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Team:Edinburgh/FAQ
From 2008.igem.org
Frequently Asked Questions
Q. Why should the entire process be contained in one organism that does not naturally do the reactions you want, and is therefore probably going to be inefficient, when you could have do the process in steps using different types of organism for each step?
A. The reasons for combining the process into a single host are many. A proportion of the product of each step would be lost with each purification, so although the organisms themselves maybe more efficient, efficiency would be lost. Coupled to this is the difficulty of purifying some of the products. For instance, glucose is soluble, and therefore difficult to purify from solution, as is glycogen. Starch on the other hand is highly insoluble making purification of this end product relatively straight forward.
Q. If one aim is to have your product converted into ethanol as a biofuel, why should the biomass be converted all the way to starch rather than simply stopping at glucose, which is easy to ferment to ethanol?
A. Again, there is a question of purification here (see previous question), but as well as this, glucose becomes inhibitory at high cellular concentrations. Starch, being insoluble, can accumulate at much higher quantities without disrupting the biochemistry of the cell.
