The enrichment culture is a primary isolation technique designed to make conditions of growth very favorable for an organism of interest while having an unfavorable environment for any competing organisms.   Enriched media is the specific medium designed so that fastidious organisms (those with unusual requirements for growth) will be supported.  For example, using the enrichment culture technique: when trying to isolate a halophile, streak plates of varying high salt concentrations (an enriched medium).  The halophile will thrive on the salty media, while other organisms will not be able to tolerate it and will die out.
 
 

Enrichment Culture Links:

“Enrichment Culture”
http://www.clt.astate.edu/dgilmore/Research%20students/enrichment_culture.htm

“ENVE 301: Environmental Microbiology :Introduction: Overview and History of Microbiology”
http://www.personal.psu.edu/faculty/k/h/khb4/enve301/301introand%20history/enve301introlecture.html

“Significant Events Of The Last 125 Years”
http://www.asmusa.org/mbrsrc/archive/SIGNIFICANT.htm