The role of bacteria in human life. Beneficial bacteria

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.

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

bacteria. Used as causative agents of lactic acid, acetic acid, butyric, acetone-butyl fermentation.

Cultural 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

C6H12O6 ® 2CH3 – CH – COOH + 75 kJ

True (homofermentative) and non-true (heterofermentative) lactic acid bacteria are involved in the production of rye bread. Homofermentative ones are involved only in acid formation, while heterofermentative ones, along with lactic acid, form volatile acids (mainly acetic), 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 plants, worsen the quality of finished products. The resulting lactic acid inhibits the vital activity of extraneous microorganisms.

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

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

C6H12O6 ® CH3CH2CH2COOH + 2CO2 + H2 + Q

Acetic acid bacteria are used to produce vinegar (acetic acid solution), because. they are able to oxidize ethyl alcohol to acetic acid according to the equation

C2H5OH + O2 ® CH3COOH + H2O +487 kJ

Acetic acid fermentation is harmful to alcohol production, because. leads to a decrease in the yield of alcohol, and in brewing it 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, in baking.

For food production, yeast is important - saccharomycetes, 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 is the genus Saccharomyces (saccharomycetes). The genus is subdivided into species, and individual varieties of a species are called races. In each industry, separate races of yeast are used. Distinguish yeast pulverized and flaky. In dust-like cells, they are isolated from each other, while in flaky cells, they stick together, forming flakes, and quickly settle.

Cultural yeast belongs to the S. cerevisiae family of Saccharomycetes. The temperature optimum for yeast propagation is 25-30 0С, and the minimum temperature is about 2-3 0С. At 40 0C, growth stops, yeast dies, and at low temperatures, reproduction stops.

There are top and bottom fermenting yeasts.

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

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

Fermentation of individual sugars occurs in a certain sequence, due to the rate of their diffusion into the yeast cell. Glucose and fructose are the fastest fermented 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 obtains energy from oxygen respiration:

C6H12O6 + 6O2 ® 6CO2 + 6H2O + 2824 kJ

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

In alcohol production, top yeast of the species S. cerevisiae is used, which have the highest fermentation energy, form a maximum of alcohol and ferment mono- and disaccharides, as well as part of 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 flocculate, quickly settle to the bottom of the fermenter. Fermentation temperature 6-8 0С.

In winemaking, yeasts are valued, which multiply rapidly, have the ability to suppress other types of yeast and microorganisms and give the wine an appropriate bouquet. The yeasts used in winemaking are S. vini and ferment glucose, fructose, sucrose and maltose vigorously. In winemaking, almost all production yeast cultures are isolated from young wines in various areas.

Zygomycetes- mold fungi, 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 starch saccharification, in brewing when malt is partially replaced by unmalted raw materials, etc.

In the production of citric acid, A. niger is the causative agent of citrate 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 gets into food production, i.e. foreign (wild) microorganisms. Wild microorganisms are common in nature (on berries, fruits, in the air, water, soil) and from the environment get into production.

Disinfection is an effective way to destroy and suppress the development of foreign microorganisms in order to comply with the correct sanitary and hygienic regime at food enterprises.

Importance of bacteria in our life. The discovery of penicillin and the development of medicine. The results of the use of antibiotics in the plant and animal world. What are probiotics, the principle of their action on the body of people and animals, plants, the benefits of using.

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

The use of microorganisms in medicine, agriculture; benefits of probiotics

Rodnikova Inna

INTRODUCTION

People acted as biotechnologists for thousands of years: they baked bread, brewed beer, made cheese, and other lactic acid products using various microorganisms and were not even aware of their existence.

Actually, the term “biotechnology” itself appeared in our language not so long ago, instead of it the words “industrial microbiology”, “technical biochemistry”, etc. were used. Probably, fermentation was the oldest biotechnological process. This is evidenced by the description of the process of making beer, discovered in 1981.

during the excavations of Babylon on a tablet, which dates back to about the 6th millennium BC. e. In the 3rd millennium BC. e. the Sumerians produced up to two dozen types of beer. No less ancient biotechnological processes are winemaking, baking and obtaining lactic acid products.

From the foregoing, we see that for quite a long time, human life has been inextricably linked with living microorganisms. And if for so many years people have successfully, albeit unconsciously, “collaborated” with bacteria, it would be logical to ask the question - why, in fact, do you need to expand your knowledge in this area?

After all, everything seems to be fine anyway, we know how to bake bread and brew beer, make wine and kefir, what else do you need? Why do we need Biotechnology? Some answers can be found in this abstract.

MEDICINE AND BACTERIA

Throughout the history of mankind (until the beginning of the twentieth century), families have had many children because.

very often children did not live to adulthood, they died from many diseases, even from pneumonia, which is easily curable in our time, to say nothing of such serious diseases as cholera, gangrene, and plague. All these diseases are caused by pathogens and were considered incurable, but finally, medical scientists realized that other bacteria, or an extract from their enzymes, could overcome the "evil" bacteria.

This was first noticed by Alexander Fleming on the example of elementary mold.

It turned out that some types of bacteria get along well with mold, but streptococci and staphylococci did not develop in the presence of mold.

Numerous previous experiments with the reproduction of harmful bacteria have shown that some of them are capable of destroying others and do not allow their development in the general environment. This phenomenon was called "antibiosis" from the Greek "anti" - against and "bios" - life. Working on finding an effective antimicrobial agent, Fleming was well aware of this. He had no doubt that on the cup with the mysterious mold he had encountered the phenomenon of antibiosis. He began to carefully examine the mold.

After some time, he even managed to isolate an antimicrobial substance from the mold. Since the mold he was dealing with had the specific Latin name Penicilium notatum, he named the resulting substance penicillin.

Thus, in 1929, in the laboratory of the London hospital of St. Mary was born the well-known penicillin.

Preliminary tests of the substance on experimental animals showed that even when injected into the blood, it does not cause harm, and at the same time, in weak solutions, it perfectly suppresses streptococci and staphylococci.

The role of microorganisms in food production technology

Fleming's assistant, Dr. Stuart Greddock, who fell ill with purulent inflammation of the so-called maxillary cavity, was the first person who decided to take an extract of penicillin.

He was injected into the cavity with a small amount of extract from the mold, and after three hours it was possible to see that his state of health had improved significantly.

Thus, the era of antibiotics began, which saved millions of lives, both in peacetime and in times of war, when the wounded died not from the severity of the wound, but from the infections associated with them. In the future, new antibiotics were developed, based on penicillin, methods for their production for widespread use.

BIOTECHNOLOGY AND AGRICULTURE

The result of a breakthrough in medicine was a rapid demographic rise.

The population increased sharply, which means that more food was needed, and due to the deterioration of the environment due to nuclear tests, the development of industry, the depletion of the humus of cultivated land, many diseases of plants and livestock appeared.

At first, people treated animals and plants with antibiotics and this brought results.

Let's take a look at these results. Yes, if you treat vegetables, fruits, herbs, etc. during the growing season with strong fungicides, this will help suppress the development of some pathogens (not all and not completely), but, firstly, this leads to the accumulation of poisons and toxins in the fruits, which means that the beneficial qualities of the fetus are reduced, and secondly, harmful microbes quickly develop immunity to substances that poison them and subsequent treatments should be carried out with more and more powerful antibiotics.

The same phenomenon is observed in the animal world, and, unfortunately, in humans.

In addition, antibiotics cause a number of negative consequences in the body of warm-blooded animals, such as dysbacteriosis, fetal deformities in pregnant women, etc.

How to be? Nature itself answers this question! And that answer is PROBIOTICS!

The leading institutes of biotechnology and genetic engineering have long been engaged in the development of new and selection of known microorganisms that have amazing viability and the ability to “win” in the fight against other microbes.

These elite strains such as "bacillus subtilis" and "Licheniformis" are widely used to treat people, animals, plants incredibly effectively and completely safely.

How is this possible? And here's how: in the body of people and animals necessarily contains a lot of necessary bacteria. They are involved in the processes of digestion, the formation of enzymes and make up almost 70% of the human immune system. If for any reason (taking antibiotics, malnutrition) a person’s bacterial balance is disturbed, then he is unprotected from new harmful microbes and in 95% of cases he will get sick again.

The same applies to animals. And elite strains, getting into the body, begin to actively multiply and destroy the pathogenic flora, because. already mentioned above, they have greater viability. Thus, with the help of strains of elite microorganisms, it is possible to maintain a macro organism in health without antibiotics and in harmony with nature, because by themselves, being in the body, these strains bring only benefit and no harm.

They are better than antibiotics also because:

The answer of the microcosm to the introduction of superantibiotics into business practice is obvious and follows from the experimental material already at the disposal of scientists - the birth of a supermicrobe.

Microbes are surprisingly perfect self-developing and self-learning biological machines capable of memorizing in their genetic memory the mechanisms of protection they have created against the harmful effects of antibiotics and transmitting information to their descendants.

Bacteria are a kind of "bioreactor" in which enzymes, amino acids, vitamins and bacteriocins are produced, which, like antibiotics, neutralize pathogens.

However, there is neither addiction to them, nor side effects typical of the use of chemical antibiotics. On the contrary, they are able to cleanse the intestinal walls, increase their permeability to essential nutrients, restore the biological balance of the intestinal microflora and stimulate the entire immune system.

Scientists took advantage of the natural way for nature to maintain the health of the macro organism, namely, from the natural environment, they isolated bacteria - saprophytes, which have the ability to suppress the growth and development of pathogenic microflora, including in the gastrointestinal tract of warm-blooded animals.

Millions of years of evolution of living things on the planet have created such wonderful and perfect mechanisms for suppressing pathogenic microflora with non-pathogenic ones that there is no reason to doubt the success of this approach.

Non-pathogenic microflora in the competitive struggle wins in the undisputed majority of cases, and if it were not so, we would not be on our planet today.

Based on the foregoing, scientists producing fertilizers and fungicides for agricultural use have also tried to move from a chemical to a biological view.

And the results were not slow to show themselves! It turned out that the same bacillus subtilis successfully fight as many as seventy varieties of pathogenic representatives that cause such diseases of horticultural crops as bacterial cancer, fusarium wilt, root and root rot, etc., previously considered incurable plant diseases with which he could not handle NOT A SINGLE FUNGICIDE!

In addition, these bacteria have a clearly positive effect on the vegetation of the plant: the period of filling and ripening of fruits is reduced, the useful qualities of fruits increase, the content of nitrates in them decreases, etc.

toxic substances, and most importantly - the need for mineral fertilizers is significantly reduced!

Preparations containing strains of elite bacteria are already taking first place at Russian and international exhibitions, they are winning medals for efficiency and environmental friendliness. Small and large agricultural producers have already begun their active use, and fungicides and antibiotics are gradually becoming a thing of the past.

Bio-Ban's products are Flora-S and Fitop-Flora-S, which offer dry peat-humic fertilizers containing concentrated humic acids (and saturated humus is a guarantee of an excellent harvest) and a bacterial strain "bacillus subtilis" for disease control. Thanks to these preparations, it is possible to restore depleted land in a short time, increase land productivity, protect your crop from diseases, and most importantly, it is possible to get excellent yields in risky farming areas!

I think the above arguments are enough to appreciate the benefits of probiotics and understand why scientists say that the twentieth century is the century of antibiotics, and the twenty-first is the century of probiotics!

The main groups of microorganisms used in the food industry

It should be maximum when receiving medicines and chemicals. The requirements for sterility in the production of alcoholic beverages are less stringent.

Such fermentation processes are said to be "protected" because the conditions that are created in the environment are such that only certain microorganisms can grow in them. For example, in the production of beer, the growth medium is simply boiled rather than sterilized; the fermenter is also used clean, but not sterile.

Getting culture. Before starting the fermentation process, it is necessary to obtain a pure, highly productive culture. Pure cultures of microorganisms are stored in very small volumes and under conditions that ensure its viability and productivity; this is usually achieved by storage at a low temperature.

The fermenter can hold several hundred thousand liters of culture medium, and the process is started by introducing culture (inoculum) into it, constituting 1-10% of the volume in which fermentation will take place. Thus, the initial culture should be grown step by step (with subculturing) until reaching the level of microbial biomass sufficient for the microbiological process to proceed with the required productivity.

It is absolutely necessary to keep the culture clean all this time, preventing it from being contaminated by foreign microorganisms.

Preservation of aseptic conditions is possible only with careful microbiological and chemical-technological control.

Growth in an industrial fermenter (bioreactor). Industrial microorganisms must grow in the fermenter under optimal conditions to form the desired product.

These conditions are strictly controlled to ensure microbial growth and product synthesis. The design of the fermenter should allow you to control the growth conditions - a constant temperature, pH (acidity or alkalinity) and the concentration of oxygen dissolved in the medium.

A conventional fermenter is a closed cylindrical tank in which the medium and microorganisms are mechanically mixed.

Air, sometimes saturated with oxygen, is pumped through the medium. The temperature is controlled by water or steam passing through the tubes of the heat exchanger. Such a stirred fermenter is used in cases where the fermentation process requires a lot of oxygen. Some products, on the contrary, are formed under anoxic conditions, and in these cases fermenters of a different design are used. Thus, beer is brewed at very low concentrations of dissolved oxygen, and the contents of the bioreactor are not aerated or stirred.

Some brewers still traditionally use open containers, but in most cases, the process takes place in closed non-aerated cylindrical containers, tapering downwards, which contributes to the sedimentation of the yeast.

The production of vinegar is based on the oxidation of alcohol to acetic acid by bacteria.

Acetobacter. The fermentation process takes place in containers called acetaters, with intensive aeration. Air and medium are sucked in by a rotating agitator and enter the walls of the fermenter.

Isolation and purification of products. At the end of the fermentation, the broth contains microorganisms, unused nutrient components of the medium, various waste products of microorganisms, and the product that they wanted to obtain on an industrial scale. Therefore, this product is purified from other components of the broth.

When receiving alcoholic beverages (wine and beer), it is enough to simply separate the yeast by filtration and bring the filtrate to standard. However, individual chemicals obtained by fermentation are extracted from a complex broth.

Although industrial microorganisms are specifically selected for their genetic properties so that the yield of the desired product of their metabolism is maximized (in a biological sense), its concentration is still small compared to that achieved by production based on chemical synthesis.

Therefore, one has to resort to complex isolation methods - solvent extraction, chromatography and ultrafiltration. Processing and disposal of fermentation waste. In any industrial microbiological processes, waste is generated: broth (liquid left after the extraction of the product of production); cells of used microorganisms; dirty water, which washed the installation; water used for cooling; water containing trace amounts of organic solvents, acids and alkalis.

Liquid waste contains many organic compounds; if they are dumped into rivers, they will stimulate the intensive growth of natural microbial flora, which will lead to the depletion of oxygen in river waters and the creation of anaerobic conditions. Therefore, the waste is subjected to biological treatment before disposal in order to reduce the content of organic carbon. Industrial microbiological processes can be divided into 5 main groups: 1) cultivation of microbial biomass; 2) obtaining metabolic products of microorganisms; 3) obtaining enzymes of microbial origin; 4) obtaining recombinant products; 5) biotransformation of substances.

microbial biomass. Microbial cells themselves can serve as the final product of the manufacturing process. On an industrial scale, two main types of microorganisms are produced: yeast, which is necessary for baking, and single-celled microorganisms, used as a source of proteins that can be added to human and animal food.

Baker's yeast has been cultivated in large quantities since the early 20th century. and was used as a food product in Germany during the First World War.

However, the technology for the production of microbial biomass as a source of food proteins was developed only in the early 1960s. A number of European companies drew attention to the possibility of growing microbes on such a substrate as hydrocarbons to obtain the so-called.

protein of unicellular organisms (BOO). A technological triumph was the development of a product added to livestock feed, consisting of dried microbial biomass grown on methanol.

The process was carried out in a continuous mode in a fermenter with a working volume of 1.5 million liters

However, due to the rise in prices for oil and products of its processing, this project became economically unprofitable, giving way to the production of soybean and fishmeal. By the end of the 1980s, the BOO plants were dismantled, which put an end to the turbulent but short period of development of this branch of the microbiological industry. Another process turned out to be more promising - obtaining fungal biomass and fungal mycoprotein protein using carbohydrates as a substrate.

metabolic products. After introducing the culture into the nutrient medium, a lag phase is observed, when no visible growth of microorganisms occurs; this period can be considered as a time of adaptation. Then the growth rate gradually increases, reaching a constant, maximum value for the given conditions; such a period of maximum growth is called the exponential, or logarithmic, phase.

Gradually, growth slows down, and the so-called. stationary phase. Further, the number of viable cells decreases, and growth stops.

Following the kinetics described above, it is possible to follow the formation of metabolites at different stages.

In the logarithmic phase, products vital for the growth of microorganisms are formed: amino acids, nucleotides, proteins, nucleic acids, carbohydrates, etc. They are called primary metabolites.

Many primary metabolites are of significant value. So, glutamic acid (more precisely, its sodium salt) is part of many foods; lysine is used as a food additive; phenylalanine is the precursor to the sugar substitute aspartame.

Primary metabolites are synthesized by natural microorganisms in quantities necessary only to meet their needs. Therefore, the task of industrial microbiologists is to create mutant forms of microorganisms - super-producers of the corresponding substances.

Significant progress has been made in this area: for example, it was possible to obtain microorganisms that synthesize amino acids up to a concentration of 100 g/l (for comparison, wild-type organisms accumulate amino acids in milligram amounts).

In the growth retardation phase and in the stationary phase, some microorganisms synthesize substances that are not formed in the logarithmic phase and do not play a clear role in metabolism. These substances are called secondary metabolites. They are synthesized not by all microorganisms, but mainly by filamentous bacteria, fungi and spore-forming bacteria. Thus, producers of primary and secondary metabolites belong to different taxonomic groups. If the question of the physiological role of secondary metabolites in producer cells was the subject of serious discussions, then their industrial production is of undoubted interest, since these metabolites are biologically active substances: some of them have antimicrobial activity, others are specific inhibitors of enzymes, and others are growth factors. , many have pharmacological activity.

Obtaining such substances served as the basis for the creation of a number of branches of the microbiological industry. The first in this series was the production of penicillin; The microbiological method for producing penicillin was developed in the 1940s and laid the foundation for modern industrial biotechnology.

The pharmaceutical industry has developed highly complex methods for screening (mass testing) of microorganisms for the ability to produce valuable secondary metabolites.

Initially, the purpose of screening was to obtain new antibiotics, but it was soon discovered that microorganisms also synthesize other pharmacologically active substances.

During the 1980s, the production of four very important secondary metabolites was established. These were: cyclosporine, an immunosuppressive drug used as an agent to prevent rejection of implanted organs; imipenem (one of the modifications of carbapenem) - a substance with the widest spectrum of antimicrobial activity of all known antibiotics; lovastatin - a drug that lowers blood cholesterol levels; Ivermectin is an anthelmintic used in medicine to treat onchocerciasis, or "river blindness", as well as in veterinary medicine.

Enzymes of microbial origin. On an industrial scale, enzymes are obtained from plants, animals and microorganisms. The use of the latter has the advantage of allowing the production of enzymes in large quantities using standard fermentation techniques.

In addition, it is incomparably easier to increase the productivity of microorganisms than that of plants or animals, and the use of recombinant DNA technology makes it possible to synthesize animal enzymes in microorganism cells.

Enzymes obtained in this way are mainly used in the food industry and related fields. The synthesis of enzymes in cells is genetically controlled, and therefore the available industrial microorganisms-producers were obtained as a result of a directed change in the genetics of wild-type microorganisms.

recombinant products. Recombinant DNA technology, better known as "genetic engineering", allows the genes of higher organisms to be incorporated into the bacterial genome. As a result, bacteria acquire the ability to synthesize "foreign" (recombinant) products - compounds that previously could only be synthesized by higher organisms.

On this basis, many new biotechnological processes have been created for the production of human or animal proteins that were not previously available or used with great health risks.

The term "biotechnology" itself became popular in the 1970s in connection with the development of methods for the production of recombinant products. However, this concept is much broader and includes any industrial method based on the use of living organisms and biological processes.

The first recombinant protein produced on an industrial scale was human growth hormone. For the treatment of hemophilia, one of the proteins of the blood coagulation system, namely the factor

VIII. Before methods were developed to obtain this protein using genetic engineering, it was isolated from human blood; the use of such a drug has been associated with a risk of infection with the human immunodeficiency virus (HIV).

For a long time, diabetes mellitus has been successfully treated with animal insulin. However, scientists believed that the recombinant product would create fewer immunological problems if it could be obtained in its pure form, without impurities from other peptides produced by the pancreas.

In addition, the number of diabetic patients was expected to increase over time due to factors such as changes in dietary habits, improved medical care for pregnant women with diabetes (and, as a result, an increase in the frequency of genetic predisposition to diabetes), and finally the expected increase the life expectancy of diabetic patients.

The first recombinant insulin went on the market in 1982, and by the end of the 1980s it had practically replaced animal insulin.

Many other proteins are synthesized in the human body in very small quantities, and the only way to obtain them on a scale sufficient for clinical use is through recombinant DNA technology. These proteins include interferon and erythropoietin.

Erythropoietin, together with myeloid colony-stimulating factor, regulates the formation of blood cells in humans. Erythropoietin is used to treat anemia associated with kidney failure and may find use as a platelet booster in cancer chemotherapy.

Biotransformation of substances. Microorganisms can be used to convert certain compounds into structurally similar, but more valuable substances. Since microorganisms can exert their catalytic action in relation to only certain specific substances, the processes occurring with their participation are more specific than purely chemical ones. The best known biotransformation process is the production of vinegar by converting ethanol to acetic acid.

But among the products formed during biotransformation, there are also such highly valuable compounds as steroid hormones, antibiotics, prostaglandins. see also GENETIC ENGINEERING. Industrial Microbiology and Advances in Genetic Engineering(special issue of Scientific American).

M., 1984
Biotechnology. Principles and application. M., 1988

Production Human use of microorganisms.

Microorganisms are widely used in the food industry, household, microbiological industry to produce amino acids, enzymes, organic acids, vitamins, etc.

Classical microbiological industries include 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 widely distributed in nature.

The history of industrial production of yeast began in Holland, where in 1870 ᴦ. The first yeast factory was founded. The main product was pressed 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. Drying has become one of the methods of industrial preservation of yeast. 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 ᴦ. In 1972 ᴦ. the second generation of dry yeast appeared, the so-called instant yeast.

The use of microorganisms in the food industry

Since the mid-1990s, a third generation of dry yeast has emerged: baker's yeast. Saccharomyces cerevisiae, which combine the virtues of instant yeast with a highly concentrated complex of specialized baking enzymes in one product.

This yeast allows not only to improve the quality of bread, but also to actively resist the process of staleness.

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

Winemaking uses many different strains 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, pickled cucumbers, pickled olives, and many other pickled foods.

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

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

At the same time, many microorganisms play a negative role in human life, being pathogens of human, animal and plant diseases; they can cause spoilage of foodstuffs, 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. The protease causes the degradation of proteins in various materials. In the East, mushroom protease has been used for centuries to make soy sauce.

Today it is used in the manufacture of detergents. When preserving fruit juices, an enzyme such as pectinase is used.

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

In recent years, new productions 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 associated with the development of physics, chemistry, biochemistry, molecular biology, etc.

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

This course focuses on food microbiology.

Many microorganisms live on the surface of the body, in the intestines of humans and animals, on plants, on food and on all objects around us. Microorganisms consume a wide variety of food, extremely easily adapt to changing living conditions: heat, cold, lack of moisture, etc.

n. Οʜᴎ multiply very quickly. Without knowledge of microbiology, it is impossible to competently and effectively manage biotechnological processes, maintain the high quality of food products at all stages of its production and prevent the consumption of products containing pathogens of foodborne diseases and poisoning.

It should be 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 difficult 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 the microbiological analysis of food quality and safety, two groups of microorganisms should be distinguished:

- specific microflora;

- nonspecific microflora.

specific- ϶ᴛᴏ cultural races of microorganisms that are used to prepare a particular product and are an indispensable link in the technology of its production.

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

Nonspecific- ϶ᴛᴏ microorganisms that enter food from the environment, contaminating them.

Among this group of microorganisms, saprophytic, pathogenic and conditionally pathogenic, as well as microorganisms that cause spoilage of products are distinguished.

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

Introduction

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

Bacteria, fungi, algae, lichens, viruses, protozoa play a significant role in people's lives. Since ancient times, people have used them in the processes of baking, making wine and beer, and in various industries.

Microorganisms assist humans in the production of efficient protein nutrients and biogas. They are used in the application of biotechnical methods of air and wastewater purification, in the use of biological methods for the destruction of agricultural pests, in the production of medicinal preparations, in the destruction of waste materials.

The main purpose of this work is to study the methods and conditions for the cultivation of microorganisms

Familiarize yourself with the areas of application of microorganisms

Study the morphology and physiology of microorganisms

To study the main types and composition of nutrient media

Give the concept and get acquainted with the bioreactor

Disclose the main methods of cultivating microorganisms

Morphology and physiology of microorganisms

Morphology

Classification of microorganisms

bacteria

Bacteria are single-celled prokaryotic microorganisms. Their value is measured in micrometers (µm). There are three main forms: spherical bacteria - cocci, rod-shaped and convoluted.

cocci(Greek kokkos - grain) have a spherical or slightly elongated shape. They differ from each other depending on how they are located after division. Solitarily arranged cocci are micrococci, arranged in pairs are diplococci. Streptococci divide in the same plane and after division do not diverge, forming chains (Greek streptos - chain). Tetracocci form combinations of four cocci as a result of division in two mutually perpendicular planes, sarcins (Latin sarcio - to bind) are formed when dividing in three mutually perpendicular planes and look like clusters of 8-16 cocci. Staphylococci, as a result of random division, form clusters resembling a bunch of grapes (Greek staphyle - bunch of grapes).

rod-shaped bacteria (Greek bacteria - stick) that can form spores are called bacilli if the spore is not wider than the stick itself, and clostridium if the spore diameter exceeds the diameter of the stick. Rod-shaped bacteria, unlike cocci, are diverse in size, shape and arrangement of cells: short (1-5 microns), thick, with rounded ends bacteria of the intestinal group; thin, slightly curved rods of tuberculosis; thin sticks of diphtheria located at an angle; large (3-8 microns) anthrax rods with "chopped off" ends, forming long chains - streptobacilli.

To tortuous forms of bacteria include vibrios, which have a slightly curved shape in the form of a comma (cholera vibrio) and spirilla, consisting of several curls. The crimped forms also include Campylobacter, which under a microscope look like the wings of a flying gull.

The structure of a bacterial cell.

Structural elements of a bacterial cell can be divided into:

a) permanent structural elements - are present in each type of bacteria, throughout the life of a bacterium; it is a cell wall, cytoplasmic membrane, cytoplasm, nucleoid;

B) non-permanent structural elements that not all types of bacteria are able to form, but those bacteria that form them can lose them and acquire them again, depending on the conditions of existence. This is a capsule, inclusions, drank, spores, flagella.

Rice. 1.1. Structure of a bacterial cell

cell wall covers the entire surface of the cell. In gram-positive bacteria, the cell wall is thicker: up to 90% is a polymeric compound peptidoglycan associated with teichoic acids and a protein layer. In gram-negative bacteria, the cell wall is thinner, but more complex in composition: it consists of a thin layer of peptidoglycan, lipopolysaccharides, proteins; it is covered by an outer membrane.

Functions of the cell wallare that it:

Is an osmotic barrier

Determines the shape of a bacterial cell

Protects the cell from environmental influences

Carries a variety of receptors that promote the attachment of phages, colicins, as well as various chemical compounds,

Nutrients enter the cell through the cell wall and waste products are excreted.

O-antigen is localized in the cell wall and endotoxin (lipid A) of bacteria is associated with it.

cytoplasmic membrane

adjacent to the bacterial cell wall cytoplasmic membrane , whose structure is similar to eukaryotic membranes ( consists of a double layer of lipids, mainly phospholipids with built-in surface and integral proteins). She provides:

Selective permeability and transport of solutes into the cell,

Electron transport and oxidative phosphorylation,

Isolation of hydrolytic exoenzymes, biosynthesis of various polymers.

The cytoplasmic membrane limits bacterial cytoplasm , which represents granular structure. Localized in the cytoplasm ribosomes and bacterial nucleoid, it can also contain inclusions and plasmids(extrachromosomal DNA). In addition to the required structures, bacterial cells may have spores.

Cytoplasm- the internal gel-like contents of a bacterial cell are permeated with membrane structures that create a rigid system. The cytoplasm contains ribosomes (in which protein biosynthesis is carried out), enzymes, amino acids, proteins, ribonucleic acids.

Nucleoid- it is a bacterial chromosome, a double strand of DNA, annularly closed, connected to the mesosome. Unlike the nucleus of eukaryotes, the DNA strand is freely located in the cytoplasm, does not have a nuclear envelope, nucleolus, or histone proteins. The DNA strand is many times longer than the bacterium itself (for example, in E. coli, the length of the chromosome is more than 1 mm).

In addition to the nucleoid, extrachromosomal factors of heredity, called plasmids, can be found in the cytoplasm. These are short circular strands of DNA attached to mesosomes.

Inclusions are found in the cytoplasm of some bacteria in the form of grains that can be detected by microscopy. For the most part, this is a supply of nutrients.

drinking(lat. pili - hairs) otherwise cilia, fimbriae, fringes, villi - short filamentous processes on the surface of bacteria.

Flagella. Many types of bacteria are able to move due to the presence of flagella. Of the pathogenic bacteria, only among the rods and convoluted forms are there mobile species. Flagella are thin elastic filaments, the length of which in some species is several times the length of the body of the bacterium itself.

The number and arrangement of flagella is a characteristic species feature of bacteria. Bacteria are distinguished: monotrichous - with one flagellum at the end of the body, lophotrichous - with a bunch of flagella at the end, amphitrichous, having flagella at both ends, and peritrichous, in which the flagella are located over the entire surface of the body. Vibrio cholerae belongs to monotrichs, and typhoid salmonella belongs to peritrichs.

Capsule- the outer mucous layer found in many bacteria. In some species, it is so thin that it is found only in an electron microscope - this is a microcapsule. In other types of bacteria, the capsule is well defined and visible in a conventional optical microscope - this is a macrocapsule.

Mycoplasmas

Mycoplasmas are prokaryotes, their size is 125-200 nm. These are the smallest of cellular microbes, their size is close to the resolution limit of an optical microscope. They lack a cell wall. The characteristic features of mycoplasmas are associated with the absence of a cell wall. They do not have a permanent shape, so there are spherical, oval, thread-like shapes.

Rickettsia

Chlamydia

actinomycetes

Actinomycetes are unicellular microorganisms that belong to prokaryotes. Their cells have the same structure as bacteria: a cell wall containing peptidoglycan, a cytoplasmic membrane; nucleoid, ribosomes, mesosomes, intracellular inclusions are located in the cytoplasm. Therefore, pathogenic actinomycetes are sensitive to antibacterial drugs. At the same time, they have a shape of branching interlacing filaments similar to fungi, and some actinomycetes belonging to the strentomycetes family reproduce by spores. Other families of actinomycetes reproduce by fragmentation, that is, the breakdown of filaments into separate fragments.

Actinomycetes are widely distributed in the environment, especially in the soil, and participate in the cycle of substances in nature. Among actinomycetes there are producers of antibiotics, vitamins, hormones. Most of the antibiotics currently used are produced by actinomycetes. These are streptomycin, tetracycline and others.

Spirochetes.

Spirochetes are prokaryotes. They have features in common with both bacteria and protozoa. These are unicellular microbes, having the form of long thin spirally curved cells, capable of active movement. Under adverse conditions, some of them can turn into a cyst.

Studies in an electron microscope made it possible to establish the structure of spirochete cells. These are cytoplasmic cylinders surrounded by a cytoplasmic membrane and a cell wall containing peptidoglycan. The cytoplasm contains the nucleoid, ribosomes, mesosomes, and inclusions.

Fibrils are located under the cytoplasmic membrane, providing a variety of movement of spirochetes - translational, rotational, flexion.

Pathogenic representatives of spirochetes: Treponema pallidum - causes syphilis, Borrelia recurrentis - relapsing fever, Borrelia burgdorferi - Lyme disease, Leptospira interrogans - leptospirosis.

Mushrooms

Mushrooms (Fungi, Mycetes) are eukaryotes, lower plants lacking chlorophyll, and therefore they do not synthesize organic carbon compounds, that is, they are heterotrophs, have a differentiated nucleus, are covered with a shell containing chitin. Unlike bacteria, fungi do not contain peptidoglycan, and therefore are insensitive to penicillins. The cytoplasm of fungi is characterized by the presence of a large number of various inclusions and vacuoles.

Among microscopic fungi (micromycetes) there are unicellular and multicellular microorganisms that differ in morphology and methods of reproduction. Fungi are characterized by a variety of methods of reproduction: division, fragmentation, budding, the formation of spores - asexual and sexual.

In microbiological studies, molds, yeasts and representatives of the combined group of so-called imperfect fungi are most often encountered.

Mold form a typical mycelium, creeping along the nutrient substrate. From the mycelium, aerial branches rise upwards, which end in fruiting bodies of various shapes that carry spores.

Mucor or capitate molds (Mucor) are unicellular fungi with a spherical fruiting body filled with endospores.

Molds of the genus Aspergillus are multicellular fungi with a fruiting body, microscopy resembling the tip of a watering can spraying streams of water; hence the name "leak mold". Some Aspergillus species are used industrially to produce citric acid and other substances. There are species that cause diseases of the skin and lungs in humans - aspergillosis.

Molds of the genus Penicillum, or brushes, are multicellular fungi with a fruiting body in the form of a brush. From some types of green mold, the first antibiotic, penicillin, was obtained. Among penicilli there are species pathogenic for humans that cause penicilliosis.

Various types of mold can cause spoilage of food, medicines, biologicals.

Yeast - yeast fungi (Saccharomycetes, Blastomycetes) have the shape of round or oval cells, many times larger than bacteria. The average size of yeast cells is approximately equal to the diameter of an erythrocyte (7-10 microns).

Viruses

Viruses- (lat. virus poison) - the smallest microorganisms that do not have a cellular structure, a protein-synthesizing system and are capable of reproducing only in the cells of highly organized life forms. They are widely distributed in nature, affecting animals, plants and other microorganisms.

A mature viral particle, known as a virion, consists of a nucleic acid - genetic material (DNA or RNA) that carries information about several types of proteins needed to form a new virus - covered with a protective protein shell - capsid. The capsid is made up of identical protein subunits called capsomeres. Viruses may also have a lipid envelope over the capsid ( supercapsid) formed from the membrane of the host cell. The capsid is composed of proteins encoded by the viral genome, and its shape underlies the classification of viruses by morphological trait. Intricately organized viruses, in addition, encode special proteins that help in the assembly of the capsid. Complexes of proteins and nucleic acids are known as nucleoproteins, and the complex of proteins of the viral capsid with the viral nucleic acid is called nucleocapsid.

Rice. 1.4. Schematic structure of the virus: 1 - core (single-stranded RNA); 2 - protein shell (Capsid); 3 - additional lipoprotein membrane; 4 - Capsomeres (structural parts of the Capsid).

Physiology of microorganisms

The physiology of microorganisms studies the vital activity of microbial cells, the processes of their nutrition, respiration, growth, reproduction, patterns of interaction with the environment.

Metabolism

Metabolism- a set of biochemical processes aimed at obtaining energy and reproducing cellular material.

Features of metabolism in bacteria:

1) the variety of substrates used;

2) intensity of metabolic processes;

4) the predominance of decay processes over synthesis processes;

5) the presence of exo- and endoenzymes of metabolism.

Metabolism consists of two interrelated processes: catabolism and anabolism.

catabolism(energy metabolism) is the process of splitting large molecules into smaller ones, as a result of which energy is released that accumulates in the form of ATP:

a) breathing

b) fermentation.

Anabolism(constructive metabolism) - provides the synthesis of macromolecules from which the cell is built:

a) anabolism (with energy costs);

b) catabolism (with the release of energy);

In this case, the energy obtained in the process of catabolism is used. The metabolism of bacteria is characterized by a high rate of the process and rapid adaptation to changing environmental conditions.

In the microbial cell, enzymes are biological catalysts. According to the structure, they distinguish:

1) simple enzymes (proteins);

2) complex; consist of protein (active center) and non-protein parts; required for enzyme activation.

According to the place of action, there are:

1) exoenzymes (act outside the cell; take part in the process of disintegration of large molecules that cannot penetrate inside the bacterial cell; characteristic of gram-positive bacteria);

2) endoenzymes (act in the cell itself, provide the synthesis and breakdown of various substances).

Depending on the chemical reactions catalyzed, all enzymes are divided into six classes:

1) oxidoreductases (catalyze redox reactions between two substrates);

2) transferases (carry out intermolecular transfer of chemical groups);

3) hydrolases (perform hydrolytic cleavage of intramolecular bonds);

4) lyases (attach chemical groups at two bonds, and also carry out reverse reactions);

5) isomerases (carry out isomerization processes, provide internal conversion with the formation of various isomers);

6) ligases, or synthetases (connect two molecules, resulting in the splitting of pyrophosphate bonds in the ATP molecule).

Food

Nutrition is understood as the processes of entry and removal of nutrients into and out of the cell. Nutrition primarily ensures the reproduction and metabolism of the cell.

Various organic and inorganic substances enter the bacterial cell in the process of nutrition. Bacteria have no special food organs. Substances penetrate the entire surface of the cell in the form of small molecules. This way of eating is called holophytic. A necessary condition for the passage of nutrients into the cell is their solubility in water and a small value (i.e., proteins must be hydrolyzed to amino acids, carbohydrates to di- or monosaccharides, etc.).

The main regulator of the entry of substances into the bacterial cell is the cytoplasmic membrane. There are four main mechanisms for the intake of substances:

-passive diffusion- along the concentration gradient, energy-intensive, without substrate specificity;

- facilitated diffusion- along the concentration gradient, substrate-specific, energy-intensive, carried out with the participation of specialized proteins permease;

- active transport- against the concentration gradient, substrate-specific (special binding proteins in combination with permeases), energy-consuming (due to ATP), substances enter the cell in a chemically unchanged form;

- translocation (transfer of groups) - against the concentration gradient, with the help of the phosphotransferase system, energy-consuming, substances (mainly sugars) enter the cell in a phorforylated form.

The main chemical elements are organogens necessary for the synthesis of organic compounds - carbon, nitrogen, hydrogen, oxygen.

Food types. The wide distribution of bacteria is facilitated by a variety of types of nutrition. Microbes need carbon, oxygen, nitrogen, hydrogen, sulfur, phosphorus and other elements (organogens).

Depending on the source of carbon production, bacteria are divided into:

1) autotrophs (use inorganic substances - CO2);

2) heterotrophs;

3) metatrophs (use organic matter of inanimate nature);

4) paratrophs (use organic substances of wildlife).

Nutritional processes must provide the energy needs of the bacterial cell.

According to energy sources, microorganisms are divided into:

1) phototrophs (able to use solar energy);

2) chemotrophs (receive energy through redox reactions);

3) chemolithotrophs (use inorganic compounds);

4) chemoorganotrophs (use organic matter).

Bacteria include:

1) prototrophs (they are able to synthesize the necessary substances from low-organized ones themselves);

2) auxotrophs (they are mutants of prototrophs that have lost genes; they are responsible for the synthesis of certain substances - vitamins, amino acids, therefore they need these substances in finished form).

Microorganisms assimilate nutrients in the form of small molecules; therefore, proteins, polysaccharides and other biopolymers can serve as food sources only after they are broken down by exoenzymes into simpler compounds.

respiration of microorganisms.

Microorganisms obtain energy through respiration. Respiration is the biological process of electron transfer through the respiratory chain from donors to acceptors to form ATP. Depending on what is the final electron acceptor, emit aerobic and anaerobic respiration. In aerobic respiration, the final electron acceptor is molecular oxygen (O 2), in anaerobic respiration, bound oxygen (-NO 3, \u003d SO 4, \u003d SO 3).

Aerobic respiration hydrogen donor H 2 O

Anaerobic respiration

Nitrate oxidation of NO 3

(facultative anaerobes) hydrogen donor N 2

Sulphate oxidation of SO 4

(obligate anaerobes) hydrogen donor H 2 S

According to the type of respiration, four groups of microorganisms are distinguished.

1.obligate(strict) aerobes. They need molecular (atmospheric) oxygen to breathe.

2.microaerophiles need a reduced concentration (low partial pressure) of free oxygen. To create these conditions, CO 2 is typically added to the culture gas mixture, for example up to 10 percent concentration.

3.Facultative anaerobes can consume glucose and reproduce under aerobic and anaerobic conditions. Among them, there are microorganisms that are tolerant to relatively high (close to atmospheric) concentrations of molecular oxygen - i.e. aerotolerant,

as well as microorganisms that are able, under certain conditions, to switch from anaerobic to aerobic respiration.

4.Strict anaerobes reproduce only under anaerobic conditions, i.e. at very low concentrations of molecular oxygen, which is harmful to them in high concentrations. Biochemically, anaerobic respiration proceeds according to the type of fermentation processes, while molecular oxygen is not used.

Aerobic respiration is energetically more efficient (more ATP is synthesized).

In the process of aerobic respiration, toxic oxidation products are formed (H 2 O 2 - hydrogen peroxide, -O 2 - free oxygen radicals), from which specific enzymes protect, primarily catalase, peroxidase, peroxide dismutase. Anaerobes lack these enzymes, as well as redox potential regulation system (rH 2).

Growth and reproduction of bacteria

Bacterial growth is an increase in the size of a bacterial cell without increasing the number of individuals in the population.

Reproduction of bacteria is a process that ensures an increase in the number of individuals in a population. Bacteria are characterized by a high rate of reproduction.

Growth always precedes reproduction. Bacteria reproduce by transverse binary fission, in which two identical daughter cells are formed from one mother cell.

The process of bacterial cell division begins with the replication of chromosomal DNA. At the point of attachment of the chromosome to the cytoplasmic membrane (replicator point), an initiator protein acts, which causes the chromosome ring to break, and then its threads are despiralized. The filaments unwind and the second filament attaches to the cytoplasmic membrane at the proreplicator point, which is diametrically opposed to the replicator point. Due to DNA polymerases, an exact copy of it is completed in the matrix of each strand. The doubling of genetic material is the signal for doubling the number of organelles. In septal mesosomes, a septum is being built, dividing the cell in half. Double-stranded DNA spiralizes, twists into a ring at the point of attachment to the cytoplasmic membrane. This is a signal for the divergence of cells along the septum. Two daughter individuals are formed.

Reproduction of bacteria is determined by the time of generation. This is the period during which cell division takes place. The duration of generation depends on the type of bacteria, age, composition of the nutrient medium, temperature, etc.

Nutrient media

For the cultivation of bacteria, nutrient media are used, to which a number of requirements are imposed.

1. Nutrition. The bacteria must contain all the necessary nutrients.

2. Isotonic. Bacteria must contain a set of salts to maintain osmotic pressure, a certain concentration of sodium chloride.

3. Optimal pH (acidity) of the medium. The acidity of the environment ensures the functioning of bacterial enzymes; for most bacteria is 7.2–7.6.

4. Optimum electronic potential, indicating the content of dissolved oxygen in the medium. It should be high for aerobes and low for anaerobes.

5. Transparency (growth of bacteria was observed, especially for liquid media).

6. Sterility (absence of other bacteria).

Classification of culture media

1. By origin:

1) natural (milk, gelatin, potatoes, etc.);

2) artificial - media prepared from specially prepared natural components (peptone, aminopeptide, yeast extract, etc.);

3) synthetic - media of known composition, prepared from chemically pure inorganic and organic compounds (salts, amino acids, carbohydrates, etc.).

2. By composition:

1) simple - meat-peptone agar, meat-peptone broth, Hottinger agar, etc.;

2) complex - these are simple with the addition of an additional nutrient component (blood, chocolate agar): sugar broth,

bile broth, serum agar, yolk-salt agar, Kitt-Tarozzi medium, Wilson-Blair medium, etc.

3. By consistency:

1) solid (contain 3-5% agar-agar);

2) semi-liquid (0.15-0.7% agar-agar);

3) liquid (do not contain agar-agar).

agar- complex polysaccharide from seaweed, the main hardener for dense (solid) media.

4. Depending on the purpose of the PS, there are:

Differential diagnostic

elective

selective

inhibitory

Culture media

Cumulative (saturation, enrichment)

Preservative

Control.

Differential diagnostic - these are complex environments on which microorganisms of different species grow in different ways, depending on the biochemical properties of the culture. They are designed to identify the species of microorganisms, are widely used in clinical bacteriology and genetic research.

Selective, inhibitory and elective PSs are designed for growing a strictly defined type of microorganism. These media serve to isolate bacteria from mixed populations and differentiate them from similar species. Various substances are added to their composition that inhibit the growth of some species and do not affect the growth of others.

The medium can be made selective due to the pH value. Recently, antimicrobial agents such as antibiotics and other chemotherapeutic agents have been used as media selective agents.

Elective PS have found wide application in the isolation of pathogens of intestinal infections. With the addition of malachite or brilliant green, bile salts (in particular sodium taurocholic acid), a significant amount of sodium chloride or citrate salts, the growth of Escherichia coli is inhibited, but the growth of pathogenic bacteria of the intestinal group does not worsen. Some elective media are prepared with the addition of antibiotics.

Culture maintenance media are formulated to be free from selective substances capable of causing culture variability.

Cumulative PS (enrichment, saturation) are media on which certain types of crops or groups of crops grow faster and more intensively than the accompanying ones. When cultivating on these media, inhibitory substances are usually not used, but, on the contrary, favorable conditions are created for a particular species present in the mixture. The basis of accumulation media are bile and its salts, sodium tetrathionate, various dyes, selenite salts, antibiotics, etc.

Preservative media are used for primary inoculation and transportation of the test material.

There are also control PS, which are used to control the sterility and total bacterial contamination of antibiotics.

5. According to the set of nutrients, they distinguish:

Minimal media that contain only food sources sufficient for growth;

Rich environments, which include many additional substances.

6. According to the scale of use, PS are divided into:

> production (technological);

> environments for scientific research with a limited scope of application.

Production PS should be available, economical, easy to prepare and use for large-scale cultivation. Research media are usually synthetic and rich in nutrients.

Selection of raw materials for the construction of culture media

The quality of PS is largely determined by the usefulness of the composition of nutrient substrates and raw materials used for their preparation. A wide variety of types of raw materials poses a difficult task of choosing the most promising, suitable for designing PS of the required quality. The decisive role in this matter is played, first of all, by the biochemical indicators of the composition of raw materials, which determine the choice of the method and modes of its processing in order to make the most complete and efficient use of the nutrients contained in it.

To obtain PS with particularly valuable properties, traditional animal protein sources are primarily used, namely meat cattle (cattle), casein, fish and products of its processing. The most fully developed and widely used PS based on cattle meat.

Given the shortage of Caspian sprat, widely used in the recent past, cheaper and more accessible non-food products of the fishing industry - dry krill, krill meat processing waste, filleted walleye pollock and its overripe caviar - began to be used to obtain fish nutritional bases. The most widespread is fish feed meal (FCM), which satisfies the requirements of biological value, availability and relative standardity.

Fairly widespread PS based on casein, which contains all the components found in milk: fat, lactose, vitamins, enzymes and salts. However, it should be noted that due to the increase in the cost of milk processing products, as well as the increase in demand for casein in the world market, its use is somewhat limited.

From non-food sources of protein of animal origin, as a raw material for the construction of full-fledged PS, it is necessary to isolate the blood of slaughtered animals, which is rich in biologically active substances and microelements and contains products of cellular and tissue metabolism.

Blood hydrolysates of farm animals are used as substitutes for peptone in differential diagnostic nutrient media.

Other types of protein-containing raw materials of animal origin that can be used to design PS include: placenta and spleen of cattle, dry protein concentrate - a product of meat waste processing, split trim obtained from skin processing, poultry embryos - a waste of vaccine production, blood substitutes with expired, curd whey, soft tissues of molluscs and pinnipeds.

It is promising to use carcasses of fur-bearing animals from fur farms, cattle blood obtained at a meat processing plant, skimmed milk and whey (waste from butter factories).

In general, PS prepared from raw materials of animal origin have a high content of main nutritional components, are complete and balanced in terms of amino acid composition, and are quite well studied.

From plant products, corn, soybeans, peas, potatoes, lupine, etc. can be used as a protein substrate for PS. However, vegetable agricultural raw materials contain protein, the unbalanced composition of which depends on the conditions of crop cultivation, as well as lipids in larger quantities than products animal origin.

An extensive group consists of PS made from protein raw materials of microbial origin (yeast, bacteria, etc.). The amino acid composition of microorganisms that serve as a substrate for the preparation of PS is well studied, and the biomass of the microorganisms used is complete in terms of nutrient composition and is characterized by an increased content of lysine and threonine.

A number of PSs of a combined composition from protein substrates of various origins have been developed. These include yeast casein broth, yeast meat, etc. Most of the known PS are based on hydrolysates of casein, cattle meat and fish (up to 80%).

The specific weight of non-food raw materials in the PS design technology is only 15% and needs to be increased in the future.

Non-food raw materials used to obtain a nutritional base (PS) must meet certain requirements, namely:

^ complete (quantitative and qualitative composition of raw materials should mainly satisfy the nutritional needs of microorganisms and cells for which PS are being developed);

^ affordable (to have a fairly extensive raw material base);

^ technological (the cost of introducing into production should be carried out using existing equipment or existing technology);

^ economical (the cost of introducing technology when switching to new raw materials and its processing should not exceed the cost norms for obtaining the target product);

^ standard (have a long shelf life without changing the physico-chemical properties and nutritional value)

Periodic system

A periodic culture system is a system in which, after the introduction of bacteria (inoculation) into the nutrient medium, neither the addition nor the removal of any components other than the gas phase is performed. It follows that the periodic system can support cell reproduction for a limited time, during which the composition of the nutrient medium changes from favorable (optimal) for their growth to unfavorable, up to the complete cessation of cell growth.

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

History of the use of microorganisms

As far back as 1000 BC, the Romans, Phoenicians and people of other early civilizations were extracting copper from mine waters or water seeping through ore bodies. In the 17th century Welsh in England (county of Wales) and in the XVIII century. the Spaniards at the Rio Tinto deposit used this "leaching" process to extract copper from minerals containing it. These ancient miners did not even suspect that bacteria played an active role in such metal extraction processes. Currently, this process, known as bacterial leaching, is used on a large scale throughout the world to extract copper from poor ores containing this and other valuable metals in small quantities. Biological leaching is also used (albeit less widely) to release uranium. Numerous studies have been carried out on the nature of organisms involved in the processes of metal leaching, their biochemical properties and possibilities of application in this field. The results of these studies show, in particular, that bacterial leaching can be widely used in the mining industry and, apparently, will be able to fully satisfy the need for energy-saving, environmentally friendly technologies.

Somewhat less well known, but just as important, is the use of microorganisms in the mining industry to extract metals from solutions. Some progressive technologies already include biological processes to obtain metals in a dissolved state or in the form of solid particles "from the washing waters left over from the processing of ores. The ability of microorganisms to accumulate metals has long been known, and enthusiasts have long dreamed of using microbes to extract valuable metals from sea water. The research carried out dispelled some hopes and largely determined the areas of application of microorganisms. Metal recovery with their participation remains a promising way to treat metal-contaminated industrial effluents cheaply, as well as economically obtain valuable metals.

It has long been known about the ability of microorganisms to synthesize polymeric compounds; in fact, most of the components of a cell are polymers. However, today less than 1% of the total amount of polymeric materials is produced by the microbiological industry; the remaining 99% is obtained from oil. So far, biotechnology has not had a decisive impact 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 course of their vital activity, microorganisms can selectively accumulate some of them in their cells, while purifying nutrient solutions from impurities. For example, fungi are used to selectively precipitate 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, spirits, vinegar, fermented milk products, cheeses and many products. Another important direction is the use of waste products of microorganisms. By the nature of these substances and by their importance for the producer, waste products can be divided into three groups.

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

2 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. In the traditional way, no more than 50% of oil is extracted from the oil reservoir. The waste products of bacteria, accumulating in the reservoir, contribute to the displacement of oil and its more complete release to the surface.

The huge role of microorganisms in creating the maintenance and preservation of soil fertility. They take part in the formation of soil humus - humus. They are used to increase crop yields.

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

The selection of microorganisms is based on the fact that microorganisms are of great benefit in industry, in agriculture, in the animal and plant world.

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 by genetic engineering. 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 the composition of vaccine preparations. More efficient production of viral proteins in animal cell cultures based on recombinant DNA technology.

In oil production:

In recent years, methods of enhanced oil recovery using microorganisms have been developed. Their perspective is connected, first of all, with ease of implementation, minimal capital intensity and environmental safety. In the 1940s, research began in many oil-producing countries on the use of microorganisms to stimulate production 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, glycerin), 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 trend towards low-calorie and plant-based foods to add variety to the taste and smell of food. Aromatic substances of plant origin can be produced by the expression of plant genes in microorganism cells.

One of the many animal kingdoms is bacteria. In this article we will talk about the role of bacteria in nature and human life, we will introduce the pathogenic representatives of this kingdom.

Bacteria in nature

These living organisms were among the first to appear on our planet. They are distributed everywhere. Bacteria live at the bottom of water bodies, in the soil, and can withstand both low and high temperatures.

The importance of these organisms in nature is undeniable. It is the bacteria that provide the cycle of substances in nature, which is fundamental to life on Earth. Organic compounds under their influence change and decompose into inorganic substances.

Soil-forming processes are provided by soil microorganisms. The remains of plants and animals decay and are transformed into humus and humus only thanks to bacteria.

In the aquatic environment, representatives of this kingdom are used to purify reservoirs, as well as wastewater. Due to their vital activity, bacteria turn dangerous organic substances into safe inorganic ones.

Rice. 1. The role of bacteria in nature.

pathogens

However, there are bacteria that harm other living organisms. Pathogens can cause disease in plants, animals, and humans. For example:

Salmonella causes typhoid fever;
Shigella - dysentery;
Clostridium - tetanus and gangrene;
Tuberculosis bacillus - tuberculosis
Staphylococci and streptococci - suppuration, etc.

Transmission routes can be varied:

when sneezing, talking, coughing from a sick person;
during physical contact;
with the help of carriers (insects, rodents);
through wound penetration.

Many diseases end in death, because of their ability to adapt to drugs, bacteria are not so easy to destroy. Modern science is actively fighting pathogens, releasing new drugs.

Rice. 2. Pathogenic microorganisms.

The study of the physiology of bacteria was founded by Louis Pasteur in the 1850s. His research was continued by M. V. Beyerink and S. N. Vinogradsky, who investigated the importance of microorganisms in nature.

Use of bacteria

Mankind has learned to use bacteria for its own benefit, for example:

in the manufacture of medicines;

There are special types of bacteria that are capable of producing the strongest antibiotics, such as tetracycline and streptomycin. By their action, they kill many pathogens.

preparation of new foodstuffs;
release of organic substances;
obtaining fermented milk products (yogurts, starter cultures, kefirs, fermented baked milk);
production of various types of cheeses;
winemaking;
marinating and fermenting vegetables.

Rice. 3. Human use of bacteria.

Bacteria have been living on planet Earth for more than 3.5 billion years. During this time they have learned a lot and adapted to a lot. Now they are helping people. Bacteria and man became inseparable. The total mass of bacteria is enormous. It is about 500 billion tons.

Beneficial bacteria perform two of the most important ecological functions - they fix nitrogen and participate in the mineralization of organic residues. The role of bacteria in nature is global. They are involved in the movement, concentration and dispersion of chemical elements in the earth's biosphere.

The importance of bacteria beneficial to humans is great. They make up 99% of the entire population that inhabit his body. Thanks to them, a person lives, breathes and eats.

Important. They provide complete life support.

Bacteria are pretty simple. Scientists suggest that they first appeared on planet Earth.

Beneficial bacteria in the human body

The human body is inhabited by both useful and. The existing balance between the human body and bacteria has been polished for centuries.

As scientists have calculated, the human body contains from 500 to 1000 different types of bacteria or trillions of these amazing residents, which is up to 4 kg of total weight. Up to 3 kilograms of microbial bodies is found only in the intestines. The rest of them is in the urogenital tract, on the skin and other cavities of the human body. Microbes fill the body of a newborn from the first minutes of his life and finally form the composition of the intestinal microflora by 10-13 years.

Streptococci, lactobacilli, bifidobacteria, enterobacteria, fungi, intestinal viruses, non-pathogenic protozoa live in the intestine. Lactobacilli and bifidobacteria make up 60% of the intestinal flora. The composition of this group is always constant, they are the most numerous and perform the main functions.

bifidobacteria

The importance of this type of bacteria is enormous.

Thanks to them, acetate and lactic acid are produced. By acidifying their habitat, they inhibit the growth that causes decay and fermentation.
Thanks to bifidobacteria, the risk of developing food allergies in babies is reduced.
They provide antioxidant and antitumor effects.
Bifidobacteria are involved in the synthesis of vitamin C.
Bifido- and lactobacilli are involved in the absorption of vitamin D, calcium and iron.

Rice. 1. The photo shows bifidobacteria. Computer visualization.

coli

The importance of this type of bacteria for humans is great.

Special attention is paid to the representative of this genus Escherichia coli M17. It is able to produce the substance cocilin, which inhibits the growth of a number of pathogenic microbes.
With the participation, vitamins K, group B (B1, B2, B5, B6, B7, B9 and B12), folic and nicotinic acids are synthesized.

Rice. 2. The photo shows E. coli (3D computer image).

The positive role of bacteria in human life

With the participation of bifido-, lacto-, and enterobacteria, vitamins K, C, group B (B1, B2, B5, B6, B7, B9 and B12), folic and nicotinic acids are synthesized.
Due to the breakdown of undigested food components from the upper intestines - starch, cellulose, protein and fat fractions.
The intestinal microflora maintains water-salt metabolism and ionic homeostasis.
Due to the secretion of special substances, the intestinal microflora inhibits the growth of pathogenic bacteria that cause putrefaction and fermentation.
Bifido-, lacto-, and enterobacteria take part in the detoxification of substances that enter from the outside and are formed inside the body itself.
The intestinal microflora plays an important role in restoring local immunity. Thanks to it, the number of lymphocytes, the activity of phagocytes and the production of immunoglobulin A increase.
Thanks to the intestinal microflora, the development of the lymphoid apparatus is stimulated.
The resistance of the intestinal epithelium to carcinogens increases.
Microflora protect the intestinal mucosa and provide energy to the intestinal epithelium.
They regulate intestinal motility.
The intestinal flora acquires the skills to capture and remove viruses from the host organism, with which it has been in symbiosis for many years.
The importance of bacteria in maintaining the body's thermal balance is great. The intestinal microflora feeds on substances that are not digested by the enzymatic system, which come from the upper gastrointestinal tract. As a result of complex biochemical reactions, a huge amount of thermal energy is produced. Heat is carried throughout the body with blood flow and enters all internal organs. That is why a person always freezes when starving.
The intestinal microflora regulates the reabsorption of bile acid components (cholesterol), hormones, etc.

Rice. 3. In the photo, beneficial bacteria are lactobacilli (3D computer image).

The role of bacteria in nitrogen production

ammonifying microbes(causing decay), with the help of a number of enzymes they have, they are able to decompose the remains of dead animals and plants. When proteins decompose, nitrogen and ammonia are released.

Urobacteria decompose urea, which man and all animals of the planet secrete daily. Its quantity is huge and reaches 50 million tons per year.

A certain type of bacteria is involved in the oxidation of ammonia. This process is called nitrofication.

Denitrifying microbes return molecular oxygen from the soil to the atmosphere.

Rice. 4. In the photo, beneficial bacteria are ammonifying microbes. They expose the remains of dead animals and plants to decomposition.

The role of bacteria in nature: nitrogen fixation

The importance of bacteria in the life of humans, animals, plants, fungi and bacteria is enormous. As you know, nitrogen is necessary for their normal existence. But bacteria cannot absorb nitrogen in the gaseous state. It turns out that blue-green algae can bind nitrogen and form ammonia ( cyanobacteria), free-living nitrogen fixers and special . All these useful bacteria produce up to 90% of the bound nitrogen and involve up to 180 million tons of nitrogen in the nitrogen fund of the soil.

Nodule bacteria coexist well with leguminous plants and sea buckthorn.

Plants such as alfalfa, peas, lupins and other legumes have so-called "apartments" for nodule bacteria on their roots. These plants are planted on depleted soils to enrich them with nitrogen.

Rice. 5. The photo shows nodule bacteria on the surface of the root hair of a legume plant.

Rice. 6. Photo of the root of a leguminous plant.

Rice. 7. In the photo, beneficial bacteria are cyanobacteria.

The role of bacteria in nature: the carbon cycle

Carbon is the most important cellular substance of the animal and plant world, as well as the plant world. It makes up 50% of the dry matter of the cell.

A lot of carbon is found in the fiber that animals eat. In their stomach, fiber decomposes under the action of microbes and then, in the form of manure, gets outside.

Decompose fiber cellulose bacteria. As a result of their work, the soil is enriched with humus, which significantly increases its fertility, and carbon dioxide is returned to the atmosphere.

Rice. 8. Intracellular symbionts are colored green, the mass of processed wood is colored yellow.

The role of bacteria in the conversion of phosphorus, iron and sulfur

Proteins and lipids contain a large amount of phosphorus, the mineralization of which is carried out You. megatherium(from the genus of putrefactive bacteria).

iron bacteria participate in the processes of mineralization of organic compounds containing iron. As a result of their activities, a large amount of iron ore and ferromanganese deposits are formed in swamps and lakes.

Sulfur bacteria live in water and soil. There are many of them in manure. They participate in the process of mineralization of sulfur-containing substances of organic origin. In the process of decomposition of organic sulfur-containing substances, hydrogen sulfide gas is released, which is extremely toxic to the environment, including to all living things. Sulfur bacteria, as a result of their vital activity, convert this gas into an inactive, harmless compound.

Rice. 9. Despite the apparent lifelessness, there is still life in the Rio Tinto River. These are various iron-oxidizing bacteria and many other species that can only be found in this place.

Rice. 10. Green sulfur bacteria in the Winogradsky column.

The role of bacteria in nature: mineralization of organic residues

Bacteria that take an active part in the mineralization of organic compounds are considered cleaners (orderlies) of the planet Earth. With their help, the organic matter of dead plants and animals turns into humus, which soil microorganisms turn into mineral salts, which are so necessary for building the root, stem and leaf systems of plants.

Rice. 11. Mineralization of organic substances entering the reservoir occurs as a result of biochemical oxidation.

The role of bacteria in nature: fermentation of pectins

The cells of plant organisms bind to each other (cement) with a special substance called pectin. Some types of butyric acid bacteria have the ability to ferment this substance, which, when heated, turns into a gelatinous mass (pectis). This feature is used when soaking plants containing a lot of fibers (flax, hemp).

Rice. 12. There are several ways to obtain trusts. The most common is the biological method, in which the connection of the fibrous part with the surrounding tissues is destroyed under the influence of microorganisms. The process of fermentation of pectin substances of bast plants is called lobe, and soaked straw is called trust.

The role of bacteria in water purification

water purifying bacteria, stabilize the level of its acidity. With their help, bottom sediments are reduced, the health of fish and plants living in the water improves.

Recently, a group of scientists from different countries have discovered bacteria that destroy detergents that are part of synthetic detergents and some drugs.

Rice. 13. The activity of xenobacteria is widely used to clean up soils and water bodies contaminated with oil products.

Rice. 14. Plastic domes that purify water. They contain heterotrophic bacteria that feed on carbon-containing materials, and autotrophic bacteria that feed on ammonia and nitrogen-containing materials. The tube system keeps them alive.

The use of bacteria in the enrichment of ores

Ability thionic sulfur-oxidizing bacteria used to enrich copper and uranium ores.

Rice. 15. In the photo, beneficial bacteria are Thiobacilli and Acidithiobacillus ferrooxidans (electron micrograph). They are able to extract copper ions for leaching of wastes that are formed during the flotation enrichment of sulfide ores.

The role of bacteria in butyric fermentation

Butyric microbes are everywhere. There are more than 25 types of these microbes. They take part in the process of decomposition of proteins, fats and carbohydrates.

Butyric fermentation is caused by anaerobic spore-forming bacteria belonging to the genus Clostridium. They are able to ferment various sugars, alcohols, organic acids, starch, fiber.

Rice. 16. In the photo, butyric microorganisms (computer visualization).

The role of bacteria in animal life

Many species of the animal world feed on plants, which are based on fiber. To digest fiber (cellulose) animals are helped by special microbes, the residence of which is certain sections of the gastrointestinal tract.

Importance of bacteria in animal husbandry

The vital activity of animals is accompanied by the release of a huge amount of manure. From it, some microorganisms can produce methane ("marsh gas"), which is used as a fuel and raw material in organic synthesis.

Rice. 17. Methane gas as a fuel for cars.

The use of bacteria in the food industry

The role of bacteria in human life is enormous. Lactic acid bacteria are widely used in the food industry:

in the production of curdled milk, cheeses, sour cream and kefir;
when fermenting cabbage and pickling cucumbers, they take part in urinating apples and pickling vegetables;
they give a special flavor to wines;
produce lactic acid, which ferments milk. This property is used for the production of curdled milk and sour cream;
in the preparation of cheeses and yogurts on an industrial scale;
lactic acid serves as a preservative during the brining process.

Lactic acid bacteria are milk streptococci, creamy streptococci, bulgarian, acidophilic, grain thermophilic and cucumber sticks. Bacteria of the genus Streptococcus and Lactobacillus give the products a thicker texture. As a result of their vital activity, the quality of cheeses improves. They give the cheese a certain cheese flavor.

Rice. 18. In the photo, beneficial bacteria are lactobacilli (pink), Bulgarian stick and thermophilic streptococcus.

Rice. 19. In the photo, beneficial bacteria are kefir (Tibetan or milk) mushroom and lactic acid sticks before being directly introduced into milk.

Rice. 20. Dairy products.

Rice. 21. Thermophilic streptococci (Streptococcus thermophilus) are used in the preparation of mozzarella cheese.

Rice. 22. There are many options for mold penicillin. Velvety crust, greenish veins, unique taste and medicinal ammonia aroma of cheeses are unique. The mushroom taste of cheeses depends on the place and duration of ripening.

Rice. 23. Bifiliz - a biological preparation for oral administration, containing a mass of live bifidobacteria and lysozyme.

The use of yeast and fungi in the food industry

The food industry mainly uses the yeast species Saccharomyces cerevisiae. They carry out alcoholic fermentation, which is why they are widely used in the baking business. The alcohol evaporates during baking, and carbon dioxide bubbles form the bread crumb.

Since 1910, yeast has been added to sausages. Yeast of the species Saccharomyces cerevisiae is used for the production of wines, beer and kvass.

Rice. 24. Kombucha is a friendly symbiosis of vinegar sticks and yeast. It appeared in our area in the last century.

Rice. 25. Dry and wet yeast are widely used in the baking industry.

Rice. 26. Microscopic view of Saccharomyces cerevisiae yeast cells and Saccharomyces cerevisiae - "real" wine yeast.

The role of bacteria in human life: acetic acid oxidation

Pasteur also proved that special microorganisms take part in acetic acid oxidation - vinegar sticks which are widely found in nature. They settle on plants, penetrate into ripened vegetables and fruits. There are many of them in pickled vegetables and fruits, wine, beer and kvass.

The ability of vinegar sticks to oxidize ethyl alcohol to acetic acid is used today to produce vinegar used for food purposes and in the preparation of animal feed - ensiling (canning).

Rice. 27. The process of ensiling fodder. Silage is a succulent feed with a high nutritional value.

The role of bacteria in human life: the production of drugs

The study of the vital activity of microbes has allowed scientists to use some bacteria for the synthesis of antibacterial drugs, vitamins, hormones and enzymes.

They help fight many infectious and viral diseases. Most antibiotics are produced actinomycetes, less often non-micellar bacteria. Penicillin, derived from fungi, destroys the cell wall of bacteria. Streptomycetes produce streptomycin, which inactivates the ribosomes of microbial cells. hay sticks or Bacillus subtilis acidify the environment. They inhibit the growth of putrefactive and conditionally pathogenic microorganisms due to the formation of a number of antimicrobial substances. Hay stick produces enzymes that destroy substances that are formed as a result of the putrefactive decay of tissues. They are involved in the synthesis of amino acids, vitamins and immunoactive compounds.

Using the technology of genetic engineering, today scientists have learned to use for the production of insulin and interferon.

A number of bacteria are supposed to be used to produce a special protein that can be added to livestock feed and human food.

Rice. 28. In the photo, spores of hay bacillus or Bacillus subtilis (painted blue).

Rice. 29. Biosporin-Biopharma is a domestic drug containing apathogenic bacteria of the genus Bacillus.

Using bacteria to produce safe herbicides

Today, the technique is widely used phytobacteria for the production of safe herbicides. toxins Bacillus thuringiensis emit Cry-toxins dangerous for insects, which makes it possible to use this feature of microorganisms in the fight against plant pests.

The use of bacteria in the production of detergents

Proteases or cleave peptide bonds between the amino acids that make up proteins. Amylase breaks down starch. hay stick (B. subtilis) produces proteases and amylases. Bacterial amylases are used in the manufacture of laundry detergent.

Rice. 30. The study of the vital activity of microbes allows scientists to apply some of their properties for the benefit of man.

The importance of bacteria in human life is enormous. Beneficial bacteria have been constant companions of man for many millennia. The task of mankind is not to disturb this delicate balance that has developed between the microorganisms living inside us and in the environment. The role of bacteria in human life is enormous. Scientists are constantly discovering the beneficial properties of microorganisms, the use of which in everyday life and in production is limited only by their properties.

Articles in the section "What do we know about microbes"Most popular

Portal for the student. Self-training

The role of bacteria in human life. Beneficial bacteria

Importance of bacteria in our life. The discovery of penicillin and the development of medicine. The results of the use of antibiotics in the plant and animal world. What are probiotics, the principle of their action on the body of people and animals, plants, the benefits of using.

The role of microorganisms in food production technology

Similar Documents

The main groups of microorganisms used in the food industry

Production Human use of microorganisms.

The use of microorganisms in the food industry

Bacteria in nature

pathogens

Use of bacteria

Beneficial bacteria in the human body

bifidobacteria

coli

The positive role of bacteria in human life

The role of bacteria in nitrogen production

The role of bacteria in nature: nitrogen fixation

The role of bacteria in nature: the carbon cycle

The role of bacteria in the conversion of phosphorus, iron and sulfur

The role of bacteria in nature: mineralization of organic residues

The role of bacteria in nature: fermentation of pectins

The role of bacteria in water purification

The use of bacteria in the enrichment of ores

The role of bacteria in butyric fermentation

The role of bacteria in animal life

Importance of bacteria in animal husbandry

The use of bacteria in the food industry

The use of yeast and fungi in the food industry

The role of bacteria in human life: acetic acid oxidation

The role of bacteria in human life: the production of drugs

Using bacteria to produce safe herbicides

The use of bacteria in the production of detergents

Portal for the student. Self-training

Importance of bacteria in our life. The discovery of penicillin and the development of medicine. The results of the use of antibiotics in the plant and animal world. What are probiotics, the principle of their action on the body of people and animals, plants, the benefits of using.

The role of microorganisms in food production technology

Similar Documents

The main groups of microorganisms used in the food industry

Production Human use of microorganisms.

The use of microorganisms in the food industry

Bacteria in nature

pathogens

Use of bacteria

Beneficial bacteria in the human body

bifidobacteria

coli

The positive role of bacteria in human life

The role of bacteria in nitrogen production

The role of bacteria in nature: nitrogen fixation

The role of bacteria in nature: the carbon cycle

The role of bacteria in the conversion of phosphorus, iron and sulfur

The role of bacteria in nature: mineralization of organic residues

The role of bacteria in nature: fermentation of pectins

The role of bacteria in water purification

The use of bacteria in the enrichment of ores

The role of bacteria in butyric fermentation

The role of bacteria in animal life

Importance of bacteria in animal husbandry

The use of bacteria in the food industry

The use of yeast and fungi in the food industry

The role of bacteria in human life: acetic acid oxidation

The role of bacteria in human life: the production of drugs

Using bacteria to produce safe herbicides

The use of bacteria in the production of detergents

RELATED ARTICLES