Feist Posted February 25, 2010 Report Share Posted February 25, 2010 So I am on my analysis for the Bio EE and I'm stuck. I did yeast fermentation but the problem is the yeast fermented fructose faster than glucose. From research, it seems glucose should be faster than fructose. Of course, this could have been due to uncertainty or lab error but I'm not sure how to explain either phenomenon. How could they be fermented differently if they're both monosaccharides? Thanks! Reply Link to post Share on other sites More sharing options...
sweetnsimple786 Posted February 26, 2010 Report Share Posted February 26, 2010 Well I googled it, and I found a PDF that said INTEREST in the phenomena of selective fermentation of mixtures of sugarsby yeast has been revived in the last decade, following the more precisemeasurements of Willstiitter and Sobotka [1922]. The facts are briefly asfollows.(1) That separate solutions containing more than 1 % of glucose or fructoseare fermented at equal rates by living yeast.(2) That glucose and fructose in mixtures are fermented at unequal rates,glucose being fermented faster than fructose by most yeasts, includingS. cerevisiae, while fructose is fermented faster than glucose by some yeasts,among which are Sauterne yeast, S. pombe and S. exiguus.I didn't read most of it, and it can be found here.It also said ...he also estimated the rates at which these two yeasts ferment separate solutions containing glucose and fructose. Theseseparate rates of fermentation are of particular interest since Hopkins foundthat, at concentrations of sugar below 1 %, brewer's yeast fermented glucosefaster than fructose. The Sauterne yeast, on the other hand, fermentedfructose faster than glucose at all concentrations of sugar tested, the effectbeing more marked in dilute sugar solutions. According to the ideas to be expressedin the present paper, the explanation of the phenomena of selectivefermentation is to be found in the relative rates of fermentation of solutionscontaining low concentrations of the separate hexoses.So perhaps more research on selective fermentation is in order? Reply Link to post Share on other sites More sharing options...
Sandwich Posted February 26, 2010 Report Share Posted February 26, 2010 Although I don't know much about yeast, this sounds to me like an enzymic thing. I can't say for sure, but to point you in a direction where you might be able to figure it out, google "km and vmax" (Link) and you might consider whether one of the enzymes involved in fermentation of fructose perhaps has a low km and vmax, whereas one of the enzymes involved in fermenting glucose has a high km and vmax. Of course your results could be due to lab error, but if they're all saying the same thing (and I assume you've done plenty of repeats!) it seems unlikely. Reply Link to post Share on other sites More sharing options...
soraby169 Posted September 4, 2021 Report Share Posted September 4, 2021 On 2/25/2010 at 6:24 PM, Feist said: So I am on my analysis for the Bio EE and I'm stuck. I did yeast fermentation but the problem is the yeast fermented fructose faster than glucose. From research, it seems glucose should be faster than fructose. Of course, this could have been due to uncertainty or lab error but I'm not sure how to explain either phenomenon. How could they be fermented differently if they're both monosaccharides? Thanks! Hi, Im looking into different Biology EEs to prep for my own and yours seems super interesting, is there anyway i can take a look at it? Reply Link to post Share on other sites More sharing options...
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