CULTURE MEDIA: Culture media are the base where microorganisms can grow with the help of nutrients and under the influence of physical growth parameters. All microorganisms can not grow in a single culture medium and in fact numerous can not grow in any given culture medium. Some organisms can not grow in artificial culture medium are known as obligate spongers.
Examples: Mycobacterium leprae, Rickettsias, Chlamydias, Treponema pallidum.
• Grounded on the thickness nature of the media, they’re classified into solid, semis-solid and liquid.
• Solid media contains agar (1.5-2.0) as solidifying agent and suitable for insulation of bacteria and determination of colony characteristics.
Nutrient agar, BAP etc.
•Semi-solid media also contains agar but the chance content is lower (0.5). This media is useful for determination of motility of bacteria and civilization of microaerophilic bacteria.
Liquid media that don’t contains agar except for needed quantum of nutrients. This media is useful for propagation of large number of organisms, turmoil studies and colorful tests (Sugar turmoil test).