Melanization Affects Susceptibility of Cryptococcus Neoformans to Heat and Cold

FEMS Microbiol Lett. 1997 Aug 15;153(2):265-72. doi: 10.1111/j.1574-6968.1997.tb12584.x.

Abstract

Cryptococcus neoformans can synthesize melanin from a variety of substrates, including L-dopa (L-3,4-dihydroxyphenylalanine). Growth in minimal medium with L-dopa resulted in progressive accumulation of melanin in stationary phase cells. Melanized and non-melanized yeast cells were exposed to heat (42-47 degrees C) and cold (-20 degrees C), and the percentage of survival determined. Melanized cells were less susceptible to heat than non-melanized cells of the same age. Melanized cells from early stationary phase cultures were less susceptible to cold than non-melanized cells of the same age. However, melanized cells from late stationary phase cultures were more susceptible to cold than non-melanized cells of the same age. There was no statistical difference in susceptibility to heat and cold between melanin-deficient cells grown with and without L-dopa. These results suggest a role for melanin in protection against heat and cold.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cold Temperature*
  • Cryptococcus neoformans / growth & development
  • Cryptococcus neoformans / metabolism*
  • Hot Temperature*
  • Melanins / biosynthesis
  • Melanins / physiology*

Substances

  • Melanins