Case scenario A waste product for cheese making is whey. You have been tasked wi
ID: 95637 • Letter: C
Question
Case scenario
A waste product for cheese making is whey. You have been tasked with finding a use for the whey from Swiss cheese (aside from a dietary supplement for humans). You isolate a microbe that is genetically related to Lactobacillus. This microbe is able to grow exceptionally well on the whey when you allow for aeration of the culture – it grows weakly without aeration and the pH drops dramatically over time due to an acidic waste product. See Figure 1 and Table 1 for the structure of lactose and the composition of whey. When you sequence the genome you identify genes for Embden Meyerhoff Parnas as well as oxidoreductases and quinones. You also notice it produces an interesting antibiotic when grown in a closed batch system.
8. Draw a diagram below to show the flow of carbon through each pathway that the microbe would use. Indicate where in the pathways the antibiotic would be created. You do not have to list all the intermediates for each pathway, just what carbon compound begins the pathway and what compounds exit the pathway to begin the next one. (3 points) An example is provided on the next page.
Here’s an example of Pseudomonas metabolic pathways.
Table 1. Composition of milk, cheese whev and casein whev % by weight Fat Lactose (milk sugar) Casein protein Whey protein Minerals Minor components Water TOTAL Milk 4.7 4.5 2.7 0.55 0.85 0.20 86.5 100.00 Cheese whey 0.05 5.0 0.10 0.65 0.50 0.30 93.4 100.00Explanation / Answer
The content of carbohydrate lactose is higher in whey protein these carbohydrates will be converted using the intermediates of EMP pathway and it will be converted to small molecules such as quinanoles and further these quinanoles are converted as secondary metabolites which are antibiotics. Hence the pathways involved in the conversion are EMPP and PYR pathway followed by the antibiotic synthesis.