Fundamentals of microbiology: classification of fungi and their structure. Systematics of mushrooms. Principles of classification of mushrooms. Zygomycetes. Ascomycetes. Basidiomycetes. Deuteromycetes. Fungi Naming Code
Mushrooms belong to the kingdom Fungi (Mycetes, Mycota). These are multicellular or unicellular non-photosynthetic (chlorophyll-free) eukaryotic microorganisms with a cell wall.
classification of mushrooms. Fungi can be divided into 7 classes: chytridiomycetes, hyphochytridiomycetes, oomycetes, zygomycetes, ascomycetes, basidiomycetes, deuteromycetes.
Eumycetes represented by ascomycetes and basidiomycetes (perfect fungi), as well as deuteromycetes (imperfect fungi). Ascomycetes (or marsupials) unite a group of fungi that have a septate mycelium and are distinguished by their ability to reproduce sexually. Ascomycetes got their name from the main fruiting organ - the bag, or ascus, containing 4 or 8 haploid sexual spores (ascospores). Ascomycetes include representatives of the genera Aspergillus, Penicillium, and others, which differ in the formation of fruiting hyphae. Aspergillus (leaching mold) has thickenings at the ends of fruit-bearing hyphaconidiophores - sterigmas, on which chains of spores - conidia are formed. Some types of aspergillus can cause aspergillosis and aflatoxicosis.
The fruit-bearing hypha in fungi of the genus Penicillium (columb) resembles a brush, since thickenings are formed from it (on the conidiophore), branching into smaller structures - sterigmas, on which there are chains of conidia. Penicillium can cause disease (penicillinosis). Many species of ascomycetes are producers of antibiotics.
Basidiomycetes are cap mushrooms with septate mycelium.
Deuteromycetes - imperfect fungi (Fungi imperfecti) - are a conditional class of fungi that combines fungi with septate mycelium that do not have sexual reproduction. They reproduce only asexually, forming conidia.
To imperfect mushrooms include fungi of the genus Candida that affect the skin, mucous membranes and internal organs (candidiasis). They are oval in shape, 2–5 µm in diameter; divide by budding (blastospores), form pseudomycelium (budding cells from the germ tube are drawn into a thread), at the ends of which are chlamydospores. These mushrooms are called yeast-like. True yeast (ascomycetes) form ascospores, do not have pseudomycelium and chlamydospores.
The vast majority of fungi that cause disease in humans (mycoses) are imperfect fungi.
General characteristics. Mushrooms are a kingdom of living organisms that combine the characteristics of plants and animals.
Brings them together with plants -. 1) the presence of a well-defined cell wall; 2) immobility in a vegetative state; 3) reproduction by spores; 4) the ability to synthesize vitamins; 5) absorption of food by absorption (adsorption). Common with animals is: 1) heterotrophy; 2) the presence of chitin in the cell wall, which is characteristic of the external skeleton of arthropods; 3) the absence of chloroplasts and photosynthetic pigments in cells; 4) accumulation of glycogen as a reserve substance; 5) the formation and release of a metabolic product - urea. These features of the structure and vital activity of fungi allow us to consider them one of the most ancient groups of eukaryotic organisms that do not have a direct evolutionary relationship with plants, as previously thought. Mushrooms and plants arose independently of the different forms of microorganisms that lived in the water.
More than 100 thousand species of mushrooms are known, and it is assumed that their real number is much larger - 250-300 thousand or more. More than a thousand new species are described worldwide each year. The vast majority of them live on land, and they are found almost everywhere where life can exist. It is estimated that 78-90% of the biomass of all microorganisms in the forest litter is accounted for by the fungal mass (approximately 5 t/ha).
The place of mushrooms in the organic world In the history of the development and formation of biology, the question of determining the place of fungi among other biological objects has been debatable until recently. Systematists and florists involved in biodiversity have always considered fungi with reservations as part of the plant kingdom, in the Tallophyta subdivision, as a special class of plants, along with bacteria, lichens, and algae. In the second half of the twentieth century. works appeared in which an analysis of modern knowledge about the structure and similarity of the evolution of cell ultrastructures of living organisms was given. Based on this, Whittaker (Whittaker, 1969) proposed a system of the organic world, including five kingdoms. It adopted an independent kingdom of fungi (Fungi), separate from the kingdoms of animals (Animalia) and plants (Plantae). Thus, only in the second half of the twentieth century. the position on the phylogenetic independence of fungal organisms becomes generally recognized. It turned out that all living organisms of the Earth are built according to a single plan. The most important ultrastructures of eukaryotic organisms include several organelles: karyomes, mitochondria, cilia (flagella, undulopodium) and photosynthetic plastids. Features of their structure, role in the life support and evolution of organisms turned out to be the most significant features and later became the basis of the megasystematics of all eukaryotes. In later years, a large number of kingdoms and divisions within them were proposed. In addition, numerous theories of the evolutionary development of the biota have been developed and continue to be developed. One of them - the theory of the symbiogenetic origin of the eukaryotic cell through the gradual symbiosis of microbial associations - gave impetus to the construction of numerous schemes of the organic world. The most accessible seems to be the five-kingdom system of the structure of the organic world: I. The super-kingdom of pre-nuclear organisms, or prokaryotes (Procariota) 1. The kingdom of monera (Monera) II. Superkingdom nuclear organisms, or eukaryotes (Eucariota) 2. Kingdom of protists (Protoctista) 3. Kingdom of fungi (Fungi) 4. Kingdom of animals (Animalia) 5. Kingdom of plants (Plantae) The evolution of microbial associations has led to the fact that the difference between eukaryotic cells ( protists, fungi, plants and animals) and prokaryotic cells devoid of a real nucleus are deeper than between the listed groups of eukaryotes. The world was divided into two parts, there was a fundamental distinction in living nature - the distinction between prokaryotes and eukaryotes.
Principles of classification of mushrooms.
Mushrooms belong to the kingdom Fungi(Mycetes, Mycota). These are multicellular or unicellular non-photosynthetic (chlorophyll-free) eukaryotic microorganisms with a cell wall.
mushroom classification. Mushrooms can be divided into 7 classes: Chytridiomycetes, Hyphochytridiomycetes, Oomycetes, Zygomycetes, Ascomycetes, Basidiomycetes, Deuteromycetes.
Among phycomycetes distinguish:
1) chytridiomycetes, or aquatic fungi that lead a saprophytic lifestyle or infect algae;
2)hypochytridiomycetes, resembling chytridiomycetes and oomycetes;
4) zygomycetes include representatives of the genus Mucor, common in soil and air and capable (for example, fungi of the genus Mucor) to cause mucormycosis of the lungs, brain and other organs.
At asexual reproduction on the fruit-bearing hyphesporangiophore is formed sporangium- a spherical thickening with a shell containing numerous spores (sporangiospores).
Sexual reproduction (oogamy) in zygomycetes are carried out by the formation zygospore or oospore.
Eumycetes are represented by ascomycetes and basidiomycetes. (perfect mushrooms), as well as deuteromycetes(imperfect mushrooms). Ascomycetes(or marsupials) unite a group of fungi that have a septate mycelium and are distinguished by their ability to reproduce sexually. Ascomycetes got their name from main fruiting organ - bags, or asuka containing 4 or 8 haploid sexual spores (ascospores). Ascomycetes are members of the genera Aspergillus, Penicillium and others, differing in the features of the formation of fruiting hyphae.
At Aspergillus(water mold) at the ends of the fruiting hyphaconidiophores there are thickenings - sterigmas, on which chains of spores - conidia are formed. Some types of aspergillus can cause aspergillosis and aflatoxicosis.
Fruiting hypha in fungi of the genus Penicillium(racus) resembles a brush, since thickenings are formed from it (on the conidiophore), branching into smaller structures - sterigmas, on which there are chains of conidia. Penicillium can cause disease (penicillinosis). Many species of ascomycetes are producers of antibiotics.
Representatives of ascomycetes are and yeast- unicellular fungi that have lost the ability to form true mycelium. Yeast have oval-shaped cells with a diameter of 3-15 microns. They are reproduce by budding, binary fission(divided into two equal cells) or sexually with the formation of ascospores. Yeast is used in biotechnological processes. Diseases caused by certain types of yeast are called yeast mycoses.
Basidiomycetes - hat mushrooms with septate mycelium.
Deuteromycetes - imperfect mushrooms(Fungi imperfecti) - are a conditional class of fungi that combines fungi with septate mycelium, not having sexual reproduction. They reproduce only asexually, forming conidia. Imperfect fungi include fungi of the genus Candida affecting the skin, mucous membranes and internal organs ( candidiasis). They are oval in shape, 2-5 microns in diameter; divide by budding (blastospores), form pseudomycelium (budding cells from the germ tube are drawn into a thread), at the ends of which are chlamydospores. These mushrooms are called yeast-like. True yeast (ascomycetes) form ascospores, do not have pseudomycelium and chlamydospores. The vast majority of fungi that cause disease in humans (mycoses) are imperfect fungi.
№ 6 Morphology of mushrooms
Mushrooms belong to the kingdom Fungi (Mycetes, Mycota ). These are multicellular or unicellular non-photosynthetic (chlorophyll-free) eukaryotic microorganisms with a cell wall.
Mushrooms have a nucleus with a nuclear membrane, a cytoplasm with organelles, a cytoplasmic membrane, and a multi-layered, rigid cell wall consisting of several types of polysaccharides, as well as protein, lipids, etc. Some fungi form a capsule. The cytoplasmic membrane contains glycoproteins, phospholipids and ergosterols. Mushrooms are gram-positive microbes, vegetative cells are not acid-resistant.
Mushrooms consist from long thin threads (hyphae) woven into a mycelium, or mycelium. Hyphae of lower fungi - phycomycetes - do not have partitions. In higher fungi - eumycetes - hyphae are separated by partitions; their mycelium is multicellular.
There are hypal and yeast forms of fungi.
Hyphal(mold) mushrooms form branching thin threads (hyphae) intertwined into a mycelium, or mycelium (mold). Hyphae growing into the nutrient substrate are called vegetative hyphae (responsible for feeding the fungus), and those growing above the surface of the substrate are called aerial or reproductive hyphae (responsible for asexual reproduction).
GIFs lower mushrooms do not have partitions. They are represented by multinucleated cells and are called coenocytic.
GIFs higher mushrooms are separated by partitions, or septa with holes.
Yeastfungi (yeasts) mainly have the appearance of individual oval cells (single-celled fungi). According to the type of sexual reproduction, they are distributed among higher fungi - ascomycete and basidiomycete. In asexual reproduction, yeast form buds or divide, resulting in single-celled growth. They can form pseudohyphae and false mycelium (pseudomycelium) in the form of chains of elongated cells - "wieners". Mushrooms that are similar to yeast but do not reproduce sexually are called yeast-like. They reproduce only asexually - by budding or division.
mushrooms multiplyspores in sexual and asexual ways, as well as vegetatively (budding or fragmentation of hyphae). Mushrooms that reproduce sexually and asexually are classified as perfect. Mushrooms that do not have or have not yet been described sexual reproduction are called imperfect. Asexual reproduction is carried out in fungi with the help of endogenous spores that mature inside a round structure - sporangia, and exogenous spores - conidia, which form at the tips of fruiting hyphae.
mushroom types.There are 3 types of fungi that have a sexual mode of reproduction (the so-called committed fungi): zygomycetes ( Zygomycota), ascomycetes (Ascomycota ) and basidiomycetes ( Basidiomycota ). Separately, a conditional, formal type / group of fungi is distinguished - deuteromycetes ( Deiteromycota ), which have only asexual reproduction (the so-called imperfect mushrooms).
Classification(from lat. classis - category (class) and lat. facere - to do) is a system of subordinate concepts (classes of objects) of any area of knowledge or activity, used as a means to establish links between these concepts or classes of objects. Scientific classification expresses the system of laws inherent in the area of reality displayed in it. Distinguish natural classifications, the basis of which is the essential features of objects (as the periodic system of chemical elements of D. I. Mendeleev), and artificial classifications(or subsidiary classifications), the basis of which is non-essential features (like alphabetical subject indexes or nominal catalogs in libraries).
Classification - the distribution of objects by categories, classes, groups, with the condition that objects with a common feature fall into one category, group, class. BUT taxonomy(in particular, biological systematics) is a scientific discipline whose tasks include the development of the very principles of the classification of living organisms and the practical application of these principles to the construction of the very system of their systematics.
1. Systematics of living organisms. Taxonomy. Nomenclature.
2. Classification of microorganisms. Principles of classification of microorganisms. Systematics of microorganisms. Natural (phylogenetic) systematics of microorganisms.
3. Artificial (key) taxonomy of microorganisms. Burgey's Bacteria Key.
4. Principles of taxonomy of microorganisms. Principles of the nomenclature of microorganisms. Categories of taxonomic hierarchy. Names of taxa in microorganisms.
5. Systematics of viruses. Features of the classification of viruses. The main criteria for the taxonomic classification of viruses.
6. Systematics of bacteria. Gram stain. Gram-positive bacteria. Gram-negative bacteria. acid-resistant bacteria.
7. Mobility of bacteria. Sliding bacteria. floating bacteria. Aerobic bacteria. anaerobic bacteria. facultative bacteria.
8. Burgey's determinant. Groups of bacteria of Bergey's guide.
10. Systematics of protozoa. Principles of classification of protozoa. Phylum Sarcomastigophora. Type Ciliophora. Type Apicomplexa.
Mushrooms assigned to the kingdom Fungi (Mycota), subdivided into the divisions Muhotusota (mushroom mushrooms) and Eumycota (true mushrooms). True mushrooms, the hyphae of which do not have partitions, are known as lower fungi. These include the classes Chrytidiomycetes, Hyphochrytidiomycetes, Oomycetes, Zygomycetes. Representatives of the classes Ascomycetes, Basidiomycetes and Deuteromycetes are higher fungi, since their hyphae have septa-septa. These include the vast majority of species that cause disease in humans.
Zygomycetes[from Greek. zygon, articulation, + mykes, fungus] are fast-growing species that usually live in the soil. When cultivated in vitro, they form an abundant grayish or white aerial mycelium. Their hyphae do not have septa or are partly septate. They reproduce sexually and asexually (see Fig. 2-10, 2-11). Asexual reproduction is realized through the formation of sporangiophores with sporangia. Sexual reproduction leads to the formation of zygotes - zygospores. Human lesions are of a pronounced opportunistic nature. Their pathogens can be representatives of the genera Absidia, Mortierella, Mucor, Rhizopus, Entomophthora, Conidiobolus and Basidiobolus.
Ascomycetes[from Greek. askos, bag, + mykes, mushroom] got its name from the presence of the main fruiting organ - a bag containing 4 or 8 haploid sexual ascospores. The hyphae have pronounced septa. They reproduce sexually (through the formation of ascospores) and asexually (through the formation of conidia) by. Ascomycetes also include yeast - unicellular fungi that have lost the ability to form mycelium. The causative agents of human mycoses are Pseudoattescheria boydii and representatives of the genera Geotrichum, Microsporum and Trichophyton.
Basidiomycetes[from Greek. basidon, small base, + mykes, mushroom] have a characteristic sporulation organ - the basidium. The latter consists of a swollen terminal cell located on a thin stalk. On the basidium, by meiotic division, basidiospores develop, lacing off from it. The only species pathogenic for humans is Filobasidiella neoformans (the sexual form of Cryptococcus neoformans var. neoformans).
Deuteromycetes[from Greek. deuteros, secondary, + mykes, fungus] do not form a real phylogenetic group, but act as a taxonomic "dump" where species are placed in which the sexual (perfect) stage of reproduction is absent or not identified. Their classification is based on the forms of sporulation or other external signs and serves only practical purposes. For them, only asexual reproduction is considered established, therefore deuteromycetes are also known as imperfect fungi (Fungi imperfecti). Morphologically, most deuteromycetes are similar to ascomycetes. Most of the causative agents of human mycoses are included in the group of imperfect fungi.
mushroom naming code
mushroom naming code contains provisions providing for the assignment of separate names to the perfect (sexual, or marsupial) and imperfect (asexual, or conidial) stages. In many fungi, asexual stages (anamorphs) are known and sexual stages (teleomorphs) are unknown. Therefore, the code allows you to give different stages (if any) different names. For example, the sex forms of the yeast fungus Cryptococcus neoformans serovars A and D are classified as Filobasidella neoformans var. neoformans or as C neoformans var. neoformans. Teleomorphs of serovars B and C - like Filobasidella neoformans var. bacillispora or as C. neoformans var. gati.