Question

these are the results of a bacterial growth curve experiment. please explain what these reuslts mean

'Cells/ and OD (2ml Те 0.04 г. 219xce a53 xiocell g/uL 220 (054 0.1102 256 1 T2 5.72x10'cellsimL 3.07x (0° &lis /м2 326 56 Т3 О.ІЮ 2. Ту 0303 5:3x102 cullstok 9.3-хір" е4.7 m) (5°, 051 6 26 6 645) 12x/* г.

Answer 1

Ans) Bacterial growth curve experiment is carried out at different time intervals to calculate how many doublings the bacterial population have undergone,their generation time can be determined, and the number of bacteria can also be determined.

In this experiment,the culture is transmitted in the side arm flask and plugged with cotton to avoid contamination and kept in shaking incubator for various time intervals. At different time intervals, suitable volume of culture is taken out and OD is measured by spectrophotometer. After we get all the OD values, we plot a standard curve (we calculate separate OD values for the standard) and extrapolate the OD values (Y-axis) on the X-axis to know the cells/ml . Usually, semi log graph is used.

According to these results, at time 4.50 we can observe the OD value to be 0.527 and 9.37x10⁷ cells/ml . At time 5.26 (T6),there were 1.57x10⁸ cells/ml was observed which were the maximum number.

If you can see, after time T1 or 2.56 , there have been increased numbers of cells/ml or you can also say that the bacteria have been in the exponential phase after time T1.