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Carotenoids represent large group of various natural pigments ensuring typical coloration of plants, microorganisms and several animals. It was confirmed by many studies, that consuming these biological active compounds has positive impact for human life. Therefore, they are applied in different industrial fields, such as pharmacy, cosmetic, food, and feed industry. Due to high demand for carotenoids we would like to discover new microorganisms overproducing carotenoids. We focused on yeasts of genus Rhodotorula sp. (forty isolates), that we screened according to growth and carotenoid production on Petri dishes and production media. After cultivation on Petri dishes we selected five strains (denoted as KF-4, KF-6, KF-24, KF-31, KF-104) with interesting pigment production and quick growth. The secondary screening on production media identified KF-104 as the best producer of carotenoid pigments with massive pigment accumulation (1.15 mg/g DCW) and yield (9.69 mg/L). The main carotenoid of KF-104 isolate was β-carotene (35.4 %) with the accumulation of 408.7 μg/g DCW and the yield of 3.4 mg/L. The rest were torularhodin, torulene and γ-carotene (62.7-79.0 %). Production of torularhodin in the cells was low (0.4 to 1.4 mg/L) as was its accumulation in cells (31.2-121.0 μg/g DCW). We continue the experimental analyses of these isolates in order understand differences in the content of individual pigments.

Grape juice of Cabernet Sauvignon was fermented with three axenic cultures of Saccharomyces cerevisiae (CS-V1, CS-V2, CS-V3) to determine the effect of yeast strain on the aroma of rosé wine. An analytical methodology based on headspace solid phase microextraction combined with comprehensive two-dimensional gas chromatography and high-resolution time-of-flight mass spectrometry was used for identification of volatile organic compounds (VOC) in resulting wines. This method allowed the identification of 97 VOC responsible for wine aroma which was strictly affected by the strain used for fermentation. Results of the statistical analysis showed that strains CS-V2 and CS-V3 had the highest similarity of VOC profiles while CS-V1 was significantly different. Wine fermented with yeast strain CS-V1 was characterized by a high concentration of hexyl octanoate, 2-phenylethyl octanoate and free terpenoids (farnesol, farnesyl acetate). Strain CS-V2 contributed to an increased relative concentration of 1-hexadecanol, 1-heptanol, 9-decenoic acid and nerolidol. Wine fermented with CS-V3 had a high level of benzaldehyde, hexyl hexanoate, benzeneacetaldehyde and terpenoids α-terpineol and nerol.<br /><br />