Minimal growth medium for bacteria such as E. Coli includes various salts with characteristic concentrations in the mM range and a carbon source. The carbon source is typically glucose and it is used at 0.5% (a concentration of 0.5g/100mL). For nitrogen, minimal medium contains ammonium chloride (NH4Cl) with a concentration of 0.1 g/100 mL. For this problem we will say that, on average, each amino acid has 5 carbon atoms, each sugar base pair has 20 carbon atoms, and each lipid has 40 carbon atoms. Of course, these are all crude estimates and as with the entirety of this problem, should be seen as a simple estimate to give a feeling for the numbers. In the case of nitrogen, we know we have about two nitrogen atoms per amino acid, each base pair has about eight nitrogen atoms, and each phospholipid molecule usually has one nitrogen atom. Finally, each DNA base pair has two phosphate atoms, while each lipid. (a) Make an estimate of the number of carbon atoms it takes to make up the macromolecular contents of a bacterium such as E. coli. Similarly, make an estimate of the number of nitrogens it takes to make up the macromolecular contents of a bacterium? What about phosphate?
(b) How many cells can be grown in a 5mL culture using minimal medium before the medium exhausts the carbon? How many cells can be grown in a 5mL culture using minimal medium before the medium exhausts the nitrogen? Note that this estimate will be flawed because it neglects the energy cost of synthesizing the macromolecules of the cell.