Biological objects of animal origin in biotechnology. Biotechnology objects and their levels

Microorganisms as objects of biotechnology. Classification. Characteristic.

Bacteria are extremely diverse in terms of living conditions, adaptability, types of nutrition and bioenergy production, in relation to macroorganisms - animals and plants. The most ancient forms of bacteria - archaebacteria - are capable of living in extreme conditions ( high temperatures and pressure, concentrated salt solutions, acidic solutions). Eubacteria (typical prokaryotes, or bacteria) are more sensitive to environmental conditions.

According to the type of nutrition, bacteria are divided according to the source of energy:

phototrophs that use energy sunlight;

· chemoautotrophs, using the energy of oxidation of inorganic substances (sulfur compounds, methane, ammonia, nitrites, ferrous iron compounds, etc.);

By type of oxidation of the substance:

organotrophs that obtain energy from the decomposition of organic substances into minerals; these bacteria are the main participants in the carbon cycle; bacteria that use the energy of fermentation belong to the same group;

lithotrophs ( inorganic substances);

By type of carbon sources:

heterotrophic – use organic substances;

· aphthotrophic – use gas;

To indicate the type of power supply:

1. the nature of the energy source is photo- or chemo;

2. Electron donors litho- or organo-;

3. Carbon sources aphtho- and hetero-;

And the term ends with the words trophy. 8 different power types.

Higher animals and plants are prone to 2 types of nutrition:

1) Chemoorganoheterotrophy (animals)

2) Photolithophthotrophy (plants)

The microorganism has all types of nutrition, and they can switch from one to another depending on their existence

There is a separate type of food:

Bacteria are convenient objects for genetic research. The most studied and widely used in genetic engineering research is Escherichia coli (E. coli), which lives in the human intestine.

Organization and structure of biotechnological production. Distinctive features biotechnological production from traditional types of technologies. Advantages and disadvantages of biotechnological production compared to traditional technologies.

Big variety biotechnological processes that have found industrial application leads to the need to consider the general, most important problems that arise when creating any biotechnological production. Industrial biotechnology processes are divided into 2 large groups: biomass production and metabolic products. However, such a classification does not reflect the most significant aspects of industrial biotechnological processes from a technological point of view. In this regard, it is necessary to consider the stages of biotechnological production, their similarities and differences depending on ultimate goal biotechnological process.

There are 5 stages of biotechnological production.

The two initial stages include the preparation of raw materials and biologically active principles. In engineering enzymology processes, they usually consist of preparing a solution of a substrate with specified properties (pH, temperature, concentration) and preparing a batch of a given type of enzyme preparation, enzymatic or immobilized. When carrying out microbiological synthesis, the stages of preparing a nutrient medium and maintaining a pure culture are necessary, which could be used constantly or as needed in the process. Maintaining a pure culture of the producer strain is the main task of any microbiological production, since a highly active strain that has not undergone undesirable changes can serve as a guarantee of obtaining the target product with the desired properties.

The third stage is the fermentation stage, at which the formation of the target product occurs. At this stage, microbiological transformation of the components of the nutrient medium occurs, first into biomass, then, if necessary, into the target metabolite.

At the fourth stage, the target products are isolated and purified from the culture liquid. For industrial micro biological processes Characteristic, as a rule, is the formation of very dilute solutions and suspensions containing, in addition to the target, a large number of other substances. In this case, it is necessary to separate mixtures of substances of a very similar nature, which are in solution in comparable concentrations, are very labile, and are easily subject to thermal destruction.

The final stage of biotechnological production is the preparation of commercial forms of products. A common property of most microbiological synthesis products is their lack of storage stability, since they are prone to decomposition and in this form provide an excellent environment for the development of foreign microflora. This forces technologists to take special measures to improve the safety of industrial biotechnology products. In addition, drugs for medical purposes require special solutions at the packaging and capping stage, so they must be sterile.

The main goal of biotechnology is the industrial use of biological processes and agents based on the production of highly effective forms of microorganisms, cultures of cells and tissues of plants and animals with desired properties. Biotechnology arose at the intersection of biological, chemical and technical sciences.

Biotechnological process - includes a number of ethanes: preparation of the object, its cultivation, isolation, purification, modification and use of products.

Biotechnological processes can be based on batch or continuous cultivation.

In many countries around the world, biotechnology is given paramount importance. This is due to the fact that biotechnology has a number of significant advantages over other types of technologies, for example, chemical technology.

1). This is, first of all, low energy intensity. Biotechnological processes are carried out at normal pressure and temperatures of 20-40° C.

2). Biotechnological production is often based on the use of standard equipment of the same type. The same type of enzymes are used to produce amino acids and vitamins; enzymes, antibiotics.

3). Biotechnological processes are easy to make waste-free. Microorganisms assimilate a wide variety of substrates, so waste from one particular production can be converted into valuable products with the help of microorganisms during another production.

4). The waste-free nature of biotechnological production makes it the most environmentally friendly

5). Research in the field of biotechnology does not require large capital investments and does not require expensive equipment.

The primary tasks of modern biotechnology include the creation and widespread development of:

1) new biologically active substances and drugs for medicine (interferons, insulin, growth hormones, antibodies);

2) microbiological means of protecting plants from diseases and harm

lei, bacterial fertilizers and plant growth regulators, new highly productive and resistant to adverse environmental factors hybrids of agricultural plants obtained by genetic and cellular engineering methods;

3) valuable feed additives and biologically active substances (feed protein, amino acids, enzymes, vitamins, feed antibiotics) to increase livestock productivity;

4) new technologies for obtaining economically valuable products for use in food, chemical, microbiological and other industries;

5) technologies for deep and efficient processing of agricultural, industrial and household waste, the use of wastewater and gas-air emissions to produce biogas and high-quality fertilizers.

Traditional (conventional) technology represents developments that reflect average level production achieved by the majority of product manufacturers in this industry. This technology does not provide its buyer with significant technical and economic advantages and product quality compared to similar products from leading manufacturers, and one cannot count on additional (above average) profits in this case. Its advantages for the buyer are the relatively low cost and the opportunity to purchase technology tested in production conditions. Traditional technology is created, as a rule, as a result of obsolescence and large-scale dissemination of advanced technology. Such technology is usually sold at prices that compensate the seller for the costs of preparing it and obtaining an average profit.

Advantages of biotechnological processes compared to chemical technology biotechnology has the following main advantages:

· the possibility of obtaining specific and unique natural substances, some of which (for example, proteins, DNA) cannot yet be obtained by chemical synthesis;

·conducting biotechnological processes at relatively low temperatures and pressures;

microorganisms have significantly higher rates of growth and accumulation of cell mass than other organisms

· cheap waste can be used as raw material in biotechnology processes Agriculture and industry;

· biotechnological processes, compared to chemical ones, are usually more environmentally friendly, have less harmful waste, and are close to natural processes occurring in nature;

·As a rule, technology and equipment in biotechnological production are simpler and cheaper.

Biotechnological stage

The main stage is the biotechnological stage itself, at which, using one or another biological agent, the transformation of raw materials into one or another target product occurs.

Usually the main task of the biotechnological stage is to obtain a certain organic substance.

The biotechnological stage includes:

Fermentation is a process carried out by cultivating microorganisms.

Biotransformation is the process of changing the chemical structure of a substance under the influence of the enzymatic activity of microorganism cells or ready-made enzymes.

Biocatalysis is the chemical transformation of a substance that occurs using biocatalysts-enzymes.

Biooxidation is the consumption of pollutants by microorganisms or the association of microorganisms under aerobic conditions.

Methane fermentation is the processing of organic waste using an association of methanogenic microorganisms under anaerobic conditions.

Biocomposting is a reduction in the content of harmful organic substances by an association of microorganisms in solid waste, which is given a special loosened structure to ensure air access and uniform moisture.

Biosorption - sorption harmful impurities from gases or liquids by microorganisms, usually attached to special solid supports.

Bacterial leaching is the process of converting water-insoluble metal compounds into a dissolved state under the influence of special microorganisms.

Biodegradation is the destruction of harmful compounds under the influence of biodestructor microorganisms.

Typically, a biotechnological stage has one liquid and one gas stream as output streams, sometimes only one liquid stream. If the process takes place in the solid phase (for example, cheese ripening or biocomposting of waste), the output is a stream of processed solid product.

Preparatory stages

The preparatory stages serve to prepare and prepare the necessary types of raw materials for the biotechnological stage.

The following processes can be used during the preparation stage.

Sterilization of the environment - for aseptic biotechnological processes where the ingress of foreign microflora is undesirable.

Preparation and sterilization of gases (usually air) necessary for a biotechnological process. Most often, air preparation consists of cleaning it from dust and moisture, ensuring the required temperature and cleaning it from microorganisms present in the air, including spores.

Preparation of seed material. Obviously, in order to carry out a microbiological process or the process of cultivating isolated plant or animal cells, it is necessary to prepare seed material - a pre-grown small amount of a biological agent compared to the main stage.

Preparation of the biocatalyst. For the processes of biotransformation or biocatalysis, it is necessary to first prepare a biocatalyst - either an enzyme in free or fixed form on a carrier, or a biomass of microorganisms previously grown to a state in which its enzymatic activity is manifested.

Pre-processing of raw materials. If raw materials enter production in a form unsuitable for direct use in the biotechnological process, then an operation is carried out to preliminary prepare the raw materials. For example, when producing alcohol, wheat is first crushed and then subjected to the enzymatic process of “saccharification”, after which the saccharified wort is converted into alcohol at the biotechnological stage by fermentation.

Product Cleaning

The task of this stage is to remove impurities and make the product as pure as possible.

Chromatography is a process similar to adsorption.

Dialysis is a process in which low molecular weight substances can pass through a semi-permeable septum, while high molecular weight substances remain.

Crystallization. This process is based on the different solubility of substances at different temperatures.

Product concentration

The further task is to ensure its concentration.

At the concentration stage, processes such as evaporation, drying, precipitation, crystallization with filtration of the resulting crystals, ultrafiltration and hyperfiltration or nanofiltration are used, which provide a kind of “squeezing” of the solvent from the solution.

Effluent and Emission Treatment

Purification of these wastewater and emissions is a special task that must be solved in our environmentally unfavorable times. Essentially, wastewater treatment is a separate biotechnological production, which has its own preparatory stages, a biotechnological stage, a stage of sedimentation of activated sludge biomass and a stage of additional wastewater treatment and sludge processing.

Types of biological objects used in biotechnology, their classification and characteristics. Biological objects of animal origin. Biological objects of plant origin.

Objects of biotechnology include: organized extracellular particles (viruses), cells of bacteria, fungi, protozoa, tissues of fungi, plants, animals and humans, enzymes and enzyme components, biogenic nucleic acid molecules, lectins, cytokinins, primary and secondary metabolites.

Currently, most biological objects of biotechnology are represented by representatives of 3 superkingdoms:

1) Acoryotac – acoryots or anucleate;

2) Procaryotac – prokaryotes or prenuclear;

3) Eucaryotac - eukaryotes or nuclear.

They are represented by 5 kingdoms: akaryotes include viruses (non-cellular organized particles); Prokaryotes include bacteria (morphological elementary unit); Eukaryotes include fungi, plants and animals. Type coding genetic information DNA (for DNA or RNA viruses).

Bactria have a cellular organization, but the nuclear material is not separated from the cytoplasm by any membranes and is not associated with any proteins. Most bacteria are single-celled; their size does not exceed 10 micrometers. All bacteria are divided into archiobacteria and eubacteria.

Mushrooms (Mycota) are important biotechnological objects and producers of a number of important food compounds and additives: antibiotics, plant hormones, dyes, mushroom protein, various types of cheeses. Micromycetes do not form the fruiting body, while macromycetes do. They have characteristics of animals and plants.

Plants (Plantae). About 300 thousand plant species are known. These are differentiated organic plants, the constituent parts of which are tissues (merimestent, integumentary, conductive, mechanical, basal and secretory). Only mimetic tissues are capable of division. Any type of plant, under certain conditions, can produce an unorganized cellular mass of dividing cells - callus. The most important biological objects are protoplasts of plant cells. They lack a cell wall. Used in cell engineering. Seaweed is often used. Agar-agar and alginates (polysaccharides used for the preparation of microbiological media) are obtained from them.

Animals (Animalia). In biotechnology, biological objects such as cells of various animals are widely used. In addition to the cells of higher animals, cells of protozoan animals are used. Cells from higher animals are used to obtain recombinant DNA and for toxicological studies.

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The first attempt to systematize information about organisms belongs to Aristotle (4th century BC). All living organisms known by that time were divided by him into two kingdoms - plants and animals. In the second half of the 19th century, the German scientist E. Haeckel proposed separating all microorganisms into a separate kingdom Protista (primal beings - from the Greek "protos" - the simplest).

Further study of microorganisms revealed their heterogeneity, which led to the division of the group into higher and lower protests. The highest protests included microscopic animals (protozoa), microscopic algae (except blue-green algae, also called cyanobacteria) and microscopic fungi (molds, yeasts), and the lower ones included all bacteria, including cyanobacteria. The division into higher and lower protests was carried out in accordance with the two discovered types of cellular organization - eukaryotic and prokaryotic. The higher protests are eukaryotes, the lower ones are prokaryotes.

These cell types have both common features and significant differences. /A cell is a piece of cytoplasm delimited by a membrane that has a characteristic ultrastructure: two electron-dense layers, each 2.5-3.0 nm thick, separated by an electron-transparent gap. Such membranes are called elementary.| In any cell there are two types of nucleic acids (DNA and RNA), proteins, lipids, and carbohydrates. Cytoplasm and the elementary membrane are essential structural elements of the cell. A prokaryotic cell has one internal cavity formed by an elementary membrane called the cytoplasmic membrane (CPM).

Eukaryotic cells, unlike prokaryotic cells, have secondary cavities. Cellular structures bounded by elementary membranes and performing certain functions in the cell are called organelles (organelles). These include the nucleus, mitochondria, ribosomes, lysosomes, Golgi apparatus, chloroplasts, etc. The nucleus acts as a custodian of genetic information, the carrier of which is DNA. The main structural and functional elements of the core, containing linear order genes are chromosomes. Mitochondria supply the cell with energy through the oxidation of substances with the participation of oxygen. They also synthesize their own mitochondrial proteins.

All other cellular proteins are synthesized on ribosomes. Lysosomes contain enzymes for breaking down various biopolymers. The Golgi apparatus (named after the Italian scientist Camillo Golgi, who received the Nobel Prize in 1906) is involved in the formation of cell waste products - various secretions, collagen, glycogen, lipids, etc., in the synthesis of glycoproteins. Chloroplasts, found only in plant cells, carry out photosynthesis.

In prokaryotic cells, the organelles listed above, typical of eukaryotes, are absent. Their nuclear DNA is not separated from the cytoplasm by a membrane. Fundamental differences in the structure of prokaryotic and eukaryotic cells were the reason for the separation of prokaryotic microorganisms, located at the most primitive level of cellular organization, into the special kingdom Mopega (R. Whittaker). Microscopic, mostly single-celled, undifferentiated life forms include the kingdom Protista. Multicellular eukaryotes are represented by three kingdoms: Plantae (plants), Fungi (fungi) and Animalia (animals).

The sizes of most bacteria are in the range of 0.5-3 microns, but there are “giants” and “dwarfs” among them. For example, the length of a spirochete cell reaches 500 microns. The smallest of prokaryotic cells are bacteria belonging to the mycoplasma group; their cell diameter is 0.1-0.15 microns. For a long time, it was believed that prokaryotic cells have the shape of a sphere (cocci), cylinder (rods) or spiral (spirilla or vibrio). IN Lately it is shown that, in addition to the indicated forms, bacteria can also have the shape of a ring or a star; Some species are characterized by branching. Multicellular prokaryotes are clusters of various configurations, most often filaments.

Bacteria are extremely diverse in terms of living conditions, adaptability, types of nutrition and bioenergy production, in relation to macroorganisms - animals and plants. The most ancient forms of bacteria - archaebacteria are capable of living in extreme conditions (high temperatures and pressures, concentrated salt solutions, acidic solutions). Eubacteria (typical prokaryotes, or bacteria) are more sensitive to environmental conditions.

Bacteria are convenient objects for genetic research. The most studied and widely used in genetic engineering research is Escherichia coli (E. coli), which lives in the human intestine.

Plants include algae, which are aquatic organisms, and higher plants, which live primarily on land. Algae do not have organs or tissues and consist of undifferentiated (identical) cells. Agar-agar and alginates are obtained from algae - polysaccharides used for the production of microbiological media and in the food industry. Higher plants are multicellular organisms with specialized organs - roots, stems, leaves. They consist of tissues formed by specialized cells. Plants serve as suppliers of nutrients for other organisms.

Despite the fact that traditional methods for extracting physiologically active and medicinal compounds from plants (extraction, distillation, filtration) are still widely used, technologies for obtaining biologically active substances from cell cultures, as well as the production of products from genetically modified plants, are becoming increasingly important.

Fungi combine features of plant and animal cells. They have a cell nucleus and, like plants, a strong cell wall. Like animal cells, they are capable of synthesizing polysaccharides - chitin and glycogen and require certain vitamins. Microscopic fungi are especially interesting for biotechnology - yeast, mold fungi, higher fungi, used in the baking, brewing and dairy industries, as well as for the production of organic acids, alcohols, antibiotics, feed protein, and various biologically active substances.

An example of such technology is the production of the antiviral drug interferon, which is used for the prevention and treatment of influenza and other viral infections. The most promising method for the production of biologically active substances is Genetic Engineering. In particular, this is how human insulin, a protein hormone, is obtained.

S.V. Makarov, T.E. Nikiforova, N.A. Kozlov

Objects used in biotechnology (they include representatives of both prokaryotes and eukaryotes) are extremely diverse in their structural organization and biological characteristics. Biotechnology objects include:

Bacteria and cyanobacteria;

Seaweed;

Lichens;

Aquatic plants;

Plant and animal cells.

The group of lower plants includes both microscopically small organisms (unicellular and multicellular) and very large ones. But they are all united like this common features, such as the lack of division of the body into vegetative organs and a variety of methods of reproduction.

The lower divisions include the following: Viruses, Bacteria, a group of divisions: Algae (Blue-green, Green, Diatoms, Brown, Red, etc.), Myxomycetes, Fungi, Lichens. According to the method of nutrition, they are divided into two groups: autotrophs (algae and lichens), capable of photosynthesis, and heterotrophs (viruses, bacteria - with a few exceptions - myxomycetes, fungi), using ready-made organic substances for nutrition.

Lower plants have gone a long way historical path development, but many of their representatives still retained the features of a primitive organization. At a certain stage of development, they gave rise to higher plants, the crown of which are angiosperms.

Structure. Viral particles (virions) have a protein capsule - a capsid containing the viral genome, represented by one or more DNA or RNA molecules. The capsid is built from capsomeres - protein complexes consisting, in turn, of protomers. Virions often have a regular geometric shape (icosahedron, cylinder). This capsid structure provides for the identity of the bonds between its constituent proteins and, therefore, can be built from standard proteins of one or more species, which allows the virus to “save” space in the genome. Capsid proteins are complementary to certain molecular structures in the host cell and interact with them necessary for the penetration and existence of the virus. The capsid protects the virus only outside a living cell. Outside the host cell, viruses behave like a substance (can be obtained in crystalline form); Once in a living cell, they again show activity.

Mechanism of infection. Conventionally, the process of viral infection on the scale of one cell can be divided into the following stages.

Attachment to the cell membrane is the so-called adsorption. Typically, in order for a virus to be adsorbed on the surface of a cell, it must have a specific protein (often a glycoprotein) in its plasma membrane - a receptor specific for a given virus. The presence of a receptor often determines the host range of a given virus, as well as its tissue specificity.

Penetration into the cell. At this stage, the virus needs to deliver its genetic information inside the cell. Some viruses also introduce their own proteins necessary for its implementation. Different viruses use different strategies to enter a cell. Viruses also differ in the localization of their replication: some viruses multiply in the cytoplasm of the cell, and some in its nucleus.

Cell reprogramming. When a cell is infected with a virus, special antiviral defense mechanisms are activated. Infected cells begin to synthesize signaling molecules, such as interferons, which convert surrounding healthy cells into an antiviral state and activate the immune system. Damage caused by the virus multiplying in a cell can be detected by internal cell control systems, and the cell will have to "commit suicide" in a process called apoptosis (or programmed cell death). Its survival directly depends on the ability of the virus to overcome antiviral defense systems. It is not surprising that many viruses, as they evolve, have acquired the ability to suppress the synthesis of interferons, the apoptotic program, etc. In addition to suppressing antiviral defense, viruses strive to create the most favorable conditions in the cell for the development of their offspring.

Persistence. Some viruses can enter a latent state (so-called persistence), weakly interfering with the processes occurring in the cell, and are activated only under certain conditions. For example, the reproduction strategy of some bacteriophages is based on this: as long as the infected cell is in a favorable environment, the phage does not kill it, is inherited by daughter cells and is often integrated into the cellular genome. However, if a phage-infected bacterium enters unfavorable environment the pathogen seizes control of cellular processes so that the cell begins to produce materials from which new phages are built. The cell turns into a “factory” capable of producing many thousands of phages. Mature particles leaving the cell break apart cell membrane, thereby killing the cell. Some cancers are associated with the persistence of viruses.

Creation of new viral components. In the most general case, virus replication involves three processes:

Transcription of the viral genome, i.e. synthesis of viral mRNA;

Translation of mRNA, i.e. synthesis of viral proteins;

Replication of the viral genome.

Many viruses have control systems that ensure optimal consumption of host cell biomaterials. For example, when enough viral mRNA has accumulated, transcription of the viral genome is suppressed, and replication, on the contrary, is activated.

Virion maturation and exit from the cell. Eventually, the newly synthesized genomic RNA or DNA is “dressed” with the appropriate proteins and leaves the cell. It should be noted that an actively replicating virus does not always kill the host cell. In some cases, daughter viruses bud from the plasma membrane without causing it to rupture. Thus, the cell can continue to live and produce the virus.

Classification of viruses. The systematics and taxonomy of viruses is codified and maintained by the International Committee on Taxonomy of Viruses (ICTV), which also maintains the taxonomic database The Universal Virus Database ICTVdB.

The form of representation of genetic information underlies the modern classification of viruses. Currently, they are divided into DNA and RNA viruses.

The meaning of viruses. Viruses cause a number of dangerous diseases in humans (smallpox, hepatitis, influenza, measles, polio, AIDS, cancer, etc.), plants (mosaic disease of tobacco, tomato, cucumber, dwarfism, strawberry wilt), animals (swine fever, foot-and-mouth disease) . However, preparations of the corresponding bacteriophages are used to treat bacterial diseases - dysentery and cholera.

The production of interferon, a special cellular protein that prevents the proliferation of viruses, is widely used in medicine, especially during outbreaks of influenza epidemics. This substance universal action, active against many viruses, although the sensitivity of different viruses to it varies. Being a product of the cell itself, interferon is completely devoid of toxic effects on it. Nowadays, ready-made interferon is used; it can be synthesized in cells cultured outside the body.

3.Bacteria

Until the end of the 1970s. the term “bacterium” served as a synonym for prokaryotes, but in 1977, based on molecular biology data, prokaryotes were divided into the kingdoms of archaebacteria and eubacteria (actually bacteria).

The structure of bacteria. The vast majority of bacteria (with the exception of actinomycetes and filamentous cyanobacteria) are unicellular. According to the shape of the cells, they can be spherical (cocci), rod-shaped (bacilli, clostridia, pseudomonads), convoluted (vibrios, spirillum, spirochetes), less often - stellate, tetrahedral, cubic, C- or O-shaped. The essential cellular structures of bacteria are:

Nucleoid;

Ribosomes;

Cytoplasmic membrane (CPM).

Prokaryotes, unlike eukaryotes, do not have a separate nucleus in the cytoplasm. All the genetic information necessary for the life of bacteria is contained in one double-stranded DNA (bacterial chromosome), which has the shape of a closed ring. It is attached to the CPM at one point. Unfolded DNA is more than 1 mm long. The bacterial chromosome is usually presented in a single copy, i.e., almost all prokaryotes are haploid, although in some cases one cell may contain several copies of its chromosome. Chromosome division is accompanied by cell division. The region of the cell in which the chromosome is localized is called the nucleoid; it is not surrounded by a nuclear membrane. 1$ connection with this, newly synthesized mRNA is immediately available for binding to ribosomes, i.e., the processes of transcription and translation can occur simultaneously. There is no nucleolus.

In addition to the chromosome, bacterial cells often contain plasmids - small DNA molecules closed in a ring that are capable of independent replication. They contain additional genes needed only under specific conditions. They encode mechanisms of resistance to certain drugs, the ability to transfer genes during conjugation, the synthesis of substances of an antibiotic nature, the ability to use certain sugars or ensure the degradation of a number of substances. That is, plasmids act as adaptation factors. In some cases, plasmid genes can be integrated into the bacterial chromosome.

Ribosomes of prokaryotes differ from those of eukaryotes and have a sedimentation constant of 70 S (in eukaryotes - 80 S).

U different groups Prokaryotes have local invaginations of the CPM - mesosomes, which perform various functions in the cell and divide it into functionally different parts. It is believed that mesosomes take part in bacterial division. When redox enzymes are located on the membranes of mesosomes, they are equivalent to the mitochondria of plant and animal cells. In photosynthetic bacteria, a pigment - bacteriochlorophyll - is embedded in the invaginations of the membranes. With its help, bacterial photosynthesis is carried out.

On the outer side of the CPM there are several layers (cell wall, capsule, mucous membrane), called the cell membrane, as well as surface structures (flagella, villi, pili).

In bacteria, there are two main types of cell wall structure, characteristic of gram-positive and gram-negative species. The cell wall of Gram-positive bacteria is a homogeneous layer 20-80 nm thick, built mainly from murein peptidoglycan with a large amount of teichoic acids and a small amount of polysaccharides, proteins and lipids. In gram-negative bacteria, the peptidoglycan layer is loosely adjacent to the CPM and has a thickness of only 2-3 nm. It is surrounded by an outer membrane, which, as a rule, has an uneven, curved shape.

On the outside of the cell wall there may be a capsule - an amorphous layer of hydrated polysaccharides that maintains contact with the wall. The mucous layers have no connection with the cell and are easily separated, while the covers are not amorphous, but have a fine structure.

Many bacteria are capable of active movement with the help of flagella - outgrowths of the cytoplasm.

Reproduction of bacteria. Bacteria do not have a sexual process and reproduce only by equal binary transverse division or budding. For one group of unicellular cyanobacteria, multiple fission (a series of rapid successive binary divisions leading to the formation of 4 to 1000 new cells under the mother cell membrane) has been described.

In prokaryotes, horizontal gene transfer can occur. During conjugation, the donor cell transfers part of its genome (in some cases the entire genome) to the recipient cell during direct contact. Sections of the donor cell's DNA can be exchanged for homologous sections of the recipient's DNA. The probability of such an exchange is significant only for bacteria of one species.

A bacterial cell can also absorb DNA that is freely present in the environment, incorporating it into its genome. This process is called transformation. Under natural conditions, the exchange of genetic information occurs with the help of bacteriophages (transduction). With horizontal transfer, new genes are not formed, but different gene combinations are created. These properties of bacteria are very important for genetic engineering.

Sporulation in bacteria. Some bacteria form spores. Their formation is typical for particularly resistant forms with slow metabolism and serves for preservation in unfavorable conditions, as well as for distribution. Spores can persist for a long time without losing viability. Thus, the endospores of many bacteria are able to withstand 10-minute boiling at 100 °C, drying for a thousand years and, according to some data, remain viable in soils and rocks for millions of years.

Metabolism of bacteria. With the exception of some specific points, the biochemical pathways through which the synthesis of proteins, fats, carbohydrates and nucleotides is carried out in bacteria are similar to those in other organisms. However, bacteria differ in the number of possible biochemical pathways and, accordingly, in the degree of dependence on the supply of organic substances from the outside. Some bacteria can synthesize all the organic molecules they need from non organic compounds(autotrophs), while others require ready-made organic compounds, which they can only transform (heterotrophs).

Classification of bacteria. The best known phenotypic classification of bacteria is based on the structure of their cell wall. On the basis of this classification, the Bergey’s Determinant of Bacteria was built, the ninth edition of which was published in 1984-1987. The largest taxonomic groups in it were four divisions: Gracilicutes (Gram-negative), Firmicutes (Gram-positive), Tenericutes (mycoplasmas) and Mendosicutes (archaea).

The meaning of bacteria. Saprophytic bacteria play a large role in the cycle of substances in nature, destroying dead organic material in ecosystems. Their role in all biogeochemical cycles on our planet is well known. Bacteria take part in the cycles of chemical elements (carbon, iron, sulfur, nitrogen, phosphorus, etc.), in soil formation processes, and determine soil fertility.

Many bacteria “inhabit” the organisms of animals and humans and guard our health.

The biotechnological functions performed by bacteria are varied. They are used in the production of various substances: vinegar (Gluconobacter suboxidans), lactic acid drinks and products (Lactobacillus, Leuconostoc), as well as microbial insecticides (Bacillus thuringiensis) and herbicides, proteins (Methylomonas), vitamins (Clostridium - riboflavin); when processing waste, producing bacterial fertilizers, solvents and organic acids, biogas and photohydrogen. The property of some bacteria, such as diazotrophy, i.e. the ability to fix atmospheric nitrogen, is widely used.

Due to their rapid growth and reproduction, as well as their simple structure, bacteria are actively used in scientific research in molecular biology, genetics and biochemistry, in genetic engineering work in the creation of genomic clone libraries and the introduction of genes into plant cells (agrobacteria). Information about the metabolic processes of bacteria has made it possible to produce bacterial synthesis of vitamins, hormones, enzymes, antibiotics, etc.

Promising areas include the purification of soils and water bodies contaminated with petroleum products or xenobiotics using bacteria, as well as the enrichment of ores using sulfur-oxidizing bacteria.

We must not forget that certain types of bacteria cause dangerous diseases in humans (plague, cholera, tuberculosis, typhoid fever, anthrax, botulism, etc.), animals and plants (bacteriosis). Some types of bacteria can destroy metal, glass, rubber, cotton, wood, oils, varnishes, and paints.

Chemical-biological processes include those in which biological objects of various natures (microbial, plant or animal) are used, for example, in the production of products for various purposes

Antibiotics, vaccines, enzymes, feed and food protein, hormones, amino acids, bio-gas, organic fertilizers, etc.

Objects of biotechnology are very diverse and their range extends from organized parts (viruses) to humans (Fig. 1.1.).

Biological objects are characterized by such indicators as the level of structural organization, the ability to reproduce (or reproduce), the presence or absence of their own metabolism when cultivated under appropriate conditions. As for the nature of biological objects, this should be understood as their structural organization. In this case, biological objects can be molecules (enzymes, immunomodulators, nucleosides, oligo- and polypeptides, etc.), organized parts (viruses, phages), unicellular (bacteria, yeast) and multicellular individuals (filamentous higher fungi, plant tissues, single-layer cultures mammalian cells), whole organisms of plants and animals. But even when a biomolecule is used as an object of biotechnology, its initial biosynthesis is carried out in most cases by the corresponding cells. Consequently, it can be argued that the objects of biotechnology belong either to microbes or to plant and animal organisms.

Thus, regardless of the systematic position of biological objects, in practice they use either naturally organized particles (phages, viruses) and cells with natural genetic information, or cells with artificially given genetic information, that is, in any case they use cells - either a microorganism, a plant, an animal or Human. Nowadays, the majority of biotechnology objects are microbes, the world of which is very large and diverse. These include all prokaryotes - bacteria, actinomycetes, rickettsia, blue-green algae and some eukaryotes - yeast, filamentous fungi, protozoa and algae (Fig. 1.2). Microbes among plants include microscopic algae, and among animals there are microscopic protozoa. The basis of modern biotechnological production is microbiological synthesis, i.e. synthesis of various substances using microorganisms. Objects of plant and animal origin have not yet found wide distribution due to the high demands on cultivation conditions, which makes production much cheaper.

For the implementation of biotechnological processes, important parameters of biological objects are: purity, rate of cell reproduction and reproduction of viral parts, activity and stability of biomolecules or biosystems.

When using enzymes (in an isolated or immobilized state) as biocatalysts, there is a need to protect them from destruction by banal saprophytic microflora, which can penetrate into the biotechnological process from the outside due to the unsterility of the system, for example, due to leaky equipment. The rate of cell reproduction and reproduction of viral parts are directly proportional to the increase in biomass and the formation of metabolites.

The activity and stability of biological objects in an active state are the most important indicators of their suitability for long-term use in biotechnology.

The main link of the biotechnological process, which determines its essence, is the cell. It is in it that the target product is synthesized. According to the apt expression of Ovchinnikov Yu.A. (1985), the cell is a miniature chemical plant that works with colossal productivity, with utmost consistency and according to a given program. Hundreds of complex compounds are synthesized in it every minute, including giant biopolymers, primarily proteins.

Biotechnology methods. Biotechnology has its own specific methods. This is a large-scale deep cultivation of biological objects in a periodic, semi-continuous or continuous mode and the cultivation of plant and animal tissue cells under special conditions. Biotechnological methods for cultivating biological objects are carried out in special equipment, for example, bacteria and fungi are grown in fermenters to obtain antibiotics, enzymes, organic acids, some vitamins, etc.

Some human cells (blasts) are grown in such fermenters to produce interferon protein, as well as some types of plant cells. However, the latter are more often grown under stationary conditions on a medium with a compacted (for example, agar) lining in glass or polyethylene containers.

Other methods used in biotechnology are shared, for example with methods in microbiology, biochemistry, organic chemistry and other sciences. It is especially necessary to highlight the methods of cellular and genetic engineering that underlie modern biotechnology.

The difference between the methods used in biotechnology is that they must be performed, as a rule, under aseptic conditions (from the Greek a - no, septicos - putrefactive), i.e. to exclude the possibility of pathogenic and saprophytic microorganisms entering the environment where biological objects are cultivated.

Pathogenic species pose an immediate threat to human production activities and to consumers final products; saprophytic species can act as competitors for nutrient substrates, antagonists, and producers of toxic substances, including pyrogens.

Biotechnology objects. Viruses. Eubacteria. Mushrooms. Lichens. Plants. Animals. The structure of animal and plant cells.

Biotechnological objects are located at different levels of organization:

a) subcellular structures (viruses, plasmids, mitochondrial and chloroplast DNA, nuclear DNA);

b) bacteria and cyanobacteria;

d) algae;

e) protozoa;

f) plant and animal cell cultures;

g) plants – lower (anabena-azolla) and higher – duckweed.

Objects of biotechnology are various representatives of living nature, which are divided into three superkingdoms: akaryotes (non-nuclear), prokaryotes (prenuclear) and eukaryotes (nuclear) and 5 kingdoms: viruses, bacteria, including microscopic algae, fungi, as well as plants and animals, including protozoa.

Mushrooms, numbering tens of thousands of species, combine the features of plant and animal cells. They have a cell nucleus, like plants - a strong cell wall; similar to animal cells, they need certain vitamins and are able to synthesize polysaccharides characteristic of animals: chitin and glycogen. Of greatest interest to biotechnology are microscopic fungi, which include yeast, molds and other microorganisms used in baking, brewing and the dairy industry. They are also used to produce alcohols, organic acids, antibiotics, various biologically active substances and feed protein.

An independent group of organisms representing a symbiosis (cohabitation) of fungi with algae or cyanobacteria consists of lichens, which are promising sources of a number of biologically active substances.

Plants, numbering about 500,000 species, they consist of nucleated cells that have a complex structure and perform various specialized functions. These include algae, which are aquatic organisms, and higher plants, which live primarily on land. Algae differ from higher plants in that they do not have organs and tissues, but are thalli consisting of undifferentiated (identical) cells. Like other plants, algae have the ability to photosynthesize and are rich in various carbohydrates and pigments. One type of algae, seaweed, is used as food. Agar-agar and alginates are extracted from algae - polysaccharides used for the production of microbiological media in the food industry and cosmetology.

Higher plants are multicellular organisms with specialized organs such as roots, stems, and leaves. They consist of tissues formed by differentiated cells. Fabrics vary chemical composition, structure and perform various functions: mechanical, integumentary, excretory, conductive and others. Of particular importance for biotechnology is one of the plant tissues, called the meristem. The cells of the meristem are capable of division, due to which growth occurs, as well as the formation of tissues and organs of plants. They do not lose their ability to divide even after being removed from the plant. When grown on special nutrient media, meristem cells produce a mass of dividing cells - callus, which can be cultivated for a long time, new plants can be obtained from it, or used to extract necessary substances. The most difficult, but more effective, is the cultivation of individual plant cells in liquid media (in suspension cultures). Thanks to the ability of plants to capture light energy from the sun and use it in the synthesis of organic substances, plants serve as suppliers of nutrients for other organisms. Plants make up most biomass of the Earth, therefore the production and processing of plant raw materials to meet various human needs has been used since ancient times. Being rich and irreplaceable sources of various carbohydrates, lipids, vitamins and many other physiologically active and medicinal substances, plants serve primarily to obtain them. Despite the outstanding achievements of biotechnology, traditional methods for extracting biogenic compounds are used: extraction, distillation, filtration. All big role acquire technologies for obtaining biologically active substances from cell cultures (biostimulants from ginseng, anticancer agent Taxol from yew bark, etc.), as well as the production of products from genetically modified plants.

Plant and animal cells are complexly organized formations, consisting of cytoplasm and a denser nucleus. The cytoplasm contains intracellular organelles: mitochondria, ribosomes and lysosomes, rough and smooth membranes of the endoplasmic reticulum, immersed in the water-soluble medium of the cell - the cytosol. The cell is surrounded by a plasma membrane, which has selective permeability due to the presence of special mechanisms for transporting substances. Cell nuclei serve to store genetic information, the carrier of which is DNA.

Mitochondria supply the cell with energy through the oxidation of substances with the participation of oxygen. They also synthesize their own mitochondrial proteins. This is an exception to general rule. All other cellular proteins are synthesized on ribosomes.

Associated with the membranes of the endoplasmic reticulum is the Golgi apparatus, which is a system of microtubules. In the Golgi apparatus, chemical modification reactions of proteins occur, as well as the synthesis of reserve substances and substances secreted from the cell.

The liquid part of the cell - the cytosol - contains synthesis enzymes and anaerobic oxidation substances, as well as low molecular weight organic and inorganic compounds.

A feature of the structure of plant cells is the presence of chloroplasts, in which photosynthesis processes occur. From animal cells plant cell It is also distinguished by a solid wall, which contains substances of a polysaccharide nature (cellulose, hemicelluloses, pectins) and the polyphenolic polymer lignin.