Bioethanol and Mead Production Using Saccharomyces cerevisiae Immobilized on Sodium Alginate Beads
學生姓名:
林敏桓
指導教授:
方翠筠
學 期:
113下
摘 要:
The purpose of this study was to investigate, during batch fermentation using immobilized Saccharomyces cerevisiae cells to convert glucose derived from oil palm empty fruit bunches into ethanol, the effects of time, temperature, pH, immobilized yeast cell loading, and the
repeated use of sodium alginate (Na-alginate) beads on ethanol production, as well as to compare the fermentation performance of immobilized and free cell systems. The results showed that time, temperature, pH, yeast mass, and the gel beads' repeated use significantly
affected both ethanol concentration and final glucose concentration. As expected, under the conditions of 30°C, pH 5, an immobilized yeast cell loading of 0.75 g, and a 48-hour fermentation, the system using immobilized yeast cells achieved the highest ethanol concentration. Under the same conditions, however, the free cell system produced a lower ethanol yield. These findings suggest that the immobilized cell system holds great potential for ethanol production because it maintains cell viability, lowers the risk of contamination, and protects yeast cells from potential inhibitory effects. In addition, this study examined the production of mead from second-category honey, employing S. cerevisiae cells immobilized in 2% and 4% sodium alginate during fermentation and assessed their reusability over five consecutive fermentations. The results indicated that immobilized cells in 4% sodium alginate exhibited higher mechanical stability, allowing for multiple reuses and making the process more economically viable. Both in the free cell (control) and immobilized cell fermentations, sugar consumption, followed a similar pattern, with free cell fermentation completing in about 72 hours, while the first use of immobilized cells required about 96 hours. Immobilized cells did not significantly affect specific fermentation parameters, such as the sugar-to-ethanol conversion, alcohol content, pH, and total acidity. However, volatile acidity slightly increased, and sulfur dioxide production decreased. Furthermore, the concentration of sodium alginate had no significant impact on the monitored fermentation parameters or the mead’s characteristics.
repeated use of sodium alginate (Na-alginate) beads on ethanol production, as well as to compare the fermentation performance of immobilized and free cell systems. The results showed that time, temperature, pH, yeast mass, and the gel beads' repeated use significantly
affected both ethanol concentration and final glucose concentration. As expected, under the conditions of 30°C, pH 5, an immobilized yeast cell loading of 0.75 g, and a 48-hour fermentation, the system using immobilized yeast cells achieved the highest ethanol concentration. Under the same conditions, however, the free cell system produced a lower ethanol yield. These findings suggest that the immobilized cell system holds great potential for ethanol production because it maintains cell viability, lowers the risk of contamination, and protects yeast cells from potential inhibitory effects. In addition, this study examined the production of mead from second-category honey, employing S. cerevisiae cells immobilized in 2% and 4% sodium alginate during fermentation and assessed their reusability over five consecutive fermentations. The results indicated that immobilized cells in 4% sodium alginate exhibited higher mechanical stability, allowing for multiple reuses and making the process more economically viable. Both in the free cell (control) and immobilized cell fermentations, sugar consumption, followed a similar pattern, with free cell fermentation completing in about 72 hours, while the first use of immobilized cells required about 96 hours. Immobilized cells did not significantly affect specific fermentation parameters, such as the sugar-to-ethanol conversion, alcohol content, pH, and total acidity. However, volatile acidity slightly increased, and sulfur dioxide production decreased. Furthermore, the concentration of sodium alginate had no significant impact on the monitored fermentation parameters or the mead’s characteristics.
林敏桓.pdf