2.3. Yeast cells immobilization
Na-alginate (A.R) powder was dissolved in distilled water in a 75–80 °C water bath for 30 min at the ratio of 2.5–3.0:100. The mature yeast cells of fermentation culture medium were mixed with the Na-alginate solution at the ratio of 1:10. The mixture was injected into 0.05 M calcium chloride (A.R) solution to form Ca-alginate particles by the equipment that was designed by us. The produced Ca-alginate particles were of near-spherical shape about 3 mm in diameter. After 12 h gelation, the immobilized yeast particles were stored at 4 °C.