Sugar rush looks at the five main sources of carbohydrates in biological systems and asks, which one is more attractive for E.coli?
Plates were prepared by making small wells in a petri dish and gently pipetting 1ml concentration of each sugar (mixed with LB-agar). The colony (E.coli) was inoculated in the centre with a bit of glycerol to keep it round and 'tight' as it begins to grow.
Of the five main sugars, the following were selected:
Two monosaccharides (glucose, fructose) and three disaccharides (lactose or "milk sugar", sucrose or "table sugar", maltose).
It takes time for the colony to reach a size where we are able to detect its preferred sugar. The issue of the sugars diffusing into the agar was solved by making the agar solution “hard” (more powder and less water).