DETERMINATION OF GLUCOSE AND ETHANOL EFFECTIVE DIFFUSION-COEFFICIENTS IN CA-ALGINATE GEL
DETERMINATION OF GLUCOSE AND ETHANOL EFFECTIVE DIFFUSION-COEFFICIENTS IN CA-ALGINATE GEL
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DOI：
10.1016/0141-0229(92)90009-d
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发表时间：
1992-05-01
影响因子：
3.4
通讯作者：
SOLA, C
中科院分区：
文献类型：
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作者：
ESTAPE, D;GODIA, F;SOLA, C
使用基于充分搅拌的溶液中溶质扩散进或出凝胶珠的实验技术测量 2% 海藻酸钙凝胶中的葡萄糖和乙醇扩散系数。 该研究的目的是在酒精发酵的典型条件下进行测量，例如葡萄糖 (100 g l-1) 和乙醇 (50 g l-1) 的浓度、葡萄糖和乙醇的同时反向扩散以及凝胶珠中细胞的存在水平为 10(9) 个细胞 g-1 珠。 此前，对与所用方法相关的误差的评估表明了实验程序如何最大限度地减少误差。 在不含细胞的 2% 海藻酸钙中单独测量葡萄糖和乙醇系数的值分别为 5.1 和 9.6 x 10(-6) cm2 s-1，低于水中的值。 当研究反扩散的效果时，两个系数均下降：葡萄糖下降 14%，乙醇下降 28%。 当细胞掺入珠子中时，只有乙醇系数显着下降，而葡萄糖系数则明显增加至6.9×10(-6) cm2 s-1。
Glucose and ethanol diffusion coefficients in 2% Ca-alginate gel were measured using the experimental technique based on solute diffusion into or out of gel beads in a well-stirred solution. The aim of the study was to make the measurements under typical conditions found in alcoholic fermentations, such as the concentrations of glucose (100 g l-1) and ethanol (50 g l-1), the simultaneous counter-diffusion of glucose and ethanol, and the presence of cells in the gel beads at a level of 10(9) cells g-1 of beads. Previously, an evaluation of the error associated with the methodology used indicated how the experimental procedure would minimize the error. The individual measurement of glucose and ethanol coefficients in 2% Ca-alginate with no cells gave values of 5.1 and 9.6 x 10(-6) cm2 s-1, respectively, which are lower than those in water. When the effect of counter-diffusion was investigated, both coefficients decreased: glucose by 14% and ethanol by 28%. When cells were incorporated into the beads, only the ethanol coefficient decreased significantly, while the glucose coefficient apparently increased its value to 6.9 10(-6) cm2 s-1.