Which organism requires an agar medium overlay with long-chain fatty acids for cultivation?

Which organism requires an agar medium overlay with long-chain fatty acids for cultivation?

• A. Candida albicans
• B. Cryptococcus neoformans
• C. Coccidioides immitis
• D. Malassezia furfur

Answer: (D)

Malassezia furfur is a lipophilic yeast that must have lipids in the growth medium. It cannot synthesize enough long-chain fatty acids on its own, so providing these nutrients externally is essential for cultivation. In the lab, this is accomplished with an agar medium overlay containing long-chain fatty acids (often using olive oil or a lipid-rich medium like modified Dixon’s agar). This lipid boost supports robust growth and the characteristic colony appearance on this organism. The other organisms listed do not require lipid overlays and can be grown on standard fungal media without added long-chain fatty acids.

Malassezia furfur is a lipophilic yeast that must have lipids in the growth medium. It cannot synthesize enough long-chain fatty acids on its own, so providing these nutrients externally is essential for cultivation. In the lab, this is accomplished with an agar medium overlay containing long-chain fatty acids (often using olive oil or a lipid-rich medium like modified Dixon’s agar). This lipid boost supports robust growth and the characteristic colony appearance on this organism. The other organisms listed do not require lipid overlays and can be grown on standard fungal media without added long-chain fatty acids.