Author/Editor		Petrovič, U; Gunde-Cimerman, N; Plemenitaš, A
Title		Salt stress affects sterol biosynthesis in the halophilic black yeast Hortaea werneckii
Type		članek
Source		Fems Microbiol Lett
Vol. and No.		Letnik 180
Publication year		1999
Volume		str. 325-30
Language		eng
Abstract		Hortaea werneckii is a black yeast recently isolated from salterns in Slovenia. Some of the adaptations of halophilic microorganisms to increased salinity and osmolarity of the environment are alterations in membrane properties. By modulating the fluidity, sterols play an important role as a component of eukaryotic biological membranes. We studied the regulation of sterol biosynthesis in H. werneckii through the activity and amount of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG R), a key regulatory enzyme in the biosynthesis of sterols. We found some differences in the characteristics of HMG R and in its regulation by different environmental salinities in H. werneckii when compared to the mesophilic baker's yeast, Saccharomyces cerevisiae. Our results suggest that halophilic black yeast regulates sterol biosynthesis through HMG R in a different way than mesophiles, which might be a consequence of the different ecophysiology of halophilic black yeasts. From this perspective, H. werneckii is an interesting novel model organism for studies on salt stress-responsive proteins as well as on sterol biosynthesis in eukaryotes.
Descriptors		YEASTS FUNGI CELL MEMBRANE STEROLS ENZYMES BIOLOGICAL TRANSPORT WATER MICROBIOLOGY SLOVENIA SEAWATER MICROBIOLOGY