Enrichment media :
* Enrichment media are usually liquid media the contain a specific nutrient that will support growth of a desired organisms or inhibitory substances that will suppress the growth of undesired organisms and thus create a favorable environment for desired organisms.
* Enrichment media is that in which nutritional environment is adjusted in such a manner that it enhances selectively the growth of a certain bacterial types within a given mixed population.
* This approach constitutes a powerful tool for the bacteriologist in the isolation and identification of pure cultures from an initially mixed population of bacteria.
* This method is used for those microbes which are in small numbers in the sample and whose growth is slow than other species present.
* The principle of enrichment culture is to control the nutrients and culture conditions (temperature, air supply, light, pH, etc) in such a way that is suits only to the given species.
* If a medium containing salt solution cellulose as sole carbon source is incubated with a sample of garden soil and incubated at 25-30°C, will enrich only cellulose producing organism.
* Cultures of other soil bacteria may be selectively enriched by varying the composition of the medium and the conditions of incubation.
* e.g. Nitrogen Free Mannitol Broth [NFMB].