The main objects of biotechnology are microscopic. Biological objects and methods of biotechnology. Biotechnology objects and their levels

as about objects biotechnologies can be: cells of microorganisms, animals and plants, transgenic animals and plants, as well as multicomponent enzyme systems of cells and individual enzymes.

The basis of most modern biotechnological industries is microbial synthesis, i.e., the synthesis of various biologically active substances with the help of microorganisms. Regardless of the nature of the object, the primary stage in the development of any biotechnological process is to obtain pure cultures organisms (if these are microbes), cells or tissues (if these are more complex organisms - plants or animals). Many stages of further manipulations with the latter (i.e. with plant or animal cells) are the principles and methods used in microbiological production. Both cultures of microbial cells and tissue cultures of plants and animals practically do not differ from cultures of microorganisms from a methodological point of view. world m microorganism extremely varied. In n. Over 100,000 different species are known to date. This prokaryotes(bacteria, actinomycetes, rickettsia, cyanobacteria) and part of e ukaryote(yeasts, filamentous fungi, some protozoa and algae). With a wide variety of microorganisms, an important problem is the correct choice of the organism that is able to provide the required product, i.e., serve industrial purposes. Microorganisms:

1)Industrial : E. coli ( E. coli), hay stick ( You. subtilis) and baker's yeast ( S.cerevisiae). Usually yavl-Xia overproducers. To obtain super-producers, genetic selection work is carried out, genetic engineering approaches (introduction of human genes into bacteria: genes for interferons, insulin, etc.). PS should be patented.

2)Basic- limited use, classified as GRAS("generally recognized as safe" bacteria) Bacillus subtilis, Bacillus amylolique-faciens, other species of bacilli and lactobacilli, species streptomyces, mushrooms Aspergillus, Penicillium, Mucor, Rhizopus, yeast Saccharomyces and others . GRAS- microorganisms are non-pathogenic, non-toxic and basically do not form antibiotics, therefore, when developing a new biotechnological process, one should focus on these microorganisms.

3) Model- bacilli (producers of proteolytic enzymes). There are catalogs of model micr.

The main criterion when choosing a biotechnological object is the ability to synthesize the target product. microorganisms must (requirements):

Have a high growth rate;

Dispose of the cheap substrates necessary for their life;

To be resistant to extraneous microflora, i.e. to be highly competitive. (requirements): ability to grow on cheap substrates, high economic coefficient, minimum formation of by-products (toxic metabolites, allergens)

All of the above provides a significant reduction in the cost of producing the target product. The following examples are given to illustrate what has been said so far.

1. unicellular organisms characterized by higher rates of growth and synthetic processes,

2. Particular attention as objects of biotechnological developments are photosynthetic microorganisms that use the energy of sunlight in their life.

3. thermophilic microorganisms growing at 60-80 °C. This property of them is an almost insurmountable obstacle to the development of extraneous microflora.

24. Advantages of microorganisms over other objects in solving modern biotechnological problems:

small size

· Omnipresent

Various types of metabolism

Phototrophs

Occupy a small volume (in 1 ml up to 1 billion individuals)

High division rate, fast growth

· Capable of living in a variety of environments.

Photosynthetic organisms are promising as producers of ammonia, hydrogen, protein.

Thermophilic microorganisms growing at 60-80 degrees, this is a reliable protection against pollution. Enzymes synthesized by thermophiles, character. increased resistance to heat, but at the same time they are inactive at ordinary temperatures.

Microorganisms as objects of biotechnology. Classification. Characteristic.

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

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

phototrophs that use the energy of sunlight;

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

According to the type of oxidation of the substance:

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

lithotrophs (inorganic substances);

By type of carbon source:

heterotrophic - use organic matter;

aphtotrophic - use gas;

To indicate the type of food is used:

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

2. Electron donors litho- or organo-;

3. Sources of carbon aphtho- and hetero-;

And the term ends with the words trophy. 8 different types of food.

Higher animals and plants are inclined towards 2 types of nutrition:

1) Chemoorganoheterotrophy (animals)

2) Photolithoaphtotrophy (plants)

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

There is a separate type of food:

Bacteria are a convenient object 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 productions. Distinctive features of biotechnological production from traditional types of technologies. Advantages and disadvantages of biotechnological productions in comparison with traditional technologies.

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

There are 5 stages of biotechnological production.

The two initial stages include the preparation of the raw material and the biologically active principle. In engineering enzymology processes, they usually consist of preparing a substrate solution with specified properties (pH, temperature, concentration) and preparing a batch of an enzyme preparation of a given type, enzymatic or immobilized. In carrying out microbiological synthesis, the steps of preparing a nutrient medium and maintaining a pure culture are necessary, which can be constantly or as needed used 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 desired properties.

The third stage is the stage of fermentation, at which the formation of the target product occurs. At this stage, the microbiological transformation of the components of the nutrient medium takes place, 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. Industrial microbiological processes are characterized, as a rule, by the formation of very dilute solutions and suspensions containing, in addition to the target, a large amount 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 subjected to thermal degradation.

The final stage of biotechnological production is the preparation of commodity forms of products. A common property of most products of microbiological synthesis is their insufficient 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 stage of packaging and sealing, 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, cell cultures and tissues of plants and animals with desired properties. Biotechnology emerged at the intersection of biological, chemical and technical sciences.

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

Biotechnological processes can be based on batch or continuous cultivation.

In many countries of 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.

1). First of all, it is low power consumption. 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 for the production of amino acids, vitamins; enzymes, antibiotics.

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

4). Waste-free biotechnological production makes them the most environmentally friendly

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

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

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

2)Microbiological plant protection against disease 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;

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

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 emissions to produce biogas and high-quality fertilizers.

Traditional (conventional) technology is a development that reflects the average level of production achieved by most manufacturers of products in the industry. Such a technology does not provide its buyer with significant technical and economic advantages and product quality compared to similar products from leading manufacturers, and in this case it is not necessary to count on additional (above average) profit. Its advantages for the buyer are relatively low cost and the possibility of acquiring field-proven technology. Traditional technology is created, as a rule, as a result of obsolescence and widespread dissemination of progressive technology. The sale of such technology is usually carried out at prices that compensate the seller for the costs of its preparation and obtaining an average profit.

Advantages of biotechnological processes in comparison with 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;

·carrying out 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 from agriculture and industry can be used as a raw material in biotechnology processes;

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

· as a rule, technology and equipment in biotechnological productions are simpler and cheaper.

Biotechnological stage

The main stage is the actual biotechnological stage, at which, using one or another biological agent, the raw material is converted into one or another target product.

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 action of the enzymatic activity of microorganism cells or ready-made enzymes.

Biocatalysis - chemical transformations of a substance proceeding with the use of biocatalysts-enzymes.

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

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

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

Biosorption - sorption of harmful impurities from gases or liquids by microorganisms, usually fixed on special solid carriers.

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

Biodegradation - destruction of harmful compounds under the influence of microorganisms-biodestructors.

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

Preparatory stages

Preparatory stages are used to prepare and prepare the necessary types of raw materials for the biotechnological stage.

The following processes can be used in the preparation phase.

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 the flow of a biotechnological process. Most often, air preparation consists in cleaning it from dust and moisture, providing the required temperature and cleaning it from microorganisms present in the air, including spores.

Seed preparation. It is obvious that in order to carry out a microbiological process or a process for cultivating isolated cells of plants or animals, it is also necessary to prepare an inoculum - a previously grown small amount of a biological agent compared to the main stage.

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

Pretreatment of raw materials. If the raw material enters production in a form unsuitable for direct use in the biotechnological process, then an operation is carried out for preliminary preparation of the raw material. For example, when producing alcohol, wheat is first crushed and then subjected to an enzymatic "saccharification" process, after which the saccharified wort is converted into alcohol at a biotechnological stage by fermentation.

Product cleaning

The task of this stage is to remove impurities, to 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 next task is to ensure its concentration.

At the stage of concentration, processes such as evaporation, drying, precipitation, crystallization with filtration of the resulting crystals, ultrafiltration and hyperfiltration or nanofiltration are used, providing, as it were, "squeezing" the solvent from the solution.

Effluent and emission treatment

Purification of these effluents and emissions is a special task that must be solved in our environmentally unfavorable time. In essence, wastewater treatment is a separate biotechnological production, which has its own preparatory stages, a biotechnological stage, a stage for settling activated sludge biomass and a stage for 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.

The 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 of the biological objects of biotechnology are represented by representatives of 3 super-kingdoms:

1) Acoryotac - acoriots or non-nuclear;

2) Procaryotac - prokaryotes or prenuclear;

3) Eucaryotac - eukaryotes or nuclear.

They are represented by 5 kingdoms: viruses (non-cellular organized particle) are classified as akaryotes; bacteria are classified as prokaryotes (morphological elementary unit); eukaryotes include fungi, plants and animals. Type of DNA encoding of genetic information (for DNA or RNA viruses).

Bactria have a cellular organization, but the material of the nucleus is not separated from the cytoplasm by any membranes and is not associated with any proteins. Basically, bacteria are unicellular, their size does not exceed 10 micrometers. All bacteria are divided into archobacteria and eubacteria.

Mushrooms (Mycota) are important biotechnological objects and producers of a number of important compounds in food products and additives: antibiotics, plant hormones, dyes, mushroom protein, various types of cheeses. Micromycetes do not form the fruiting body, and macromycetes form. They have signs 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, basic and secretory). Only mirimestant tissues are capable of division. Any kind of plant under certain conditions can produce an unorganized cell mass of dividing cells - callus. The most important biological objects are the 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, such biological objects as cells of various animals are widely used. In addition to cells of higher animals, cells of protozoa are used. Cells of higher animals are used to obtain recombinant DNA and to conduct toxicological studies.

The main object of the biotechnological process is the cell. It synthesizes the target product. In fact, the cell is a miniature chemical plant, where hundreds of complex compounds are synthesized every minute.

The basis of modern biotechnological production is the synthesis of various substances with the help of microorganism cells. Cells of higher plants and animals have not yet found wide application, due to their high demands on cultivation conditions.

The initial stage of biotechnological development is getting pure cultures of cells and tissues. Further manipulations with these cultures are characterized by the uniformity of approaches based on classical microbiological methods. At the same time, cultures of cells and tissues of higher plants and animals are likened to cultures of microorganisms.

Eukaryotes and prokaryotes. Most microorganisms are single-celled creatures. A microbial cell is separated from the external environment by a cell wall, and sometimes only by a cytoplasmic membrane, and contains various subcellular structures. There are two main types of cell structure, which differ from each other in a number of fundamental features. These are eukaryotic and prokaryotic cells. Microorganisms with a true nucleus are called eukaryotes (eu - from Greek - true, karyo - nucleus). Microorganisms with a primitive nuclear apparatus are classified as prokaryotes (pre-nuclear).

Among microorganisms to prokaryotes include bacteria, actinomycetes and blue-green algae (cyanobacteria), to eukaryotes- other algae (green, brown, red), mycomycetes (mucus molds), lower fungi - micromycetes (including yeast), protozoa (flagellates, ciliates, etc.).

Their common property is their small size, they are visible only through a microscope. Currently, more than 100 thousand species of various microorganisms are known.

Prokaryotes do not undergo the processes of mitosis and meiosis. They reproduce more often by simple cell division.

in a eukaryotic cell there is a nucleus separated from the cytoplasm surrounding it by a two-layer nuclear membrane with pores. In the nucleus there are 1-2 nucleoli - centers for the synthesis of ribosomal RNA and chromosomes - the main carriers of hereditary information, consisting of DNA and protein. During division, chromosomes are distributed between daughter cells as a result of complex processes - mitosis and meiosis. The cytoplasm of eukaryotes contains mitochondria, and in photosynthetic organisms, chloroplasts. The cytoplasmic membrane surrounding the cell passes inside the cytoplasm into the endoplasmic reticulum; there is also a membrane organelle - the Golgi apparatus.

prokaryotic cells arranged more simply. They do not have a clear boundary between the nucleus and the cytoplasm, there is no nuclear membrane. The DNA in these cells does not form structures similar to eukaryotic chromosomes. Prokaryotes do not undergo the processes of mitosis and meiosis. Most prokaryotes do not form intracellular organelles limited by membranes; there are no mitochondria and chloroplasts.

Selection of forms of microorganisms with desired properties

The selection of forms of microorganisms with desired properties necessary for cultivation includes several stages.

2.1. Isolation of microorganisms. Samples are taken from the habitats of microorganisms (soil, plant residues, etc.). With regard to hydrocarbon-oxidizing microorganisms, such a place can be the soil near gas stations, wine yeasts are abundant on grapes, anaerobic cellulose-decomposing and methane-forming microorganisms live in large quantities in the rumen of ruminants.

2.2. Obtaining storage cultures. Samples are introduced into liquid nutrient media of a special composition, creating favorable conditions for the development of the producer (temperature, pH, sources of energy, carbon,
nitrogen, etc.). For the accumulation of the producer of cholesterol oxidase, media with cholesterol as the only source of carbon are used; hydrocarbon-oxidizing microorganisms - environments with paraffins; producers of proteolytic or lipolytic enzymes - media containing proteins or lipids.

2.3. Isolation of pure cultures. Samples from enrichment cultures are inoculated on dense nutrient media. Individual cells of microorganisms on dense nutrient media form isolated
colonies or clones, when they are reseeded, pure cultures are obtained, consisting of cells of one type of producer.

Another way to select microorganisms is from existing collections. For example, the producers of antibiotics are often actinomycetes, ethanol - yeast.

Clone- single cell culture pure culture- a group of individuals of the same type of microorganism strains- cultures isolated from different natural environments or from the same environment at different times.

2.4. Determination of the ability to synthesize the target product - the main criterion in the selection of producers. Microorganisms must meet the following requirements:

1) have a high growth rate;

2) use cheap substrates for life;

3) be resistant to infection by foreign microflora.

Unicellular organisms are characterized by higher rates of synthetic processes than higher plants and animals. So, a cow weighing 500 kg during one day synthesizes about 0.5 kg of protein. The same amount of protein in one day can be obtained with 5 g of yeast. Of interest are photosynthetic microorganisms that use light energy and are capable of assimilating atmospheric nitrogen. Thermophilic microorganisms are advantageous. Their use reduces additional costs for sterilization of industrial equipment. The growth rate and metabolism of these organisms is 1.5-2 times higher than that of mesophiles. The enzymes they synthesize are resistant to heat, acids, and organic solvents.

Methods of biotechnology

There are 2 methods in biotechnology: 1) Selection; 2) Genetic engineering. Selection methods are used to obtain highly active products. With the help of selection, industrial strains of microorganisms have been obtained, the synthetic activity of which exceeds the activity of the original strains by tens and hundreds of times.

Selection

Selection - directed selection of mutants (organisms whose heredity has undergone an abrupt change). The general way of selection is the transition from simple selection of producers to the conscious construction of their genomes. At each stage, the most highly effective clones are selected from the population of microorganisms. In this way, for a long time, strains of beer, wine, baker, acetic yeast, propionic acid bacteria, etc. were selected. Stepwise selection is used: at each stage, the most highly effective clones are selected from the population of microorganisms. The limitation of the selection method based on spontaneous mutations is associated with their low frequency, which greatly complicates the intensification of the process. Changes in the DNA structure are rare. A gene must double on average 10 6 -10 8 times for a mutation to occur. An example of the selection of the most productive mutants during cultivation in a continuous mode is the selection of yeast on the basis of resistance to ethanol, a yeast waste product. Induced mutagenesis leads to a significant acceleration of selection - a sharp increase in the frequency of mutations in a biological object with artificial damage to the genome. Ultraviolet, X-ray or y-radiation, some chemical compounds that cause changes in the primary structure of DNA have a mutagenic effect. The best known and used mutagens include nitrous acid, alkylating agents, etc.

Carry out a thorough check (screening) obtained clones. Having selected the most productive clones, the treatment with the same or another mutagen is repeated, the most productive variant is again selected, etc., i.e. we are talking about stepwise selection on the basis of interest.

Labor intensity is the main disadvantage of the method of induced mutagenesis and subsequent stepwise selection. The disadvantage of the method is also the lack of information about the nature of the mutations, the researcher selects according to the final result.

genetic engineering

Genetic engineering is a directed modification of biological objects as a result of the introduction of artificially created genetic programs. Levels of genetic engineering:

1)genetic– direct manipulation of recombinant DNA, including individual genes;

2)chromosomal– manipulation with groups of genes or individual chromosomes;

3)genomic(cellular) - the transfer of all or most of the genetic material from one cell to another (cellular engineering). In the modern sense, genetic engineering includes recombinant DNA technology.

Work in the field of genetic engineering includes 4 stages: 1) obtaining the desired gene; 2) embedding it into a vector capable of replication; 3) the introduction of a gene using a vector into the body; 4) nutrition and selection of cells that have acquired the desired gene.

Genetic engineering of higher plants is carried out at the cellular, tissue and organismal levels.

The basis of cell engineering is the hybridization of somatic cells - the fusion of non-sex cells to form a single whole. Cell fusion can be complete or with the introduction of their individual parts (mitochondria, chloroplasts, etc.).

Somatic hybridization allows the crossing of genetically distant organisms. Plant, fungal and bacterial cells are freed from the cell wall before fusion and protoplasts are obtained. Then, the outer cytoplasmic membranes are depolarized by an alternating electric or magnetic field, Ca + cations are used. The cell wall is subjected to enzymatic hydrolysis.

Questions for self-examination

1. What is the object of biotechnology?

2. What are the types of cell structure?

3. What are the stages of culture growth?

4. What is selection and genetic engineering?

4 The main link of the biotechnological process is a biological object capable of carrying out a certain modification of the feedstock and forming one or another necessary product. Cells of microorganisms, animals and plants, transgenic animals and plants, fungi, as well as multicomponent enzyme systems of cells and individual enzymes can serve as such objects of biotechnology. The basis of most modern biotechnological industries is microbial synthesis, i.e., the synthesis of various biologically active substances with the help of microorganisms. Unfortunately, objects of plant and animal origin, for a number of reasons, have not yet found such a wide application. Therefore, in the future, it is reasonable to consider microorganisms as the main objects of biotechnology.

1 Microorganisms - the main objects of biotechnology Currently, more than 100 thousand different types of microorganisms are known. These are primarily bacteria, actinomycetes, cyanobacteria. With such a wide variety of microorganisms, a very important, and often complex problem is the correct choice of exactly the organism that is able to provide the desired product, i.e. serve industrial purposes. 5

Many biotechnological processes use a limited number of microorganisms that are classified as GRAS ("generally recognized as safe"). Such microorganisms include the bacteria Bacillus subtilis, Bacillus amyloliquefaciens, other types of bacilli and lactobacilli, Streptomyces species. This also includes species of fungi Aspergillus, Penicillium, Mucor, Rhizopus, yeast Saccharomyces, etc. GRAS-microorganisms are non-pathogenic, non-toxic and generally do not form antibiotics, therefore, when developing a new biotechnological process, one should focus on these microorganisms as the basic objects of biotechnology. 6

The microbiology industry currently uses thousands of microbial strains that were initially isolated from natural sources based on their beneficial properties and then improved using various methods. In connection with the expansion of production and the range of products, more and more representatives of the world of microbes are involved in the microbiological industry. It should be noted that in the foreseeable future, none of them will be studied to the same extent as E. coli and Bac. subtilis. The reason for this is the enormous laboriousness and high cost of this kind of research. 7

Consequently, the problem arises of developing a research strategy and tactics that would make it possible, with a reasonable expenditure of labor, to extract from the potential of new microorganisms all the most valuable in the creation of industrially important producer strains suitable for use in biotechnological processes. The classical approach is to isolate the desired microorganism from natural conditions. Material samples are taken from the natural habitats of the proposed producer (material samples are taken) and inoculated into a selective medium that ensures the predominant development of the microorganism of interest, i.e. so-called storage cultures are obtained. 8

The next step is to isolate a pure culture with further study of the isolated microorganism and, if necessary, an approximate determination of its productive capacity. There is another way to select producer microorganisms - this is the choice of the desired species from the available collections of well-studied and thoroughly characterized microorganisms. This, of course, eliminates the need to perform a number of labor-intensive operations. 9

The main criterion for choosing a biotechnological object is the ability to synthesize the target product. However, in addition to this, the technology of the process itself may contain additional requirements, which are sometimes very, very important, not to say decisive. In general terms, microorganisms must have a high growth rate, utilize the cheap substrates necessary for their vital activity, be resident in foreign microflora, i.e., be highly competitive. All of the above provides a significant reduction in the cost of producing the target product. 10

Here are some examples proving the role of microorganisms as objects of biotechnology: 1. Unicellular organisms, as a rule, are characterized by higher rates of growth and synthetic processes than higher organisms. However, this is not the case for all microorganisms. Some of them grow extremely slowly, but they are of a certain interest, since they are able to produce various very valuable substances. eleven

2. Particular attention as objects of biotechnological development is represented by photosynthetic microorganisms that use the energy of sunlight in their life. Some of them (cyanobacteria and photosynthetic eukaryotes) utilize CO2 as a carbon source, and some representatives of cyanobacteria, in addition to all of the above, have the ability to assimilate atmospheric nitrogen (i.e., they are extremely undemanding to nutrients). Photosynthetic microorganisms are promising as producers of ammonia, hydrogen, protein, and a number of organic compounds. However, due to the limited fundamental knowledge about their genetic organization and molecular biological mechanisms of life, progress in their use should not be expected in the near future. 12

3. Some attention is paid to such objects of biotechnology as thermophilic microorganisms growing at °C. This property of them is an almost insurmountable obstacle to the development of foreign microflora during relatively non-sterile cultivation, i.e. is a reliable protection against pollution. Among thermophiles, producers of alcohols, amino acids, enzymes, and molecular hydrogen have been found. In addition, their growth rate and metabolic activity are 1.5-2 times higher than those of mesophiles. Enzymes synthesized by thermophiles are characterized by increased resistance to heat, some oxidizing agents, detergents, organic solvents, and other adverse factors. At the same time, they are not very active at normal temperatures. 13

Thus, the proteases of one of the representatives of thermophilic microorganisms at 20 °C are 100 times less active than at 75 °C. The latter is a very important property for some industrial productions. For example, the Tag polymerase enzyme from the thermophilic bacterium Thermus aquaticus has found wide application in genetic engineering. We have already mentioned another very essential property of these organisms, namely, that when they are cultivated, the temperature of the environment in which they reside significantly exceeds the temperature of the environment. This high temperature difference ensures fast and efficient heat exchange, which allows the use of biological reactors without bulky cooling devices. And the latter, in turn, facilitates mixing, aeration, defoaming, which together significantly reduces the cost of the process. 14

2 Isolation and selection of microorganisms An integral component in the process of creating the most valuable and active producers, i.e. when selecting objects in biotechnology, is their selection. The main way of selection is the conscious construction of genomes at each stage of selection of the desired producer. This situation could not always be realized due to the lack of effective methods for changing the genomes of selectable organisms. An important role in the development of microbial technologies has been played by methods based on the selection of spontaneously occurring altered variants characterized by the desired useful traits. 15

With such methods, stepwise selection is usually used: at each stage of selection, the most active variants (spontaneous mutants) are selected from the population of microorganisms, from which new, more effective strains are selected at the next stage, and so on. Despite the obvious limitation of this method, which consists in the low frequency of occurrence of mutants, it is too early to consider its possibilities as completely exhausted. 16

The selection process of the most effective producers is significantly accelerated when using the method of induced mutagenesis. As mutagenic effects, UV, X-ray and gamma radiation, certain chemicals, etc. are used. However, this technique is also not without drawbacks, the main of which is its laboriousness and lack of information about the nature of the changes, since the experimenter selects according to the final result. 17

For example, the body's resistance to heavy metal ions can be associated with suppression of the bacterial cell uptake of these cations, activation of the process of removing cations from the cell, or rearrangement of the system (s) that is subjected to the inhibitory effect of the cation in the cell. Naturally, knowledge of the mechanisms for increasing stability will make it possible to conduct a directed action in order to obtain the final result in a shorter time, as well as to select options that are better suited to specific production conditions. The use of these approaches in combination with the methods of classical breeding is the essence of modern breeding of microorganism-producers. 18

For example, the body's resistance to heavy metal ions can be associated with suppression of the bacterial cell uptake of these cations, activation of the process of removing cations from the cell, or rearrangement of the system (s) that is subjected to the inhibitory effect of the cation in the cell. Naturally, knowledge of the mechanisms for increasing stability will make it possible to conduct a directed action in order to obtain the final result in a shorter time, as well as to select options that are better suited to specific production conditions. The use of these approaches in combination with the methods of classical breeding is the essence of modern breeding of microorganism-producers. 19

EXAMINATION TICKET No. 1

Biotechnology objects and their levels

Biotechnology means any kind of technology involving the use of biological systems, living organisms or their derivatives to make or modify products or processes for their specific use. Biotechnological resources are biological resources used in biotechnological processes.

Objects for production must meet certain requirements: - ability to grow on cheap nutrient media; - high growth rate and formation of the target product; - minimal formation of by-products; - stability of the producer and the ratio of production properties; - harmlessness of the producer and the target product for humans and the environment environment. An important property of a biological object is resistance to infection, which is important for maintaining sterility and phage resistance. The functions of a bioobject consist in the complete biosynthesis of the target product, including a series of successive enzymatic reactions or catalysis of only one enzymatic reaction, which is of key importance for obtaining the target product.

The objects of biotechnology are very diverse and their range extends from organized parts (viruses) to humans. A bioobject that performs the complete biosynthesis of the target product is called a producer.

b) bacteria and cyanobacteria;

d) algae;

e) protozoa;

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

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, monolayer 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. Therefore, it can be argued that the objects of biotechnology belong either to microbes or to plant and animal organisms.

What are the abilities of the cells of organisms?

A cell is an elementary biological system capable of self-renewal, self-reproduction and development. Cellular structures underlie the structure of plants and animals. No matter how diverse the structure of organisms may seem, it is based on similar structures - cells.
The cell has all the properties of a living system:
carries out the exchange of matter and energy;
is growing;
reproduces and inherits its characteristics;
responds to external signals (stimuli);
able to move.
It is the lowest level of organization, possessing all these properties, the smallest structural and functional unit of the living. It can also live separately: isolated cells of multicellular organisms continue to live and multiply in a nutrient medium.

Functions in a cell are distributed among various organelles, such as the cell nucleus, mitochondria, etc. All living organisms either, like multicellular animals, plants and fungi, consist of many cells, or, like many protozoa and bacteria, are single-celled organisms. unicellular organisms- an extra-systematic category of living organisms, the body of which consists of one (as opposed to multicellular) cells ( unicellularity). It can include both prokaryotes and eukaryotes. It is believed that the first living organisms on Earth were single-celled. The most ancient of them are bacteria and archaea. multicellular organism- a non-systematic category of living organisms, the body of which consists of many cells, most of which (except for stem cells, for example, cambium cells in plants) are differentiated, that is, they differ in structure and functions. Should be distinguished multicellularity And coloniality. Colonial organisms lack true differentiated cells, and hence the division of the body into tissues. Modern cell theory includes the following provisions:
1) a cell is a unit of structure and development of all organisms;
2) the cells of organisms from different kingdoms of wildlife are similar in structure, chemical composition, metabolism, and the main manifestations of vital activity;
3) new cells are formed as a result of division of the mother cell;
4) in a multicellular organism, cells form tissues;
5) Organs are made up of tissues.

The cells of fungi, plants and animals have a similar structure. There are three main parts in a cell: nucleus, cytoplasm and plasma membrane. The plasma membrane is made up of lipids and proteins. It ensures the entry of substances into the cell and their release from the cell. In the cells of plants, fungi, and most bacteria, there is a cell membrane above the plasma membrane. It performs a protective function and plays the role of a skeleton. In plants, the cell wall consists of cellulose, while in fungi, it is made up of a chitin-like substance. Animal cells are covered with polysaccharides that provide contacts between cells of the same tissue.

EXAM TICKET -3

1. Requirements for biological objects? Bioobject- this is a producer that biosynthesizes the desired product, or a catalyst, an enzyme that catalyzes its inherent reaction.

Requirements for biological objects

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

It should be borne in mind that when creating favorable conditions for a selected biological object of biotechnology, the same conditions may turn out to be favorable, for example, for microbes - contaminants or pollutants. Representatives of the contaminating microflora are viruses, bacteria and fungi found in cultures of plant or animal cells. In these cases, microbes-contaminants act as pests of production in biotechnology. When using enzymes as biocatalysts, it becomes necessary to protect them in an isolated or immobilized state from destruction by banal saprophytic (not pathogenic) microflora, which can penetrate into the biotechnological process from the outside due to the non-sterility of the system.

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

Thus, regardless of the systematic position of the biological object, in practice either natural organized particles (phages, viruses) and cells with natural genetic information, or cells with artificially given genetic information are used, that is, in any case, cells are used, be it a microorganism, a plant, animal or person. For example, we can name the process of obtaining the polio virus on a culture of monkey kidney cells in order to create a vaccine against this dangerous disease. Although we are interested here in the accumulation of the virus, its reproduction takes place in the cells of the animal organism. Another example is with enzymes to be used in an immobilized state. The source of enzymes is also isolated cells or their specialized associations in the form of tissues, from which the necessary biocatalysts are isolated.

List gene resources?

Biological resources - organisms that are or may be objects of fishing; all living environment-forming components of the biosphere (producers, consumers, decomposers). They belong to the category of exhaustible renewable natural resources. Distinguish between plant resources, wildlife resources, hunting, grazing, etc. Genetic resources are especially singled out, that is, hereditary genetic information contained in the genetic code of living beings.

The development of biotechnology is closely related to the use of genetic resources. They, as a rule, are a unique property of certain regions of the world, and centuries-old traditions and national characteristics of agriculture, animal husbandry, and medicine are often based on their use.

Genetic resources - genetic material of actual or potential value.

In turn, genetic material is defined as any material of plant, animal, microbial or other origin containing functional units of heredity.

Biological resources - genetic resources, organisms or their parts, populations or any other biotic components of ecosystems that have actual or potential utility or value for humanity.

What are the functions of biological objects?

Bioobjects are the main link of the biotechnological process.

Bioobject - a central and indispensable element of biotechnological production, which creates its specificity.

A biological object can be an integral multicellular or unicellular organism that has retained its viability. They can be isolated cells of a multicellular organism, as well as viruses and multienzyme complexes isolated from cells, included in a certain metabolic process. Also, an individual isolated enzyme can be a bioobject.

Bioobject function- complete biosynthesis of the target product, including a series of consecutive enzymatic reactions or catalysis of only one enzymatic reaction, which is of key importance for obtaining the target product.

It has been proven that the use of enzymes in production in an immobilized form, i.e. associated with an insoluble carrier is the most rational, since in this case their multiple use and the standardization of repetitive production cycles are ensured.

Bioobjects include both macromolecules and micro- and macroorganisms. Enzymes are used as macromolecules. Their use is the most rational, since in this case the multiple use of them and the standard character of repeating derivative cycles are ensured.

Viruses are used as biological objects for the preparation of vaccines. The dominant position in the modern biotechnological process is occupied by microbial cells of eukaryotes and prokaryotes. They are producers (a bioobject that carries out the complete biosynthesis of the target product) of primary metabolites used as medicines.

Higher plants are the most extensive source of medicines. When using plants as biological objects, the main attention is focused on the cultivation of plant tissues in artificial media.

Biotechnological objects are 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.

Types and functions of DNA?

Nucleic acids

Among other chemical substances, DNA was isolated in a separate group in 1869. However, the structure and three-dimensional structure of DNA was deciphered by the English scientist F. Crick and the American J. Watson only in 1953. They built a DNA model. It is a double helix, both strands of which are twisted around an imaginary axis.

DNA consists of many units of deoxyribonucleotides, which are divided into four types. They form specific sequences characteristic of each specific living organism. These deoxyribonucleotides are three-component formations that consist of a heterocyclic base (purines - adenine or guanine, or pyrimidines - thymine or cytosine), which in turn combine with deoxyribose.

Prokaryotic cells contain one chromosome, which includes a double strand of DNA. Eukaryotic cells contain several DNA molecules that are associated with proteins and are organized within the nucleus. The nucleus is surrounded by a two-membrane system.

Function of DNA consists in the fact that it stores genetic information that is used to encode the structure of all proteins and all types of RNA of each type of organism, regulates the cellular and tissue biosynthesis of components and ensures the individuality of each organism. Some viruses also use DNA as their genetic material. Viral DNA is smaller than bacterial DNA.

Structure of DNA. In DNA, it is conditionally possible to distinguish primary, secondary and tertiary structures.

Primary structure of DNA- this is the quantity, quality and order of arrangement of deoxyribonucleotide residues in polynucleotide chains.

Secondary structure of DNA- represents the organization of polynucleotide chains in a DNA molecule. The DNA molecule consists of two polynucleotide chains directed opposite to each other and right-handed around the helical axis to form a double helix type. Its diameter is 1.8-2.0 nm with an identity period of 3.4 nm.

The carbohydrate-phosphate groups in the helix are located on the outside (sugar-phosphate base), and the nitrogenous bases are on the inside. The nitrogenous bases of the two chains are linked by hydrogen bonds according to the principle of complementarity: adenine forms a double bond with thymine, and guanine, in turn, forms three bonds with cytosine. The double helix is ​​a characteristic structure for most DNA molecules. Some viruses contain single-stranded DNA, as well as circular forms of DNA - plasmids.

Tertiary structure of DNA- this is the formation in space of helical and supercoiled forms of the DNA molecule. The tertiary structure of DNA (prokaryotes and eukaryotes) differs in some features that are associated with the structure and function of cells. The tertiary structure of eukaryotic DNA is formed due to the multiple supercoiling of the molecule and is realized in the form of DNA complexes with proteins.

EXAMINATION TICKET No. 5_____

Classification of biological objects

macromolecules

Enzymes of all classes (often hydrolases and transferases); including in immobilized form (associated with the carrier) providing multiple use and standardization of repetitive production cycles;

DNA and RNA - in an isolated form, as part of foreign cells.

Microorganisms

Viruses (with attenuated pathogenicity are used to produce vaccines);

Prokaryotic and eukaryotic cells are producers of primary metabolites: amino acids, nitrogenous bases, coenzymes, mono- and disaccharides, enzymes for replacement therapy, etc.); -producers of secondary metabolites: antibiotics, alkaloids, steroid hormones, etc.;

Normoflora - the biomass of certain types of microorganisms used for the prevention and treatment of dysbacteriosis;

Pathogens of infectious diseases - sources of antigens for the production of vaccines;

Transgenic m / o or cells - producers of species-specific protein hormones for humans, protein factors of nonspecific immunity, etc.

Macroorganisms

Higher plants are raw materials for obtaining biologically active substances;

Animals - mammals, birds, reptiles, amphibians, arthropods, fish, molluscs, humans;

transgenic organisms.

Types and functions of RNA?

One of the most important discoveries in the second half of the twentieth century was the nucleic acids RNA and DNA, thanks to which man came closer to unraveling the mysteries of nature.

Nucleic acids are organic compounds with high molecular weight properties. They include hydrogen, carbon, nitrogen and phosphorus.

It is a single polynucleotide chain (except for viruses), which is much shorter than that of DNA. One RNA monomer is the residues of the following substances: nitrogen bases; five-carbon monosaccharide; phosphorus acids. RNAs have pyrimidine (uracil and cytosine) and purine (adenine, guanine) bases. Ribose is the monosaccharide of the RNA nucleotide.

The RNA cell was first discovered by a biochemist from Germany, R. Altman, while studying yeast cells. In the middle of the twentieth century, the role of DNA in genetics was proven. Only then were RNA types and functions described.

Depending on the type of RNA, its functions also differ. There are several types:

1) Messenger RNA (i-RNA). This biopolymer is sometimes referred to as messenger RNA (mRNA). This type of RNA is located both in the nucleus and in the cytoplasm of the cell. The main purpose is the transfer of information about the structure of the protein from deoxyribonucleic acid to ribosomes, where the protein molecule is assembled. Relatively small population of RNA molecules, less than 1% of all molecules.

2) Ribosomal RNA (r-RNA). The most common type of RNA (about 90% of all molecules of this type in the cell). R-RNA is located in ribosomes and is a template for the synthesis of protein molecules. It has the largest dimensions compared to other types of RNA. The molecular weight can reach 1.5 million Daltons or more.

3) Transfer RNA (t-RNA). It is located mainly in the cytoplasm of the cell. The main purpose is the implementation of transport (transfer) of amino acids to the site of protein synthesis (into ribosomes). Transfer RNA makes up to 10% of all RNA molecules located in the cell. It has the smallest size compared to other RNA molecules (up to 100 nucleotides).

4) Minor (small) RNA. These are RNA molecules, most often with a small molecular weight, located in various parts of the cell (membrane, cytoplasm, organelles, nucleus, etc.). Their role is not fully understood. It has been proven that they can help maturation of ribosomal RNA, participate in the transfer of proteins across the cell membrane, promote the reduplication of DNA molecules, etc.

5) Ribozymes. A recently identified type of RNA that is actively involved in the enzymatic processes of the cell as an enzyme (catalyst).

6) Viral RNA. Any virus can contain only one kind of nucleic acid: either DNA or RNA. Accordingly, viruses that have an RNA molecule in their composition are called RNA-containing. When a virus of this type enters a cell, the process of reverse transcription (the formation of new DNA based on RNA) can occur, and the newly formed virus DNA is integrated into the cell genome and ensures the existence and reproduction of the pathogen. The second variant of the scenario is the formation of complementary RNA on the matrix of the incoming viral RNA. In this case, the formation of new viral proteins, the vital activity and reproduction of the virus occurs without the participation of deoxyribonucleic acid, only on the basis of the genetic information recorded on the viral RNA.

Types and functions of genes?

Gene, classification and organization of genes
Genetics studies the patterns of heredity and variability that are universal for all living organisms.
The elementary discrete units of heredity are genes. The reproduction and action of genes is directly related to matrix processes. At present, the gene is considered as a unit of functioning of the hereditary material. The chemical basis of a gene is the DNA molecule.
There are several approaches to the classification of genes, each of which reflects the features of their functioning in the process of ontogeny. Genes, as units of the function of hereditary material, are divided into structural, regulatory, and modulator genes.
Structural genes contain information about the structure of the protein (polypeptides) and ribonucleic acids (ribosomal and transport), while genetic information is realized in the process of transcription and translation or only transcription. There are about 30,000 structural genes in humans, but only a part of them is expressed.
The vital activity of cells is provided by a small set of functioning genes, among them there are “household” genes - GOF (genes of general cellular functions) and “luxury” genes - GSP (genes of specialized functions). GOFs provide for the implementation of universal cellular functions that are necessary for the activity of all cells (histone genes, r-RNA and t-RNA genes, etc.). GSP: 1- are selectively expressed in specialized cells, determining their phenotype (genes of globins, immunoglobulins, etc.); 2 - function under certain environmental conditions and represent the "adaptive response" genes. Belonging to the GOF or GSP is determined by the structure of the initiator.
Regulatory genes (gene - regulator of the lactose operon, TFM gene, etc.) coordinate the activity of structural genes at the cell level, as well as derepression and repression of genes at the organism level. Along with regulatory genes, there are regulatory sequences (promoter, operator, terminator, enhancers, silencers, an element before the promoter), the function of which is revealed in interaction with specific proteins.
Modulator genes enhance or weaken the action of structural genes, changing their functional activity.
Structural genes are organized differently in prokaryotes and eukaryotes.
In prokaryotes, structural genes are organized as independent genes, transcription units, and operons.
Independent genes consist of a continuous sequence of codons, they are constantly expressed and are not regulated at the level of transcription (lactose operon regulator gene). Transcriptional units are groups of different genes that are functionally linked and transcribed simultaneously, which subsequently provides the same amount of synthesized products. Usually these are genes for proteins or nucleic acids (in E. coli, one of the transcriptons contains two t-RNA genes, three r-RNA genes).
An operon is a group of structural genes following one after another, under the control of an operator - a certain section of DNA.
Structural genes have a common promoter, operator, and terminator, are involved in the same metabolic cycle, and are regulated in a coordinated manner.
In eukaryotes, structural genes whose function is associated with regulatory ones are organized as independent genes, repetitive genes, and gene clusters.
Independent genes, as a rule, are located individually, their transcription is not associated with the transcription of other genes. The activity of some of them is regulated by hormones.
Repetitive genes are present in the chromosome in the form of repeats (copies) of one gene - genes for histones, tRNA, rRNA. The reason for the repetition of histone genes is determined by the need to synthesize a large number of histones, which are the main structural proteins of the nucleus (the total mass of histones is equal to the mass of DNA).
A gene cluster is a group of different genes with related functions, localized in certain regions of the chromosomes. The cluster includes actively functioning genes and pseudogenes (The nucleotide sequences of pseudogenes are similar to the sequences of functionally active genes, but pseudogenes are not expressed and do not form a protein. Clusters are often a gene family descended from some ancestor gene.
A classic example is the globin genes in the A and B clusters. Hemoglobin is represented by heme and the protein tetramer-globin. The globin tetramer consists of two identical chains and two identical chains. The amino acid sequence of each globin chain is encoded by its own gene, which is part of the A or B cluster, respectively. In humans, the A cluster is located on chromosome 16, and the B cluster is on chromosome 11 (Fig. 20). Cluster B occupies a 50 thousand bp DNA segment and includes five functionally active genes and one pseudogene: a gene (epsilon); two genes (gamma); pseudogene (beta); gene (delta) and gene (beta).
Cluster A is located more compactly and occupies a stretch of DNA with a size of more than 28 thousand base pairs and includes an active gene (zeta), pseudogene (zeta), pseudogene (alpha), and genes (alpha) two and (alpha) one, encoding identical proteins. Globin genes are mosaic in internal structure.
Repeating genes and clusters of globin genes belong to the multigene family

EXAMINATION TICKET No. 7_____

Protein producers

The production of microbial biomass is the largest microbiological production. Microbial biomass can be a good protein supplement for pets, birds and fish. The production of microbial biomass is especially important for countries that do not cultivate soybeans on a large scale (soybean meal is used as a traditional protein supplement for feed).

When choosing a microorganism, the specific growth rate and biomass yield on a given substrate, stability during in-line cultivation, and cell size are taken into account. Yeast cells are larger than bacteria and are more easily separated from the liquid by centrifugation. Yeast polyploid mutants with large cells can be grown. Currently, only two groups of microorganisms are known that have the properties necessary for large-scale industrial production: the yeast of the genus Candida on n-alkanes (normal hydrocarbons) and the bacteria Methylophillus methylotrophus on methanol.

Microorganisms can also be grown on other nutrient media: on gases, oil, waste from coal, chemical, food, wine and vodka, and woodworking industries. The economic advantages of their use are obvious. So, a kilogram of oil processed by microorganisms gives a kilogram of protein, and, say, a kilogram of sugar - only 500 grams of protein. The amino acid composition of the yeast protein practically does not differ from that obtained from microorganisms grown on conventional carbohydrate media. Biological tests of preparations from yeast grown on hydrocarbons, which were carried out both in our country and abroad, revealed the complete absence of any harmful effect on the body of the tested animals. Experiments were carried out on many generations of tens of thousands of laboratory and farm animals. Unprocessed yeast contains non-specific lipids and amino acids, biogenic amines, polysaccharides and nucleic acids, and their effect on the body is still poorly understood. Therefore, it is proposed to isolate the protein from yeast in a chemically pure form. Releasing it from nucleic acids has also already become uncomplicated.

In modern biotechnological processes based on the use of microorganisms, protein producers are yeast, other fungi, bacteria and microscopic algae.

From a technological point of view, the best of them are yeast. Their advantage lies primarily in "manufacturability": yeast is easy to grow under production conditions. They are characterized by a high growth rate, resistance to foreign microflora, are able to absorb any food sources, are easily separated, and do not pollute the air with spores. Yeast cells contain up to 25% dry matter. The most valuable component of yeast biomass is protein, which in terms of amino acid composition is superior to cereal grain protein and only slightly inferior to milk and fishmeal proteins. The biological value of yeast protein is determined by the presence of a significant amount of essential amino acids. In terms of vitamin content, yeast is superior to all protein feeds, including fishmeal. In addition, yeast cells contain trace elements and a significant amount of fat, which is dominated by unsaturated fatty acids. When feeding fodder yeast to cows, milk yield and fat content in milk increase, and the quality of fur improves in fur-bearing animals. Of interest are also yeasts that have hydrolytic enzymes and are able to grow on polysaccharides without their preliminary hydrolysis. The use of such yeast will avoid the costly step of hydrolysis of polysaccharide-containing wastes. More than 100 yeast species are known to grow well on starch as the only source of carbon. Among them, two species stand out especially, which form both glucoamylases and β-amylases, grow on starch with a high economic coefficient and can not only assimilate, but also ferment starch: Schwanniomyces occidentalis and Saccharomycopsis fibuliger. Both species are promising producers of protein and amylolytic enzymes on starch-containing waste. Searches are also being made for such yeasts that could break down native cellulose. Cellulases have been found in several species, for example, in Trichosporon pullulans, but the activity of these enzymes is low and there is no need to talk about the industrial use of such yeasts. Yeast from the genus Kluyveromyces grows well on inulin, the main reserve substance in Jerusalem artichoke tubers, an important fodder crop that can also be used to obtain yeast protein.

Enzyme classification

The classification of enzymes is based on the mechanism of their action and includes 6 classes.

Enzymes as biocatalysts have a number of unique properties, such as high catalytic activity and selectivity of action. In some cases, enzymes have absolute specificity, catalyzing the transformation of only one substance. Each enzyme has its own pH optimum at which its catalytic activity is maximum. With a sharp change in pH, enzymes are inactivated due to irreversible denaturation. The acceleration of the reaction with increasing temperature is also limited by certain limits, since already at a temperature of 40-50 ° C, many enzymes are denatured. These properties of enzymes have to be taken into account when developing the technology of a new drug.

Since enzymes are substances of a protein nature, it is almost impossible to determine their quantity in a mixture with other proteins. The presence of an enzyme in a preparation can be established only by the course of the reaction catalyzed by the enzyme. In this case, the content of the enzyme can be quantified by determining either the amount of the formed reaction products or the amount of the consumed substrate. A unit of enzyme activity is taken to be that amount that catalyzes the conversion of one micromole of substrate in 1 minute under given standard conditions - a standard unit of activity.

The main part of the enzymes obtained industrially are hydrolases. These include, first of all, amylolytic enzymes: α-amylase, β-amylase, glucoamylase. Their main function is the hydrolysis of starch and glycogen. Starch is hydrolysed into dextrins and then into glucose. These enzymes are used in the alcohol industry, bakery.

Proteolytic enzymes form a class of peptide hydrolases. Their action is to accelerate the hydrolysis of peptide bonds in proteins and peptides. Their important feature is the selective nature of the action on peptide bonds in the protein molecule. For example, pepsin acts only on the bond with aromatic amino acids, trypsin on the bond between arginine and lysine. In industry, proteolytic enzymes are classified according to their ability to be active in a specific pH range:

pH 1.5 - 3.7 - acid proteases;

pH 6.5 - 7.5 - proteases;

· pH > 8.0 - alkaline proteases.

Proteases are widely used in various industries:

meat - to soften meat;

leather - softening of skins;

· film production - dissolution of the gelatinous layer during the regeneration of films;

perfumery - additives in toothpaste, creams, lotions;

· manufacture of detergents - additives for removal of pollution of the proteinaceous nature;

medicine - in the treatment of inflammatory processes, thrombosis, etc.

Pectolytic enzymes reduce the molecular weight and reduce the viscosity of pectin substances. Pectinases are divided into two groups - hydrolases and transeliminases. Hydralases cleave off methyl residues or break glycosidic bonds. Transeliminases accelerate non-hydrolytic cleavage of pectin substances with the formation of double bonds. They are used in the textile industry (flax soaking before processing), in winemaking - clarification of wines, as well as in the preservation of fruit juices.

EXAM TICKET 8

1 What are the most common representatives of cyanobacteria? Cyanobacteria, or blue-green algae (lat. Cyanobacteria) is an extensive group of large gram-negative bacteria, the distinguishing feature of which is the ability to photosynthesize. Cyanobacteria are the most complex and differentiated prokaryotes. Cyanobacteria are common in the seas and fresh water bodies, soil cover, can participate in symbioses (lichens). Rare species are toxic and opportunistic to humans. Blue-green algae are the main elements that cause "blooming" of water, which leads to mass death of fish, poisoning of animals and people. Some species are characterized by a rare combination of properties: the ability to photosynthesis and at the same time fix nitrogen from the atmospheric air.

Cyanobacteria are unicellular organisms, can form colonies, filamentous forms are known. Reproduction is carried out by binary fission, multiple fission is possible. The life cycle under favorable conditions is 6-12 hours.

Cyanobacteria are widely distributed in a wide variety of ecological niches around the globe, for which they are called cosmopolitan organisms. Such a wide distribution is associated with the biological properties of cyanobacteria - specific metabolism, high resistance to changes in such environmental parameters as temperature, humidity, illumination, salinity, ultraviolet and radiation exposure, etc. Cyanobacteria live in the tundra, in snow and ice, in deserts, in hot springs with temperatures up to 80C, in saline lakes and soil.

EXAMINATION TICKET №9

EXAMINATION TICKET №10

EXAMINATION TICKET No. 11

EXAMINATION TICKET No. 12

1. What are beneficial bacteria called? Give examples of such bacteria?

Beneficial bacteria are called eubacteria. Acetic acid bacteria, represented by the genera Gluconobacter and Acetobacter, are Gram-negative bacteria that convert ethanol to acetic acid and acetic acid to carbon dioxide and water. The genus Bacillus belongs to Gram-positive bacteria that are able to form endospores and have peritrichous flagella. B.subtilis is a strict aerobe, while B.thuringiensis can also live in anaerobic conditions. Anaerobic, spore-forming bacteria are represented by the genus Clostridium. C.acetobutylicum ferments sugars into acetone, ethanol, isopropanol and n-butanol (acetobutanol fermentation), other species can also ferment starch, pectin and various nitrogen compounds.