Author/Editor     Kogej, Tina; Gorbushina, Anna A; Gunde-Cimerman, Nina
Title     Hypersaline conditions induce changes in cell-wall melanization and colony structure in a halophilic and a xerophilic black yeast species of the genus Trimmatostroma
Type     članek
Source     Mycol Res
Vol. and No.     , št. 110
Publication year     2006
Volume     str. 713-24
Language     eng
Abstract     Melanized yeast-like meristematic fungi are characteristic inhabitants of highly stressed environments and are rare eukaryotic extremophiles. Therefore, they are attractive organisms for studies of adaptations. In this study we compared two meristematic species of the genus Trimmatostroma on media of differing water potentials isolated from distinct waterstressed environments: T. salinum from the hypersaline water of a solar saltern, and T. abietis from a marble monument in Crimea. The morphology and melanization of both isolates in response to sodium chloride-induced water stress were investigated by means of light and electron microscopy. We describe and compare the colony form and structure, ultrastructure, and degree of cell-wall melanization of both species in reaction to salinity and to inhibited melanin synthesis. The halophilic T. salinum responded to changed salinity conditions on the level of individual cell ultrastructure and degree of cell wall melanization, whereas the xerophilic rock-inhabiting T. abietis responded with modification of its colony structure. Surprisingly, both the halophilic and the xerophilic Trimmatostroma species were able to adapt to hypersaline growth conditions, although their growth patterns show distinct adaptation of each species to their natural ecological niches.
Descriptors     YEASTS
SODIUM CHLORIDE
ADAPTATION, BIOLOGICAL
CELL WALL
MELANINS
ECOSYSTEM
SEAWATER
MICROSCOPY, ELECTRON