The role of bacteria in nature and human life. Presentation on the topic “the importance of bacteria in nature and human life” Bacteria harmful to humans

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Classification of bacteria - bacteria of decomposition and decay; - soil bacteria; - lactic acid bacteria; - pathogenic bacteria.

1. Bacteria of decomposition and decay The soil contains a huge number of bacteria - hundreds of millions per gram. In poor tundra soils or sandy desert soils there are up to a billion of them, in slightly podzolic soils - up to a billion, and in chernozem rich in organic matter - up to 2 billion and more. This is about 35 dry weight of the soil. Bacteria take part in the weathering of rocks and minerals. Thus, iron bacteria formed large deposits of iron ores.

2. Nitrogen-fixing (soil) bacteria NODULE BACTERIA - a genus of bacteria that form nodules on the roots of many leguminous plants and fix molecular nitrogen from the air in conditions of symbiosis with the plant. They enter into symbiosis with leguminous plants. Settling in the roots of legumes, they cause the formation of nodules on them, for which they received the name nodule bacteria. The plant supplies the bacteria with the carbohydrates and mineral salts they need for growth and development, and in return receives nitrogen, which the nodule bacteria are able to fix.

3. Lactic acid bacteria Lactic acid bacteria are involved in the creation of fermented milk products. Fermented milk products are a group of dairy products produced from whole cow's milk or its derivatives (cream, skim milk and whey) by fermentation with starter cultures. Lactic acid products are also made from the milk of sheep, goats, mares and other animals.

Fermented milk products - ayran; - acidophilus; -kefir; - yogurt; -ryazhenka; - Varenets; - kaymak; - curdled milk; -Koumiss.

Ayran A type of fermented milk drink based on katyk or a type of kefir among the Turkic and Caucasian peoples (in different languages ​​the exact meaning of the name and the preparation technology are slightly different, but the common thing is that it is a dairy product produced with the help of lactic acid bacteria).

Acidophilus is a dietary product - milk fermented with special (acidophilus) bacteria. It is produced from milk fermented with pure culture starters, one of which is acidophilus bacillus. In 1910, the Russian scientist Hartier E.E. proved that acidophilus bacillus can be successfully used for therapeutic and preventive purposes in the fight against gastrointestinal diseases, and that this bacterium cleanses the intestines of putrefactive and some pathogenic microbes.

Kefir Kefir is a fermented milk drink made from whole or skim cow's milk by fermented milk and alcohol fermentation using kefir “fungi” - a symbiosis of several types of microorganisms: lactic acid streptococci and rods, acetic acid bacteria and yeast

Yogurt Yogurt (a fermented milk product that is made from whole milk by fermenting it with special cultures - Lactobacillus bulgaricus (Bulgarian bacillus) and Streptococcus thermophilus (thermophilic streptococcus).

Ryazhenka Ryazhenka is a fermented milk drink made from baked cow's milk by combined lactic acid and alcohol fermentation. Fermentation is carried out with thermophilic lactic acid streptococci and pure cultures of Bulgarian bacillus, fermented for 3-6 hours. It has a yellowish-brownish tint and a traditional fermented milk taste. In fact, it is a type of unflavored yogurt.

Varenets Varenets. Baked milk, prepared by slowly melting (evaporating) milk in clay jars in a Russian oven so that it reduces by at least a third of its volume and acquires a reddish tint. To do this, milk is placed in the oven after the bread for several hours, during which it “dries out” but does not boil. Then the baked milk is seasoned (fermented) with sour cream (at the rate of 200 g per liter) and kept covered for 3-4 hours in a warm room.

Kaymak Kaymak - thick, thick, pancake-like, boiled foam, prepared from fatty baked milk. Milk for kaymak is boiled over low heat in a flat container and, as the foams thicken, they are removed and layered one on top of the other, then allowing them to sour slightly over the course of a day or two. Kaymak also has a special microflora created in it as a result of acid fermentation, which turns it not only into a pleasant, tasty, nutritious, but also into a healthy product, especially for those who find it difficult to tolerate ordinary fats.

Kumis Kumis is a whitish fermented milk drink made from mare's milk, obtained as a result of lactic and alcoholic fermentation using Bulgarian and acidophilic lactic acid rods and yeast.

Lactic acid bacteria are involved in the fermentation of cabbage and pickling of cucumbers and tomatoes.

Curdled milk Produced by lactic acid fermentation of milk

Cheeses Roquefort cheese is obtained as a result of the activity of lactic acid bacteria and special fungi

4. Pathogenic bacteria Cause diseases such as typhoid, dysentery, cholera, brucellosis, tuberculosis, sore throat, glanders, anthrax, tetanus, plague.

Pathogenic bacteria Staphylococcus aureus

Streptococcus and streptococcal infection

Vibrio cholerae

Fighting pathogenic bacteria Disease prevention measures: - close your mouth when coughing; - boil handkerchiefs; - exercise medical control over water sources and food products; - disinfect premises; - get preventive vaccinations.

BIOLOGICAL DICTANT 1) Primitive unicellular, nuclear-free organisms are ..... 2) Bacteria that have a spherical shape are called ..... 3) Rod-shaped bacteria are .... 4) Spiral-shaped bacteria are called ..... 5) Bacteria in the shape of a comma are called .... 6) Bacteria that feed on ready-made organic substances are ...... 7) Bacteria that feed on organic substances of living organisms are classified as ..... 8) In unfavorable conditions, bacteria form ......

Louis Pasteur (1822 – 1895) Founder of medical microbiology and immunology Studied lactic acid fermentation Discovered butyric acid bacteria (anaerobes) PASTEURIZATION method (up to degrees) VACCINATION method (vaccines against rubella, anthrax, rabies)

Pathogenic bacteria DISEASE is a consequence of the activity of pathogenic bacteria. Infectious diseases: -diphtheria, tuberculosis (with sneezing, coughing) -Dysentery, typhoid fever, cholera (through water), plague (flea bites) -Anthrax, tetanus, gas gangrene (soil getting into the wound) -Botulism (in canned food, meat, fish - without access to oxygen) - Plague, glanders, tularemia - OZ

Is it possible to exist
modern biosphere and
human in it without bacteria?

Task 2. Write the name of the forms of bacterial cells.

Bacteria of decay and decomposition

Soil bacteria

Nitrogen-fixing bacteria

Lactic acid bacteria

Lactic acid bacteria

Various types of bacteria cause food spoilage. Botulism is a disease caused by products contaminated with botulism bacilli.

Bacteria spoil the hay in the stacks. Books in book depositories suffer from them.

Pathogenic bacteria

Bacterial plant diseases

Bacterial diseases of animals and humans

Plague

Sources of infection

Cholera

Sources of infection

anthrax

Sources of infection

Tuberculosis is one of the oldest infectious diseases

Factors contributing to tuberculosis disease

Routes of infection

Prevention of infectious diseases

Answer: Life without bacteria on Earth is impossible. a) Bacteria played a key role in the creation of soil. b) bacteria decompose organic matter

"Chemosynthesis" - Methanobacteria. Some chemosynthetics (in particular, sulfur bacteria) are used for wastewater treatment. Chemosynthesis was discovered in 1887 by S. N. Vinogradsky. Chemosynthesis is... Chemosynthesis. Iron bacteria. Nitrifying bacteria. This method of obtaining energy is used only by bacteria. Information support for the lesson.

“Structure and significance of bacteria” - The cells of many bacteria have non-chromosomal genetic elements - plasmids. Bacteria play a huge role in both the biosphere and human life. Discovered in 1887 by S.N. Vinogradsky. Physiology of bacteria. Flagella. The source of hydrogen for the reduction of carbon dioxide is water. Humans also use bacteria to purify wastewater.

“Chemosynthesis of bacteria” - Molecular oxygen that appeared in the Earth’s atmosphere acted as a strong oxidizing agent. Nitrifying bacteria - oxidize ammonia to nitrates. Anaerobic chemoautotrophs. Bacteria also come into play, working with hydrogen, nitrogen compounds and methane. Back in 1887, Russian microbiologist S.N. Winogradsky discovered bacterial chemosynthesis.

“Fungi and Bacteria” - Mushrooms. Setting lesson goals and objectives, familiarizing yourself with the lesson plan. 2.Warm up. Seaweed. "The fifth is odd." Answer the questions. Repeat and summarize the knowledge acquired on the topic. 1. Organizational moment. Lesson content: Spirogyra, chlorella, ulotrix, ulva, kelp. Hyphae, mycelium, basidia, sclerotia, rhizoids.