Author/Editor		Malc, Karin
Title		Biotransformacija progesterona s halofilno črno kvasovko Hortaea werneckii
Translated title		Biotransformation of progesterone with halophilic black yeast Hortaea werneckii
Type		monografija
Place		Ljubljana
Publisher		Biotehniška fakulteta, oddelek za biologijo
Publication year		2001
Volume		str. 52
Language		slo
Abstract		Extremophilic microorganisms (among them are halophilic microfungi) offer potential applications in biotechnology for the production of new biomolecules. Until now biotransfonmations with halophilic black yeasts have not yet been investigated. The aim of this research was to establish the way of biotransformation of progesterone as a model substance and the influence of salinity of the growth medium on the biotransfonmation and on the production of different products. The biotransformation of progesterone with the halophilic black yeast Hortaea werneckii was found to be dependent on the salinity of the growth media at 0%, 17% and 25% NaCI. The products of the biotransformation were identified with TLC and GC/MS. It was established that the transformation of progesterone with H. werneckii without NaCI in the medium after four days of growth led to the production of androstenedione and testosterone, with small amounts of the hydroxylated products. Several hydroxylated products were produced at 17% NaCI after four days and not so many at 25% NaCI. The presence of cyclohexymide resulted in much smaller amounts of the hydroxylated products. Two different profiles of progesterone biotransformation were found to be growth phase dependent In the logarithmic phase progesterone acts as a stressor and the fungus responds with the detoxification mechanisms; mostly hydroxylated products were detected, corresponding enzymes were of an inducible nature. In the stationary phase mostly reduced products were found, the corresponding enzymes were constitutive.
Descriptors		YEASTS BIOTRANSFORMATION PROGESTERONE SODIUM CHLORIDE CULTURE MEDIA ANDROSTENEDIONE TESTOSTERONE CHROMATOGRAPHY, THIN LAYER CHROMATOGRAPHY, GAS SPECTRUM ANALYSIS, MASS