This bachelor’s thesis focuses on the preparation and characterization of functional materials based on exopolysaccharides (EPS) produced by the yeast Rhodotorula toruloides. The aim was to evaluate the potential of these biopolymers as carriers for vitamins in dermal applications. The theoretical section summarizes the issues surrounding microbial polysaccharide production, methods for their isolation, and nanofiber spinning techniques, with a focus on the electrospinning.
The experimental part of the study began with the cultivation of the yeast Rhodotorula toruloides, followed by biomass separation and the isolation of exopolysaccharides (EPS). Analysis of cellular lipids using gas chromatography confirmed the presence of saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA), which underscores the technological potential of the studied strain. The isolated polymers were subsequently tested for their processability using the electrospinning method because of no nanofibre forming by using forcespinning. However, due to the unsuitable rheological properties of pure EPS solutions, it was not possible to obtain stable nanofibers also by electrospinning; therefore, attention was shifted to the preparation of composite materials with polyethylene oxide (PEO).
While PEO solutions with added vitamins were processed using thin-film casting, the combination of EPS and PEO enabled the successful production of nanofiber structures by electrospinning. Concurrently, HPLC methods for the determination of retinol, ascorbate, and tocopherol were optimized. Although technological limitations prevented the final incorporation of vitamins directly into the nanofibers, this work provides fundamental insights into the miscibility of EPS with PEO and defines the limits of electrospinning of microbial polymers for the future development of biocompatible carriers.