Dictionary of Agricultural Microbiology and Virology. Microbiology of plants. Aquatic Microbiology studies the quantitative and qualitative composition of the microflora of salt and fresh waters and its role in the biochemical processes occurring in water bodies.
The causative agent of the disease was isolated in 1953 in Australia by Simmons and Hull, in New Zealand by Byudl and Boyce. In 1956, Brucella ovis was identified as a new independent species. Pathogen: Brucella ovis - coccoid or slightly elongated bacterium. The microbe is immobile and does not form spores. It grows well on media with fuchsin and thionine in the presence of carbon dioxide, the stability is low, at 60 ° C it dies in 30 minutes, at 70 ° C - in 5-10 minutes; at 100°C - instantly. In milk, bacteria persist for 4-7 days, in frozen meat - 320 days, in wool - 14-19 days. In the surface layers of the soil - up to 40 days.
Epizootology. Course and symptoms.
Susceptible: Sheep aged 2-7 years. In sheep, the disease is acute and chronic. In an acute course in sheep, the temperature rises to 41-42 ° C, oppression, inflammation of the testes and their appendages are observed. The scrotum is inflamed and enlarged several times. The appendages of the testicles are enlarged, bumpy, dense. Atrophy of one or both testes occurs. Ewes have abortions, weak, unviable lambs are born. Often, after lambing, the afterbirth is delayed and endometritis develops. pathological changes. In rams pat. changes are detected mainly in the genital organs. The common vaginal membrane fuses with the testis. At the head of the appendage, connective tissue grows in the form of thin strands. Fibrous growths are found in the affected appendage, necrotic lesions are filled with an odorless creamy liquid. The tissue of the testicles is compacted.Diagnostics.
The diagnosis is established on the basis of clinical and bacteriological or serological studies, taking into account epizootic data. The bacteriological diagnostic method involves the isolation of the pathogen. Affected appendages, testicles, placenta of sheep, aborted and born non-viable lambs can serve as material for research. Sometimes it is possible to isolate brucella from other organs in sick sheep. Intravital diagnostics: RSK, RDSK. Differential diagnosis. It is necessary to exclude pseudotuberculosis, diplococcal infection, brucellosis, trauma.Pseudotuberculosis.
Lymph nodes in the groin, testicles and appendages are characterized by the development of inflammatory processes that tend to encapsulate and compact the pus, which turns into a dry, dense, crumbly mass. With diplococcal septicemia, in addition to the phenomena of a septic process with inflammation, hemorrhages are observed on the epicardium, the mucous membrane of the small intestine, on the omentum, and the peritoneum. With brucellosis: orchitis, sometimes with suppuration, in this case, bacteriological examination is carried out. In case of injuries, one should keep in mind the violation of the integrity of the skin, the presence of hemorrhages.Prevention and treatment.
Treatment has not been developed. For prophylaxis, the following is used: a live dry vaccine from the Rev-1 strain of Brucella melitensis for immunization of sheep and goats against ram brucellosis and infectious ram epididymitis caused by the causative agent Brucella ovis. Veterinary and sanitary examination. Sheep (ewes), rams, young animals diagnosed with a disease caused by brucella are subjected to immediate slaughter, regardless of their breeding value. The order of slaughter of these animals and the study of meat, other meat products, raw materials are carried out, as in brucellosis. For disinfection of places of keeping and slaughter of animals, a 2% hot (70-80 ° C) solution of caustic soda, 2% formalin solution are used; bleach solution containing 2% active chlorine. For diagnostics, treatment and prevention, please contact your veterinarian!infectious epididymitis of sheep (Epididymitis infectiosa arietum), a chronic infectious disease manifested in sheep by inflammation of the appendages of the testicles, in sheep by abortion, the birth of an unviable offspring and barrenness. The disease is common in many countries of the world, in the Russian Federation it is registered in many regions and republics; causing significant economic damage.
Etiology. The causative agent of the disease is Brucella ovis, one of the species of the Brucella group. Small, immobile, non-spore-forming, gram-negative coccobacteria, in size, shape, tinctorial and cultural-biochemical properties do not differ from other types of brucella (see Brucellosis). Cultures of the pathogen are a homogeneous population in a state of dissociation (persistent R-forms); their antigenic structure differs from other types of Brucella (S‑forms), as a result of which their serological differentiation is possible. However, the genetic relationship and commonality of deep protein antigens in all species and forms of Brucella cause cross-immunity and allergic reactions in animals.
Epizootology. Adult rams and sheep are most susceptible. Young growth shows considerable resistance, as a result of which only individual lambs become infected from sick sheep. The source of the infectious agent is sick animals. Sick rams excrete the pathogen with sperm, sheep - with the fetus, fruit membranes and water. Infection occurs mainly through the mucous membranes of the genital tract during mating.
Immunity. As the infectious process develops, antibodies appear in the blood, a state of allergy occurs, which indicates an immunological restructuring of the body. The effectiveness of killed and live vaccines from strains of Brucella of different species was studied. The best results were obtained when young rams were immunized with a live vaccine from the Br. melitensis Rev-1 (immunity for 4 years).
Course and symptoms. In an acute course in sheep, an increase in body temperature to 41-42 ((°)) C, depression, exudative inflammation of the testes and their appendages are noted. The inflamed tosticle is swollen and can be enlarged 3-5 times (Fig. 1). The skin of the scrotum is tense, hot, reddened, painful. After 2 weeks (sometimes earlier), the body temperature drops, the swelling of the scrotum gradually disappears and the disease takes on a chronic course. At the same time, the appendages of the testis (one or both) are enlarged in volume, bumpy and dense. The mobility of the testes in the scrotum is reduced or they are completely immobile. Sometimes there is atrophy of one or both testes. In many rams, the volume of ejaculate, the mobility and density of sperm are reduced, its color becomes yellow-gray and even yellow-green. It contains leukocytes, lumps of mucus and cells of desquamated epithelium. In sheep, abortions or barrenness (due to placentitis) are often the only signs of illness. Sometimes lambs are born poorly developed and soon die.
pathological changes. In rams, in the chronic course of the disease, fusion of the common vaginal membrane with the testicle and appendage is often observed; in the affected appendage, fibrous growths are found (Fig. 2) and sequesters of various sizes filled with a serous, pus-like or curdled mass.
The diagnosis is made on the basis of the clinical picture, microscopic (sperm, postabortal discharge), bacteriological (testes and appendages, lymph nodes, aborted fetuses), serological (prolonged complement fixation reaction, indirect hemagglutination reaction) and allergic (brucella VIEV) studies of animals, taking into account epizootological and pathological data. E. i. differentiate from pseudotuberculosis, diplococcal infection, brucellosis caused by other types of brucella, consequences of injuries, etc.
Treatment of sick animals is impractical.
Prevention and control measures. The rams newly introduced into the economy are quarantined and examined for E. and. Before the breeding season, as well as when suspicious clinical signs appear in animals, sheep are examined by clinical and serological methods. When the disease is established, the flock is declared unfavorable and kept in isolation. At the same time, the ewes of those flocks in which sick rams were used as producers are examined, and in case of illness of young rams, the ewes from which they descend are examined. Sick animals are handed over for slaughter, regardless of their breeding value. Sheep from unfavorable flocks are examined clinically, and blood from them is examined serologically every 20-30 days, until 2-fold negative results are obtained. Then conduct a study after 3 months. Sheep are examined serologically 1 and 2 months after lambing, as well as before the start of the breeding season, and artificially inseminated with the sperm of healthy studs.
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MINISTRY OF AGRICULTURE OF THE RUSSIAN FEDERATION
FEDERAL STATE EDUCATIONAL
INSTITUTION OF HIGHER PROFESSIONAL EDUCATION
Ural State Agricultural Academy
Test
"Plant Microbiology"
Completed by: Bunkov I.A.
Yekaterinburg 2012
Introduction
5. Microbiology of feed, hay
6. The role of microorganisms in nature and agriculture production
Conclusion
Introduction
Microbiology (from micro... and biology), a science that studies microorganisms - bacteria, mycoplasmas, actinomycetes, yeasts, microscopic fungi and algae - their systematics, morphology, physiology, biochemistry, heredity and variability, distribution and role in the circulation of substances in nature, practical value.
The science of the smallest organisms that are not visible to the naked eye. Microbiology studies the structure of microbes (morphology), their chemical organization and patterns of life (physiology), variability and heredity (genetics of microorganisms), relationships with other organisms, including humans, and their role in the formation of the biosphere. During the historical The development of microbiology as a science was divided into general, agricultural, veterinary, medical and industrial. General microbiology studies the patterns of vital activity of microbes as organisms, as well as the role of microbes in maintaining life on Earth, in particular, their participation in the cycle of carbon, nitrogen, energy, etc.
1. Three areas of practical application
So, microbiology is a science that studies microorganisms, their properties, distribution and role in the cycle of substances in nature. Three areas of practical application of microbiological knowledge are widely known, three main areas, without which it is impossible to imagine modern life. One of these areas is medical microbiology, which studies pathogenic microorganisms and develops methods to combat them. Medical microbiology. includes bacteriology, which studies bacteria - the causative agents of infectious diseases, mycology - a section on pathogenic fungi, protozoology, the object of study of which are pathogenic unicellular animal organisms, and, finally, honey. Virology is the study of pathogenic viruses. Reliable information about microbes was first obtained in the second half of the 17th century. by the Dutch scientist A. Leeuwenhoek, who described "living animals" in water, plaque, and infusions when viewed through a simple microscope that magnified objects 250-300 times.
Another is technical microbiology, under the "protection" of which is the production of alcohol and dairy products (using fermentation processes), vitamins, antibiotics and hormones that are so necessary for a person. Technical, or industrial, microbiology studies the chemical processes caused by microbes that lead to the formation of alcohols, acetone, and other products important to humans. In recent years, such areas of technical microbiology as the production of vitamins, amino acids and antibiotics have also developed widely.
The third independent area of this science is soil microbiology, which studies the participation of microorganisms in soil processes in order to optimize their use in agricultural production.
Microbiology entered the circle of scientific disciplines in the 17th century: its appearance is closely connected with the invention of the microscope. The golden age of microbiology began at the end of the 19th century, when the industrial and technical development of human society, together with the development of the chemistry of dyes, the progress of optics, and the remarkable discoveries of bacteriologists, produced a real revolutionary revolution in medicine and medical thinking. The discovery of the causative agents of a significant part of the infectious diseases of humans and animals - pathogens found in a peculiar kingdom of microorganisms can be attributed to separate links of this "revolution".
About what exactly refers to the motley galaxy of microorganisms, to the sphere controlled by microbiology, many do not always have an accurate and complete idea. Over the years, microbiology has become a vast and complex scientific discipline, and the reason for this lies not in some artificial complication of it, but in the fact that groups of microorganisms were discovered that could not be adjusted to any single, common denominator. This forced the division of microbiology into several special departments.
So far, five such “provinces” have been identified in the “state” of microbiology. True, its further development and differentiation definitely show that this five-membered subdivision is not final. But for today it satisfies us quite well. Here is a brief listing and definition of the groups mentioned.
Virology is the study of viruses.
Bacteriology deals with the study of bacteria (experts consider them the most ancient inhabitants of the Earth) and actinomycetes (single-celled microorganisms similar in organization to bacteria).
Mycology is the study of lower (microscopic) fungi.
Algology is the study of microscopic algae.
Protozoology has the object of its study of the simplest - unicellular animals, standing in the classification system on the verge of the plant and animal world.
We have listed these divisions according to the increase in the size of microorganisms.
Viruses in comparison with other groups of microorganisms are immeasurably smaller. It was their negligible size that gave microbiologists (in the period of the birth of virology) the main opportunity to distinguish them from bacteria. Viruses range in size from 20 to 300 nanometers (one nanometer is equal to a millionth of a millimeter).
In the "young years" of virology, the term "filterable virus" (from Latin virus - poison) was used to refer to a non-bacterial pathogen of any disease.
The original term emphasized the peculiar property of pathogens - the ability to pass through filters that do not let the smallest bacteria pass.
Further studies have shown that viruses represent a special group of infectious agents and their study requires the use of completely new methods. As a result, a new independent branch of microbiology, virology, emerged. This allocation was unconditionally accepted by all scientists. From the very beginning, virology was regarded as the younger sister of bacteriology.
However, between these two branches of science, or rather, their objects, there is an essential difference.
Bacteriologists have relatively long discovered, along with pathogenic bacteria, those that are simply necessary for the life of humans, animals and plants, for the normal course of the natural circulation of substances in nature and many technological processes in the food and pharmaceutical industries.
2. Emergence and development of microbiology
microorganism biology food
Several thousand years before the emergence of microbiology as a science, man, unaware of the existence of microorganisms, widely used them for the preparation of koumiss and other fermented milk products, for the production of wine, beer, vinegar, for ensiling fodder, and flax lobe. For the first time, bacteria and yeast were seen by A. Leeuwenhoek, who examined dental plaque, herbal infusions, beer, etc. with the help of microscopes he made. The creator of microbiology as a science was L. Pasteur, who elucidated the role of microorganisms in fermentations (winemaking, brewing) and in the occurrence of animal and human diseases. Of exceptional importance for the fight against infectious diseases was the method of preventive vaccinations proposed by Pasteur, based on the introduction of weakened cultures of pathogenic microorganisms into the body of an animal or person. Long before the discovery of viruses, Pasteur proposed vaccination against a viral disease - rabies. He also proved that in modern terrestrial conditions spontaneous generation of life is impossible. These works served as a scientific basis for the sterilization of surgical instruments and dressings, the preparation of canned food, the pasteurization of food products, etc. Pasteur's ideas on the role of microorganisms in the circulation of matter in nature were developed by the founder of general microbiology in Russia, S. N. Vinogradsky, who discovered chemoautotrophic microorganisms (they absorb carbon dioxide from the atmosphere due to the energy of oxidation of inorganic substances; see Chemosynthesis), nitrogen-fixing microorganisms, and bacteria that decompose cellulose under aerobic conditions. His student V. L. Omelyansky discovered anaerobic bacteria that ferment, that is, decompose cellulose under anaerobic conditions, and bacteria that form methane. A significant contribution to the development of microbiology was made by the Dutch school of microbiologists, who studied the ecology, physiology, and biochemistry of various groups of microorganisms (Mikrobiology Beijerinck, A. Kluiver, and K. van Niel). An important role in the development of medical microbiology belongs to R. Koch, who proposed dense nutrient media for growing microorganisms and discovered the pathogens of tuberculosis and cholera. The development of medical microbiology and immunology was promoted by E. Behring (Germany), E. Roux (France), S. Kitazato (Japan), and in Russia and the USSR by I.I. Mechnikov, L.A. Tarasevich, D.K. Zabolotny, N.F. Gamaleya.
The development of microbiology and the needs of practice led to the separation of a number of sections of microbiology into independent scientific disciplines. General microbiology studies the fundamental laws of the biology of microorganisms. Knowledge of the basics of general microbiology is necessary when working in any of the special sections of microbiology; the content, boundaries and tasks of general microbiology have gradually changed.
Previously, the objects studied by her also included viruses, protozoa of plant or animal origin (protozoa), higher fungi and algae. Foreign manuals on general microbiology still describe these objects.
The task of technical or industrial microbiology includes the study and implementation of microbiological processes used to obtain yeast, feed protein, lipids, bacterial fertilizers, as well as the production of antibiotics, vitamins, enzymes, amino acids, nucleotides, organic acids, etc., by microbiological synthesis. . (see also Microbiological Industry).
Agricultural microbiology elucidates the composition of soil microflora, its role in the cycle of substances in the soil, as well as its significance for the structure and fertility of the soil, the effect of processing on microbiological processes in it, and the effect of bacterial preparations on plant productivity. The task of agricultural microbiology includes the study of microorganisms that cause plant diseases, and the fight against them, the development of microbiological methods of controlling insects - pests of agricultural crops. plants and forest species, as well as methods of fodder conservation, flax lobe, crop protection from spoilage caused by microorganisms.
Geological microbiology studies the role of microorganisms in the circulation of substances in nature, in the formation and destruction of mineral deposits, and proposes methods for obtaining (leaching) metals (copper, germanium, uranium, and tin) and other minerals from ores with the help of bacteria.
Aquatic Microbiology studies the quantitative and qualitative composition of the microflora of salt and fresh waters and its role in the biochemical processes occurring in water bodies, monitors the quality of drinking water, and improves microbiological methods of wastewater treatment.
The task of medical microbiology includes the study of microorganisms that cause human diseases and the development of effective methods to combat them. The same questions regarding agricultural and other animals are solved by veterinary microbiology.
The peculiarity of the structure and reproduction of viruses, as well as the use of special methods for their study, led to the emergence of virology as an independent science that is not related to microbiology.
Both general microbiology and its special sections are developing exceptionally rapidly. There are three main reasons for this development. First, thanks to advances in physics, chemistry, and technology, microbiology has acquired a large number of new research methods. Secondly, the practical use of microorganisms has sharply increased. Thirdly, microorganisms began to be used to solve the most important biological problems, such as heredity and variability, biosynthesis of organic compounds, regulation of metabolism, etc. The successful development of modern microbiology is impossible without a harmonious combination of research conducted at the population, cellular, organoid and molecular levels. . To obtain cell-free enzyme systems and fractions containing certain intracellular structures, apparatuses are used that destroy microorganism cells, as well as gradient centrifugation, which makes it possible to obtain cell particles with different masses. To study the morphology and cytology of microorganisms, new types of microscopic equipment have been developed. In the USSR, the method of capillary microscopy was invented, which made it possible to discover a new, previously unobservable world of microorganisms with a peculiar morphology and physiology.
To study the metabolism and chemical composition of microorganisms, various methods of chromatography, mass spectrometry, the method of isotope indicators, electrophoresis, and other physical and physicochemical methods have become widespread. Pure preparations of enzymes are also used to detect organic compounds. New methods for isolating and chemically purifying waste products of microorganisms (adsorption and chromatography on ion-exchange resins, as well as immunochemical methods based on the specific adsorption of a certain product, such as an enzyme, by animal antibodies formed after the introduction of this substance) are proposed. The combination of cytological and biochemical research methods led to the emergence of functional morphology of microorganisms. With the help of an electron microscope, it became possible to study the fine features of the structure of cytoplasmic membranes and ribosomes, their composition and functions (for example, the role of cytoplasmic membranes in the processes of transport of various substances or the participation of ribosomes in protein biosynthesis).
Laboratories were enriched with fermenters of various capacities and designs. Continuous cultivation of microorganisms, based on the constant influx of fresh nutrient medium and the outflow of liquid culture, has become widespread. It has been established that along with cell reproduction (culture growth), culture develops, i.e. age-related changes in the cells that make up the culture, accompanied by a change in their physiology (young cells, even multiplying intensively, are not able to synthesize many waste products, for example, acetone, butanol , antibiotics produced by older cultures). Modern methods of studying the physiology and biochemistry of microorganisms have made it possible to decipher the features of their energy metabolism, the pathways for the biosynthesis of amino acids, many proteins, antibiotics, certain lipids, hormones, and other compounds, and also to establish the principles of regulation of metabolism in microorganisms.
3. Connection of microbiology with other sciences
Microbiology is to some extent connected with other sciences: morphology and taxonomy of lower plants and animals (mycology, algology, protistology), plant physiology, biochemistry, biophysics, genetics, evolutionary theory, molecular biology, organic chemistry, agrochemistry, soil science, biogeochemistry , hydrobiology, chemical and microbiological technology, etc. Microorganisms are favorite objects of research in solving general problems of biochemistry and genetics (see Genetics of microorganisms, Molecular genetics). So, with the help of mutants that have lost the ability to carry out one of the stages of the biosynthesis of any substance, the mechanisms for the formation of many natural compounds (for example, the amino acids lysine, arginine, etc.) were deciphered. The study of the mechanism of molecular nitrogen fixation for reproducing it on an industrial scale is aimed at searching for catalysts similar to those that, under mild conditions, carry out nitrogen fixation in bacterial cells. There is constant competition between microbiology and chemistry in choosing the most economical routes for the synthesis of various organic substances. A number of substances that were previously obtained microbiologically are now produced on the basis of a purely chemical synthesis (ethyl and butyl alcohols, acetone, methionine, the antibiotic chloramphenicol, etc.). Some syntheses are carried out both chemically and microbiologically (vitamin B2, lysine, etc.). In a number of industries, microbiological and chemical methods are combined (penicillin, steroid hormones, vitamin C, etc.). Finally, there are products and preparations that so far can only be obtained by microbiological synthesis (many antibiotics of complex structure, enzymes, lipids, feed protein, etc.).
4. Practical importance of microbiology
Actively participating in the cycle of substances in nature, microorganisms play an important role in soil fertility, in the productivity of water bodies, in the formation and destruction of mineral deposits. The ability of microorganisms to mineralize the organic remains of animals and plants is especially important. The ever-increasing use of microorganisms in practice has led to the emergence of the microbiological industry and to a significant expansion of microbiological research in various branches of industry and agriculture. Previously, technical microbiology mainly studied various fermentations, and microorganisms were used mainly in the food industry. New areas of technical microbiology are also developing rapidly, requiring a different instrumentation for microbiological processes. The cultivation of microorganisms began to be carried out in large-capacity closed fermenters, methods were improved for separating the cells of microorganisms from the cultural liquid, isolating from the latter and chemically purifying their metabolic products. One of the first arose and developed the production of antibiotics. Amino acids (lysine, glutamic acid, tryptophan, etc.), enzymes, vitamins, and fodder yeasts are obtained on a large scale microbiologically from nonfood raw materials (sulfite liquors, hydrolyzates of wood, peat, and agricultural plant waste, petroleum hydrocarbons, and natural gas, phenolic or starchy wastewater, etc.). Microbiological production of polysaccharides is being carried out and industrial biosynthesis of lipids is being mastered. The use of microorganisms in agriculture has increased dramatically. The production of bacterial fertilizers has increased, in particular nitragin, which is prepared from cultures of nodule bacteria that fix nitrogen under conditions of symbiosis with leguminous plants and is used to infect seeds of leguminous crops. New direction of page - x. microbiology is connected with microbiological methods of struggle against insects and their larvae - pests of page - x. plants and forests. Bacteria and fungi that kill these pests with their toxins have been found, and the production of appropriate drugs has been mastered. Dried cells of lactic acid bacteria are used to treat intestinal diseases of humans and page - x. animals.
The division of microorganisms into useful and harmful is conditional, because. evaluation of the results of their activities depends on the conditions in which it manifests itself. Thus, the decomposition of cellulose by microorganisms is important and useful in plant residues or in the digestion of food in the digestive tract (animals and humans are not able to absorb cellulose without its preliminary hydrolysis by the microbial cellulase enzyme). At the same time, cellulose-decomposing microorganisms destroy fishing nets, ropes, cardboard, paper, books, cotton fabrics, etc. To obtain protein, microorganisms are grown on hydrocarbons of oil or natural gas. At the same time, large quantities of oil and products of its processing are decomposed by microorganisms in oil fields or during their storage. Even pathogenic microorganisms cannot be classified as absolutely harmful, because. vaccines are prepared from them that protect animals or humans from diseases. Spoilage by microorganisms of plant and animal raw materials, foodstuffs, building and industrial materials and products has led to the development of various methods for their protection (low temperature, drying, sterilization, canning, adding antibiotics and preservatives, acidification, etc.). In other cases, it becomes necessary to accelerate the decomposition of certain chemicals, such as pesticides, in the soil. The role of microorganisms in wastewater treatment (mineralization of substances contained in wastewater) is great.
5. Microbiology of feed, hay
Ordinary hay is made from cut grasses that have a moisture content of 70-80% and contain a large amount of free water. Microorganisms use this water for their development. During the drying process, free water evaporates and remains bound, which is inaccessible to microorganisms.
At a hay moisture content of 12-17%, microbiological processes stop, which stops the destruction of dried plants. After drying, a large number of epiphytes remain in the hay, which are in an anabiotic state, since in such an environment there are no conditions for their reproduction. When water gets inside the stack or stack, the activity of microorganisms begins to intensify. The process is characterized by an increase in temperature to 40-50 degrees and above.
In this case, the death of mesophiles occurs, and the activity of microorganisms begins to intensify. After 4-5 days, the temperature rises to 70-80 degrees, charring occurs, the plants become first brown and then black. At 90 degrees, microorganisms cease their activity. Brown hay is prepared as follows: mowed and well-dried grass is folded into small piles, then into stacks, stacks. Since the plant mass still contains free water, microorganisms begin to multiply, heat is released, which contributes to the final drying of the plants.
Senage - a method of preserving dried herbs, mainly legumes, harvested at the beginning of budding. Grasses are mowed, laid in rolls. A day later, the grass, dried to 50-55% moisture, is picked up, crushed and loaded into well-insulated feed storages.
In trenches, the plant mass is compacted, insulated with a plastic film, on which straw, sawdust, and then earth are placed. Haylage is a green plant mass with low humidity, preserved under the influence of physiological dryness and biochemical processes caused by microorganisms, when it is in feed storage facilities isolated from atmospheric oxygen. The number of lactic acid and putrefactive microbes in haylage is 4-5 times less than in silage.
The maximum number of microorganisms is formed on the 15th day. The rate of flow of microbiological processes is associated with the formation of organic acids. Carbohydrates serve as energy material for animals and microorganisms. Microorganisms convert soluble carbohydrates into organic acids and thereby deplete the feed.
In haylage, as a result of the hydrolysis of polysaccharides, the amount of sugar increases. Increased osmotic pressure primarily inhibits the growth of butyric microbes, then lactic acid and putrefactive ones. This creates favorable conditions for the development of lactic acid bacteria. This lowers the pH, which, together with pressure, prevents the development of butyric acid bacteria, so there is no butyric acid in the silage. Feed yeasting is a microbiological method of preparing feed for feeding.
Yeast enriches food not only with protein, but also with vitamins and enzymes. For economic purposes, cultural races of yeast have been bred: beer, baker, fodder. Yeast contains 48-52% proteins, 13-16 carbohydrates, 2-3 fats, 22-40 BEV, 6-10% ash, many amino acids.
Yeast requires oxygen for its growth and development, a temperature of 25-30 degrees, the yeast process lasts 9-12 hours. Yeast thrives on plant-derived foods that are rich in carbohydrates. Feed of animal origin should not be yeasted, as putrefactive microorganisms quickly develop on such media.
Yeast is carried out in a dry, bright and spacious room. 3 ways: steamy, steamless, starter. Spongy: prepare a sponge - diluted pressed yeast 1% is mixed with food (fifth), for 6 hours every 20 minutes is stirred, then the rest of the food is added, double the amount of water and mixed again.
The mixture is left for another 3 hours, during which, with occasional stirring, yeast occurs. The safe method is based on the yeasting of the entire mass of feed at once. Take 1% pressed yeast, dilute with warm water, mix with food and double the amount of water. For 8-10 hours, the mixture is stirred every 30 minutes.
The starter method is used when there is little yeast. The starter is prepared: 0.5 kg of pressed yeast is propagated in a small amount of well-fermenting carbohydrate feed at a temperature of 30 degrees for 5 hours. Then the food is malted, doused with boiling water, and kept at a temperature of at least 60 degrees for 5-6 hours. The same amount of water and half of the leaven are added to the malted feed. Stir, cover and leave for 6 hours in a warm place.
The second part of the starter is added to a new portion of the malted feed and this is done 5-10 times, after which a new primary starter is prepared.
6. The role of microorganisms in nature and agricultural production
The wide distribution of microorganisms indicates their enormous role in nature. With their participation, the decomposition of various organic substances in soils and water bodies occurs, they determine the circulation of substances and energy in nature; soil fertility, the formation of coal, oil, and many other minerals depend on their activity. Microorganisms are involved in rock weathering and other natural processes. With the most active, wide participation of microorganisms in nature, mainly in the soil and hydrosphere, two opposite processes are constantly carried out: the synthesis of complex organic compounds from mineral substances and, conversely, the decomposition of organic substances into mineral ones. The unity of these opposite processes underlies the biological role of microorganisms in the circulation of substances in nature.
Among the various processes of transformation of substances in nature, in which microorganisms take an active part, the circulation of nitrogen, carbon, phosphorus, sulfur, iron is of paramount importance for the implementation of the life of plants, animals and humans on Earth. Many microorganisms are used in industrial and agricultural production. Thus, baking, the manufacture of fermented milk products, winemaking, the production of vitamins, enzymes, food and feed proteins, organic acids, and many substances used in agriculture, industry, and medicine are based on the activity of various microorganisms.
The use of microorganisms in crop production and animal husbandry is especially important. The enrichment of the soil with nitrogen, the control of pests of agricultural crops with the help of microbial preparations, the proper preparation and storage of feed, the creation of feed protein, antibiotics and microbial substances for animal feed depend on them. Microorganisms have a positive effect on the processes of decomposition of substances of non-natural origin - xenobiotics, artificially synthesized, falling into soils and water bodies and polluting them.
Along with beneficial microorganisms, there is a large group of so-called disease-causing, or pathogenic, microorganisms that cause various diseases of agricultural animals, plants, insects and humans. Some microorganisms cause damage to agricultural products, lead to soil depletion in nitrogen, cause pollution of water bodies, and the accumulation of toxic substances (for example, microbial toxins). As a result of their vital activity, epidemics of contagious diseases of humans and animals arise, which affects the development of the economy and the productive forces of society. The latest scientific data not only significantly expanded the understanding of soil microorganisms and the processes they cause in the environment, but also made it possible to create new industries in industry and agricultural production.
For example, antibiotics secreted by soil microorganisms have been discovered, and the possibility of their use for the treatment of humans, animals and plants, as well as for the storage of agricultural products, has been shown. The ability of soil microorganisms to form biologically active substances was discovered: vitamins, amino acids, plant growth stimulants - growth substances, etc. Ways have been found to use the protein of microorganisms for feeding farm animals. Microbial preparations have been identified that enhance the flow of nitrogen into the soil from the air. The discovery of new methods for obtaining hereditarily modified forms of beneficial microorganisms has made it possible to use microorganisms more widely in agricultural and industrial production, as well as in medicine.
The development of gene or genetic engineering is especially promising. Its achievements ensured the development of biotechnology, the emergence of highly productive microorganisms synthesizing proteins, enzymes, vitamins, antibiotics, growth substances and other products necessary for animal husbandry and crop production. Humanity has always been in contact with microorganisms, for millennia without even knowing it.
Since time immemorial, people have observed dough fermentation, prepared alcoholic beverages, fermented milk, made cheese, suffered various diseases, including epidemic ones. However, until the middle of the last century, no one even imagined that various kinds of fermentation processes and diseases could be the result of the activity of negligibly small creatures.
Conclusion
On the basis of certain facts, it can be assumed that virological research will retain the role of the main driving force in microbiology for at least the next thirty to fifty years. The current state of this rapidly developing research suggests that the progress made in improving and accelerating the diagnostic processes for viral diseases, so important for immediate and specific therapeutic measures, will continue.
Why is immediate intervention so important? Yes, because as soon as the virus in the cells begins to multiply and causes the characteristic symptoms of the disease in the patient's body, the introduction of any drugs will no longer be able to achieve full success.
In connection with the development of diagnostics, undoubtedly, new “generations” of drugs will be created faster, more perfectly “fitted” to a given disease. When making them, they will proceed from knowledge of the characteristics of the molecular biology of reproduction of certain types of viruses, as well as the specifics of the biochemical properties of various types of cells (nerve, liver cells, etc.).
With a high probability, we can expect a significant expansion and deepening of knowledge about the viral origin of many lesions of the central nervous system that proceed according to the degenerative type, from which many people suffer. Undoubtedly, the list of diseases, either caused by viruses or those in which the virus plays a dominant role along with other factors, will expand significantly.
The accelerated and increasingly effective progress of infectious disease research in the modern era can be illustrated by many compelling facts. From 1880 to 1950, new discoveries accumulated relatively slowly, although it was during these 70 years that many major observations were made. In the subsequent period, virology began to develop at a much faster pace due to the use of new scientific approaches and techniques.
Virologists have received a more or less complete picture of the structure of viruses and information about the mechanism of infection of a cell with a virus. Great progress can also be noted in studies of viral infections at the molecular level, in connection with which success can also be expected in the search for new antiviral substances. There are already some encouraging facts here, including tumors of viral origin.
Thanks to the efforts of the World Health Organization and the intensive development of medicine in many countries of the world, the system of virological and epidemiological surveillance has been improved in the elimination of mass viral infections, as well as in the detection of contagious diseases that had not previously been found in these areas. The medical service strictly controls passenger and goods, international and intercontinental transport in order to prevent the "import" of infections from other countries not only by passengers, crew, but also by animals and even plants transported. The search for possible centers of infectious diseases is carried out in the most remote corners of our planet, and highly specialized units of the health service penetrate into developing countries, where even in the recent past it was difficult to even think about eliminating infectious diseases. In our time of heavy use of transport and a brisk exchange of goods, the seriousness of "local" infections cannot be neglected. Today, such an infection that occurs in one country can, thanks to high-speed transport, manifest itself in a place hundreds and thousands of kilometers away from the original focus.
List of used literature
1. Achievements of Soviet microbiology, Microbiology, 1989; Microbiology, Fundamentals of Microbiology, trans. from English, Microbiology, 1995;
2. Rabotnova I.L., General microbiology, Microbiology, 1966; "Microbiology", 1987, v. 36, c. 6;
3. Meynell J., Meynell E., Experimental microbiology, trans. from English, Microbiology, 1967;
4. Schlegel G., General microbiology, trans. from German, Microbiology, 1972.
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- The subject of microbiology and its importance for agricultural production
Microbiology (from micro... and biology ), the science that studies microorganisms bacteria, mycoplasmas, actinomycetes, yeast , microscopic mushrooms and algae - their systematics, morphology, physiology, biochemistry, heredity and variability, distribution and role in the circulation of substances in nature, practical significance.
The development of microbiology and the needs of practice led to the separation of a number of sections of microbiology into independent scientific disciplines. General microbiologist AI studies the fundamental regularities of the biology of microorganisms. Knowledge of the basics of general microbiology is necessary when working in any of the special sections of microbiology.
Agricultural microbiology finds out the composition of soil microflora, its role in the circulation of substances in the soil, as well as its significance for the structure and fertility of the soil, the effect of processing on microbiological processes in it, the effect of bacterial preparations on plant productivity. In the task of s.-x. microbiology includes the study of microorganisms that cause plant diseases, and the fight against them, the development of microbiological methods of combating insects - pests of agricultural crops. plants and forest species, as well as methods of fodder conservation, flax lobe, crop protection from spoilage caused by microorganisms.
To the task technical or industrial microbiology includes the study and implementation of microbiological processes used to obtain yeast, feed protein, lipids, bacterial fertilizers, as well as the production of antibiotics, vitamins, enzymes, amino acids, nucleotides, organic acids, etc. by microbiological synthesis. Geological microbiology studies the role of microorganisms in the circulation of substances in nature, in the formation and destruction of mineral deposits, and proposes methods for obtaining (leaching) metals (copper, germanium, uranium, tin) and other minerals from ores with the help of bacteria. Aquatic microbiology studies the quantitative and qualitative composition of the microflora of salt and fresh waters and its role in the biochemical processes occurring in reservoirs, monitors the quality of drinking water, improves microbiological methods of wastewater treatment. To the task medical microbiology includes the study of microorganisms that cause human diseases and the development of effective methods to combat them. The same questions regarding agricultural and other animals are solved veterinary microbiology.
The practical importance of microbiology. Actively participating in the cycle of substances in nature, microorganisms play an important role in soil fertility, in the productivity of water bodies, in the formation and destruction of mineral deposits. The ability of microorganisms to mineralize the organic remains of animals and plants is especially important. The ever-increasing use of microorganisms in practice has led to the emergence of the microbiological industry and to a significant expansion of microbiological research in various branches of industry and agriculture. The use of microorganisms in agriculture has increased dramatically. The production of bacterial fertilizers has increased, in particular nitragin, which is prepared from cultures of nodule bacteria that fix nitrogen under conditions of symbiosis with leguminous plants and is used to infect seeds of leguminous crops. New direction of page - x. microbiology is connected with microbiological methods of struggle against insects and their larvae - wreckers of page - x. plants and forests. Bacteria and fungi that kill these pests with their toxins have been found, and the production of appropriate drugs has been mastered. Dried cells of lactic acid bacteria are used to treat intestinal diseases of humans and page - x. animals.
2. A brief history of the development of microbiology
The emergence and development of microbiology.
Several thousand years before the emergence of microbiology as a science, man, not knowing about the existence of microorganisms, widely used them for the preparation of koumiss and other fermented milk products, for the production of wine, beer, vinegar, for ensiling fodder, and flax lobe. Bacteria and yeast were first seen by A. Leeuwenhoek , who examined dental plaque, herbal infusions, beer, etc. with the help of microscopes he made. The creator of microbiology as a science was L. Pasteur who elucidated the role of microorganisms in fermentations (winemaking, brewing) and in the occurrence of animal and human diseases. Of exceptional importance for the fight against infectious diseases was the method of preventive vaccinations proposed by Pasteur, based on the introduction of weakened cultures of pathogenic microorganisms into the body of an animal or person. Long before the discovery of viruses, Pasteur proposed vaccination against a viral disease - rabies. He also proved that in modern terrestrial conditions spontaneous generation of life is impossible. These works served as a scientific basis for the sterilization of surgical instruments and dressings, the preparation of canned food, the pasteurization of food products, etc. Pasteur's ideas about the role of microorganisms inmatter cyclein nature were developed by the founder of general M. in Russia, S. N. Vinogradsky , who discovered chemoautotrophic microorganisms (assimilate atmospheric carbon dioxide due to the energy of oxidation of inorganic substances; chemosynthesis), nitrogen-fixing microorganismsand bacteria that decompose cellulose under aerobic conditions. His student V.L. Omelyansky discovered anaerobic bacteria that ferment, that is, decompose cellulose under anaerobic conditions, and bacteria that form methane. A significant contribution to the development of microbiology was made by the Dutch school of microbiologists who studied the ecology, physiology, and biochemistry of various groups of microorganisms (M. Beijerinck, A. Kluiver, K. van Niel). An important role in the development of medical microbiology belongs to R. Kohu , who proposed dense nutrient media for growing microorganisms and discovered the pathogens of tuberculosis and cholera. Development of medical microbiology and immunology E. Behring (Germany), E. Roux (France), S. Kitazato (Japan), and in Russia - I.I. Mechnikov , L. A. Tarasevich , D. K. Zabolotny , N. F. Gamaleya .
3. Significance of Pasteur's work in the development of microbiology
For the first time, bacteria and yeast were seen by A. Leeuwenhoek, who examined dental plaque, herbal infusions, beer, etc. with the help of microscopes he made. The creator of microbiology as a science was L. Pasteur, who elucidated the role of microorganisms in fermentations (winemaking, brewing) and in the occurrence of animal and human diseases. Of exceptional importance for the fight against infectious diseases was the method of preventive vaccinations proposed by Pasteur, based on the introduction of weakened cultures of pathogenic microorganisms into the body of an animal or person. Long before the discovery of viruses, Pasteur proposed vaccination against a viral disease - rabies. He also proved that in modern terrestrial conditions spontaneous generation of life is impossible. These works served as a scientific basis for the sterilization of surgical instruments and dressings, the preparation of canned food, the pasteurization of food products, etc. Pasteur's ideas on the role of microorganisms in the circulation of substances in nature were developed by S. N. Vinogradsky, the founder of general meteorology in Russia.
Pasteur Louis (1822-1895), French microbiologist and chemist, founder of modern microbiology and immunology. The first director of the research microbiological institute (Pasteur Institute), established in 1888 with funds raised by international subscription. In this institute, along with other foreign scientists, Russians also worked fruitfully - I. I. Mechnikov, S. N. Vinogradsky, N. F. Gamaleya, V. M. Khavkin, A. M. Bezredka and others. connection between theory and practice. From 1857 he studied the processes of fermentation (lactic acid, alcohol, acetic, butyric, discovered by him). Contrary to the prevailing "chemical" theory of the German chemist J. Liebig, he proved that fermentation is caused by the activity of various types of microorganisms. At the same time, he discovered the phenomenon of anaerobiosis (the ability to live in the absence of free O 2) and the existence of obligate (strictly) anaerobic bacteria. He showed that fermentation serves as a source of energy for the microorganisms that cause it. He laid the scientific foundations for winemaking, brewing and other branches of the food industry. He proposed a method for protecting wine from spoilage (pasteurization), which was then used in the production of other food products (beer, milk, fruit and berry juices). He finally refuted (by experiment) the idea of the possibility of spontaneous generation of living beings in modern conditions.
Having studied the nature of the silkworm disease (1870), Pasteur established the contagiousness of the disease, the time of its maximum manifestation, and recommended measures to combat it. He studied a number of other contagious diseases of animals and humans (anthrax, puerperal fever, rabies, chicken cholera, rubella of pigs, etc.), finally establishing that they are caused by specific pathogens. Based on the idea he developed about artificial immunity, he proposed a method of protective vaccinations, in particular, vaccination against anthrax (1881). In 1880, together with E. Roux, Pasteur began research on rabies. The first protective vaccination against this disease was given to him in 1885.
4. The creative contribution of Russian scientists to the development of microbiology (Vinogradsky, Ivanovsky, Omelyansky, Voronin, Khudyakov, Kononov, Mishustin, etc.)
Pasteur's ideas about the role of microorganisms in the circulation of substances in nature were developed by the founder of general microbiology in Russia S. N. Vinogradsky, discoverer of chemoautotrophic microorganisms(assimilate atmospheric carbon dioxide due to the energy of oxidation of inorganic substances; Chemosynthesis), nitrogen-fixing microorganisms and bacteria that decompose cellulose under aerobic conditions. Vinogradsky Sergey Nikolaevich [.1856 -1953], Russian microbiologist, corresponding member of the St. Petersburg Academy of Sciences. In 1891-1912 he was the head of the department of general microbiology at the Institute of Experimental Medicine in St. Petersburg. Actively participated in the organization of the Russian Microbiological Society (1903) and for the first 2 years was its chairman. In 1922 he left for France and until the end of his life he headed the Agrobacteriological Department of the Pasteur Institute near Paris.Vinogradsky was the first to prove that there are special microorganisms (anorgooxidants) that obtain energy as a result of the oxidation of inorganic substances. The resulting energy is used to assimilate carbon dioxide or carbonates; the process of assimilation of carbon dioxide based on this is called chemosynthesis. The discovery of chemosynthesis by Vinogradsky made it possible for Russian microbiology to occupy a leading position and had a great influence on its development in other countries. In 1893, Vinogradsky was the first to isolate the anaerobic spore-bearing bacterium Clostridium Pasteurianum, which assimilates molecular nitrogen, from the soil. His student V. L. Omelyansky discovered anaerobic bacteria that ferment, that is, decompose cellulose under anaerobic conditions, and bacteria that form methane.Omelyansky Vasily Leonidovich, Russian microbiologist, academician of the Academy of Sciences of the USSR (1923; corresponding member 1916). A student of S. N. Vinogradsky. Graduated from St. Petersburg University (1890). In 1893-1928 he worked in the Department of General Microbiology of the Institute of Experimental Medicine, from 1912 the head of the department. The main work on elucidating the role of microorganisms in the cycle of nitrogen and carbon in nature. He proposed methods for the isolation and cultivation of nitrifying bacteria, studied their morphology and physiology. For the first time, he singled out cultures of anaerobic and spore-bearing bacteria that ferment fiber with the formation of organic acids and hydrogen. He studied an aerobic nitrogen-fixing bacterium (from the genus Azotobacter) and proved the existence of bacteria that form methane from ethyl alcohol. He established that the amount of nitrogen assimilated by nitrogen-fixing microorganisms is proportional to the assimilation of organic matter. The first pointed to the possibility of using microorganisms as chemical indicators. Editor of the journal "Archive of Biological Sciences" (1906-28). His books Fundamentals of Microbiology (1909) and Practical Guide to Microbiology (1922) contributed to the formation of several generations of Soviet microbiologists. . Dmitry Iosifovich Ivanovsky(1864 - 1920) - Russian plant physiologist and microbiologist, founder of virology. He graduated from St. Petersburg University in 1888 and was left at the Department of Botany. Under the guidance of A. N. Beketov, A. S. Famintsyn and X. Ya. Gobi studied plant physiology and microbiology.
He discovered crystalline inclusions (“Ivanovsky crystals”) in the cells of diseased plants, thus opening a special world of pathogens of non-bacterial and non-protozoal nature, later called viruses. Ivanovsky considered them as the smallest living organisms. In addition, Ivanovsky published works on the features of physiological processes in diseased plants, the effect of oxygen on alcoholic fermentation in yeast, the state of chlorophyll in plants, its resistance to light, the importance of carotene and xanthophyll, and on soil microbiology.
Voronin Mikhail Stepanovich- botanist (1838 - 1903). Numerous scientific works of Voronin concern mainly the class of fungi (mycology) and those lower organisms that stand on the verge between animals and plants. He discovered, studied in detail and described many lower organisms that are highly important not only in the botanical but also in the general biological sense. The fungal disease of sunflower was discovered and studied by him; the same must be said about the disease of cabbage plants, etc. All of Voronin's works are distinguished by great accuracy. His drawings, without which the latest morphology cannot do, are exemplary.
Khudyakov Nikolai Nikolaevich(1866-1927) - Russian microbiologist. The works are devoted to issues anaerobiosis and soil microbiology. In the work "On the study of anaerobiosis" (1896) he established the possibility of cultivating anaerobes in the presence of oxygen and stated the position that anaerobiosis in bacteria is an adaptation to the conditions of existence. In the field of soil microbiology discovered the adsorption of bacteria by soil particles, which is of great importance for their activity in soil processes. The author of the first in Russian. the language of the course "Agricultural Microbiology" (1926), which was of great importance for the development of microbiology in the USSR.
- Morphology and taxonomy of bacteria
There are three main forms of bacteria - spherical, rod-shaped and tortuous.
spherical bacteria, or cocci
The form spherical or oval.
micrococci- isolated cells.
diplococci- arranged in pairs.
streptococci- cells of a rounded or elongated shape that make up a chain.
Sarcins - arranged in the form of "packages" of 8 or more cocci.
Staphylococci- cocci arranged in the form of a bunch of grapes as a result of division in different planes.
rod-shaped bacteria
The form rod-shaped, the ends of the cell can be pointed, rounded, chopped off, split, expanded. Sticks can be regular and irregular in shape, including branching, for example, in actinomycetes.
By the nature of the arrangement of cells in smears, they distinguish:
Monobacteria- located in separate cells.
Diplobacteria - arranged in two cells.
streptobacteria- after division, they form chains of cells.
Rod-shaped bacteria can form spores: bacilli and clostridia.
Convoluted bacteria
The form- a curved body in one or more turns.
Vibrios- the curvature of the body does not exceed one turn.
Spirochetes- bends of the body in one or more turns.
Bacteria size
Microorganisms are measured in micrometers and nanometers.
The average size of bacteria is 2 - 3 x 0.3 - 0.8 microns.
Shape and size are important diagnostic features.
The ability of bacteria to change their shape and size is called polymorphism.
Questions for the exam
by discipline "Agricultural Microbiology"
for engineering students
specialties 1-74 02 01 Agronomy
1. Microbiology as a biological science. Subject and methods of research.
2. History of the development of microbiology. Morphological, physiological, biochemical, ecological and genetic period of development.
3. The main tasks and directions of development of microbiology at the present stage.
4. Distribution and role of microorganisms in nature.
5. Prokaryotic and eukaryotic microorganisms, their cellular organization and main differences.
6. The main forms of bacteria and their sizes.
7. General scheme of the structure of a bacterial cell.
8. External structures of a bacterial cell (capsule, outgrowths). movement of bacteria.
9. Structure, chemical composition and functions of the bacterial shell. Gram-positive and gram-negative bacteria, L-forms.
10. Structure and functions of the cytoplasmic membrane. Mesosomes.
11. Cytoplasm and its structures (nucleoid, ribosomes, inclusions).
12. Endospores: formation, structure and properties. Other resting forms.
13. Location of spores in the cell. Germination of spores.
14. Methods of reproduction of prokaryotes. Growth of cell mass of microorganisms on nutrient media.
15. Principles of taxonomy and nomenclature of microorganisms, taxonomic categories. The concept of strain and clone.
16. Systematics according to D. Bergi. Classification criteria.
17. General characteristics of department 1 - Gracilicutes. Bacteria, bacteria with anoxic and oxygen type of photosynthesis.
18. General characteristics of department 2 - Firmicutes. Firmibacteria and tallobacteria.
19. General characteristics of department 3 - Tenericutes. Mycoplasmas.
20. General characteristics of department 4 - Mendosicutes. Archaebacteria.
21. Actinomycetes, their systematic position, structure and reproduction. The value of actinomycetes in the soil-forming process.
22. Microscopic fungi: mucor, penicillium, aspergillus. Yeast.
23. Practical use of molds and yeasts.
24. Viruses: structure, properties, classification. Viroids and prions.
25. Structure and reproduction of bacteriophages. Virulent and temperate phages.
26. Hereditary factors of bacteria. Nucleoid and plasmids.
27. Mutational and recombinative variability in prokaryotes.
28. Transformation, conjugation and transduction as sources of hereditary variability.
29. Practical use of genetic engineering in microbiology.
30. Methods of nutrition and intake of nutrients into the cell.
31. Chemical composition and nutritional needs of microorganisms.
32. The main types of nutrition of microorganisms in relation to energy sources, hydrogen donor, carbon source.
33. Sources of nitrogen and vitamins in microorganisms. Assimilation of ash elements.
34. Nutrient media for growing microorganisms. Classification by consistency, by purpose, by origin.
35. The concept of metabolism: anabolism and catabolism.
36. The main ways of obtaining energy by microorganisms: aerobic respiration, incomplete oxidation, anaerobic respiration, fermentation.
37. Influence on microorganisms of humidity and concentration of solutions. Osmophilic and halophilic organisms.
38. The ratio of microorganisms to temperature. Thermal sterilization methods.
39. Impact on organisms of light, radiation, pressure, ultrasound, electricity, mechanical shocks.
40. The ratio of microorganisms to oxygen.
41. The influence of the acidity of the environment on the development of microbes.
42. The action of chemically toxic substances on microorganisms. Disinfection and antiseptics.
44. Antibiotics of microbial and animal origin, phytoncides.
45. Theoretical foundations of methods of storage, processing and conservation of food products.
46. Carbon cycle in nature and the role of microorganisms.
47. Alcoholic and glycerin fermentation. Pathogens, conditions, chemistry and meaning.
48. Lactic acid fermentation: homofermentative and heterofermentative.
49. Pathogens, conditions, chemistry and significance.
50. Propionic acid fermentation. Pathogens, conditions, chemistry and meaning.
51. Butyric and acetone-butyl fermentation. Pathogens, conditions, chemistry and meaning.
52. Decomposition of pectin substances. Pathogens, conditions, chemistry and meaning. Rosy lobe of flax.
53. Decomposition of starch. Pathogens, conditions, chemistry and meaning.
54. Obtaining acetic and citric acids. Pathogens, conditions, chemistry and meaning.
55. Oxidation of fats by microorganisms. Pathogens, conditions, chemistry and meaning.
56. General scheme of the nitrogen cycle in nature.
57. Ammonification of proteins. Pathogens, conditions, chemistry and meaning.
58. Immobilization of nitrogen in the soil. The influence of this process on the nitrogen nutrition of plants.
59. Nitrification. Pathogens, conditions, chemistry and meaning.
60. Denitrification: direct and indirect. Pathogens, conditions, chemistry and meaning.
61. Biological fixation of molecular nitrogen. Its essence and chemistry.
62. Free-living nitrogen-fixing microorganisms: Clostridiumpasteurianum,Azotobacter,Beijerinskia ,Derxia,Azomonas, cyanobacteria.
63. Symbiotic nitrogen fixation in legumes and non-legumes. Characteristics of the genus Rhizobium and Frankia. Optimal conditions for nitrogen fixation. bacterial preparations.
64. Associative nitrogen fixation in the rhizosphere and phyllosphere. Characteristic azospirillum,pseudomonas,Klebsiella,Flavobacterium and their use.
65. Cycle of sulfur in nature: mineralization, sulfification and desulfurization. Pathogens, conditions, chemistry and meaning.
66. Cycle of phosphorus in nature. Mineralization of organic phosphorus and mobilization of phosphates.
67. The cycle of iron in nature. Pathogens, conditions, chemistry and meaning.
68. Soil as a habitat for microorganisms.
69. Participation of microorganisms in the soil-forming process.
70. Methods for determining the composition and activity of soil microorganisms. The method of breeding and sowing on dense nutrient media, the method of direct counting.
71. Microflora of various types of soils. Microorganisms-indicators.
72. Influence of tillage, fertilizers and pesticides on the activity and species composition of soil microflora.
73. The use of microbial preparations in the control of pests and diseases of agricultural crops.
74. Microflora of rhizoplane and rhizosphere. Mycorrhiza. role in plant life.
75. Microflora of the phyllosphere, its composition and role in plant life. Grain microflora and its changes under different storage conditions.
76. Microbiological processes during hay drying and silage.
77. Feed ensiling. Vigorous plants. Silo quality indicators.
78. Spread of microorganisms in water. Water treatment methods and the use of microorganisms.
79. Quantitative and qualitative composition of air microflora.
80. Spread of infectious diseases through water and air.
81. Application of bioconversion methods in agriculture.
Compiled by:
Associate Professor of the Department, Ph.D.S. Freezing