Biosynthesis of β(1,3)/(1,6)-glucans of cell wall of the yeast Candida utilis ATCC 9950 strains in the culture media supplemented with deproteinated potato juice water and glycerol

Beta(1,3)/(1,6)-glucans are structural polysaccharides of the yeast cell wall. They exhibit diverse functional properties, including therapeutic, thanks to which they find an application in the pharmaceutical, cosmetic, food, and other industries [23]. They serve as biological modifiers of the immune response. Additionally, they stimulate antimicrobial and anti-inflammatory activities; adsorb mycotoxins; decrease the fraction of LDL (low-density lipoprotein) cholesterol; exhibit anticancer, antimutagenic, and antioxidant properties; and promote wound healing [4, 7, 18, 25, 40]. They can act as emulsifiers, gelling agents, or waterand fat-binding substitutes of fat, prebiotics, and film-forming substances [23, 31]. Since 2011, β(1,3)/(1,6)-glucans extracted from the yeast Saccharomyces cerevisiae have been used in the EU countries in certain food categories, as components of the functional foods and of particular nutritional uses [8]. It opens the possibility for searching new, efficient sources of these polymers. It is reasonable especially because the content of structural components of the cell wall and their chemical structure vary considerably depending on the species and strain of yeast, culture conditions (type and amount of carbon and nitrogen sources, type and availability of minerals, pH, temperature, culture period, and degree of culture aeration), and age of cells [1, 3, 11, 14, 15, 17, 30, 45]. The influence of the above-mentioned factors on the biosynthesis and the construction of structural polymers of the yeast cell wall have not been described precisely in the literature. Parameters such as molecular structure, degree of polymerization, molecular branching, molecular weight, and polysaccharides solubility of the yeast wall determine the functional properties of these polymers [4]. Abstract Yeast cell wall β-glucans exhibit valuable functional properties, including therapeutic ones. The possibility of using deproteinated potato juice water (DPJW) with the addition of glycerol in yeast culture of Candida utilis ATCC 9950 for biosynthesis of β(1,3)/(1,6)-glucans of cell wall was determined. The biosynthesis of β-glucans was preferably intensified by media prepared from DPJW at pH 5.0 with 5 or 10 % addition of glycerol. Cells from these cultures were characterized and found to possess thickest cell walls and β-glucan layers. The content of β-glucans in the walls’ preparations was estimated to be approximately 44–45 % and was significantly higher in comparison with the content after culturing in synthetic YPD medium (approximately 31 %). The new developed media may be used in the production of C. utilis biomass with enhanced content of functional β-glucans. It creates the possibility of a favorable, simultaneous management of waste potato juice water and glycerol in the formation of β(1,3)/ (1,6)-glucans.