You have obtained a bacterial sample that has about 1.0 x 108 cells/mL. Three serial 10-2 dilutions of 0.1mL of the bact
Posted: Thu Jun 30, 2022 6:30 pm
You have obtained a bacterial sample that has about 1.0 x 108 cells/mL. Three serial 10-2 dilutions of 0.1mL of the bacteria were made with sterile Letheen broth as the diluent (each diluent tube containing 10mL). From the final tube of bacterial suspension (10-6), 0.2mL and 0.5mL was plated onto letheen agar, spread and incubated at 35 degrees celsius for 48hrs. 0.1ml of the final bacterial suspension (10-6) was put into 9.9mL containing your product, then incubated at room temperature for 14 days.
Please keep in mind the dilution series followed at each time point and the results, using letheen broth and agar again:
On day 0, there were 95 CFU, day 7 (10-4) 37 CFU, day 14 (10-2) 33 CFU, day 28 (no dilution) 6 CFU.
1. Calculate the final concentration of bacteria in your product on Day 0.
2. What tests do you expect to perform on Day 7 and Day 14?
3. What are your dilution factors for each time point (day 0, day, 7, day 14, and day 28)? What are your volumes plated?
4. Calculate the final concentration of bacteria on day, 7, day 14, and day 28.
5. Using semilog paper, graph the data known. The x axis is time, and the y axis is concentration.
Please keep in mind the dilution series followed at each time point and the results, using letheen broth and agar again:
On day 0, there were 95 CFU, day 7 (10-4) 37 CFU, day 14 (10-2) 33 CFU, day 28 (no dilution) 6 CFU.
1. Calculate the final concentration of bacteria in your product on Day 0.
2. What tests do you expect to perform on Day 7 and Day 14?
3. What are your dilution factors for each time point (day 0, day, 7, day 14, and day 28)? What are your volumes plated?
4. Calculate the final concentration of bacteria on day, 7, day 14, and day 28.
5. Using semilog paper, graph the data known. The x axis is time, and the y axis is concentration.