Application of immobilized yeast in bacterial cellulose to the repeated batch fermentation in wine- making

This study focused on wine fermentation by immobilized yeast in bacterial cellulose. During 10 consecutive cycles of the repeated batch fermentation, the sugar uptake rate of the immobilized yeast increased from 1.71 g/L.h (cycle 1) to 3.28 g/L.h (cycle 7) and then reduced to 2.75 g/L.h (cycle 10). Similarly, the ethanol production rate of the fixed yeast augmented during the first 7 cycles, achieved maximum level of 1.21 g/L.h and subsequently decreased during the last 3 cycles. However, the sugar uptake rate and ethanol production rate of the immobilized yeast during the repeated batch fermentation were 16.4 - 91.8% and 19.6 - 116.1%, respectively higher than those of the free yeast. In addition, the fixed yeast in bacterial cellulose did not affect negatively the sensory quality of the final product.