(2 points) S. cerevisiae uses glycolysis-based fermentation to produce ethanol, while Z. mobilis
uses the Entner-Doudoroff pathway. Give a reason for why more ethanol can be obtained per
unit weight of Z. mobilis cells compared to unit weight of S. cerevisiae cells. Simply stating
what is in the article is not sufficient. You need to explain your reasoning based on what is
different between the ethanol producing pathways in the two organisms, and how that relates to
cell mass. (1 point) Name one enzyme you would introduce into Z. mobilis to decrease the flux
through its ethanol-producing pathway
Solution
A) Z.mobilis produce more ethanol in comparison to S.cerevisiae because of higher sugar uptake
and ethanol yield (approx. 2.5times higher).It involves low biomass production and higher
ethanol tolerance.This organism does not require any controlled addition of oxygen during the
process of fermentation and have capability of genetic manipulations.Zymomonas mobilis
degrades sugars to pyruvate by the Entner-Doudoroff pathway where pyruvate is fermented to
produce ethanol and carbon dioxide.
B) To decrease flux enzyme that can be introduced is glucose-6-phosphate dehydrogenase. Their
substrate range is limited to glucose,fructose and sucrose..
(2 points) S. cerevisiae uses glycolysis-based fermentation to produc.pdf
1. (2 points) S. cerevisiae uses glycolysis-based fermentation to produce ethanol, while Z. mobilis
uses the Entner-Doudoroff pathway. Give a reason for why more ethanol can be obtained per
unit weight of Z. mobilis cells compared to unit weight of S. cerevisiae cells. Simply stating
what is in the article is not sufficient. You need to explain your reasoning based on what is
different between the ethanol producing pathways in the two organisms, and how that relates to
cell mass. (1 point) Name one enzyme you would introduce into Z. mobilis to decrease the flux
through its ethanol-producing pathway
Solution
A) Z.mobilis produce more ethanol in comparison to S.cerevisiae because of higher sugar uptake
and ethanol yield (approx. 2.5times higher).It involves low biomass production and higher
ethanol tolerance.This organism does not require any controlled addition of oxygen during the
process of fermentation and have capability of genetic manipulations.Zymomonas mobilis
degrades sugars to pyruvate by the Entner-Doudoroff pathway where pyruvate is fermented to
produce ethanol and carbon dioxide.
B) To decrease flux enzyme that can be introduced is glucose-6-phosphate dehydrogenase. Their
substrate range is limited to glucose,fructose and sucrose.
