Research work on the biology of bacteria. "Ah, those bacteria!" Research work

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Purpose of the study: study the characteristics of the vital activity of bacteria; learn about diseases caused by bacteria and their prevention.

• study the available literature on the subject;
• analyze the effect of pathogenic bacteria on the human body;
• receive and summarize information from the infectious diseases doctor of Rospotrebnadzor about bacterial diseases in our area, their prevention.

Research methods:

• study of literature;
• collection of information;
• analysis of the collected information and systematization;
• presentation of results.

Lesson progress

Introduction.

In the 5th grade we started to study a new subject - biology. I was interested in the chapter “Bacteria Kingdom” and I had questions:

Why are bacteria, relatively simple microscopic single-celled organisms, so viable?

What conditions contribute to the spread of pathogenic bacteria and what preventive measures are in place?

Theoretical part

Bacteria were first seen through an optical microscope and described by the Dutch naturalist Anthony van Leeuwenhoek in 1676. Like all microscopic creatures, he called them "animalcules".

The name "bacteria" was coined by Christian Ehrenberg in 1828.

Louis Pasteur in the 1850s initiated the study of the physiology and metabolism of bacteria, and also discovered their pathogenic properties.

Medical microbiology was further developed in the works of Robert Koch, who formulated general principles definition of the causative agent of the disease (Koch's postulates). In 1905 he was awarded the Nobel Prize for tuberculosis research.

The study of the structure of a bacterial cell began with the invention of the electron microscope in the 1930s.

The body of bacteria consists of a single cell. This cell is arranged completely differently than the cells of plants, animals and fungi. If their cells are separated by numerous partitions (membranes) into special compartments where the processes of respiration, nutrition, photosynthesis, etc. are carried out, then the “blocking” of the bacterium is in its most rudimentary stage. The most important difference is that bacteria do not have a nucleus. Another difference is that there are no mitochondria and plastids. DNA in bacteria is located in the center of the cell, folded into a chromosome. If you “unroll” the DNA of a bacterium, its length will be about 1 mm.

Under favorable conditions, bacterial cells multiply very quickly, dividing in two. If a cell doubles every half an hour, then in a day it is able to give offspring. And some bacteria can multiply even faster.

And another one interesting ability bacteria. Under adverse conditions, they can often turn into spores. Such disputes remain alive for tens and hundreds of years, and in exceptional cases, even millions of years.

These features of bacteria allow them to survive in any conditions.

Depending on the shape of the cells, bacteria are divided into several groups: spherical - cocci, rod-shaped - bacilli or rods, spiral - spirilla, in the form of a comma - vibrios.

Human diseases caused by bacteria

Bacterial diseases are among the most common human diseases. Such diseases include some pneumonia (causative agent streptococcus), anthrax (causative agent - bacilli anthrax), cholera (causative agent Vibrio cholerae), tuberculosis (causative agent - tuberculosis bacillus (Koch's bacillus), plague (causative agent - plague bacillus) and others.

"Black Death" in ancient times and in the Middle Ages was called this disease, which inspired people with panic horror. In the VI century. the plague epidemic killed 100 million people. Some states, such as the Byzantine Empire, were almost completely depopulated.

From 1346 to 1351, 24 million people died from the plague (“great pestilence”, as they said then) - a quarter of the population of then Europe. With a story about the plague epidemic in 1348, the Italian Renaissance writer Giovanni Boccaccio begins his book “The Decameron”: people called them buboes. In a short time, this deadly tumor spread to other parts of the body, and then the symptom of this disease changed into black and purple spots that appeared on all parts of the body. It seemed that neither the doctor's advice nor the strength of the medicine helped or benefited against this disease ... neither the wisdom nor the foresight of a person helped against it. Almost everyone died on the third day after the appearance of these signs.

In the XX century. plague epidemics practically ceased to threaten humans. Why did this happen? Of course, the systematic fight against this disease has played its role. Almost disappeared, displaced by the gray rat, the black rat, whose fleas served as carriers of the disease. But still, an exhaustive and accurate answer to the question of why the plague epidemics stopped has not yet been found.

Cholera is often compared to the plague because of its short duration and lethality. Cholera was brought to Europe only around 1816 from India, where it had been known since ancient times. In Russia, before 1917, more than 5 million people had been ill with cholera, and half of them died.

By the end of the XX century. epidemics of cholera have become quite rare thanks to prevention. We are currently living in the era of the 7th pandemic. For Russia, the problem remains relevant, the epidemic situation is assessed as unstable.

cholera prevention

Since cholera is a “disease of dirty hands”, it is necessary to wash your hands systematically before each meal, and in no case should you touch the mucous membranes of your mouth with unwashed hands. Wash hands only with hot water. Products must be kept in a place protected from flies and insects. Hygiene skills are the main weapon in the fight against cholera.

TUBERCULOSIS.

The sinister symptoms of pulmonary tuberculosis (consumption) - weakness, shortness of breath, and with advanced disease and hemoptysis - were familiar to the inhabitants of ancient Egypt and people who lived hundreds of thousands of years ago. This was shown by studies of their remains.
In antiquity and in the Middle Ages, there was a belief that crowned persons could cure tuberculosis with their touch. English King Charles II in the 17th century. touched more than 90 thousand patients. For the "treatment" a considerable fee was charged, which went to the royal treasury.

Only in the 19th century the first tuberculosis sanatoriums appeared. But the real fight against this disease began after the discovery of the tuberculosis bacterium by Robert Koch in 1882.

Tuberculosis has not been completely eradicated even today. In the former Soviet Union, prisons and camps have become breeding grounds for tuberculosis, where a significant proportion of prisoners become infected with the disease. Tuberculosis is a social infection. “The poorer the population, the more often it suffers from tuberculosis”

Prevention of tuberculosis

For newborns, BCG vaccination is essential. Further, according to the stage of their maturation, a mandatory (every 8-12 months) setting of the Mantoux reaction is carried out. It is desirable to choose a place of residence in dry, well-lit places. The apartment is systematically done wet cleaning and ventilation.

Ways of transmission of pathogenic bacteria

Airborne way;

Handshake;

Houseware;

contaminated water and food;

Carriers of diseases are rodents, fleas, ticks, lice, cattle.

The poet Vladimir Mayakovsky, who undertook any kind of propaganda work, even wrote a poetic explanation for a poster dedicated to the fight against cholera. : “Citizen!

Not to die from cholera
take such steps in advance.
Don't drink raw water.
Drink only boiled water.
Also, do not drink kvass on the street.
Boiling water is a lot of work.
To keep up with your kvass early,
they just cook it from the tap...”

How does a bacterial infection progress?

With the development of a bacterial infection one of the first symptoms will be fever. Fever is a protective reaction of the body, as body temperature up to 39 degrees stimulates the immune system. If the body temperature rises above 39 degrees, then it must be brought down with paracetamol or, indirectly, with antibiotics (a decrease in body temperature within 24-48 hours from the start of antibiotic therapy is a sign of a properly selected antibacterial drug).

Another manifestation of the bacterial infectious process is the intoxication syndrome. It is manifested by a deterioration in well-being, apathy, a decrease in mood, headaches, pain in muscles and joints, nausea, vomiting, and the like are possible. To relieve these symptoms, you need to drink plenty of warm water (at least 2 liters per day). Excess water will dilute the bacterial toxins, reducing their concentration, and also remove some of them in the urine.

These two signs of bacterial inflammation are universal to almost all infections. All other signs are due to the characteristics of a particular pathogen, their exotoxins and other factors of aggression.

Immunity- immunity of the body to a foreign agent, in particular, to bacteria.

Human immunity protects our body constantly and always.

Task and human immunity find and neutralize bacteria that have entered the body, as well as their toxins.

To prevent the disease, some bacterial diseases are vaccinated. At the same time, weakened pathogens or poisons secreted by them are introduced into the body of a healthy person. The body creates special substances that help the vaccinated person to quickly cope with pathogenic bacteria in the future.

Practical part

It must be said that in Lately there is a “crowding out” of bacterial infections by viral ones, but their significance does not cease to be relevant. So, for example, in the 90s, having “calmed down” that diphtheria was not registered, the percentage of those vaccinated against this infection decreased, as a result, an increase in the incidence, outbreaks of this infection with fatal outcomes that could have been avoided. Among bacterial infections, intestinal infections occupy a huge place:

• cholera
• typhoid fever
• dysentery
• salmonellosis.

Incidence of bacterial infections by country

№	Diseases	cases	Causes	Prevention
1.	Cholera	1994 - Chechen Republic, 415 cases; 2005 - Rostov region; 2006 - Murmansk region; 2008 - Bashkiria; 2010 - Moscow.	Changing socio-economic conditions: refugees, tourism, pilgrims; worsening of the ecological situation poor water quality	- Improving water quality Cleaning, sewerage of populated areas; Strict supervision of the work of public catering, the quality of products, suspension of patients from work; Compliance with the rules of personal hygiene; Veterinary Animal Control
2.	Typhoid fever	Cases of infection are constantly recorded in Russia	Migration, unsatisfactory state of cleaning of populated areas; poor quality of water supply, catering
3.	Dysentery Salmonellosis		Non-compliance with the rules of personal hygiene, eating contaminated products
4.	Tuberculosis	IN last years the number of new cases is constantly growing	Social - poverty of the population	- Early immunization of newborns; Statement of the Mantoux reaction for all children; Fluorography (adult population)

What about bacterial infections in our area? What are their causes and prevention? I learned about this from a doctor - an infectious disease specialist of the territorial department of Rospotrebnadzor in the Valdai district of Guseva Natalya Tomovna.

Incidence of bacterial infections by region

Disease	2005		2006		2007		2008		2009		2010		2011			2012
																area		region
	abs	per 100 thousand	abs	per 100 thousand	abs	per 100 thousand	abs	per 100 thousand	abs	per 100 thousand	abs	per 100 thousand	abs	per 100 thousand	abs		per 100 thousand	abs
Dysentery	9	59,4	5	33,0	5	34,0	-	-	-	-	-	-	-	-	-		-
salmonellosis	-	-	-	-	2	13,7	-	-	-	-	-	-	3	23,7	1		8,0
Scarlet fever	1	6,6	-	-	15	103,2	3	20,6	7	49,2	4	28,7	-	-	1		8,0
Diphtheria	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-		-	7
Whooping cough	-	-	-	-	-	-	-	-	-	-	3	21,5	-	-	-		-	7221
meningococcal infection	1	6,6	-	-	-	-	-	-	-	-	1	7,2	-	-	1		8,0
Tuberculosis	9	59,4	3	19,8	7	48,1	9	61,9	10	70,3	11	79,0	4	31,6	3		24

The diagram shows that over the past 5 years, no cases of dysentery and diphtheria have been registered (although 7 cases were noted in the region in 2012). Meningococcal infection (there was 1 death), salmonellosis and scarlet fever are constantly recorded. But the most noticeable increase is the number of new cases of tuberculosis patients and the average number of annually registered patients in our region is 6-7 people.

Recently, there have been many parents who refuse to vaccinate their children, thereby exposing their children to mortal danger, as well as endangering other children. It is reliably known that a decrease in the incidence is possible only with a high level of immunization of the population - 99%, in 2012 this figure for all infections in our region decreased to 94%.

The implementation of this study allowed me to develop the skills of working with additional literature, the ability to conduct research, and substantiate the results of research.

During my research work, I came to the conclusion:

1) bacterial diseases are still one of the most common diseases;

2) to protect yourself from bacteria, you need to follow the rules of personal hygiene, do not eat unwashed fruits and vegetables, do not drink unboiled water, eat only fresh food, and, of course, do not forget to wash your hands more often.

3) an effective measure for the prevention of bacterial infections is the immunization of children and adults.

Practical value work consists in the fact that the obtained materials can be used in biology lessons when studying the topic “Bacteria” or during extracurricular activities.

LITERATURE

1. Borisov L.B. etc. Medical microbiology, virology, immunology. M.: Medicine, 1994.

2. Vasiliev K.G. Segal A.E. History of epidemics in Russia. Moscow: Medgiz, 1960.

3. Likum A. Children's encyclopedia "Everything about everything." M.: AST, 2008

4. Galpershtein L.Ya. My first encyclopedia. ROSMEN, 2007.

5. Children's encyclopedia "I know the world." The medicine. M.: Astrel, 2006.

6. Internet resources (illustrated materials for the presentation)

bacteria work- — Topics oil and gas industry EN bacteria action … Technical Translator's Handbook

The medicine- I Medicine Medicine is a system of scientific knowledge and practice aimed at strengthening and maintaining health, prolonging people's lives, and preventing and treating human diseases. To accomplish these tasks, M. studies the structure and ... ... Medical Encyclopedia

Water- Since ancient times, people began to understand the great importance of water not only for people and all kinds of animal and plant organisms, but also for all life on Earth. Some of the first Greek philosophers even put water at the head of the understanding of things in nature, and ... ...

ENGLISH FILTERS- ENGLISH FILTERS. With water pipes that take water from rivers, lakes, ponds and some other bodies of water, sand filters are usually arranged. or americ. systems through which they purify water before sending it to the water supply network. A. f. ... ...

Biotechnology- Biotechnology is the integration of natural and engineering sciences, which allows the most complete realization of the possibilities of living organisms or their derivatives for the creation and modification of products or processes for various purposes. Most often used in ... ... Wikipedia

Terminology 1: : dw Number of the day of the week. "1" corresponds to Monday Term definitions from various documents: dw DUT The difference between Moscow and UTC, expressed as an integer number of hours Term definitions from ... ... Dictionary-reference book of terms of normative and technical documentation

BACTERIOLOGY- BACTERIOLOGY. Contents: I. Departments of bacteriology .......... 696 II. History of bacteriology, the main stages of its development............... 697 III. Methods Development, Teaching and Practical Importance 703 IV. Institutes and Laboratories… Big Medical Encyclopedia

BLOOD- BLOOD, a fluid that fills the arteries, veins and capillaries of the body and consists of a transparent pale yellowish. the color of the plasma and the shaped elements suspended in it: red blood cells, or erythrocytes, white, or leukocytes, and blood plaques, or ... Big Medical Encyclopedia

THE USSR. Natural Sciences- Maths Scientific research in the field of mathematics began to be carried out in Russia in the 18th century, when L. Euler, D. Bernoulli, and other Western European scientists became members of the St. Petersburg Academy of Sciences. According to the plan of Peter I, academicians foreigners ... ... Great Soviet Encyclopedia

Saltpeter formation* encyclopedic Dictionary F. Brockhaus and I.A. Efron

Saltpeter formation- saltpeter fermentation or nitrification in nature takes place on a large scale and is very important both because saltpeter is the most suitable source of nitrogenous food for plants, and because the huge mass of this ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

Books

• Soil Microbiology: Problems and Methods, S. N. Vinogradsky. "Soil Microbiology" by S. N. Vinogradsky is a collection of his selected works. It consists of ten different parts. The first part is devoted to autotrophs and ... Buy for 2003 rubles
• Hyperbots. Amazing robots, invented by nature itself, Becker H.. “People are arranged in a special way. In many ways, they are not as intelligent as we robots, because their circuits are less programmed. They say it has its benefits." Yes, as long as it's just...

Research Topic : Determination of contamination with spores of bacteria and fungi of different school premises

Job done :

Zharkova A., Petrunina D., Safoneeva V. students of the 10th grade.

MBOU high school №2

Lyskovo

Supervisor: Blinov A.E. biology teacher of the 1st category

different areas of the school

Research hypothesis .

• It is known that airing the room can reduce the level of bacterial air pollution, however, due to the cold winter, this possibility is limited.

2. It is also known that many indoor plants have volatile properties and can also reduce the number of microorganisms in the air.

3. It is possible to presumably include bacterial microorganisms, which can be opportunistic pathogens, and fungal organisms, which are allergens, in the composition of the air pool of the school.

choice of methodology, place of experiments and preparation of equipment; preparation and conduct of experiments; description and processing of the received data; conclusions." width="640"

Determination of bacterial and fungal spore contamination different areas of the school

aim of this study was the study of the microflora of the air basin of school premises, as well as the study of the cleanliness of the hands of students primary school. In the course of the research, the quantitative and qualitative composition of the air microflora of school No. 2 and the cleanliness of hands were studied.

Based on this, tasks studies were as follows:

Choice of technique, place of experiments and preparation of equipment;

Preparation and conduct of experiments;

Description and processing of the received data;

Conclusions.

Determination of bacterial and fungal spore contamination different areas of the school

The urgency of the problem.

Microbes are ubiquitous throughout environment. Air is a medium containing a significant number of microorganisms. The largest number of microorganisms contains the air of industrial cities, the air of enclosed spaces with a large crowd of people.

At present, when the use of disinfectants and disinfectants has been sharply weakened, there is a spread of diseases that were considered defeated. Outbreaks and epidemics of bacterial and viral diseases often occur in children's and school groups: dysentery, diphtheria, typhoid fever, hepatitis and many others. This circumstance makes it necessary to strengthen the sanitary and environmental control of air, especially in children's and school premises, in order to improve its sanitary condition.

Method for preparing nutrient media for growing microorganisms.

For the cultivation of microorganisms, various nutrient media are used. This is necessary for the differentiation of infectious diseases, for the preparation of vaccines, antibiotics, etc.

The following requirements are imposed on nutrient media: they must contain all the necessary substances for the nutrition of microbes, have a certain reaction of the medium, be sterile and must be moist. Nutrient media are divided into simple and complex.

Simple media include meat-peptone broth, meat-peptone agar, and meat-peptone gelatin (MPG). All simple nutrient media are prepared in meat water. For its preparation, the meat is separated from fat and fascia, crushed, poured with water in a ratio of 1: 2 and boiled for 30-60 minutes. Then it is filtered, topped up to the original volume and sterilized at a pressure of 0.1 MPa for 30 minutes.

Culture medium preparation

Dense gelatinous nutrient medium.

Ingredients: edible gelatin 30 g, Gallina Blanca chicken cube, fish, water 200 ml.

Cooking: pour gelatin into a glass of boiled water at room temperature, leave for 40 - 60 minutes. Boil fish - got fish broth. Dissolve chicken cube in fish broth, add gelatin and heat without boiling.

The method of sowing microorganisms on a nutrient medium

The method of sedimentation of dust particles containing spores of bacteria and fungi was used. Petri dishes were placed in various rooms of the school (canteen, recreation, toilet, hall in front of the entrance) and chaotic movements were made around these dishes (dust was raised) for 5 minutes.

Petri dishes were closed and placed in a dark cabinet.

The study of hand cleanliness in primary school students

Samples of fingerprints were taken on a nutrient medium from students elementary school(4 "B" class), Petri dishes are also placed in a dark cabinet.

Growing microorganisms

Growing microorganisms on a nutrient medium provides for the growth of these organisms for approximately 2 weeks to 2 months.

1st floor (recreation at the entrance)

Bacteria colony

Bacteria colony

Method for counting microorganisms

For quantitative accounting of microorganisms, such 3 dilutions are selected, when sown on a nutrient medium in a Petri dish, at least 50 and no more than 300 colonies grow. If few or many small colonies have grown, then they are counted with a magnifying glass, turning the cup upside down. If a large number of colonies have grown, then the bottom of the cup is divided into sectors, and counting is carried out in each sector. With a very large number of grown colonies, a special Wolfgügel counting chamber is used.

• Dining room - 6 large colonies of mold fungi;
• Recreation -3 large colonies of mold fungi;
• Hall - 1 large bacterial colony;
• Toilet colonies of bacteria and mold spores were not found.

• The first row is 10 bacterial colonies;
• Second row - 83 bacterial colonies;
• Third row - 54 bacterial colonies; 1 colony of fungi.

The most polluted room in the school is the canteen, and the cleanest is the bathroom. node. Why? Cleaning in the bathroom The unit is produced with a more concentrated solution of bleach (bleach), so contamination with spores of mold fungi and bacteria is minimal.

The school most visited by children is, of course, the dining room and buffet. It is because of this that it is the most polluted building in the school.

The cleanliness of the hands of children leaves much to be desired, on the hands of a large number of bacteria.

• Do a wet cleaning of the dining room more often.
• Use weak solutions of detergents and antiseptics.
• Carry out general cleaning of the premises at least 2 times a week.
• Ventilate rooms more often.
• Students must practice personal hygiene.
• Wash your hands not only before eating, but also between meals. training sessions(after 2, 3 lessons).

Maslov Arseniy

Research work of a 3rd grade student on the topic "Bacteria: harmful and beneficial."

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Relevance… Once I asked my parents why people get sick? Mom said that bacteria enter the body and the person gets sick. And then I thought, what are bacteria, where do they live, how do they reproduce and why are they dangerous? And are all bacteria harmful? The purpose of the study: to study the characteristics of the life of bacteria and find out whether they can be beneficial and harmful. Tasks: to study the literature on the chosen topic, to get acquainted with the diversity and classification of bacteria, to find out what are the harmful and beneficial bacteria, to cook homemade kefir

Object and subject of study Object of study: bacteria Subject of study: the importance of bacteria for humans Hypothesis Hypothesis: suppose that many bacteria live in the human body, they can be both beneficial and harmful and they can be propagated at home. Research methods: Working with additional sources, searching for the necessary information; Observations and analysis of the received information; Experiences; Test; Data processing

History of Bacteria Bacteria were first seen through an optical microscope and described in 1676 by the Dutch naturalist Anthony van Leeuwenhoek. The name "bacteria" was coined in 1828 by Christian Ehrenberg. The study of bacteria and their structure is carried out by microbiology, which was formed in the second half of the 19th century as the science of pathogens, that is, as a branch of medicine. It is difficult to find a place on Earth where there would be no bacteria. They are found in a wide variety of places: in the atmosphere and at the bottom of the oceans, in fast-flowing rivers and in permafrost, in fresh milk and in nuclear reactors; however, especially a lot of them in the soil

The structure of bacteria The bacterium has a complex structure The cell wall protects unicellular organism from external influences, gives a certain shape, provides nutrition and preservation of its internal contents. The plasma membrane contains enzymes, participates in the process of reproduction, biosynthesis of components. Flagella are called surface structures that serve to move cells in a liquid medium or on a solid surface. Cytoplasm serves to perform vital functions. In many species, the cytoplasm contains DNA, ribosomes, and various granules. Pili are filamentous formations, much thinner and smaller than flagella. They are of various types, differ in purpose, structure. Pili are needed to attach the body to the affected cell.

Types of bacteria cocci (have a rounded shape); bacilli (have a rod-shaped form); spirilla (have the shape of a spiral); spirilla (have the shape of a spiral);

Classification of bacteria Beneficial bacteria Escherichia coli It is an integral part of the intestinal flora of humans and most animals. Its benefits can hardly be overestimated: it breaks down indigestible monosaccharides, promoting digestion; prevents the development of pathogenic and pathogenic microorganisms in the intestine. Lactic acid bacteria Representatives of this order are present in milk, dairy and fermented products, and at the same time are part of the microflora of the intestines and oral cavity. Able to ferment carbohydrates and in particular lactose and produce lactic acid, which is the main source of carbohydrates for humans. By maintaining a constantly acidic environment, the growth of unfavorable bacteria is inhibited. Bifidobacteria Through the production of lactic and acetic acids, they completely prevent the development of putrefactive and pathogenic microbes in the child's body. In addition, bifidobacteria: contribute to the digestion of carbohydrates; protect the intestinal barrier from the penetration of microbes and toxins into the internal environment of the body

Harmful bacteria Salmonella This bacterium is the causative agent of a very acute intestinal infection, typhoid fever. Salmonella produces toxins that are dangerous only for humans. Tetanus bacillus This bacterium is one of the most persistent and at the same time the most dangerous in the world. Produces an extremely toxic poison, tetanus exotoxin, leading to almost complete defeat nervous system. Mycobacteria Mycobacteria are a family of bacteria, some of which are pathogenic. Various representatives of this family cause such dangerous diseases as tuberculosis, mycobacteriosis, leprosy (leprosy) - they are all transmitted by airborne droplets.

My experiences… Making homemade kefir

Cultivation of hay bacillus Among the bacteria that are widespread in nature is hay bacillus. It was first described in 1835. And it got its name due to the fact that initially the culture was isolated from rotten hay. This bacterium is one of the largest. It has a straight elongated shape with blunt rounded ends and is usually colorless. This bacterium is quite easy to obtain at home. For work, I needed the following: hay (you can buy it at a pet store), a pot of water, a jar with a wide neck, gauze for filtering. For one liter of water you need to take 10 grams of hay. Boil the hay for 20 minutes. The resulting broth is filtered and poured into a jar, diluted 1: 1 with settled cold water. In another jar, I decided to pour undiluted broth and see what happens. Banks put in a warm place. The best conditions for the life of hay sticks are a large amount of dissolved organic matter, an abundance of oxygen and a temperature of about +30 degrees. Under such conditions, a film consisting entirely of bacteria should form on the surface of the hay decoction in two days.

Results of the "Bacteria" test It turned out that many guys do not know about the kingdom of bacteria and the existence of beneficial bacteria in our dairy products.

Conclusion By studying bacteria, I got acquainted with their diversity and classification, I was able to grow bacteria on my own at home. I learned that there is a huge amount of beneficial bacteria that we consume every day with fermented milk products and about harmful bacteria (dangerous to humans) I found out that bacteria are an indispensable part of our life and all living things. They are absolutely everywhere and in everything, play a colossal role in human life. People have learned to use bacteria: Based on the above material and the studies, I believe that my hypothesis was confirmed: “Many bacteria live in the human body, they are both beneficial and harmful and they can be propagated at home”

Olga Gil
Research work on the topic: "Microorganisms that surround us"

Research

on the topic:

« Microorganisms, that surround us»

I've done the work:

Lyba Artem 6 years old

Supervisor:

Gil O.P.

Introduction

I often hear the same question from my parents when I sit down to eat, come back from a walk, return from kindergarten: "Did you wash your hands?" Parents take care and teach us to clean our hands, because dirty hands have a lot of microbes.

So I decided to learn more about organisms, which we do not see but we often talk about them.

the purpose of my research: find out what is microorganisms; helpful or harmful microorganisms.

Tasks:

Study and analyze information about microorganisms;

Conduct experiments with microorganisms

An object research: microorganisms

Subject research: benefit and harm from microorganisms.

Hypothesis: If microbes are harmful to health microorganisms are only harmful.

Methods research:

Analysis of literature, Internet materials;

Experiment.

Main part

During research i want to find out, what's happened microorganisms, establish their benefit and harm to us; conduct experiments to discover microorganisms; develop recommendations on how to protect yourself from harmful microbes.

What's happened microorganisms? I learned from literature interesting information about opening microorganisms. There was a time when even scientists believed that the smallest living creatures in the world were fleas! It never occurred to anyone that next to us, inside and around we have a huge world "invisible". Scientists have discovered this wonderful world using the device microscope, which the greatly magnified the object in question. And they did not immediately believe! But then they made sure. And they named the representatives of this world microbes or microorganisms(from the Greek word « micros» - little). Microorganisms(microbes) - invisible to the naked eye organisms of plant and animal origin. Invisible, but existing everywhere. Microbes- the real invisible masters of the Earth. Scientists have established that microbes appeared on Earth before all other living organisms. Microorganisms divided into several groups: bacteria, yeast, molds, viruses.

The main place among microbes are occupied by bacteria. It can be said that our entire earthly life largely depends on these bacteria. bacteria live everywhere: in the air and on the ground, in water and soil, in plants, animals and in humans.

Harm and benefit from microbes. Some bacteria, entering the human body, cause various diseases. For example, angina, diphtheria, pneumonia and all infections in open wounds are caused by certain types of bacteria. They are called pathogens. Infection occurs when drinking raw water or stale food. And also when communicating with sick people.

However, there are also beneficial bacteria, without which living on earth would be much more difficult.

If there were no decay-causing bacteria on Earth, our planet would gradually become covered with the remains of dead plants and animals. But rotting bacteria help these remains to rot.

Bacteria also help plants. Plants thrive best in soil rich in nitrogen. Nitrogen enters the soil through special bacteria. Some Bacteria are involved in the formation of minerals.

For many years man has used lactic bacteria to create many dairy products. If you add different bacteria to milk, you get cheese, yogurt, kefir, yogurt, cottage cheese. Bacteria help us ferment cabbage for the winter.

A sourdough starter is made from acetic bacteria.

Bacteria help ruminants animals: cows, elks, goats, horses digest plant foods.

Our stomach contains many intestinal bacteria: they help to cope with food: digest it. Most bacteria human body very useful for a person. The most beneficial bacteria, bifidobacteria, are the real defenders of the human body. As soon as it wants to penetrate any "harmful" bacteria, they fight it and kill it. People need to consume fermented milk products, as they contain a lot of bifidobacteria.

Thus, in the world of bacteria, not everyone is our enemy. Most bacteria are helpful.

My experiments

Not required to have microscope, to see microbes. I tried to find them right in my kitchen.

How to make kefir at home?

Many of us love kefir. And how to cook it? Of course with the help of useful microorganisms-bacteria. For this I needed raw milk, sour cream. We heat the milk until warm. We take a glass and put a couple of teaspoons of sour cream on the bottom. Pour in warm milk, stir until smooth and put in a warm place. I did everything in the evening, and in the morning the kefir was already ready.

Output: This happened due to the fact that in milk, sour cream there are always some bacteria - lactic acid. When warm, they begin to multiply rapidly. As a result, the fermentation process begins in the milk and a lot of lactic acid appears in it. Which is what I observed.

Live yeast. Dry yeast is like little lifeless balls. But this is only until millions of tiny microbes, which dormant in a cold and dry form.

I needed flour, milk and dry yeast. Let's knead the dough. We put one part of the dough in a warm place, and the other in a cool place. After 30 minutes, compare and see the difference. In a warm place, fermentation was faster.

This is the result work of microbes - yeast.

In a warm place:

In a cold place:

Output: Yeast is sensitive to temperature, the warmer it is, the faster fermentation will occur.

Fungi - we can also see in our kitchen. If you leave any piece of food for a long time in a warm, dark and humid place (namely, such places microbes love the most, then mold will form on it.

To get mold, I need a piece of bread, a container. At the bottom of the container, I put bread, added a little water, put the container in a warm place. After a few days, mold developed.

Output: favorable terms: temperature, high humidity, so mold appeared.

Conclusion

Our hypothesis was not confirmed. Microbes are harmful and beneficial. I was able to establish that more beneficial microbes. I found out where they live microbes what benefits we get from them, what harm they can do to us.

I have been able to experiment which prove the existence microbes.

I plan to continue work on the study of microorganisms, since the world microbes are very large.

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