The rhizosphere region of the soil is a highly favorable habitat for the proliferation, activity and metabolism of numerous microorganisms. The magnitude of this area depends on the plant and the size of the roots that the plant possesses. Bacteria are among the microorganisms living in the rhizosphere. They are the oldest, structurally simplest, and the most abundant forms of life on earth. They are also the only organisms with prokaryotic cellular organization. Life on earth could not exist without bacteria because bacteria make possible many of the essential functions of ecosystems, including the production of antibiotics. Soil bacteria can be rod (bacilli), cocci (spherical), spirilla (spirals), of these bacillus are more numerous than the others.
Secondary metabolites are organic compounds derived from the modification of primary metabolite synthases of bacteria. They do not play a role in growth, development, and reproduction like primary metabolites do. They are typically formed during the end or near the stationary phase of growth. Many of the identified secondary metabolites serve as antibiotics. Bacteria are often maligned as the cause of human and animal diseases. However, certain bacteria produce antibiotics. The term “antibiotic” literally means “against life”. In everyday usage, however, it is used to describe a set of chemicals that inhibit or kill bacteria. In 1982, the British scientist Alexander Fleming is credited with being first to notice that another organism could inhibit growth. He noticed that growth of bacterium Staphylococcus aureus was inhibited by a mold (fungus) that contaminated his plate. The mold was later identified as Penicillin notatum and the antibiotic isolated a short time later was named penicillin.
*bacteria that