An antibiotic is defined as a substance that is produced by microorganisms that in miniscule amounts inhibits the growth of another microorganism (Tortora 2010). Antibiotics can be found naturally in the environment or they can be manufactured with chemicals. They are specifically designed to hinder the growth and development in other microbes. Yet, these antimicrobial drugs should not cause extreme harm to normal microorganisms (Tortora 2010). The vast majority of antibiotics that have been produced in the past were used to treat various infectious diseases (Walsh 2003).
Although there are too many varieties of antibiotics to name, these antibiotics come from only a few particular drugs. Antibiotics are divided up into three major divisions, such as: eukaryotic molds and bacteria that form spores as well (Todar 2011). A small amount of the antibiotics we use today are formed by Bacillus, the endospore-forming bacteria. The others are produced by the molds, mostly Penicillium and Cephalosporium (Tortora 2010). The major subcategories of antibiotics are Penicillins, Cephalosporins, Macrolides, Fluoroquinolones, Sulfonamides, Tetracyclines, and Aminoglycosides (Tortora 2010).
Microorganisms that produce antibiotics do so at a specific time during the life cycle of the cell. These antimicrobial drugs are produced during the stationary phase of the cycle. The cells are not growing and dividing rapidly at this point, therefore they produce secondary metabolites. Secondary metabolites are produced after the initial exponential growth segment. This is part of the bacterial growth curve (Todar 2011). The term penicillin makes reference to the vast collection of related antibiotics. Each member of the penicillin family has a general core that contains a beta-lactam ring. This ring is referred to as the nucleus. These antibiotics can occur one of two ways, naturally or can be produced synthetically. They work by preventing the linking
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