual process occurs differently in different species.However, only three possibilities: heterogamy, oogamy and isogamy.In any case, the point is the confluence of germ cells to form the zygote.Most often, it is covered with a dense shell and in a state of rest for a while.After this begins to form mycelium and sprouting new organism.Even in the case of multicellular representatives of the existence of male and female parts of the question.Just indicate the presence of "+" and "-" side of the mycelium, which merge to form dikaryons.
course, there are characteristics that help identify some representatives.However, the overall patterns of reproduction is unicellular fungi such as those described above.
Penicillium and its characteristics
What penicillium - a single-celled fungus, we can not say.The fact is that he belongs to a class of mold representatives, most of whom are the simplest of the organization.So often he is credited with similar features.However, the penicillium, and his close friend, Aspergillus - is the holder of a multicellular branching mycelium.
This fungus was discovered by Ernest Duchesne in 1897.It was he who first drew attention to the way in Arabia used the strange greenish patina for wound healing horses.Examining the structure, the young man (and Duchesne was only 23 years old) came to the conclusion that the organism - a fungus that has antibacterial properties, as can destroy eysherihiyu if - one of the most pernicious and pathogenic bacteria.
a long time for its opening no one listened.In 1949, Fleming proved antiseptic and antibacterial properties of this mushroom, and merit was recognized by Duchesne, right after the death of the latter.
main component, which is used for the manufacture of a medicament penicillin - an antibiotic produced during the life of the organism.
Moulds
If the answer to the question: "Describe the role of the single-celled fungi in nature," one can not say about the other representatives of the mold.After all, most of them settled on the ground, giving it a grayish or bluish tinge in the form of plaque.At the same time the decomposition of dead organic matter.Therefore, the nature of the fungus plays the role of nurses.
For someone very important are the following representatives:
- Aspergillus;
- penicillium;
- "noble rot";
- "noble rot".
All of them - active participants in the process of preparation of the rare and delicious cheeses, wines, food additives, antibiotics, and other valuable substances.
Mucor
most typical representative of the organism in question - Mucor.Unicellular fungus that is large enough branching mycelium formed with only one cell.There are no partitions.It refers to the molds department zygomycetes.
Calling helpful this fungus is difficult, because his main achievement - a spoilage and formation of numerous mucormycosis.However, some species are still used for the manufacture of man "Chinese yeast".This is a special starter, serving for the preparation of certain foods.For example, soy cheese.Some species Mucor a source of enzymes, and antibiotics.
On the basis of the data and products of the colony of fungi form a fluffy coating of beige and gray, are clearly distinguishable to the naked eye.
yeast to unicellular fungi and this is representative of how the yeast fungus.However, these organisms should be regarded as a second single-celled because they live mnogopochkuyuschimisya colonies.The mycelium of each representative unicellular, without partitions.But the close co-existence of multiple forms of multicellular makes one think.
Generally, yeast - very useful mushrooms.Not all, of course, but many of them.So, since ancient times people used them for baking bread, wine making and brewing.More 6 ths. Years BC.e.these being used everywhere in Egypt.
bread baked with remnants of the old leaven.This led to the degeneration of culture, it becomes quite clear and genetically uniform.So today there are "rock" of yeast that were not created by the evolution in nature, and were the result of human activities.
interesting feature of yeast that they are facultative parasites.That is, in the presence of oxygen they breathe freely, releasing carbon dioxide.But even under anaerobic conditions is not lost, oxidizing sugars (fermentation).
Different types of yeast capable of handling uneven substrate.Some can only ferment simple sugars, the hexoses.But there are those that are treated not only carbohydrates, but also proteins, lipids, carboxylic acid.
person is important to those products that stand out as a result of vital activity of these fungi.Namely:
- diacetyl;
- isoamyl alcohol;
- fusel oil;
- dimethylsulfide and others.
The combination of these substances determines the quality of the products obtained.This is directly reflected in its organoleptic properties.
parasitic single-celled fungi representatives
Among the most dangerous single-celled parasites are those that cause fungal infections in humans and animals, as well as a variety of mold and rot in plants.
- Trichophyton and mikrosporum - two species that cause serious skin diseases in humans.
- Mushrooms Candida - Candida cause disease.
- dermatophytes - fungi that cause disease of the nail plate - onychomycosis.
- Piedra, ekzofila, malaziza - cause a variety of lichens on the parts of the body.
- Hari black fungus causes the disease, which manifests itself with black patches on the tongue of man and animals.
- Phytophthora - a dangerous fungus that infects the plant and causes the formation of black rot in the roots and leaves.
And this is a partial list of those representatives who are pathogenic, harmful and extremely harmful to health and crops.
role of unicellular fungi in nature
If you face the challenge of such a plan: "Describe the role of the single-celled fungi," the first thing should be to identify all the advantages.We have a lot of the above mentioned:
- used in the chemical industry;
- food;
- serve to prepare the agricultural feed;
- are natural decomposers of organic matter, that is, nurses and others.
But also we should not forget about the disadvantages, of which there are plenty.The majority of single-celled fungi - parasitic organisms.
