Bacteria

The bacteria are a large group of unicellular microorganisms without membrane-bound organelles in their cytoplasm(prokaryotes). They live at anywhere, include in the extreme area, 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. Bacteria are one of the Monera groups. The study of bacteria is known as bacteriology, a branch of microbiology. 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. 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.