Bacteria are almost everywhere—in the food you eat, in the air you breathe, in the water you drink, and even at great ocean depths. Bacteria are prokaryotes because they have no true nucleus. Bacteria are grouped into two kingdoms—Eubacteria and Archaebacteria. The bacteria that normally inhabit your home and body are of three shapes—spheres, rods, and spirals. Most bacteria float freely in the environment in the air and water currents, your hands, your shoes or your family pet. Most live in moist conditions and have tails called flagella to help them move.
All bacteria are considered eubacteria or true bacteria. These organisms live in much less harsh environments than archaebacteria. Bacteria reproduce by fission; fission produces two cells with genetic material identical to that of the parent cell. It is the simplest form of asexual cell reproduction. Some bacteria exchange genetic material through a process similar to sexual reproduction. Most bacteria live in places where there is a supply of oxygen; such bacteria are called aerobes, some organisms called anaerobes can live without oxygen.
Kingdom Archaebacteria contain certain kinds of anaerobic bacteria which are thought to have existed for billions of years. They are found in extreme conditions such as the hot springs, salty lakes, muddy swamps, the intestines of cattle, and near the deep ocean vents where life exists without sunlight. Archaebacteria are divided into three groups based on how they get energy.
Uses of Bacteria: Bacteria called saprophytes help maintain nature’s balance. A saprophyte is any organism that uses dead material as food and energy source. The roots of plants such as peanuts contain nitrogen fixing bacteria will change the nitrogen from the air into forms useful for plants and animals. Many industries depend on bacteria for making medicines, enzymes, cleansers, adhesives, and other products.
Harmful bacteria are called pathogens. A pathogen is an organism that produces a disease. An antibiotic is a substance produced by one organism that inhibits or kills another organism. Some bacterial diseases can be prevented by vaccines. Some pathogens produce poisons; called toxins. Pasteurization is a process of heating food to a temperature that kill harmful bacteria, it is used in the food industry.