KINGDOM OF PROKARYOTES
SUBKINGDOM BACTERIA

Bacteria are prokaryotes.
These are the simplest, smallest and
widespread organisms
which have existed on earth for more than 2 billion years, but at the same time constantly
developing. Bacteria are so
differ from other living organisms that they are classified into a special kingdom. There are not many places in the world that are free of bacteria.
They live in water, soil, air,
inside and on the surface of animal bodies
and plants.

Structure of a bacterial cell

SIZES OF BACTERIA

Bacterial cells are very small.

GROUPS OF TRUE BACTERIA

cocci (spherical) - solitary

diplococci (collected in twos)

streptococci (in the form of a chain)

staphylococci (in the form of a bunch of grapes)

Sarcinas (in the form of dense packs)

bacilli (rod-shaped)

convoluted - vibrios (comma-shaped)

spirilla (one or more
correct curls)

Bacteria are divided into two groups based on their feeding method.

HETEROTROPHS
(they are not capable
synthesize
organic
substance,
and eat ready-made)

AUTOTROPHES
(able
synthesize
organic matter
from
inorganic)

Heterotrophs are divided into three groups

SAPROPHYTES
bacteria that
eat organic
dead substances
organisms
(lactic acid
bacteria,
putrefaction bacteria)

SYMBIOTES
close cohabitation
bacteria with live
organisms
beneficial
each other
(nodule bacteria
on legume roots)

Slide No. 10

Most bacteria can use almost any organic compound as an energy source, even substances used to destroy them (for example, penicillin, which kills many bacteria). This is due to the fact that bacteria can live both in the presence of oxygen in the environment and in its absence.

Slide No. 11

Bacteria are divided into two groups based on their feeding method.

Anaerobic
(decompose organic substances without oxygen)

Aerobic
(during breathing
use oxygen
for the oxidation of organic matter)

Slide No. 12

In relation to the development temperature, bacteria are also very diverse: some develop over a wide range of temperature changes, others - only at certain temperatures (low, high or in a narrow temperature range).

Slide No. 13

BACTERIAL REPRODUCTION

Under favorable conditions, bacterial cells multiply very quickly, dividing in two. If a cell doubles every half hour, then it can produce 281474976710656 offspring per day. And some bacteria can multiply even faster.

Slide No. 14

The rapid proliferation of lactic acid bacteria in milk causes it to turn sour in a matter of hours.

Slide No. 15

Slide No. 16

Education dispute

Under unfavorable conditions, for example, lack of water, many bacteria go into a dormant state. The cell loses water, shrinks somewhat and remains dormant until water appears again. Some species survive periods of drought, heat or cold in the form of spores. The formation of spores in bacteria is not a method of reproduction, since each cell produces only one spore and the total number of individuals does not increase.

Slide No. 17

When a spore forms, the cell shrinks, rounds within the existing cell wall and produces a new thick wall inside the old one. Under favorable conditions (humid conditions), the spore germinates. The spores are very resistant: they can withstand prolonged drying, boiling for several hours, and dry heating up to 140oC. Some spores can withstand temperatures of -245oC. They are also resistant to toxic substances and remain viable for a long time. Thus, anthrax bacilli remain viable, remaining in the form of spores for 30 years.

Slide No. 18

Survival of bacteria during desiccation

Vibrio cholerae up to 2 days
Plague stick up to 8 days
Diphtheria bacillus up to 30 days
Typhoid stick up to 70 days
Tubercle bacilli up to 90 days
Staphylococcus bacillus up to 90 days

Slide No. 19

Positive value of bacteria

It is determined by their participation in many biological processes, especially in the cycle of substances in nature. Bacteria, as a result of their vital activity, are able to decompose complex organic compounds into simple inorganic substances, which are again used by green plants. Bacteria are capable of decomposing proteins, carbohydrates, and fats.

Slide No. 20

A number of substances produced by bacteria as a result of metabolism are very valuable for humans. The activity of bacteria is used in various industries and agriculture for the production of lactic acid products, for sauerkraut, forage silage, for the production of organic acids, alcohols, acetone, enzymatic preparations, etc.

Slide No. 21

Currently, bacteria are becoming extremely important as producers of many biologically active substances (antibiotics, amino acids, vitamins, etc.) used in medicine, veterinary medicine and animal husbandry. Without the participation of bacteria, the processes that occur during the preparation of leather for tanning, maceration of flax and hemp fibers are impossible.

Slide number 22

People also use bacteria to treat wastewater: when wastewater is slowly passed over gravel and sand, solid particles settle and, under the influence of various bacteria, are transformed into a material that, after drying, is used as fertilizer. When passing through sand and gravel, pathogenic bacteria die and are digested by putrefactive bacteria.

Of the plant diseases caused by bacteria, the following are known: burn that affects fruit plants - apple trees, pears, etc.; black rot of cabbage; soft rot of many plants; tumors of plant roots Despite the harm caused (bacterial root cancer); tumor-like growths on leaves (galls), etc.

Presentation on the topic: bacteria

Bacteria

What types of bacteria are there?

Beneficial and harmful bacteria.

Bacteria are...

Where can bacteria be found?

What do bacteria eat?

Cellular structure of bacteria

Bacteria are typical organisms. Bacteria are the most ancient settlers of the earth, they have lived for two billion years. Scientists know about 2,500 species. Ba

Slide 1

Slide 2

1. History of the study of bacteria 2. Structure and vital activity of bacteria: Form Structure Distribution Nutrition Reproduction Spore formation 3. The role of bacteria in nature and for humans
Lesson Plan

Slide 3

Acquaintance with the peculiarities of the structure and activity of bacteria; Finding out the significance of bacteria in nature and for humans
The purpose of the lesson:
Equipment:
Microscopes with microslides Electronic presentation

Slide 4

Bacteria are the oldest known group of organisms. Layered stone structures - stromatolites - dated in some cases to the beginning of the Archaeozoic (Archaean), i.e. arose 3.5 billion years ago, is the result of the vital activity of bacteria, usually photosynthesizing, the so-called blue-green algae.
Bacteria
Precambrian stromatolite

Slide 5

Similar structures (bacterial films impregnated with carbonates) are still formed today, mainly off the coast of Australia, the Bahamas, in the California and Persian Gulfs, but they are relatively rare and do not reach large sizes, because herbivorous organisms, such as gastropods, feed on them.
Bacteria

Slide 6

The first nucleated cells evolved from bacteria approximately 1.4 billion years ago. The archaeobacteria thermoacidophiles are considered to be the most ancient of existing living organisms. They live in hot spring water that is highly acidic. At temperatures below 55oC (131oF) they die!
Bacteria

Slide 7

The bacteria were first seen through an optical microscope and described by the Dutch naturalist Antonie van Leeuwenhoek in 1676. Like all microscopic creatures, he called them “animalcules.”
History of the study of bacteria
Leeuwenhoek's drawings

Slide 8

The name “bacteria” was coined by Christian Ehrenberg in 1828.
Ehrenberg Christian Gottfried Corresponding Member, Foreign Member, Honorary Member of the RAS

Slide 9

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

Slide 10

Medical microbiology was further developed in the works of Robert Koch, who formulated the general principles for determining the causative agent of a disease (Koch's postulates). In 1905 he was awarded the Nobel Prize for his research on tuberculosis.
ROBERT KOCH (Koch, Robert) (1843–1910),

Slide 11

The foundations of general microbiology and the study of the role of bacteria in nature were laid by M. V. Beyerinck and S. N. Vinogradsky.
BEYERINCK Martin (1851-1931), Dutch botanist
VINOGRADSKY Sergei Nikolaevich (09/13/1856, Kyiv, – 02/24/1953, Paris)

Slide 12

The study of the structure of bacterial cells began with the invention of the electron microscope in the 1930s.
Scanning electron microscope

Slide 13

According to the shape of the cells, they can be: spherical (cocci) rod-shaped (bacillus, clostridia, pseudomonads) convoluted (vibrios, spirilla, spirochetes) stellate tetrahedral cubic C- or O-shaped The shape determines the abilities of bacteria such as attachment to the surface, motility, absorption nutrients
Bacteria shape

Slide 14

belong to prokaryotes (“pre-nuclear” single-celled organisms) there is no nucleus and most other organelles The bacterial cell is surrounded by a cell wall and a protective capsule Rod-shaped bacteria (bacilli) are covered with hairs - pili, which are attached to the nutrient substrate or to other cells.
Structure of bacteria

Slide 15

On average they are 0.5-5 microns. Escherichia coli, for example, has dimensions of 0.3-1 by 1-6 microns Staphylococcus aureus - diameter 0.5-1 microns Bacillus subtilis 0.75 by 2-3 microns. The largest known bacterium is Thiomargarita namibiensis, reaching a size of 750 microns (0.75 mm). The second is Epulopiscium fishelsoni, which has a diameter of 80 microns and a length of up to 700 microns and lives in the digestive tract of the surgical fish Acanthurus nigrofuscus. Achromatium oxaliferum reaches sizes of 33 by 100 microns; Beggiatoa alba - 10 by 50 microns.
Dimensions

Slide 16

Spirochetes can grow up to 250 µm in length with a thickness of 0.7 µm. At the same time, bacteria include the smallest organisms with a cellular structure. Mycoplasma mycoides is 0.1-0.25 microns in size, which is similar to the size of large viruses such as tobacco mosaic, cowpox or influenza. According to theoretical calculations, a spherical cell with a diameter of less than 0.15-0.20 microns becomes incapable of independent reproduction, since it physically does not contain all the necessary biopolymers and structures in sufficient quantities.
Dimensions

Slide 17

Spread of bacteria
There are many bacteria in the soil, at the bottom of lakes and oceans - wherever organic matter accumulates. They live in the cold, when the thermometer is just above zero, and in hot acidic springs with C. Some bacteria tolerate very high salinity with temperatures above 90 degrees; in particular, they are the only organisms found in the Dead Sea.

Slide 18

In the atmosphere they are present in water droplets, and their abundance there usually depends on the dust content of the air. Thus, in cities, rainwater contains much more bacteria than in rural areas. There are few of them in the cold air of high mountains and polar regions, however, they are found even in the lower layer of the stratosphere at an altitude of 8 km.
Spread of bacteria

Slide 19

Most - ready-made organic substances Blue-green (cyanobacteria) - create organic matter themselves
Nutrition of bacteria
Multicellular filamentous cyanobacterium Anabaena sphaerica

Slide 20

Slide 21

By dividing one cell into two. Under favorable conditions - every 20-30 minutes.
Reproduction

Slide 22

Education dispute
“Spore” - from Greek. “spore” - “seed” Formed under unfavorable conditions (lack of food, moisture, sudden changes in temperature) Easily spread by wind, water, etc. In favorable conditions, the spore becomes a viable bacterium - this is an adaptation to survival in unfavorable conditions.

Slide 23

Participate in the formation of the structure and fertility of soils, in the formation of minerals and the destruction of dead plants and animals; maintain reserves of carbon dioxide and oxygen in the atmosphere; They are especially important for herbivores, who feed not so much on plant food, but on the products of its transformation.
The role of bacteria in nature

Slide 24

The human intestine is normally home to 300 to 1000 species of bacteria with a total mass of up to 1 kg, although the number of their cells is an order of magnitude greater than the number of cells in the human body. They play an important role in the digestion of carbohydrates, synthesize vitamins, and displace pathogenic bacteria. For thousands of years, people have used lactic acid bacteria to produce cheese, yogurt, kefir, vinegar, and fermentation.
The role of bacteria for humans

Slide 25

Currently, methods have been developed for the use of phytopathogenic bacteria as safe herbicides, and entomopathogenic bacteria instead of insecticides. The most widely used plant is Bacillus thuringiensis, which produces toxins that affect insects. In addition to bacterial insecticides, bacterial fertilizers are used in agriculture. Bacteria that cause human disease are used as biological weapons.
The role of bacteria for humans

Slide 26

Due to their rapid growth and reproduction, as well as their simple structure, bacteria are actively used in scientific research in molecular biology, genetics, genetic engineering and biochemistry. The most well-studied bacterium is Escherichia coli. Information about the metabolic processes of bacteria has made it possible to produce bacterial synthesis of vitamins, hormones, enzymes, antibiotics, etc. A promising direction is the enrichment of ores using sulfur-oxidizing bacteria, the purification of soils and water bodies contaminated with petroleum products or xenobiotics by bacteria.
The role of bacteria for humans

Slide 27

Slide 28

Plants and animals are also susceptible to bacterial infections. Many bacteria that are normally safe for humans or even common inhabitants of their skin or intestines, in case of impaired immunity or general weakening of the body, can act as pathogens.
Pathogenic bacteria

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BACTERIA Bacteria are prenuclear organisms, which we call microbes; they have a cellular structure. These are very ancient organisms that appeared on Earth about 3 billion years ago. The human eye first saw bacteria 300 years ago.

5 slide

It took another two hundred years before microbiology became an independent science. The new branch of biology gradually revealed the enormous role microorganisms play in human life, accompanying him from cradle to grave.

6 slide

ROLE OF BACTERIA Bacteria decompose dead organisms and restore conditions for the life of new creatures. Microorganisms are human helpers, enemies and companions in everyday life.

7 slide

The purpose of the work is to identify microorganisms that are companions of humans. To identify the dependence of the number of microorganisms on the operating mode of the school. Detect and count the number of microorganisms on the hands and objects of daily use of students.

8 slide

Description of the structure of microbes Bacteria are very small. They can only be seen under a microscope. Their body consists of only one cell. They are simpler than all other organisms – their cells don’t even have a nucleus.

Slide 9

Scientists know of at least 2,500 species of bacteria. They are found everywhere: in the air, in water, in soil, in the bodies of other living beings.

10 slide

Based on the shape and characteristics of the cell association, several groups of true bacteria are distinguished. Bacteria are simply structured and, in addition to the membrane and cytoplasm, they have hereditary material.

11 slide

The role of bacteria in nature The role of bacteria in nature is enormous - they are used to produce kefir, cheese, alcohols and citric acid. Many bacteria live in the body of plants - helping to absorb nitrogen from the air, others in the body of animals - help digest food, and still others are sources of various diseases.

12 slide

Slide 13

Materials and methods of research The research was carried out within the walls of our school. Air samples were taken in the school corridors and mathematics and biology classrooms, in addition, swabs were taken from the hands of primary schoolchildren, from the telephone receiver and from the pages of our textbooks.

Slide 14

To study bacteria, a medium was prepared: meat-peptin agar. (20 grams of agar-agar, 15 grams of meat broth, 500 grams of water were taken, boiled, filtered and poured into sterile Petri dishes. The prepared dishes with the medium were used for experiments.

15 slide

To study the air, Petri dishes with the prepared sterile medium were opened for 15 minutes (according to the Koch and Clark-and-Gager method). Fingerprints (fingerprint method by V.N. Krylov, R.B. Goldin) were taken by lightly touching the fingers on a sterile nutrient medium.

16 slide

We examined: 1. The air in the classroom before lessons. 2. Air in the corridor on the 1st floor hanger after 4 lessons 3. Air in the classroom after evening cleaning

Slide 17

Condition of hand cleanliness - Swabs were taken from clean fingers - immediately after washing with laundry soap and an hour and a half after washing hands. Hand swabs of seventh graders after lunch

18 slide

Smears from a handset after long-term use from a handset, after treatment with alcohol Smears from the pages of an old textbook and pages of a new textbook

Slide 19

Then the results of the experiments were visually examined; the presence of bacteria was determined mainly by quantity, by counting the colonies that settled on the nutrient medium and calculated by the area of ​​the dish.

20 slide

To find out what could reduce the number of bacteria, a new culture of bacteria was done and tablets of chloramphenicol and tetracycline were placed on these cultures, and pieces of Kalanchoe leaves, fragrant geranium and drops of laundry soap were also used.

21 slides

EXPLORED - The air in the corridor with pills. levomitsitina The air in the corridor with drops of laundry soap The air in the classroom after lessons with Kalanchoe The air in the classroom after lessons with geranium.

22 slide

Research results Experiment results: the air environment at school is cleaner in the morning - 6 colonies. After 4 lessons the number of colonies became -13 After 7 lessons - 57 colonies

Slide 23

Bacteria in the air SAMPLE PLACE NUMBER OF BACTERIA COLONIES air in the classroom before lessons 6 air after 4 lessons 13 air after 7 lessons 57

24 slide

The result of swabs from fingerprints on the pages of books and a telephone. Clean fingerprints - 21 colonies. Fingerprints after 1 hour after washing - 23 colonies, and for a student after the cafeteria - 35 colonies. The result of an examination of the telephone receiver and pages of books, you can see the results in the diagram

25 slide

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What did you find? Among the grown pure colonies of streptococci (STREPTOCOCCUS SALIVARUS), we distinguished staphylococci by color and examined them stained blue under a microscope with a magnification of 400 times

Slide 27

What helps to retard the growth of microbes The samples show that the tablets laid out on the culture media crops do not allow bacteria to develop - around tetracycline and levomycetin there is a clean nutrient medium (without bacteria) along the rim of 0.2 cm, pieces of leaves of fragrant geranium, Kalanchoe and a drop of soap foam., also inhibit the development of bacteria with a diameter of 0.1 to 0.5 cm.

Look at the slide. Organisms from one of the kingdoms of living nature are involved in these processes. Who do you think they are?

Topic: “Kingdom of Bacteria”

Topic: “Kingdom of Bacteria”

What associations do you have when talking about bacteria? What do you think, bacteria: enemies or friends for humans? What should people know about these organisms in order to resist bacterial infections, to treat the resulting disease, to use bacteria in practical human activities?

Bacteria are prokaryotes. These are the simplest, smallest and most widespread organisms that have existed on earth for more than 3.5 billion years, but at the same time constantly evolving. Bacteria are so different from other living organisms that they are classified as a separate kingdom.

Prokaryotes (nucleated) are cells in which the nuclear substance is not hidden in the nucleus.
Dictionary

Dictionary
Eukaryotes (nuclear) - cells with a formed nucleus

Bacteria are the oldest known group of organisms. Layered stone structures - stromatolites - dated in some cases to the beginning of the Archaeozoic (Archaean), i.e. arose 3.5 billion years ago, is the result of the vital activity of bacteria, usually photosynthesizing, the so-called blue-green algae.
Bacteria
Precambrian stromatolite
For almost a billion years they were the only living creatures on our planet.

Cyanobacteria are bacteria capable of photosynthesis.
Dictionary

Bacteria are single-celled organisms
Bacteria (translated from Greek means “sticks”) are the simplest, most common organisms that have existed on Earth for more than 2 billion years, but at the same time are constantly evolving. They live in water, soil, air, inside and on the surface of the bodies of animals and plants. Bacteria can live where life seems impossible. Some of them do not die even in a solution of sulfuric acid. Bacteria can only be seen under a microscope.

The first nucleated cells evolved from bacteria approximately 1.4 billion years ago. The archaeobacteria thermoacidophiles are considered to be the most ancient of existing living organisms. They live in hot spring water that is highly acidic. At temperatures below 55oC (131oF) they die!
Bacteria

History of discovery
In 1676, the Dutchman Leeuwenhoek studied why the roots of some plants are so pungent and pungent in taste. To understand this, he put the roots in water for a while, and then observed a drop of the resulting infusion under a microscope. In it he saw small “animals” that scurried in the water and had a variety of shapes. He found a huge number of these unusually fast-moving “animals” in dental plaque.
What properties and characteristics of organisms are described in the story? Outline the steps required to study these creatures?

The bacteria were first seen through an optical microscope and described by the Dutch naturalist Antonie van Leeuwenhoek in 1676. Like all microscopic creatures, he called them “animalcules.”
History of the study of bacteria
Leeuwenhoek's drawings

Microbiology is the science that studies bacteria.
Dictionary

The name “bacteria” was coined by Christian Ehrenberg in 1828.
Ehrenberg Christian Gottfried Corresponding Member, Foreign Member, Honorary Member of the RAS

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 the general principles for determining the causative agent of a disease (Koch's postulates). In 1905 he was awarded the Nobel Prize for his research on tuberculosis.
ROBERT KOCH (Koch, Robert) (1843–1910),

The foundations of general microbiology and the study of the role of bacteria in nature were laid by M. V. Beyerinck and S. N. Vinogradsky.
BEYERINCK Martin (1851-1931), Dutch botanist
VINOGRADSKY Sergei Nikolaevich (09/13/1856, Kyiv, – 02/24/1953, Paris)

The study of the structure of bacterial cells began with the invention of the electron microscope in the 1930s.
Scanning electron microscope
Bacteria living in the intestines

Structure of bacteria

Bacterial cell structure
Bacteria are very small single-celled organisms. Their sizes are tens of times smaller than eukaryotes. The outside of a bacterial cell is covered with a dense cell wall, which resembles the cell wall of plant cells. Beneath the cell wall lies the cell membrane. Often on top of the cell wall there is an additional protective layer of mucus - a capsule, the thickness of which can be many times greater than the diameter of the cell. The capsule protects the bacteria from drying out. Some bacteria have long flagella or short thin villi. With their help, bacteria move.

Structure of bacterial cells
Inside the bacterial cell there is a dense, immobile cytoplasm without vacuoles. Bacterial cells do not have a formed nucleus. For this reason they are called nuclear-free. Although the hereditary substance itself (molecules of organic matter) is present in the cell, it is not separated from the cytoplasm, but is attached to the cell membrane.

belong to prokaryotes (“pre-nuclear” single-celled organisms) there is no nucleus and most other organelles The bacterial cell is surrounded by a cell wall and a protective capsule There is a dense cell wall, sometimes flagella. Rod-shaped bacteria (bacilli) are covered with hairs - pili, which are attached to the nutrient substrate or to other cells.
Structure of bacteria

Cocci with villi (fimbriae). Enlarge 12000 times

Organelles of locomotion in bacteria
Villi in a rod-shaped bacterium. Magnification 15,000 times.

Methods of transportation
Among bacteria there are mobile and immobile forms. Motile ones move due to flagella (twisted helical threads). There may be one or more flagella. In some bacteria they are located at one end of the cell, in others - at two or over the entire surface.

Shapes of bacteria
Bacteria are varied in shape: spherical (cocci), rod-shaped (bacilli), curved (vibrios), spiral (spirilla), chain-shaped (streptococci), nail-shaped (staphylococci). Some bacteria have flagella.

Fill out the table: “Shapes of bacteria”
Shape Description Drawing

GROUPS OF TRUE BACTERIA
cocci (spherical) - single diplococci (collected in twos) streptococci (in the form of a chain)

staphylococci (in the form of a bunch of grapes) sarcina (in the form of dense packs) bacilli (rod-shaped)

convoluted - vibrios (comma-shaped) spirilla (one or more regular curls)

The shape determines the abilities of bacteria such as attachment to the surface, mobility, and absorption of nutrients.
Bacteria shape

Eating methods
Aphthotrophic due to photosynthesis. Since the cells of these bacteria contain chlorophyll.
Heterotrophic. Bacteria do not have chlorophyll and feed on ready-made organic substances.

Types of bacterial respiration
Aerobes - lovers of oxygen
Anoerobes are those who are afraid of oxygen.
Botulism bacteria
Pseudomonas aeruginosa

Bacteria reproduction

SIZES OF BACTERIA
Bacterial cells are very small.
Their thickness is usually 0.5–2.0 µm, and their length is 1.0–8.0 µm. A quarter of a million bacteria fit in a spot

On average they are 0.5-5 microns (Micrometer 1 micron = 0.001 mm). Escherichia coli, for example, has dimensions of 0.3-1 by 1-6 microns. Staphylococcus - diameter 0.5-1 microns. Bacillus subtilis 0.75 by 2-3 microns.
Dimensions
Staphylococcus