Related topics: proceedings of the national academy of sciences , antibiotics , e coli , antibiotic resistance , microbes
Bacteria
hideActinobacteria (high-G+C) Firmicutes (low-G+C) Tenericutes (no wall)
Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Deinococcus-Thermus Fusobacteria Gemmatimonadetes Nitrospirae Proteobacteria Spirochaetes Synergistetes
Acidobacteria Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Dictyoglomi Fibrobacteres Planctomycetes Thermodesulfobacteria Thermotogae
The bacteria [bækˈtɪərɪə] (help·info) (singular: bacterium)[α] are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals. Bacteria are ubiquitous in every habitat on Earth, growing in soil, acidic hot springs, radioactive waste, water, and deep in the Earth's crust, as well as in organic matter and the live bodies of plants and animals. There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water; in all, there are approximately five nonillion (5×1030) bacteria on Earth, forming much of the world's biomass. Bacteria are vital in recycling nutrients, with many steps in nutrient cycles depending on these organisms, such as the fixation of nitrogen from the atmosphere and putrefaction. However, most bacteria have not been characterized, and only about half of the phyla of bacteria have species that can be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology.
There are approximately ten times as many bacterial cells in the human flora of bacteria as there are human cells in the body, with large numbers of bacteria on the skin and as gut flora. The vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, and a few are beneficial. However, a few species of bacteria are pathogenic and cause infectious diseases, including cholera, syphilis, anthrax, leprosy and bubonic plague. The most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people a year, mostly in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and in agriculture, so antibiotic resistance is becoming common. In industry, bacteria are important in sewage treatment, the production of cheese and yoghurt through fermentation, as well as in biotechnology, and the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and rarely harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two very different groups of organisms that evolved independently from an ancient common ancestor. These evolutionary domains are called Bacteria and Archaea.
For more information about Bacteria, read the full article at
Wikipedia.
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News tagged with bacteria
Genetic study reveals the origins of cavity-causing bacteria
Dec 23, 2009 |
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Researchers have uncovered the complete genetic make-up of the cavity-causing bacterium Bifidobacterium dentium Bd1, revealing the genetic adaptations that allow this microorganism to live and cause decay in the human oral ...
Novel nanotechnology heals abscesses caused by resistant staph bacteria
Nanotechnology / Bio & Medicine
Dec 22, 2009 |
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Researchers at the Albert Einstein College of Medicine of Yeshiva University have developed a new approach for treating and healing skin abscesses caused by bacteria resistant to most antibiotics. The study ...
Deadly infection more common than realized
Dec 22, 2009 |
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Staphylococcus aureus causes far more serious infections than previously realised, with more than 3,000 Swedes affected every year, reveals a thesis from the Sahlgrenska Academy at the University of Gothenburg, Sweden.
Swimming Bacteria Could Become Model for Micromachines
Dec 21, 2009 |
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(PhysOrg.com) -- UConn researchers say Spiroplasma's propulsion style is optimal for converting energy into motion.
Mutation leads to new and severe form of bacterial disease
Dec 18, 2009 |
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(PhysOrg.com) -- Everybody gets sick, but how sick you get is in your genes. New research now reveals a mutation on a gene that makes children susceptible to a severe form of mycobacterial disease. The work not only supports ...
New Vaccines May Help Thwart E. coli O157:H7
Dec 18, 2009 |
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(PhysOrg.com) -- Immunizing calves with either of two forms of a vaccine newly developed by Agricultural Research Service (ARS) scientists might reduce the spread of sometimes deadly Escherichia coli O157:H7 ...
Invasion without a stir
Dec 17, 2009 |
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Bacteria of the genus Salmonella cause most food-borne illnesses. The bacteria attach to cells of the intestinal wall and induce their own ingestion by cells of the intestinal epithelium. Up till now, researchers assumed ...
Should flowers be banned in hospitals?
Dec 17, 2009 |
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Does flower water harbour potentially deadly bacteria? Do bedside blooms compete with patients for oxygen? Do bouquets pose a health and safety risk around medical equipment?
Argonne scientists use bacteria to power simple machines (w/ Video)
Dec 16, 2009 |
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(PhysOrg.com) -- Scientists at the U.S. Department of Energy's Argonne National Laboratory and Northwestern University, Evanston, have discovered that common bacteria can turn microgears when suspended in ...
Bacteria wouldn't opt for a swine flu shot
Dec 16, 2009 |
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Bacteria inhabited our planet for more than 4 billion years before humans showed up, and they'll probably outlive us by as many eons more. That suggests they may have something to teach us.
Cold war - Fighting the threat of latent TB (w/ Podcast)
Dec 15, 2009 |
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(PhysOrg.com) -- Scientists are making breakthroughs in studying the latent form of Mycobacterium tuberculosis. This work could revolutionise the treatment of TB.
New Bacterial Behavior Discovered
Dec 15, 2009 |
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(PhysOrg.com) -- Bacteria dance the electric slide, officially named electrokinesis by the USC geobiologists who discovered the phenomenon.
Foodborne Staph Toxin Pinpointed by New Assay
Dec 15, 2009 |
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(PhysOrg.com) -- Most people need about two days to recover from being sickened by foods contaminated with what's known as staphylococcal enterotoxin A, or "SEA." Produced by Staphylococcus aureus bacteria, ...
'Rock-breathing' bacteria could generate electricity and clean up oil spills
Dec 14, 2009 |
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A discovery by scientists at the University of East Anglia (UEA) could contribute to the development of systems that use domestic or agricultural waste to generate clean electricity.
Mechanism discovered by which body's cells encourage tuberculosis infection
Dec 10, 2009 |
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Scientists have discovered a signaling pathway that tuberculosis bacteria use to coerce disease-fighting cells to switch allegiance and work on their behalf. Epithelial cells line the airways and other surfaces ...
