面包酵母高糖发酵力与蔗糖酶活力关系的研究

本文研究了面包酵母高糖耐性与蔗糖酶活性的关系。通过对八株酵母菌株的蔗糖酶活性和高糖面团发酵力比较分析,其中ADY2蔗糖酶酶活最大,BY-6最小,分别为128.70 U/g干酵母和30.55 U/g干酵母,而在高糖面团中发酵力却是BY-6最大,ADY2最小,CO2的产生量分别为850 ccm和225 ccm,证实了较低蔗糖酶活性的面包酵母菌株具有在高糖面团中发酵力较高的特性。通过测定蔗糖酶酶活相差较大的株菌BY-6和ADY2在蔗糖模拟面团中的蔗糖消耗和葡萄糖积累曲线,结果表明ADY2不仅蔗糖消耗速度比BY-6快,且其积累葡萄糖的速度比BY-6快,同时所积累的最高葡萄糖量也比BY-6高,分别为5.89?10-2和4.50?10-2 g/mL。此外,即便是蔗糖酶酶活低且高糖面团发酵力大菌株BY-6在蔗糖模拟面团培养基中仍有较多葡萄糖积累,因此选育蔗糖酶水解生成葡萄糖速度与其利用葡萄糖速度一致或相差不大的菌株是我们选育耐高糖面包酵母菌株的一个控制靶点。

The Relationship between Fermentation Activity of Saccharomyces cerevisiae in High-sugar Dough and Sucrase Activity

Six active dry yeasts with two strains BY-6 and BY-14 were used as the tested strains. The sucrase activities, specific growth rates in different types of culture medium and fermentation activities in high and low sugar dough were detected. The yeast ADY2 and BY-6 showed the highest and lowest sucrase activities, respectively, being of 128.70 U/g dry yeast and 30.55 U/g dry yeast, respectively. For the fermentation activity in high-sugar dough, the outputs of CO2 were 850 ccm and 225 ccm, respectively. It was proved that the strain with lower sucrase activity had better fermentation activity in high-sugar dough. By measuring the consumption of sucrose and accumulation of glucose in the simulation of high-sugar dough, the results showed that ADY2 with higher sucrase activity consumed more sucrose and accumulated glucose faster than BY-6 with lower sucrase activity; meanwhile, it accumulated more glucose than BY-6. For BY-6 with lower sucrase activity and strong fermentation activity, there was still a large number of glucose accumulations in the simulation of high-sugar dough. Therefore it was a control target spot to breed the strains whose sucrase activity was consistent with the speed of glucose consumption.