Step 4: My Experiment / Cool Calculations
Plastic is a simple molecule (see image below), it is essentially a huge molecule with a 2 Carbon: 4 Hydrogen ratio.
The weight ratio is 3.98x10^-23g Carbon : 6.68x10^-24g Hydrogen
The ratio in % is 85.6% Carbon : 14.4% Hydrogen
The approximate number of carbon atoms per E.coli cell = 7x10^9 cells
Weight of Carbon in a single cell= 1.40x10^-13g
Using this information the weight of the Carbon atoms lost from the plastic can be calculated. Divide that number by the number of days the experiment took place to get the weight loss per day. And although this is a rough estimate, the weight of the Carbon loss can be translated into the number of microbial cells that grew based on that weight, and then the growth of these cells per day can be calculated as well. :)