Bacteria
See text.
Bacteria Earth's crust. Bacteria are vital in numerous stages of a atmosphere. the nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents together with cold seeps, extremophile bacteria dispense the nutrients needed to sustain life by converting dissolved compounds, such(a) as hydrogen sulphide and methane, to energy. Bacteria also survive in symbiotic and parasitic relationships with plants and animals. almost bacteria earn not been characterised and there are many style that cannot be grown in the laboratory. The discussing of bacteria is required as bacteriology, a branch of microbiology.
Humans and almost other animals carry millions of bacteria. Most are in the gut, and there are numerous on the skin. Most of the bacteria in and on the body are harmless or rendered so by the protective effects of the immune system, though many are beneficial, especially the ones in the gut. However, several generation of bacteria are pathogenic and draw infectious diseases, including cholera, syphilis, anthrax, leprosy, tuberculosis, tetanus and bubonic plague. The most common fatal bacterial diseases are respiratory infections. Antibiotics are used to treat bacterial infections and are also used in farming, creating antibiotic resistance a growing problem. Bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, the recovery of gold, palladium, copper and other metals in the mining sector, as well as in biotechnology, and the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes "fission fungi", 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 listed all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two very different groups of organisms that evolved from an ancient common ancestor. These evolutionary domains are called Bacteria and Archaea.