不同糖源对酵母生长及糖利用的影响

采用含有不同糖源的液体培养基对酵母进行培养,模拟面团中3种不同的糖源,研究其对酵母生长及糖利用的影响。结果表明:酵母在含有葡萄糖和麦芽糖的培养基中均表现出明显的延滞期、对数期和稳定期,在葡萄糖培养基中的酵母较早进入对数期,且对数期生长速率高于在麦芽糖培养基中,但酵母在淀粉和无糖环境中没有表现出明显的生长阶段;葡萄糖培养基与麦芽糖培养基中的酵母细胞在对数期呈椭圆形,细胞体积显著增大,细胞呈聚集状态,且大量出芽;酵母培养过程中,葡萄糖培养基中的葡萄糖浓度呈显著下降的趋势,最后趋于平稳,麦芽糖培养基中的葡萄糖浓度呈先升高后下降的趋势。葡萄糖和麦芽糖培养基pH值呈先下降后趋于稳定的趋势,无糖和淀粉培养基pH值变化不显著。葡萄糖和麦芽糖显著影响酵母的生长速率、细胞形态、糖的利用和培养基的pH值,为酵母利用面团中不同糖源发酵提供参考。

Effects of different sugar sources on yeast growth and sugar utilization

In this study,yeast was cultured in a liquid medium containing different sugar sources to simulate different sugar sources in the dough and study the effects of different sugar sources on yeast growth and sugar utilization.The results showed that the yeast showed significant lag phase,log phase and stable phase in the medium containing glucose and maltose.The yeast in the glucose medium entered the log phase earlier,and the logarithmic growth rate was higher than that in the maltose medium.Yeast did not show obvious growth stage in starch and sugar-free environment;in glucose medium and maltose medium,yeast cells showed elliptical shape,significantly increased volume,aggregation state and a large amount of budding in logarithmic phase.The glucose concentration in the glucose culture showed a significant decline in the yeast culture process,and finally stabilized;in the maltose medium,the glucose concentration increased first and then decreased.The pH of the glucose and maltose medium decreasd first and then stabilized,and the pH of the sugar-free and starch medium did not change significantly.Therefore,glucose and maltose significantly affect the growth rate of yeast,cell morphology,sugar utilization and pH in the medium,which provides references for studies of yeast fermentation using different sugar sources in the dough.