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I'd like to do an experiment on what concentration of sugar would be best for fastest yeast fermentation. I'm thinking to put some active dry yeast into different concentrations of sugar water and measure the fermentation activity after a certain amount of time (like 15 minutes or so). I know at a certain concentration the yeast will effectively die as the sugar solution becomes hypertonic, but I don't really know what range would be most effective right now. Any papers I've found are on yeast for alcohol.

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When glucose and fructose are fermented separately, the uptake profiles indicate that both sugars are utilized at similar rates. However, when fermentations are conducted in media containing an equal concentration of glucose and fructose, glucose is utilized at approximately twice the rate of fructose. The preferential uptake of glucose also occurred when sucrose, which was first rapidly hydrolyzed into glucose and fructose by the action of the enzyme invertase, was employed as a substrate. Similar results were observed in the fermentation of brewer's wort and wort containing 30% sucrose and 30% glucose as adjuncts. In addition, the high levels of glucose in the wort exerted severe catabolite repression on maltose utilization in the Saccharo~ myces uvarum (carlsbergensis) brewing strain. Kinetic analysis of glucose and fructose uptake in Saccharomyces cerevisiae revealed a Km of 1.6 mM for glucose and 20 mM for fructose. Thus, the yeast strain has a higher affinity for glucose than fructose. Growth on glucose or fructose had no repressible effect on the uptake of either sugar. In addition, glucose inhibited fructose uptake by 60% and likewise fructose inhibited glucose uptake by 40%. These results indicate that glucose and fructose share the same membrane transport components


References

D'Amore, Tony, Inge Russell, and Graham G. Stewart. "Sugar utilization by yeast during fermentation." Journal of industrial microbiology 4.4 (1989): 315-323.

Thirwell, A.J. and R.L. Busby. 1982. Liquid sugar as a brewing adjunct. Inst. Brew. Proc. Conv. (Aust. and N.Z. Sect.) 17:77 84. , http://www.123HelpMe.com/view.asp?id=121963

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  • $\begingroup$ you can also add this citation because the other two cannot be found (but they seem valid because they are cited) $\endgroup$ – WYSIWYG Jan 17 '16 at 19:36

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