Microorganisms are widely used in the food industry, households, and the microbiological industry to produce amino acids, enzymes, organic acids, vitamins, etc. Classic microbiological production includes winemaking, brewing, making bread, lactic acid products and food vinegar. For example, winemaking, brewing and the production of yeast dough are impossible without the use of yeast, which is widespread in nature.

The history of industrial production of yeast began in Holland, where the first factory producing yeast was founded in 1870. The main type of product was compressed yeast with a moisture content of about 70%, which could be stored for only a few weeks. Long-term storage was impossible, since the pressed yeast cells remained alive and retained their activity, which led to their autolysis and death. One of the methods for industrially preserving yeast is drying. In dry yeast, at low humidity, the yeast cell is in an anabiotic state and can persist for a long time. The first dry yeast appeared in 1945. In 1972, the second generation of dry yeast, the so-called instant yeast, appeared. Since the mid-1990s, a third generation of dry yeast has emerged: baker's yeast Saccharomyces cerevisiae, which combine the benefits of instant yeast with a highly concentrated complex of specialized baking enzymes in one product. This yeast not only improves the quality of bread, but also actively resists the process of staling.

Baker's yeast Saccharomyces cerevisiae are also used in the production of ethyl alcohol.

Winemaking uses many different races of yeast to produce a unique brand of wine with unique qualities.

Lactic acid bacteria are involved in the preparation of foods such as sauerkraut, pickles, pickled olives and many other pickled foods.

Lactic acid bacteria convert sugar into lactic acid, which protects food products from putrefactive bacteria.

With the help of lactic acid bacteria, a wide range of lactic acid products, cottage cheese, and cheese are prepared.

However, many microorganisms play a negative role in human life, being pathogens of diseases in humans, animals and plants; they can cause food spoilage, destruction of various materials, etc.

To combat such microorganisms, antibiotics were discovered - penicillin, streptomycin, gramicidin, etc., which are metabolic products of fungi, bacteria and actinomycetes.

Microorganisms provide humans with the necessary enzymes. Thus, amylase is used in the food, textile, and paper industries. Protease causes the breakdown of proteins in various materials. In the East, protease from mushrooms was used several centuries ago to make soy sauce. Currently, it is used in the production of detergents. When canning fruit juices, an enzyme such as pectinase is used.

Microorganisms are used for wastewater treatment and food processing waste. The anaerobic decomposition of organic matter in waste produces biogas.

In recent years, new production facilities have appeared. Carotenoids and steroids are obtained from mushrooms.

Bacteria synthesize many amino acids, nucleotides and other reagents for biochemical research.

Microbiology is a rapidly developing science, the achievements of which are largely related to the development of physics, chemistry, biochemistry, molecular biology, etc.

To successfully study microbiology, knowledge of the listed sciences is required.

This course focuses primarily on food microbiology. Many microorganisms live on the surface of the body, in the intestines of humans and animals, on plants, on food products and on all objects around us. Microorganisms consume a wide variety of foods and adapt extremely easily to changing living conditions: heat, cold, lack of moisture, etc. They multiply very quickly. Without knowledge of microbiology, it is impossible to competently and effectively manage biotechnological processes, maintain high quality food products at all stages of its production and prevent the consumption of products containing pathogens of foodborne illnesses and poisoning.

It should be especially emphasized that microbiological studies of food products, not only from the point of view of technological features, but also, no less important, from the point of view of their sanitary and microbiological safety, are the most complex object of sanitary microbiology. This is explained not only by the diversity and abundance of microflora in food products, but also by the use of microorganisms in the production of many of them.

In this regard, in microbiological analysis of food quality and safety, two groups of microorganisms should be distinguished:

– specific microflora;

– nonspecific microflora.

Specific– these are cultural races of microorganisms that are used to prepare a particular product and are an essential link in the technology of its production.

This microflora is used in the technology of producing wine, beer, bread, and all fermented milk products.

Nonspecific are microorganisms that enter food products from the environment, contaminating them. Among this group of microorganisms, saprophytic, pathogenic and opportunistic microorganisms are distinguished, as well as microorganisms that cause food spoilage.

The degree of contamination depends on many factors, which include the correct procurement of raw materials, their storage and processing, compliance with technological and sanitary regimes for the production of products, their storage and transportation.

Microorganisms and their metabolic products are currently widely used in industry, agriculture, and medicine.

History of the use of microorganisms

As early as 1000 BC, the Romans, Phoenicians and other early civilizations extracted copper from mine waters or waters that seeped through ore bodies. In the 17th century Welsh in England (County Wales) and in the 18th century. The Spaniards at the Rio Tinto mine used this "leaching" process to extract copper from the minerals containing it. These ancient miners had no idea that bacteria played an active role in such metal extraction processes. This process, known as bacterial leaching, is now used on a large scale throughout the world to extract copper from low-grade ores containing trace amounts of this and other valuable metals. Bioleaching is also used (though less widely) to release uranium. Numerous studies have been carried out on the nature of the organisms involved in metal leaching processes, their biochemical properties and potential applications in this area. The results of these studies show, in particular, that bacterial leaching can be widely used in the mining industry and, in all likelihood, can fully meet the need for energy-saving, environmentally friendly technologies.

Somewhat less known, but equally important, is the use of microorganisms in the mining industry to extract metals from solutions. Some advanced technologies already include biological processes to obtain metals in dissolved or particulate form from wash waters remaining from ore processing. The ability of microorganisms to accumulate metals has long been known, and enthusiasts have long dreamed of using microbes to extract valuable metals from seawater. The studies carried out dispelled some hopes and largely determined the areas of application of microorganisms. Metal-assisted recovery remains a promising method for low-cost treatment of metal-contaminated industrial wastewater and economical recovery of valuable metals.

It has long been known about the ability of microorganisms to synthesize polymer compounds; in fact, most cell components are polymers. However, today less than 1% of the total amount of polymer materials is produced by the microbiological industry; the remaining 99% comes from petroleum. So far, biotechnology has not had a decisive influence on polymer technology. Perhaps in the future, with the help of microorganisms, it will be possible to create new materials for special purposes.

Another important aspect of the use of microorganisms in chemical analysis should be noted - the concentration and isolation of trace elements from dilute solutions. By consuming and assimilating microelements in the process of life, microorganisms can selectively accumulate some of them in their cells, while purifying nutrient solutions from impurities. For example, molds are used for selective precipitation of gold from chloride solutions.

Modern Applications

Microbial biomass is used as livestock feed. The microbial biomass of some crops is used in the form of various starter cultures that are used in the food industry. So the preparation of bread, beer, wine, alcohol, vinegar, fermented milk products, cheeses and many products. Another important area is the use of waste products of microorganisms. Based on the nature of these substances and their importance for the producer, waste products can be divided into three groups.

1 group- These are large molecules with molecular weight. This includes a variety of enzymes (lipases, etc.) and polysaccharides. Their use is extremely wide - from the food and textile industries to the oil industry.

2nd group- these are primary methanobolites, which include substances necessary for the growth and development of the cell itself: amino acids, organic acids, vitamins and others.

3 group- secondary methanobolites. These include: antibiotics, toxins, alkaloids, growth factors, etc. An important area of ​​biotechnology is the use of microorganisms as biotechnical agents for the transformation or transformation of certain substances, purification of water, soil or air from pollutants. Microorganisms also play an important role in oil production. Using the traditional method, no more than 50% of the oil is extracted from an oil reservoir. The waste products of bacteria, accumulating in the formation, contribute to the displacement of oil and its more complete release to the surface.

The huge role of microorganisms in creating, maintaining and preserving soil fertility. They take part in the formation of soil humus - humus. Used to increase crop yields.

In recent years, another fundamentally new direction of biotechnology has begun to develop - cell-free biotechnology.

Selection of microorganisms is based on the fact that microorganisms bring enormous benefits in industry, agriculture, animal and plant life.

Other Applications

In medicine

Traditional methods of vaccine production are based on the use of weakened or killed pathogens. Currently, many new vaccines (for example, for the prevention of influenza, hepatitis B) are obtained using genetic engineering methods. Antiviral vaccines are obtained by introducing into the microbial cell the genes of viral proteins that exhibit the greatest immunogenicity. When cultivated, such cells synthesize a large amount of viral proteins, which are subsequently included in vaccine preparations. The production of viral proteins in animal cell cultures based on recombinant DNA technology is more efficient.

In oil production:

In recent years, methods for increasing oil recovery using microorganisms have been developed. Their prospects are associated, first of all, with ease of implementation, minimal capital intensity and environmental safety. In the 1940s, many oil-producing countries began research on the use of microorganisms to stimulate flow in production wells and restore the injectivity of injection wells.

In food and chemical industry:

The most well-known industrial products of microbial synthesis include: acetone, alcohols (ethanol, butanol, isopropanol, glycerol), organic acids (citric, acetic, lactic, gluconic, itaconic, propionic), flavorings and substances that enhance odors (monosodium glutamate). The demand for the latter is constantly increasing due to the tendency to consume low-calorie and plant-based foods to add variety to the taste and smell of food. Plant-derived aromatic substances can be produced by expressing plant genes in microbial cells.



Due to the wide variety of enzymes they synthesize, microorganisms can perform many chemical processes more efficiently and economically than if these processes were carried out by chemical methods. The study of the biochemical activity of microorganisms made it possible to select conditions for their maximum activity as producers of various useful enzymes - causative agents of the necessary chemical reactions and processes. Microorganisms are increasingly used in various branches of the chemical and food industries, agriculture, and medicine.

In our country, a new industry has been created and is successfully developing - microbiological, all production of which is based on the activity of microorganisms.

Microorganisms with the help of which food products are produced are called cultural. They are obtained from pure cultures that are isolated from individual cells. The latter are stored in museum collections and supplied to various industries.

As a result of chemical reactions carried out by cultural microorganisms, plant or animal raw materials are transformed into food products. Many vital food products are obtained with the help of microorganisms, and although their production has been familiar to man since ancient times, the role of microorganisms in it has been discovered relatively recently.

Bakery production.

Bread baking is based on the activity of yeast and lactic acid bacteria developing in the dough. The combined action of these microorganisms leads to the fermentation of flour sugars. Yeast causes alcoholic fermentation, and lactic acid bacteria cause lactic acid fermentation. The resulting lactic and other acids acidify the dough, maintaining an optimal pH level for yeast activity. Carbon dioxide loosens the dough and accelerates its ripening.

The use of cultural microorganisms in the form of pressed baker's yeast, dried or liquid starters improves the taste and aroma of bread.

Cheese production.

Cheese making is based on the activity of many types of microorganisms: lactic acid bacteria (thermophilic streptococcus), propionic acid bacteria, etc. Under the influence of lactic acid bacteria, lactic acid accumulates and milk is fermented; under the influence of other beneficial microorganisms, cheese ripens. Some molds are also involved in this process. Rennet and lactic acid bacteria produce deep breakdown of proteins, sugar and fat. Various bacteria cause the accumulation of volatile acids in sharp cheeses, giving them a specific aroma.

Production of fermented milk products.

Cottage cheese, sour cream, butter, acidophilus, and yogurt are prepared using pure cultures using various starter cultures. The milk is pre-pasteurized. Mesophilic lactic acid bacteria are used to produce cottage cheese and sour cream; fermented baked milk, Varenets and similar products - thermophilic streptococci and Bulgarian bacillus; acidophilus - acid-tolerant lactic acid bacteria; kefir - multicomponent starter cultures consisting of yeast, lactic acid and often acetic acid bacteria. To make cultured butter, a starter of lactic acid bacteria is introduced into pasteurized cream and kept until the required acidity.

Brewing, alcohol, distillery and wine production.

Wine, beer, kvass, vodka and other drinks are prepared using yeast, which causes alcoholic fermentation of sugar-containing liquids. As a result of fermentation of liquid (wort, mash, juice, etc.), alcohol, CO 2 and small amounts of by-products are formed. Lactic acid bacteria play a supporting role: they acidify the environment and facilitate the activity of yeast (for example, in the production of kvass). In the production of alcohol and beer, enzyme preparations of fungal and bacterial origin are also used to saccharify mashes.

Pickling and salting.

The essence of this method of preservation is to create conditions for the preferential development of some microorganisms - lactic acid bacteria - and suppress the development of others - putrefactive bacteria. Cabbage, cucumbers, tomatoes, apples, and watermelons are fermented. This method is also used when storing livestock feed for long-term storage - green mass from herbs, plant residues, etc. is fermented. This process is called feed ensiling.

Preparation of organic acids.

Acetic, lactic and citric acids are also produced with the help of microorganisms. Lactic acid is produced by fermentation from sugar-containing raw materials - molasses, starch, whey, etc.

Lactic acid bacteria are grown on media containing up to 15% sugar. The yield of lactic acid reaches 60-70% of the mass of sugar contained in the mash.

The industrial production of vinegar for food purposes is based on acetic acid fermentation. Acetic acid bacteria in special vats on beech shavings oxidize the incoming nutrient medium - acetic-alcohol solution - to acetic acid.

Citric acid was previously obtained from citrus fruits. Currently, it is also obtained by fermentation. The causative agent of fermentation is the fungus Aspergillus niger, the main raw material is black molasses. Fermentation occurs in a solution containing 15% sugar under aerobic conditions at a temperature of about 30 °C. Citric acid is used in the confectionery industry, production of soft drinks, syrups, cooking and medicine.

Modern biotechnology is based on the achievements of natural science, engineering, technology, biochemistry, microbiology, molecular biology, and genetics. Biological methods are used to combat environmental pollution and pests of plant and animal organisms. The achievements of biotechnology also include the use of immobilized enzymes, the production of synthetic vaccines, and the use of cell technology in breeding.

Hybridomas and the monoclonal antibodies they produce are widely used as diagnostic and therapeutic drugs.

Bacteria, fungi, algae, lichens, viruses, and protozoa play a significant role in human life. Since ancient times, people have used them in the processes of baking bread, making wine and beer, and in various industries. Currently, due to the problems of obtaining valuable protein substances, increasing soil fertility, cleaning the environment from pollutants, obtaining biological products and other goals and objectives, the range of study and use of microorganisms has expanded significantly. Microorganisms help humans in the production of effective protein nutrients and biogas. They are used when applying biotechnical methods of air and wastewater purification, when using biological methods for exterminating agricultural pests, when obtaining medicinal drugs, and when destroying waste materials.

Some types of bacteria are used to regenerate valuable metabolites and drugs; they are used to solve problems of biological self-regulation and biosynthesis, and purify water bodies.

Microorganisms, and above all bacteria, are a classic object for solving general problems of genetics, biochemistry, biophysics, and space biology. Bacteria are widely used to solve many problems in biotechnology.

Microbiological reactions, due to their high specificity, are widely used in the processes of chemical transformations of biologically active natural compounds. There are about 20 types of chemical reactions that are carried out by microorganisms. Many of them (hydrolysis, reduction, oxidation, synthesis, etc.) are successfully used in pharmaceutical chemistry. When performing these reactions, different types of bacteria, actinomycetes, yeast-like fungi and other microorganisms are used.

A biotechnological industry has been created to produce antibiotics, enzymes, interferon, organic acids and other metabolites, the producers of which are many microorganisms.

Some fungi of the genera Aspergillus and Fusarium (A.flavus, A.ustus, A.oryzae, F.sporotrichiella) are capable of hydrolyzing cardiac glucosides, xylosides and rhamnosides, as well as glycosides containing glucose, galactose or arabinose as final sugars. Nicotinic acid is obtained using A.terreus.

In pharmacy, microbiological transformations are used to obtain physiologically more active substances or semi-finished products, the synthesis of which by purely chemical means is achieved with great difficulty or is not possible at all.

Microbiological reactions are used to study the metabolism of drugs, their mechanism of action, as well as to determine the nature and action of enzymes.

Many protozoa are producers of biologically active substances. In particular, protozoa living in the rumen of ruminants produce the enzyme cellulase, which promotes the decomposition of fiber (cellulose).

Protozoa are producers not only of enzymes, but also of histones, serotonin, lipopolysaccharides, lipopolypeptidoglucans, amino acids, and metabolites used in medicine and veterinary medicine, food and textile industries. They are one of the objects used in biotechnology.

The causative agent of South American trypanosomiasis, Trypanosoma cruzi, is a producer of the antitumor drug crucin and its analogue, trypanose. These drugs have a cytotoxic effect on malignant cells.

Trypanosoma lewisi, Crithidia oncopelti and Astasia longa are also producers of anti-blastoma inhibitors.

The drug astaliside, produced by Astasia longa, has not only an antiblastoma effect, but also an antibacterial effect (against E. coli and Pseudomonas aeruginosa), as well as an antiprotozoal effect (against Leischmania).

Protozoa are used to produce polyunsaturated fatty acids, polysaccharides, histones, serotonin, enzymes, glucans for use in medicine, as well as in the food and textile industries.

Herpetomonas sp. And Crithidia fasciculate produce polysaccharides that protect animals from Trpanosoma cruzi.

Since protozoan biomass contains up to 50% protein, free-living protozoa are used as a source of feed protein for animals.

Aspergillus oryzae enzyme preparations are used in the brewing industry, and A. niger enzymes are used in the production and clarification of fruit juices and citric acid. Baking of baked goods is improved with the use of A.oryzae and A.awamori enzymes. In the production of citric acid, vinegar, feed and bakery products, production indicators are improved when Aspergillus niger and actinomycetes are used in the technological process. The use of purified pectinase preparations from A. niger mycelium when obtaining juices helps to increase their yield, reduce viscosity and increase clarification.

Bacterial enzymes (Bac.subtilis) are used to preserve the freshness of confectionery products and where deep decomposition of protein substances is undesirable. The use of enzyme preparations from Bac.subtilis in confectionery and bakery production helps improve the quality and slow down the process of russeting of products. Enzymes

Bac.mesentericus activate depelling of leather raw materials.

Microorganisms are widely used in the food and fermentation industries.

Milk yeast is widely used in the dairy industry. With their help, kumys and kefir are prepared. The enzymes of these microorganisms decompose milk sugar into alcohol and carbon dioxide, as a result of which the taste of the product improves and its digestibility by the body increases. When producing lactic acid products in the dairy industry, yeast is widely used, which does not ferment milk sugar and does not decompose proteins and fat. They help preserve oil and increase the viability of lactic acid bacteria. Filmy yeast (mycoderma) promotes the ripening of lactic acid cheeses.

Penicillum roqueforti mushrooms are used in the production of Roquefort cheese, and Penicillum camemberi mushrooms are used in the ripening process of snack cheese.

In the textile industry, pectin fermentation is widely used, provided by the enzymatic activity of Granulobacter pectinovorum, Pectinobacter amylovorum. Pectic fermentation underlies the initial processing of fibrous flax, hemp and other plants used to make yarn and fabrics.

Almost all natural compounds are decomposed by bacteria due to their biochemical activity, not only in oxidative reactions involving oxygen, but also anaerobically with such electron acceptors as nitrate, sulfate, sulfur, carbon dioxide. Bacteria participate in the cycles of all biologically important elements and ensure the circulation of substances in the biosphere. Many key reactions in the cycling of substances (for example, nitrification, denitrification, nitrogen fixation, oxidation and reduction of sulfur) are carried out by bacteria. The role of bacteria in destruction processes is decisive.

Many types and varieties of yeast have the ability to ferment various carbohydrates to form alcohol and other products. They are widely used in the brewing, wine-making and bakery industries. Typical representatives of such yeasts are Saccharomyces cerevisial, S.ellipsoides.

Many microorganisms, including yeast-like and some types of microscopic fungi, have long been used in the transformation of various substrates to produce various types of food products. For example, the use of yeast to produce porous bread from flour, the use of fungi of the genera Rhisopus, Aspergillus for the fermentation of rice and soybeans, the production of lactic acid products using lactic acid bacteria, yeast, etc.

Auxotrophic mutants of Candida guillermondii are used to study flavinogenesis. Hyphal fungi absorb carbons from oil, paraffin, n-hecasdecane, and diesel fuel well.

For varying degrees of purification of these substances, species of the genera Mucorales, Penicillium, Fusarium, and Trichoderma are used.

Penicillium strains are used to utilize fatty acids, and fatty secondary alcohols are better processed in the presence of Penicillium and Trichoderma strains.

Species of fungi Aspergillus, Absidia, Cunningham, Ella, Fusarium, Mortierella, Micor, Penicillium, Trichoderma, Periconia, Spicaria are used in the disposal of paraffins, paraffin oil, diesel fuel, aromatic hydrocarbons, polyhydric alcohols, fatty acids.

Penicillium vitale is used to obtain a purified glucose oxidase preparation that inhibits the development of pathogenic dermatomycetes Microsporum lanosum, Achorion gypseum, Trichophyton gypseum, Epidermophyton kaufman.

The industrial use of microorganisms to obtain new food products contributed to the creation of such types of industries as baking and dairy, the production of antibiotics, vitamins, amino acids, alcohols, organic acids, etc.

The use of true lactic acid bacteria (Bact.bulgaricum, Bact.casei, Streptococcus lactis, etc.) or their combinations with yeast in the food industry makes it possible to obtain not only lactic acid, but also lactic acid and sour vegetable products. These include yogurt, matsoni, fermented baked milk, sour cream, cottage cheese, sauerkraut, pickled cucumbers and tomatoes, cheeses, kefir, sour bread dough, bread kvass, koumiss and other products. For the preparation of yogurt and cottage cheese, Str.lactis, Str.diacetilactis, Str.paracitrovorus, Bact.acidophilum are used.

When preparing the oil, flavoring bacteria and lactic acid streptococci Str.lactis, Str.cremoris, Str.diacetilactis, Str.citrovorus, Str.paracitrovorus are used.

False lactic acid bacteria (E. coli commune, Bact. Lactis aerogenes, etc.) are involved in the silage processes of green fodder.

Among the metabolites of a microbial cell, a special place is occupied by substances of a nucleotide nature, which are intermediate products in the process of biological oxidation. These substances are very important raw materials for the synthesis of nucleic acid derivatives, valuable antimicrobial and anti-blastoma drugs and other biologically active substances for the microbiological industry and agriculture.

Microbiological synthesis basically represents reactions occurring in living cells. To carry out such synthesis, bacteria are used that are capable of phosphorylating purine and pyrimidine bases, their nucleosides or synthetic analogues of low molecular weight components of nucleic acids.

E.coli, S.typhimurium, Brevibacterium liguefaciens, B.ammonia genes, Mycobacterium sp., Corynebacterium flavum, Murisepticum sp., Arthrobacter sp. have such abilities.

Microorganisms can also be used in the extraction of coal from ores. Lithotrophic bacteria (Thiobacillus ferrooxidous) oxidize ferrous sulfate to ferrous sulfate. Iron sulfate, in turn, oxidizes tetravalent uranium, as a result of which uranium precipitates into solution in the form of sulfate complexes. Uranium is extracted from solution using hydrometallurgy.

In addition to uranium, other metals, including gold, can also be leached from solutions. Bacterial leaching of metals due to the oxidation of sulfides contained in the ore allows the extraction of metals from poor balanced ores.

A very profitable and energy-efficient way to convert organic matter into fuel is methanogenesis with the participation of a multicomponent microbial system. Methane-forming bacteria, together with acetonogenic microflora, transform organic substances into a mixture of methane and carbon dioxide.

Microorganisms can be used not only to produce gaseous fuel, but also to increase oil production.

Microorganisms can form surface-active substances that reduce surface tension at the interface between oil and the water displacing it. The displacing properties of water increase with increasing viscosity, which is achieved by using bacterial mucus consisting of polysaccharides.

With existing methods of developing oil fields, no more than half of the geological reserves of oil are recovered. With the help of microorganisms, it is possible to wash oil out of formations and release it from bituminous shale.

Methane-oxidizing bacteria placed in the oil layer decompose the oil and contribute to the formation of gases (methane, hydrogen, nitrogen) and carbon dioxide. As gases accumulate, their pressure on the oil increases and, in addition, the oil becomes less viscous. As a result, oil from the well begins to gush out like a fountain.

It must be remembered that the use of microorganisms in any conditions, including geological ones, requires the creation of favorable conditions for a complex microbial system.

The use of the microbiological method to increase oil production largely depends on the geological situation. The development of sulfate-reducing bacteria in the formation can lead to excessive formation of hydrogen sulfide and corrosion of equipment, and instead of increasing porosity, bacteria and their mucus may seal the pores.

Bacteria contribute to the leaching of metals from old mines from which ore is selected and from waste dumps. In industry, microbiological leaching processes are used to obtain copper, zinc, nickel, and cobalt.

In the mining area, due to the oxidation of sulfur compounds in mines by microorganisms, acidic mine waters are formed and accumulated. Sulfuric acid has a destructive effect on materials, structures, the environment, and carries metals with it. You can purify water, remove sulfates and metals, and make the reaction alkaline using sulfate-reducing bacteria.

Biogenic formation of hydrogen sulfide can be used to purify water from metallurgical production. Anaerobic photosynthetic bacteria cause deep decomposition of organic matter.

Strains of bacteria have been found that can recycle plastic products.

The introduction of excess anthropogenic substances leads to a disruption of the established natural balance.

In the early stages of industry development, it was sufficient to disperse pollutants into watercourses, from which they were removed through natural self-purification. Gaseous substances were dispersed into the air through tall pipes.

Currently, waste disposal has grown into a very serious problem.

In purification systems, when purifying water from organic substances, a biological method is used using a system of mixed microflora (aerobic bacteria, algae, protozoa, bacteriophages, fungi), activated sludge, biofilm, and oxidizing incoming substances.

Representatives of the microbial mixture contribute to the intensification of natural water purification processes. But it should be remembered that the condition for the sustainable operation of the microbial community is the constancy of the composition of the environment

Bacteria, phyto- and zooplankton are used to treat wastewater to maintain the quality of surface and groundwater. Biological treatment of wastewater can be carried out at different levels - before discharging it into a reservoir, in the surface water itself, in groundwater during self-purification processes.

Microorganisms are widely used in biological purification of sea waters from oil products.

The process must be ensured by the supply of oxygen in sufficient quantities at a constant temperature.

One of the tasks of biotechnology is the development of technology for obtaining protein using microorganisms from various types of plant substrates, from methane and purified hydrogen, from a mixture of hydrogen and carbon monoxide, from heavy petroleum hydrocarbons using methylotrophic yeasts or bacteria, Candida tropicalis, methane-oxidizing and cellulose-degrading bacteria and other microbes.

The use of active strains of microscopic fungal species contributes to the enrichment of proteins and amino acids in feed such as feed, pulp, and bran. For this purpose, selected non-toxic fast-growing species of thermo- and mesophilic micromycetes Fusarium sp., Thirlavia sp., as well as some types of higher fungi, are used.

Another example of the industrial use of fungi in biotechnology is the cultivation of entomopathogenic fungal species, in particular Beanvtria bassiana and Entomophthora thaxteriana for the preparation of the preparations “boverina” and “afedina”, used to combat phytopathogenic aphids.

Selected strains of the natural hypersynthetic carotene fungus Blakeslee trispora are used in the industrial production of carotene, which is important in the processes of growth and development of animals, increasing their resistance to diseases.

Selected strains of Trichoderma viride are used in the industrial production of hectares based on the drug trichodermin to combat phytopathogenic fungi, especially when growing plants in greenhouse conditions (fusarium of cucumbers, diseases of flower plants).

Phosphobacterin, obtained from Baccilus megathrtium, is an effective means of increasing the yield of fodder beets, cabbage, potatoes, and corn. Under the influence of this drug, the content of soluble phosphorus in the rhizosphere soil, as well as phosphorus and nitrogen in the green mass, increases.

The most important condition for high productivity of leguminous plants is the improvement of the synthesis of nitrogen substances by leguminous plants at the expense of air nitrogen. Nodule microbes from the genera Rhizobium, Eubacteriales, Actinomycetales, Mycobacteriales, Azotobacter chroococcum, Clostridium pasterianum species play a major role in the absorption of atmospheric nitrogen by plants.

Nitrogen-fixing preparations have been obtained from the cells of Clostridium pasterianum, Rhodospirillum rubrum, Bac.polymixa, bacteria of the genera Chromatium and Klebsiella, which promote the absorption of air nitrogen by plants.

In agriculture, in order to increase productivity, bacterial fertilizers such as azotobacterin (prepared from Azotobacter), nitragin (from nodule bacteria), phosphobacterin (from Bac. Megatherium) are used.

Agriculture uses fertilizers and pesticides. Once in natural conditions, these substances have a negative impact on natural relationships in biocenoses, and ultimately, along the feed chain, these substances have a negative impact on human health. Aerobic and anaerobic microorganisms play a positive role in the destruction of these substances in water.

In agriculture, biological protection of plants from pests is used. For this purpose, various organisms are used - bacteria, fungi, viruses, protozoa, birds, mammals and other organisms.

The idea of ​​a microbiological method of combating harmful insects was first put forward by Mechnikov in 1879.

Nowadays, microbiological preparations are produced that destroy many harmful insects.

With the help of enterobacterin, you can fight almost all butterfly caterpillars. Among the pests of fruit and berry plants are apple moth, hawthorn, lacewing, ringed silkworm, leaf rollers, etc.

The viral drug Virin is very effective against caterpillars that damage forest trees.

Soil microorganisms are one of the largest ecological groups. They play an important role in the mineralization of organic matter and the formation of humus. In agriculture, soil microorganisms are used to produce fertilizers.

Some types of soil microorganisms - bacteria, fungi (mainly ascomycetes), protozoa enter into complex associations (associations) with algae, which are components of the biocenoses of both water and soil.

Algae, as active components of soil microflora, play an important role in the biological cycle of ash elements.

Algae, along with other microorganisms, are used in biotechnology.

Microbiological processes are widely used in various sectors of the national economy. Many processes are based on metabolic reactions that occur during the growth and reproduction of certain microorganisms.

With the help of microorganisms, feed proteins, enzymes, vitamins, amino acids, organic acids, etc. are produced.

Main groups of microorganisms used in the food industry

The main groups of microorganisms used in the food industry are bacteria, yeast and molds.

Bacteria. They are used as activators of lactic acid, acetic acid, butyric acid, and acetone-butyl fermentation.

Cultured lactic acid bacteria are used in the production of lactic acid, in baking, and sometimes in alcohol production. They convert sugar into lactic acid according to the equation

C 6 H 12 O 6 ® 2CH 3 – CH – COOH + 75 kJ

True (homofermentative) and non-true (heterofermentative) lactic acid bacteria are involved in the production of rye bread. Homofermentatives are involved only in acid formation, while heterofermentatives, along with lactic acid, form volatile acids (mainly acetic acid), alcohol and carbon dioxide.

In the alcohol industry, lactic acid fermentation is used to acidify yeast wort. Wild lactic acid bacteria adversely affect the technological processes of fermentation production and deteriorate the quality of the finished product. The resulting lactic acid inhibits the vital activity of foreign microorganisms.

Butyric acid fermentation, caused by butyric acid bacteria, is used to produce butyric acid, the esters of which are used as aromatic substances.

Butyric acid bacteria convert sugar into butyric acid according to the equation

C 6 H 12 O 6 ® CH 3 CH 2 CH 2 COOH + 2CO 2 + H 2 + Q

Acetic acid bacteria are used to produce vinegar (acetic acid solution), because they are capable of oxidizing ethyl alcohol into acetic acid according to the equation

C 2 H 5 OH + O 2 ® CH 3 COOH + H 2 O +487 kJ

Acetic acid fermentation is harmful for alcohol production, because leads to a decrease in alcohol yield, and in brewing causes spoilage of beer.

Yeast. They are used as fermentation agents in the production of alcohol and beer, in winemaking, in the production of bread kvass, and in bakery.

For food production, yeasts are important - Saccharomyces, which form spores, and imperfect yeast - non-Saccharomycetes (yeast-like fungi), which do not form spores. The Saccharomyces family is divided into several genera. The most important genus is Saccharomyces (saccharomycetes). The genus is divided into species, and individual varieties of the species are called races. Each industry uses separate races of yeast. There are dusted and flocculated yeasts. In dust-like cells, the cells are isolated from each other, while in flocculent cells, they stick together, forming flakes, and quickly settle.

Cultivated yeast belongs to the Saccharomyces family S. cerevisiae. The optimum temperature for yeast reproduction is 25-30 0 C, and the minimum temperature is about 2-3 0 C. At 40 0 ​​C, growth stops, the yeast dies off, and at low temperatures, reproduction stops.

There are top-fermenting and bottom-fermenting yeasts.

Of the cultivated yeasts, bottom-fermenting yeasts include most wine and beer yeasts, and top-fermenting yeasts include alcohol, bakery and some races of brewer's yeasts.

As is known, in the process of alcoholic fermentation, two main products are formed from glucose - ethanol and carbon dioxide, as well as intermediate secondary products: glycerin, succinic, acetic and pyruvic acids, acetaldehyde, 2,3-butylene glycol, acetoin, ethers and fusel oils (isoamyl , isopropyl, butyl and other alcohols).

Fermentation of individual sugars occurs in a certain sequence, determined by the rate of their diffusion into the yeast cell. Glucose and fructose are fermented most quickly by yeast. Sucrose, as such, disappears (inverts) in the medium at the beginning of fermentation under the action of the yeast enzyme b - fructofuranosidase, with the formation of glucose and fructose, which are easily used by the cell. When there is no glucose and fructose left in the medium, the yeast consumes maltose.

Yeast has the ability to ferment very high concentrations of sugar - up to 60%; they also tolerate high concentrations of alcohol - up to 14-16 vol. %.

In the presence of oxygen, alcoholic fermentation stops and the yeast receives energy through oxygen respiration:

C 6 H 12 O 6 + 6O 2 ® 6CO 2 + 6H 2 O + 2824 kJ

Since the process is more energy rich than the fermentation process (118 kJ), the yeast spends sugar much more economically. The cessation of fermentation under the influence of atmospheric oxygen is called the Pasteur effect.

In alcohol production, the yeast species S. cerevisiae is used, which has the highest fermentation energy, produces maximum alcohol and ferments mono- and disaccharides, as well as some dextrins.

In baker's yeast, fast-growing races with good lifting power and storage stability are valued.

In brewing, bottom-fermenting yeast is used, adapted to relatively low temperatures. They must be microbiologically clean, have the ability to form flocs, and quickly settle to the bottom of the fermentation apparatus. Fermentation temperature 6-8 0 C.

In winemaking, yeast is valued because it multiplies quickly, has the ability to suppress other types of yeast and microorganisms and give the wine an appropriate bouquet. The yeast used in winemaking belongs to the species S. vini and vigorously ferments glucose, fructose, sucrose and maltose. In winemaking, almost all production yeast cultures are isolated from young wines in various areas.

Zygomycetes– molds, they play an important role as enzyme producers. Fungi of the genus Aspergillus produce amylolytic, pectolytic and other enzymes, which are used in the alcohol industry instead of malt for the saccharification of starch, in brewing when partially replacing malt with unmalted raw materials, etc.

In the production of citric acid, A. niger is the causative agent of citric acid fermentation, converting sugar into citric acid.

Microorganisms play a dual role in the food industry. On the one hand, these are cultural microorganisms, on the other hand, an infection enters food production, i.e. foreign (wild) microorganisms. Wild microorganisms are common in nature (on berries, fruits, air, water, soil) and enter production from the environment.

To maintain proper sanitary and hygienic conditions in food enterprises, an effective way to destroy and suppress the development of foreign microorganisms is disinfection.