Abstract Tetracyclines belong to the first broad-spectrum, well-tolerated, and easy-to-administer antibiotics, which are effective against plague, cholera, typhoid, syphilis, Legionnaire’s disease, anthrax. Some can also be used treat malaria, Lyme tuberculosis, Rocky Mountain spotted fever, leprosy. Humans encountered these chemical species involuntarily in ancient times, as evidenced from ana...

The Streptomycetes are gram positive bacteria with a filamentous form that present in a wide variety of soil including composts, water and plants. The most characteristic of Streptomycetes is the ability to produce secondary metabolites such as antibiotics. They produce over two-thirds of the clinically useful antibiotics of natural origin (e.g., neomycin and chloramphenicol. Another characteri...