Basic Nutrition Principles of Production Media PDF

Basic nutrition principles of production media Components of media chemical composition of media Dr Jitendra General Nutritional Requirement of Microbes Growing bacteria in the laboratory requires knowledge of their nutritional needs and the ab...

Basic nutrition principles of production media Components of media chemical composition of media Dr Jitendra General Nutritional Requirement of Microbes Growing bacteria in the laboratory requires knowledge of their nutritional needs and the ability to provide the needed substances in a medium. Through years of experience in culturing bacteria in the laboratory, microbiologists have learned what nutrients must be supplied to each of many different organisms. Certain organisms, such as those that cause syphilis and leprosy, still cannot be cultured in laboratory media. They must be grown in cultures that contain living human or other animal cells. Many other organisms whose nutritional needs are reasonably well known can be grown in one or more types of media. Types of Media Laboratory media are generally synthetic media, as opposed to the natural media mentioned previously. A synthetic medium is a medium prepared in the laboratory from materials of precise or reasonably well-defined composition. A defined synthetic medium is one that contains known specific kinds and amounts of chemical substances. Examples of defined synthetic media are given in Tables 6.3 and 6.4. A complex medium, or chemically nondefined medium, is one that contains reasonably familiar materials but varies slightly in chemical composition from batch to batch.  Such media contain blood or extracts from beef, yeasts, soybeans, and other organisms. A common ingredient is peptone, a product of enzyme digestion of proteins. It provides small peptides that microorganisms can use. Although the exact concentrations are not known, trace elements and vitamins are present in sufficient quantities in complex media to support the growth of many organisms. Both liquid nutrient broth and solidified agar medium used to culture many organisms are complex media. An example of a complex medium is given in Table 6.5.