![]() ![]() Some bacteria are also used in the production of tea, coffee and tobacco.Ģ. The action of bacteria (and yeast) on carbohydrates, which we use in these processes, is often referred to as fermentation. Some bacteria are used to make alcohol and vinegar, while others are used to make yoghurt and cheese from milk. Bacteria reproduce by binary fission, a mode of asexual reproduction in which one cell divides into two. ![]() ‘Favourable conditions’ means plenty of food, a temperature range of 30-37☌ and a moist environment. Under unfavourable conditions, some bacteria form spores or cysts, or rest inside a protective coating. Thus, a single bacterium can produce millions of bacteria in a day. For example, Escherichia coli, found in the intestines of man and many animals, takes about 20 minutes to reproduce. Growth and reproduction :īacteria grow and multiply very fast under favourable conditions. Some, called anaerobic bacteria, can live without oxygen. Most bacteria need oxygen to break down food and release energy. There are many that live harmlessly in our intestines, for example. Remember that all parasitic bacteria do not cause diseases. Most, however, are saprophytic or parasitic. Nutrition :Ī few bacteria can make their own food by a process similar to photosynthesis. Many bacteria have flagella or cilia to help them move, and some have thin outgrowths called fimbriae (singular: fimbria). The nuclear material, which is enclosed inside a nucleus in our cells, lies naked in the cytoplasm of bacteria. The thing common to all bacterial cells is that they do not have a nucleus. Whatever the shape, most bacteria have a rigid cell wall. Then there are spiral bacteria, called spirilla (singular: spirillum), and comma-shaped ones, called vibrios (singular: vibrio). Spherical bacteria are called cocci (singular: coccus), e.g., pneumonia is caused by Streptococcus pneumonia. Rod-shaped bacteria are called bacilli (singular: bacillus), e.g., Bacillus anthracis, which causes the disease anthrax. They are unicellular, but they sometimes cling together to form colonies.īacteria can have four different shapes and are named according to their shape. They produce an enzyme that turns the milk thick and a little sour.īacteria are the simplest of organisms and are believed to be the first living beings to have appeared on earth. The spoonful of yoghurt has millions of bacteria, which grow and multiply in the milk. What do people do when they want to make yoghurt? They add a spoonful of yoghurt to a bowl of warm milk and cover the bowl. tuberculosis is challenging and requires patients to take a combination of drugs for an extended time.Bacteria: Shape and Structure, Nutrition and Other Details (with diagram)! tuberculosis and millions of new infections occur each year. It has been estimated that one-third of the world’s population has been infected with M. tuberculosis is the causative agent of tuberculosis, a disease that primarily impacts the lungs but can infect other parts of the body as well. The genus Mycobacterium is an important cause of a diverse group of infectious diseases. Because of this, a special acid-fast staining procedure is used to visualize these bacteria. This waxy coat protects the bacteria from some antibiotics, prevents them from drying out, and blocks penetration by Gram stain reagents (see Staining Microscopic Specimens). The genus Mycobacterium is represented by bacilli covered with a mycolic acid coat. (credit a: modification of work by “GrahamColm”/Wikimedia Commons credit b: modification of work by Centers for Disease Control and Prevention credit c: modification of work by Mwakigonja AR, Torres LM, Mwakyoma HA, Kaaya EE) This micrograph shows a Pap smear from a woman with vaginosis. (c) The gram-variable bacterium Gardnerella vaginalis causes bacterial vaginosis in women. (b) Corynebacterium diphtheria causes the deadly disease diphtheria. \): (a) Actinomyces israelii (false-color scanning electron micrograph ) has a branched structure. ![]()
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