A large class of microbes. A wide range of some 2,000 species of very widespread. Diameter of mostly 0 3 ~ 2 0 microns. Basic form of a spherical, rod-shaped and the spiral of three. Some encapsulated, spore, flagella, and other special structures. Most reproduce by splitting the two decile.
Translated by Google
xì jūn
Composed of a large class of fission Basidiomycetes small plant with round, rod-shaped, spiral or filamentous single-cell bacteria or cells, often gathered into a colony, living in soil, water, organic matter or live action, plants, their chemical effects (such as nitrogen-fixing, corruption and all kinds of fermentation) and the role of human pathogens have a significant impact
Translated by Google
体积极微小的单细胞生物
Extremely small volume single-celled organisms. Size of about one to several microns, must be seen with a microscope. The shape of spherical, rod-shaped, spiral, curved, linear and other. Usually split propagation. Are found in soil, water, air, organic matter and organisms inside and outside of the natural world plays a major role in material cycle. Some bacteria break down large amount of organic material, can be used in fermentation industry, food production, chemicals, pharmaceuticals and agricultural fertilizers. But some bacteria make humans, livestock disease occurrence.
Translated by Google
Introduction
细菌 简介
Bacteria are the major groups of organisms, one belonging to bacteria domain. Bacteria are all living in one of the largest number of classes, it is estimated that the total of about 5 × 10 of the thirtieth square one. Individual bacteria are very small, the smallest known bacteria only 0.2 microns long, so most of them can only be seen under the microscope. Bacteria are generally single cell, the cell structure is simple, lack nuclei, cytoskeleton and membranous organelles, such as mitochondria and chloroplasts. Based on these characteristics, the bacteria are prokaryotes (prokaryota). There is also another type of biological prokaryotes called the Archaea (archaea), a scientist based on evolutionary relationships and open up the category. To distinguish the class of creatures known as true bacteria (eubacteria). Bacteria are widely distributed in soil and water, or a symbiotic with other organisms. Human body also has a considerable number of bacteria. It is estimated that the human body and the total number of bacterial cells on the skin is about ten times the total number of human cells. In addition, there are some species distributed in extreme environments, such as hot springs, and even radioactive waste, they are classified as extremophiles, which is one of the most famous type of sea bacteria Thermus gowns (thermotoga maritima), scientists is a submarine volcano in Italy found that the bacteria. However, the types of bacteria are so many scientists have studied and named the species only a small part of them. Bacterial domain, all doors, only about half of the included species can be cultured in the laboratory. Nutrition of bacteria and heterotrophic methods are self-employed, in which the saprophytic heterotrophic bacteria are important ecosystem decomposers, so that the carbon cycle can be carried out smoothly. Part of the bacteria to fix nitrogen, so nitrogen can be converted to a form of bio-energy use.
Translated by Google
Taxonomic status
细菌 分类地位
Domain: Bacteria domain bacteria Doors: Water production strains door aquificae Hot gowns bacteria door thermotogae Bacillus door thermodesulfobacteria thermal desulfurization Abnormal bacteria - Thermus door deinococcus-thermus Gold-producing bacteria door chrysiogenetes Green Door chloroflexi curved bacteria Thermal micro-bacteria door thermomicrobia Nitrification pylori door nitrospirae Iron bacteria off the door deferribacteres Cyanophyta cyanobacteria Green bacteria door chlorobi Proteobacteria door proteobacteria Firmicutes firmicutes Door actinobacteria Actinomyces Floating gate planctomycetes mold Chlamydia door chlamydiae Burgdorferi spirochaetes door Bacillus door fibrobacteres fiber Acid bacteria door acidobacteria Bacteroides door bacteroidetes Flavobacterium door flavobacteria Sphingomonas spp door sphingobacteria Fusobacterium door fusobacteria Micro-bacteria door verrucomicrobia warts Network Group bacterial phyla dictyoglomi Shoot the door gemmatimonadetes Aeromonas
Translated by Google
The study of history
细菌 研究历史
Bacteria from the German scientists first term Ehrenberg (christian gottfried ehrenberg, 1795-1876) proposed in 1828, used to refer to some kind of bacteria. The word comes from the Greek βακτηριον, meaning "small stick." In 1866, German zoologist Haeckel (ernst haeckel, 1834-1919) recommend the use of "protists", including all single-cell organisms (bacteria, algae, fungi and protozoa). In 1878, French surgeon Sadie Wyatt (charles emmanuel sedillot, 1804-1883) put forward the "micro" to describe the bacterial cells, or more commonly used to refer to small organisms. Because the bacteria are single cell microorganisms, with the naked eye can not see the need to observe with a microscope. In 1683, Leeuwenhoek (antony van leeuwenhoek, 1632 ╟ 1723) first used their own design to the single-lens microscope of bacteria, about 200 times magnification. Louis Pasteur (louis pasteur, 1822-1895) and Robert Koch (robert koch, 1843-1910) pointed out that the bacteria can cause disease.
Translated by Google
Morphology
Bacilli, bacteria, spirochetes, vibrios in different forms, but mainly consists of the following structures. (A) of the cell wall By bacterial cell wall thickness varies, usually 15-30nm. The main component of peptidoglycan, the n-acetyl glucosamine and n-acetyl muramic acid disaccharide unit constitutes, to β (1-4) glycosidic linkage National Cheng Kung University molecules. n-acetyl muramic acid peptide molecule has four side chains, between the fibers adjacent peptide glycans by peptide bridges (Gram-positive bacteria) or a peptide bond (Gram-negative bacteria) bridge to form a peptidoglycan layers, the same as plywood, glue layers. Peptidoglycan polysaccharide chains in the same in all species, but a kind of cross between a short peptide chain is different. Gram-positive bacteria cell wall thickness of 20 ~ 80nm, a layer of peptidoglycan layers 15-50, each of thickness 1nm, with 20-40% of the teichoic acid (teichoic acid), and some also have a small amount of protein. Gram-negative bacteria cell wall thickness of about 10nm, only 2-3 layers of peptidoglycan and other components are more complex, from outside to inside followed by LPS, bacterial outer membrane and lipoprotein. In addition, there are gaps between the cell membrane. Peptidoglycan cell wall of gram-positive bacteria is the main component of peptidoglycan structure who can destroy or inhibit the synthesis of the material, have antibacterial or bactericidal effect. If lysozyme is n-acetyl muramic acid enzyme, penicillin inhibition of GGT activity, inhibitory peptide bridge formation. Bacterial cell wall features include: maintaining cell shape; inhibition of mechanical and osmotic damage (Gram-positive bacteria cell walls can withstand the pressure 20kg/cm2); mediated interactions (invasive host); prevent macromolecular invasion; help cells movement and division. Bacterial cell wall called off protoplasts (bacterial protoplast) or a spherical body (spheroplast, off the wall due to incomplete), off the wall of bacteria after protoplast survival and activity greatly reduced. (B) of the cell membrane Is a typical unit membrane structure, thickness 8 ~ 10nm, close to the outer cell wall, some Gram-negative bacteria also have cell membrane. Usually do not form a membrane system, in addition to ribose in vitro, there is no other similar organelles in eukaryotic cells, respiratory and photosynthetic electron transport chain located in the cell membrane. Photosynthesis in some prokaryotes (cyanobacteria and purple bacteria), the formation of membrane folds within the lining combined with pigment, and light harvesting reaction. Some of the plasma membrane of Gram-positive bacteria formed small tubular structures within the fold, called the membrane body (mesosome) or indirectly (Fig. 3-11), the expansion of the cell membrane surface area of the body, improve metabolic efficiency, the proposed mitochondria (chondroid) is known, in addition to dna replication may be related. (C) cytoplasmic and nuclear plastid Like bacteria and other prokaryotes, there is no nuclear membrane, dna concentrated in the cytoplasm of low electron density area, said the nucleus or nuclear plasmid (nuclear body). Bacteria generally have 1-4 nuclear plasmids, and more up to more than 20. Nuclear double-stranded circular plasmid is the dna molecule contains the genetic information coding for proteins from 2000 to 3000, the space is very thin build and no introns. As Meiyou nuclear membrane, so the 复制 dna, rna transcription and protein synthesis could be conducted qualitative, rather than the real cells, as these biochemical reactions in time and space are strictly separated from the past. Each bacterial cell contains about 5,000 ~ 50,000 ribosomes, some attached to the inside of the cell membrane, most divorced from the cytoplasm. Bacterial ribosome sedimentation coefficient of 70s, the large subunit (50s) and small subunit (30s) form, large subunit contains 23srrna, 5srrna with 30 kinds of proteins, small subunit contains 16srrna and 20 kinds of proteins. 30s in the small subunit is sensitive to tetracycline and streptomycin, 50s of the large subunit is sensitive to erythromycin and chloramphenicol. Dna bacteria outside the nuclear region, can be independently replicated genetic factor, called the plasmid (plasmid). Plasmids are circular double-stranded dna molecules exposed, the genetic information contained 2 to 200 genes that can replicate themselves, sometimes integrated into the nuclear dna to go. Plasmid dna in genetic engineering research is important, commonly used for recombinant DNA and gene transfer vector. Cytoplasmic particles in the cytoplasm of the particles, since the role of temporary storage of nutrients, including polysaccharides, lipids, polyphosphates and so on. (D) Other structures The appearance of many bacteria and covered with a layer of polysaccharides, the border was known as the capsule (capsule), such as pneumococcus, obvious boundary layer called the mucous (slime layer), such as Staphylococcus aureus. Capsule of the bacteria is important for survival, bacterial capsule can be used not only to withstand adverse environment; protect themselves from phagocytic; and can _select_ively to specific cell adhesion on the surface, showing a specific attack on the target cells capacity. For example, typhoid Salmonella to specific violations of intestinal lymphoid tissue. Bacterial capsule fibrils but also digestive enzymes secreted by the bacteria stored up, to prepare for use against target cells. The movement of certain bacterial flagellum organs, by a known flagellar protein (flagellin) of the elastin composition, structure, different from eukaryotic flagella. Bacteria can adjust the direction of flagellar rotation (cis and counterclockwise) to change the state of motion. Pili is the existence of a surface of some bacteria finer than flagella, shorter and straight filaments hard to be with the electron microscope. Features are: small, short, straight, hard, more sports has nothing to do with bacterial pili, based on morphology, structure and function can be divided into two types of common pili and sex pili. The former host on bacterial attachment and colonization, which is hollow tubes, and pass on genetic material.
Translated by Google
Type
Bacteria can be classified according to different methods. Bacteria have different shapes. Most bacteria are the following three categories: bacteria are rod-like; bacteria are spherical (such as Streptococcus and Staphylococcus); pylori is a spiral. Another, vibrio, is a comma-shaped. The structure is very simple bacteria, prokaryotes, there is no membrane organelles such as mitochondria and chloroplasts, but the cell wall. According to the composition of the cell wall, bacteria are divided into Gram-positive bacteria and gram-negative bacteria. "Gram" comes from the Danish bacteriologist Gram (hans christian gram), he invented the Gram stain. Some outside the bacterial cell wall polysaccharide capsule formation, forming a layer of covering or envelope. Capsule can help bacteria in the dry season in a dormant state, and can store food and waste. Changes in the classification of bacteria reflects a fundamental change in the history of ideas, many species and often changed or renamed. Recently as gene sequencing, genomics, bioinformatics and computational biology, bacteriology was placed in a suitable location. In addition to cyanobacteria first outside (it has not been classified as bacteria, but classified as blue-green algae), other bacteria are considered a class of fungi. With their particular structure of prokaryotic cells was found, which is obviously different from other organisms (they are eukaryotes), leading to bacteria classified as a separate species, at different times is known as prokaryotes, bacteria, prokaryotes sector . Generally believed that eukaryotes from prokaryotes. Through research rrna sequence, the U.S. microbiologist Woods (carl woese) made in 1976, contains two large groups of prokaryotes. He called true bacteria (eubacteria) and archaea (archaebacteria), later renamed the bacteria (bacteria) and archaea (archaea). Woods pointed out that these two types of bacteria and eukaryotic cells by a primitive biological origin of different types, respectively. Researchers have abandoned this model, but the three domains of the system gained general acceptance. In this way, the bacteria can be divided into several sectors, while in other systems is considered a profession. They are usually considered to be a single-source group, but this method is still controversial. Archaea Archaea (archaeobacteria) (can be called ancient archaea or bacteria) is a very special kind of bacteria, many living in extreme ecological environment. Some features with prokaryotes, such as the nuclear membrane and membrane system; also have eukaryotic features, such as the methionine initiation of protein synthesis, ribosomes are not sensitive to chloramphenicol, rna polymerase, and true similar cells, dna introns combined with histone; also is different from the prokaryotic cells have also different from the characteristics of eukaryotic cells, such as: membrane lipids is not saponification; cell wall without peptidoglycan Some protein-based, some impurity polysaccharides, and some similar to the peptidoglycan, but do not contain muramic acid, d-amino acids and two amino G acid.
Translated by Google
Reproduction
In a good environment, the bacteria can form aggregates visible to the naked eye, such as bacteria cluster. Bacteria reproduce by binary fission of the way, some of the bacteria in the unfavorable environment, or run out of nutrients, the formation of endospores, also known as Bacillus, is a strong resistance to adverse sleep environment body, the spores formed in bacterial cells often called the endospore. Very tenacious vitality of spores, some lake sediment bacteria spores in soil by 500-1000 years after the still dynamic, Clostridium botulinum spores can be tolerated when the ph 7.0 100 ℃ boiling 5-9.5 hours. Spores from the inside and outside are the following components: 1. Bacillus protoplasts (spore protoplast, the core of core): containing concentrated protoplasm. 2. Intima (inner membrane): the membrane-type bacteria from breeding the formation of spores surrounded by protoplasm. 3. Spore wall (spore wall): the reproduction-type composition of bacterial peptidoglycan, surrounded by the inner membrane. A bacterial cell wall after germination. 4. Cortex (cortex): Bacillus capsule is the most thick layer, the peptidoglycan composition, but different from the cell wall peptidoglycan structure, crosslinking little support for the cell wall polysaccharides but not cell wall acid anhydride, four peptide side chains composed of the l-ala. 5. Outer membrane (outer membrane): is formed by the bacterial cell membrane. 6. Shell (coat): Bacillus shell, hard and tough and compact keratin composition by class (keratinlike protein), contains a large number of disulfide bonds, with hydrophobic characteristics. 7. Wall (exosporium): spore coat is the outermost layer of spores from the lipoproteins and carbohydrates (sugars), with loose structure.
Translated by Google
Metabolism
Metabolism of bacteria in many different ways. Some bacteria need only carbon dioxide as their carbon source, known as autotrophs. Those obtained through photosynthesis from the light energy, called photosynthetic autotrophs. Oxidation of compounds that depend on access to energy, known as the chemoautotrophic organisms. Other bacteria rely on organic forms of carbon as carbon source, known as heterotrophic organisms. Photoautotrophic bacteria, including cyanobacteria, which is the oldest known organisms, may in the manufacture of oxygen in Earth's atmosphere play an important role. Some other photosynthetic bacteria do not produce oxygen in the process. Including the green sulfur bacteria, green non-sulfur bacteria, purple sulfur bacteria, purple non-sulfur bacteria and the sun bacilli. Normal nutrients needed for growth, including nitrogen, sulfur, phosphorus, vitamins and metallic elements, such as sodium, potassium, calcium, magnesium, iron, zinc and cobalt.
Translated by Google
Sports
Sports bacteria can rely on flagella, bacterial gliding, or changes in buoyancy to move around. Another type of bacteria, spirochetes, have some similar structure flagella, called axial filaments, connecting the two periplasmic membrane. When they moved, the body presents a distorted spiral. Pylori did not show the axis of wire, but with the flagella. Bacterial flagella arranged in different ways. Bacteria can have a separate one end of a very flagella, or a clump of flagella. Zhou Mao bacterial flagella scattered surface. Sport-specific stimulation of bacteria can be attracted or expelled, this behavior is called chemotaxis, for example, chemotaxis, phototaxis, chemotaxis, mechanical. In a special kind of bacteria, myxobacteria, individual bacteria attract each other, gathered the group to form a fruiting body.
Translated by Google
Use and risk
Bacteria in the environment, both human and animal use another hazard. Some bacteria to become pathogens, leading to tetanus, typhoid, pneumonia, syphilis, cholera and tuberculosis. In plants, bacteria cause leaf spot, fire blight and wilt. Method of Infection, including contact, airborne, food, water and contaminated microorganisms. Pathogens can be used antibiotic treatment, sterilization type and antibacterial antibiotics are divided into type. Yeasts and bacteria normally associated with other types of fungi with yeast for 醤 food, such as vinegar and the traditional manufacturing process, is the use of acetic acid bacteria in the air (acetobacter) the wine into vinegar. Other food products manufactured using bacteria also cheese, pickles, soy sauce, vinegar, wine, yogurt and so on. Bacteria can also secrete a variety of antibiotics, such as streptomycin is produced by Streptomyces (steptomyces) secreted. Bacteria can degrade the ability of many organic compounds are often used to clear the pollution, called bio-remediation (bioremediation). For example, scientists addicted methanogens (methanotroph), Georgia, USA to break down TCE and PCE contamination. Bacteria also have a great impact of human activities. On the one hand, bacteria are the causative agent of many diseases, including tuberculosis, gonorrhea, anthrax, syphilis, plague, trachoma and other diseases are caused by bacteria. However, humans often use bacteria, such as cheese and yogurt production, the manufacture of some antibiotics, wastewater treatment, are related with the bacteria. In the biotechnology field, the bacteria are also a wide range of use. [A] generation of bacteria Biologists predicted that the 21st century will be the era of bacterial generation the benefit of mankind. Speaking of bacterial generation, dating back to 1910, the British botanist use of platinum as the electrode into the culture medium in E. coli and successfully created the world's first bacterial cell. In 1984, U.S. scientists to design a spacecraft to use the bacteria cell, the electrode active material is an astronaut's urine and live bacteria. However, when the bacterial cell discharge efficiency is low. By the 20th century, late 80s, the bacteria have a major breakthrough in power generation, the British chemist to bacterial decomposition of molecules in the battery pack in order to release electrons to the anode to generate electricity. The approach is to add some sugar, such as dyes and the like aromatic compounds as diluent, to improve the ability of biological systems, electronic transmission. During power generation in bacteria, but also to keep the battery in the inflatable to bacterial culture medium and stirring the mixture of oxide material. It has been calculated using the bacteria cell, 100 grams of sugar per Coulomb of electricity available to 1,352,930, and its efficiency up to 40%, far higher than the efficiency of the battery currently in use, but also 10% of the potential to be tapped. As long as there continue to be _insert_ed into the battery can get 2 amps of current sugar, and can last for months. Power generation using principles of bacteria, bacteria can build power stations. In the 10-meter square cube containers full of liquid bacterial culture, you can build a 1000 MW power plant bacteria, consumption of sugar per hour to 200 kilograms, the power generation cost is a little high, but it is one that does not pollute the environment "green" power, not to mention technological development, can use such as sawdust, straw, leaves and other organic waste materials instead of sugar hydrolysis, so the prospect of generating bacteria is very attractive. Now, the developed countries like the Eight Immortals, fancy: the United States to design a comprehensive bacterial cells, is a single-cell algae cells in the first use of sunlight to carbon dioxide and water into sugar and then let the bacteria use sugar to generate electricity ; Japan, the two kinds of bacteria into the cell a special syrup, so a bacteria produce acetic acid and organic acid ingestion syrup, and let the other bacteria of these acids into hydrogen, the hydrogen into the phosphoric acid fuel cell power generation; UK invented a solution of methanol as a battery to platinum as the electrode alcohol dehydrogenase of bacteria cells. And now, a variety of bacterial cells one after another. For example, bacteria have an integrated battery, first cell in the single-cell algae use sunlight to carbon dioxide and water into sugar, then let the bacteria use sugar to generate electricity. There are two kinds of bacteria in a bacterial cell sucked into the battery of special syrup, so a bacteria produce acetic acid and organic acid ingestion syrup, let the other bacterial conversion of these acids into hydrogen, the use of hydrogen into the phosphoric acid fuel battery power. It was also surprised to find that bacteria also have to capture solar energy and put it directly into electricity "special abilities." Recently, U.S. scientists found in the Dead Sea and Great Salt Lake, a halophilic bacteria, they contain a purple pigment, in the accepted about 10% of sunlight into chemical substances, to generate electric charge. Scientists use them to create a small experimental solar bacterial cells, results showed that halophilic bacteria can be used to generate electricity, and salt instead of sugar, the cost is greatly reduced. Thus, the bacteria is not far away for the human idea of power, but soon the reality. [B] gastrointestinal bacteria benefits Body decomposition of the large intestine by intestinal bacteria within the waste of life. Because these things can not be digested, the body refused to deal with their system. The bacteria themselves are equipped with a range of metabolic enzymes and channels. In this way, they can continue to decompose the remaining organic compounds. Most of them are the work of decomposition of plant carbohydrates. Most of the bacteria within the intestine is anaerobic bacteria, meaning that they live without oxygen state. They are not outgoing and incoming oxygen, but by the carbohydrates broken down into small molecules of fatty acids and carbon dioxide molecules to obtain energy. This process is called "fermentation." Some fatty acids through the intestinal wall was re-absorption of the large intestine, which will give us extra energy. The remaining fatty acids help bacteria grow rapidly. Its speed allows them to breed once every 20 minutes. Because they are some of the synthesis of vitamin k vitamin b and more than they need, so they are very generous to give them the extra supply of vitamins in this group of other creatures, is also available to you - their host. Although you can not own production of these vitamins, but you can rely on these for your very friendly bacteria to continuously supplied to you. Scientists are just beginning to understand this collective of different complex relationship between bacteria and their colleagues in the host interactions. This is a dynamic system, with the host in the diet and changes in age, this system also make the appropriate adjustments. You begin to birth in the body of your choice collection of species of bacteria. When your diet changed from breast milk, but also as a different solid food, your body and there will be new bacteria to dominate the. Accumulation of bacteria in the colon wall after the experienced survivors of a difficult journey. Starting from the mouth through the small intestine, digestive enzymes and acids they are attacked. After the completion of travel that the safe arrival of bacteria in the encounter more obstacles. To grow, they must have lived with the bacteria for space and nutrition. Fortunately, these "friendly" bacteria can be very skilled to put myself into the colon wall and paste any of the available places. These friendly bacteria can produce acids and some known as "bacteriocins" antibacterial compounds. These factors may help bacteria resist the invasion of those nasty bacteria. Those friendly bacteria to control the number of bacteria more dangerous and increase awareness of "probiotic" food of interest. The culture of food containing bacteria, yogurt is one of them. In the time you drank a bottle of yogurt, check labels to see what kind of bacteria will become the next group of guests in your body.
Translated by Google
Training
Common bacterial culture media Recipe for a beef extract agar 0.3 g beef extract, peptone 1.0 g, sodium chloride 0.5 g, agar 1.5 g, 1000 ml of water In 100 ml beaker, add water, add beef extract, peptone and sodium chloride, in the beaker with a crayon mark on the outside for after the fire heating. Components to be dissolved within the beaker, add agar, stirring constantly to avoid sticking at the end. After the agar is completely dissolved, etc. make up the water loss, with 10% hydrochloric acid or sodium hydroxide 10% to adjust the ph value of 7.2 to 7.6, packed in each test tube, add the cotton plug, with high-pressure steam sterilization for 30 minutes. Two medium potatoes recipe Fresh bovine heart (remove fat and blood vessels) 250 grams, with a knife carefully chopped into minced meat, add 500 ml of distilled water and 5 grams of peptone. Good mark on the beaker, boiling, switch to simmer for 2 hours. Filter, filter out the minced meat drying, the filtrate transferred about 7.5 ph value. Added to each tube 10 ml broth and a little crumbly, dry beef heart, sterilization and _set_ aside. Recipe three Rhizobium culture 10 grams of glucose, 0.5 g dipotassium hydrogen phosphate 3 grams calcium carbonate 0.2 grams of magnesium sulfate Yeast extract, 20 g fat 0.4 Keqiong Water 1000 ml of 1% crystal violet solution of 1 ml Add boiling water agar dissolved first, and then other components were added, allows the dissolved after mixing, packaging, sterilization, reserve.
Translated by Google
Introduction
Bacteria (in English: germs; scientific name: bacteria) is the generalized bacterial prokaryotes is a large class of nuclear-free membrane package, there is only known to be nucleus (nuclear region) (or proposed nuclear) of the original single naked DNA cell biology, including the true bacteria (eubacteria) and archaea (archaea) two groups. Apart from a few of which are Archaea, most of the prokaryotes are the true bacteria. Can be roughly divided into 6 types, namely, bacteria (narrow), actinomycetes, spirochetes, mycoplasma, rickettsia and chlamydia. Commonly referred to is the narrow sense of bacteria, bacteria in the narrow sense as a class of prokaryotic microorganisms, is a kind of fine, short form, simple structure, and more ways to reproduce binary fission in prokaryotes, is the most widely distributed in nature, individual the largest number of organisms, material recycling is a key player in nature. Mainly by the bacteria cell wall, cell membrane, cytoplasm, nuclear plastid and other parts, some bacteria have also capsule, flagella, fimbriae, and other special structures. Most bacteria in the diameter of between 0.5 ~ 5μm. Can be divided into three categories based on shape, namely: cocci, bacilli and spiral-shaped bacteria (including Vibrio, Lo bacteria, Helicobacter). Way of life by bacteria to be classified into two categories: autotrophic bacteria and heterotrophic bacteria, including heterotrophic bacteria and parasites, including saprophytes. Oxygen demand by bacteria to classification, can be divided into aerobic (completely aerobic and micro-aerobic) and anaerobic (not completely anaerobic, aerobic tolerance and completely anaerobic) bacteria. By bacteria to survive the temperature classification, can be divided into cold-, three types of normal and hi heat. Bacteria Discovered: Dutch businessman Anton Leeuwenhoek. Bacteria are the major groups of organisms, one belonging to bacteria domain. Bacteria are all living in one of the largest number of classes, it is estimated that the total of about 5 × 10 of the thirtieth square one. Individual bacteria are very small, the smallest known bacteria only 0.2 microns long, so most of them can only be seen under the microscope. Bacteria are generally single cell, the cell structure is simple, lack nuclei, cytoskeleton and membranous organelles, such as mitochondria and chloroplasts. Based on these characteristics, the bacteria are prokaryotes (Prokaryota). There is also another type of biological prokaryotes called the Archaea (Archaea), a scientist based on evolutionary relationships and open up the category. To distinguish the class of creatures known as true bacteria (Eubacteria). Bacteria are widely distributed in soil and water, or with other biological symbiosis. Human body also has a considerable number of bacteria. It is estimated that the human body and the total number of bacterial cells on the skin is about ten times the total number of human cells. In addition, there are some species distributed in extreme environments, such as hot springs, and even radioactive waste, they are classified as extremophiles, which is one of the most famous type of sea bacteria Thermus gowns (Thermotoga maritima), scientists is a submarine volcano in Italy found that the bacteria. However, the types of bacteria are so many scientists have studied and named the species only a small part of them. Bacterial domain, all doors, only about half of the included species can be cultured in the laboratory. Nutrition of bacteria and heterotrophic methods are self-employed, in which the saprophytic heterotrophic bacteria are important ecosystem decomposers, so that the carbon cycle can be carried out smoothly. Part of the bacteria to fix nitrogen, so nitrogen can be converted to a form of bio-energy use.
Translated by Google
Taxonomic status
细菌 分类地位
Domain: Bacteria Bacteria domain Sector: Bacterial community Doors: Water production strains door Aquificae Hot gowns bacteria door Thermotogae Bacillus door Thermodesulfobacteria thermal desulfurization Abnormal bacteria - the door Thermus Deinococcus-Thermus Gold-producing bacteria door Chrysiogenetes Green curved door Chloroflexi bacteria Thermal micro-bacteria door Thermomicrobia Nitrification pylori door Nitrospirae Iron bacteria off the door Deferribacteres Cyanobacteria Cyanophyta Green bacteria door Chlorobi Proteobacteria Proteobacteria door Firmicutes Firmicutes Door Actinobacteria Actinomyces Mold floating gate Planctomycetes Door Chlamydiae Chlamydia Spiral door Spirochaetes Bacillus door Fibrobacteres fiber Acid bacteria door Acidobacteria Bacteroidetes Bacteroides door Flavobacterium door Flavobacteria Sphingomonas spp door Sphingobacteria Fusobacterium door Fusobacteria Warts micro bacterial phyla Verrucomicrobia Network Group bacterial phyla Dictyoglomi Shoot the door Gemmatimonadetes Aeromonas
Translated by Google
Culture method
Common bacterial culture media Recipe for a beef extract agar 0.3 g beef extract, peptone 1.0 g, sodium chloride 0.5 g, agar 1.5 g, 1000 ml of water In 100 ml beaker, add water, add beef extract, peptone and sodium chloride, in the beaker with a crayon mark on the outside for after the fire heating. Components to be dissolved within the beaker, add agar, stirring constantly to avoid sticking at the end. After the agar is completely dissolved, etc. make up the water loss, with 10% hydrochloric acid or 10% sodium hydroxide to adjust pH value to 7.2 ~ 7.6, packed in each test tube, add the cotton plug, with high-pressure steam sterilization for 30 minutes. Two medium potatoes recipe Fresh bovine heart (remove fat and blood vessels) 250 grams, with a knife carefully chopped into minced meat, add 500 ml of distilled water and 5 grams of peptone. Good mark on the beaker, boiling, switch to simmer for 2 hours. Filter, filter out the minced meat drying, the filtrate transferred to about 7.5 pH value. Added to each tube 10 ml broth and a little crumbly, dry beef heart, sterilization and _set_ aside. Recipe three Rhizobium culture 10 grams of glucose, 0.5 g dipotassium hydrogen phosphate 3 grams calcium carbonate 0.2 grams of magnesium sulfate 0.4 Keqiong yeast 20 grams of fat Water 1000 ml of 1% crystal violet solution of 1 ml Add boiling water agar dissolved first, and then other components were added, allows the dissolved after mixing, packaging, sterilization, reserve. Other Bacteria are very ancient organisms, some appeared 3.7 billion years ago. Two eukaryotic cells organelles: mitochondria and chloroplasts, usually considered from the symbiotic bacteria. There are a large number of microorganisms found in food, moisture, suitable temperature, for them to breed and grow. Bacteria can be air from one place to another. The human body is the habitat of a large number of bacteria; to the skin surface, gut, mouth, nose and other body parts to find. They exist in the human breathing air, drinking water, eating food. Books on the bacteria There are many books in the United States on the bacteria (GERMS) where there is the story of a book called <GERMS!GERMS!GERMS!>. It is the author of "bobbi katz" I personally think it is a very good book. Suggest that you refer to when doing homework refer to this book. (This represents only my views do not represent the position of others)
Translated by Google
Bacteria and food chain
Most bacteria are decomposers, at the bottom of the food chain. Bacteria are also part of the consumers and producers. Such as sulfur bacteria, iron bacteria, they are chemosynthetic heterotrophic, the producer, you can use non-polar materials such as iron sulfur organic manufacturing their own needs. And rhizobia is the consumer, they are mutually beneficial symbiosis with legumes, legume consumption of organic matter produced by photosynthesis, therefore for consumers. Of course, the most important role of bacteria, or decomposers, fungi, bacteria and other microorganisms if not, the world will be a sea of dead bodies.
Translated by Google
Encyclopedia
细菌 百科辞典
xijun Bacteria bacteria A single-cell micro-organisms with cell walls. Belongs to the original native biological cells in type, which form tiny, simple structure, no typical nucleus, only nuclear transfer (chromosome), no nuclear membrane and nucleolus, without mitosis; addition to nuclear protein, has no other organelles. The shape of bacteria are spherical, rod-shaped, spiral three basic forms, some with spores, flagella, or capsule. A simple way to reproduce the second division. Widely distributed in soil, water, air and biological body and the body surface. Bacteria involved and ensure the circulation of materials in nature and plays an important role in industrial and agricultural production. However, there are a few different ways bacteria can cause disease in humans.
Translated by Google
Medical Dictionary
Shape is generally spherical, rod-shaped or spiral-shaped, usually in the way of reproduction binary fission in prokaryotes. Tiny individual bacteria, usually bacteria from 0.5 to 1.0 microns in diameter, 1 micron wide and bacteria, 2 microns long. Bacteria is widely distributed in nature, present in the soil, water, air and surface and digestive tract flora and fauna, etc., in which bacteria in soil is the main distribution site, per gram of dry soil bacterium contains about 10 to the 8th power ~ 10 power of 10 months. Most of heterotrophic bacteria, a small number of self-support, including chemoautotrophic and energy self-support. Most of heterotrophic bacteria in the saprophytic, rarely parasitic. Bacteria have a strong ability to decompose organic matter, and some also for nitrogen fixation and nitrification, the bacteria in the natural material cycle, the formation of humus in the soil plays an important role in animal and plant life and agricultural production is also important. In medicine, Staphylococcus aureus can cause human food poisoning, plague Ye Erxun coli, Vibrio cholerae, Salmonella typhi, Shigella dysenteriae, Mycobacterium tuberculosis, Treponema pallidum, etc. can cause a variety of human the prevalence of infectious diseases. In human history, infectious disease caused by bacteria has claimed the lives of countless people. With the progressive human understanding of pathogenic bacteria, many infectious diseases have been controlled. A small number of bacteria can cause poultry, livestock and crop epidemics, suffered large losses in agricultural production. There are also many bacteria have been used in the food industry, chemical industry, such as the use of Bacillus subtilis protease and amylase production, hair removal for leather, cotton desizing; use of lactic acid bacteria, acetic acid bacteria produce lactic acid, acetic acid and other chemicals. Bacteria in biological wastewater treatment, methane fermentation also plays an important role. Biology of bacteria is an important experimental materials, scientists have discovered and confirmed with the pneumococcal DNA is the genetic material. With the rise of genetic engineering, scientists have obtained the E. coli to produce insulin, and the decomposition of hydrocarbons have a strong ability of new strains of Pseudomonas.
Translated by Google
English Expression
: Bacteria
n.: germ, bacilli, bacillus, bacterium, germs, bacterium; germ, simplest and smallest forms of plant life, microscopic organisms that exist in large numbers in air, water and soil, and also in living and dead creatures and plants, and are often a cause of disease, bacterial, virus
