Question: 70°C Group Details Time (min) 0 1 2 5 10 15 20 25 Group 0 Dilution 10^-2 (1 In 100) = 100 GG Number Of Colonies 58 Concentration Of Viable Cells (Number Of Colonies X Dilution X 10), Inthsi Example: 58 X 100 X 10=5.8 X 10^4 58000 Group 1 Dilution 100 10 10 1 1 1 1 1 Number Of Colonies 187 165 131 7 0 0 0 0 Concentration Of Viable Cells Group 2 Dilution …

70°C        
           
           

Group details          
           
           

Time (min)      0 1 2 5 10  
15   20   25

Group 0    Dilution   10^-2 (1 in 100) =
100          
           
   

GG   Number of colonies   58  
           
           

   Concentration of viable cells (Number of colonies x
Dilution x 10), inthsi example: 58 x 100 x 10=5.8 x
10^4   58000      
           
       

Group 1   Dilution 100  
10   10   1   1  
1   1   1

   Number of colonies 187  
165   131   7   0  
0   0   0

   Concentration of viable cells   
           
           
   

Group 2   Dilution 100  
10   10   1   1  
1   1   1

   Number of colonies 165  
151   292   2   0  
0   0   0

   Concentration of viable cells   
           
           
   

Group 3   Dilution 100  
10   10   1   1  
1   1   1

   Number of colonies 201  
147   144   1   1  
0   0   0

   Concentration of viable cells   
           
           
   

Group 4   Dilution 100  
10   10   1   1  
1   1   1

   Number of colonies 195  
161   138   4   0  
0   0   0

   Concentration of viable cells   
           
           
   

Group 5   Dilution 100  
10   10   1   1  
1   1   1

   Number of colonies 213  
155   176   0   0  
0   0   0

   Concentration of viable cells
QUESTIONS:

Select one of the temperatures and one set of results at that
temperature. Look at the results obtained at that incubation
temperature and briefly discuss the differences in the number of
colonies between plates from the same sample (time) but different
dilutions. What difference did you expect to find?
Give an example of how you calculated the concentration of
viable cells from the number of colonies counted for your chosen
dilution (plate).
A pure culture of Bacillus subtilis was used for this
experiment. What would it mean if more than one type of
microorganism, observed as different colonies, was present?
Using one set of data at the temperature that you selected for
Part 1, produce a graph of log cfu/ml vs time. Calculate the
corresponding D value.
Produce a graph of log cfu/ml vs time using ALL data at ALL the
temperatures used and calculate the D values. You will have to
calculate mean values at each time point and for each
temperature
Discuss briefly any difference in the D values obtained from 4.
and 5.
Calculate the Z value from the D value data that you have
obtained? Please show the calculation and explain what the Z value
is and how it is determined.
Give an example of the D and Z value for a named species of
Bacillus that you have found in the literature (citing the
reference).