The spectrophotometer analysis of Escherichia coli growth during heat application
The purpose of this experiment is to determine the rate of Escherichia coli (E. coli) growth over 100 minutes in a liquid growth medium (control), and to determine the rate of E. coli growth over 100 minutes in a heated liquid growth medium. The prediction is that the control E. coli culture will grow at a faster rate exponentially over 100 minutes than the experimental bacteria culture. Consequently due to heat application, the experimental bacteria will not grow over the 100 minutes, and will either move into G0 of its cell cycle or will produce descending results as cell death occurs.
The null hypothesis for this experiment is that the experimental E. coli …show more content…
coli are added to two separate test tubes. The control tube is placed into a rotating incubator, and the experimental tube is placed into a hot water bath between 70-80 degrees Celsius. To maintain this temperature, add hot water frequently to the bath. Next, add 2 mL of the control formula into a cuvette, and place into a spectrophotometer (after it has been zeroed at a wave length of 660 nm). Record the optical density reading on the spectrophotometer, and repeat for the experimental solution. This reading should be recorded as time 0. Be sure to measure the optical density for the experimental E. coli at 0 minutes before the tube is placed in the hot water bath. Wait 20 minutes, and measure the optical density for the two tubes again. Continue this process every 20 minutes for 100 minutes.
Results
After analyzing the growth of bacteria with and without heat application, my laboratory group and I determined that heat application slowed down E. coli growth over 100 minutes. Table 1 outlines the data gathered during the experiment. Note the growth of the control bacteria verses the growth of the experimental bacteria. The control bacteria acquired an optical density (OD) from 0.02 nm to 0.109 nm, whilst the experimental bacteria that were placed into a hot water bath stayed between the OD of 0.01-0.019
The purpose of this experiment is to determine the rate of Escherichia coli (E. coli) growth over 100 minutes in a liquid growth medium (control), and to determine the rate of E. coli growth over 100 minutes in a heated liquid growth medium. The prediction is that the control E. coli culture will grow at a faster rate exponentially over 100 minutes than the experimental bacteria culture. Consequently due to heat application, the experimental bacteria will not grow over the 100 minutes, and will either move into G0 of its cell cycle or will produce descending results as cell death occurs.
The null hypothesis for this experiment is that the experimental E. coli …show more content…
coli are added to two separate test tubes. The control tube is placed into a rotating incubator, and the experimental tube is placed into a hot water bath between 70-80 degrees Celsius. To maintain this temperature, add hot water frequently to the bath. Next, add 2 mL of the control formula into a cuvette, and place into a spectrophotometer (after it has been zeroed at a wave length of 660 nm). Record the optical density reading on the spectrophotometer, and repeat for the experimental solution. This reading should be recorded as time 0. Be sure to measure the optical density for the experimental E. coli at 0 minutes before the tube is placed in the hot water bath. Wait 20 minutes, and measure the optical density for the two tubes again. Continue this process every 20 minutes for 100 minutes.
Results
After analyzing the growth of bacteria with and without heat application, my laboratory group and I determined that heat application slowed down E. coli growth over 100 minutes. Table 1 outlines the data gathered during the experiment. Note the growth of the control bacteria verses the growth of the experimental bacteria. The control bacteria acquired an optical density (OD) from 0.02 nm to 0.109 nm, whilst the experimental bacteria that were placed into a hot water bath stayed between the OD of 0.01-0.019