Some microbes require special conditions in which to grow or will not grow in normal culture media. Mycobacterium leprae will only grow well in the body of the armadillo. Rabbits are generally used to culture Treponema pallidum, while viruses, chlamydias and rickettsias can be cultured in eggs, cell and tissue cultures.
Microbes that require oxygen content in between strict aerobic and anaerobic conditions, such as aerotolerant and microaerophiles such as capnophiles (requiring CO2 concentrations between 3%-15%) like Neisseria gonorrhoeae can be cultured in a candle jar apparatus, though chemical gas packs have replaced candles in most laboratories.
Enrichment media contain a nutrient or nutrients only one species in a sample containing many can utilize. Cold enrichment, use to culture Vibrio cholerae, involves incubating a medium in a refrigerator (4 oC) to inhibit enteric bacteria but allow Vibrio which can tolerate cold, to grow.