This is the record of the culture absorbance and fermenter parameters.
Hence, The Graph of cell growth !
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Discussion of HISTORY PLOT !
In order for cells to proliferate and grow in high yields,
the following conditions must be present.
the following conditions must be present.
1. Dissolved oxygen (pO2
must be present to provide oxygen for the cells.
2. pH level
must be optimum.
3. Temperature
must remain constant.
4. Spargers and impeller
were required for aeration and stirring of the contents.
Hence, In this history plot,
pO2 value
- When cell are at the lag phase, the pO2 values have increased
- When cell are at the lag phase, the pO2 values have increased
as it was the period of adaption for the cells in a new environment.
- As the cells reaches exponential phase, the pO2 value have
hence, the demand of pO2 increased.
- After about 10hours, the pO2 values have started to increase.
It was due to the fact that cells are now in the stationery phase where; -
Rate of cell growth = Rate of cell death.
Hence the demand of pO2 was not high.
Rate of cell growth = Rate of cell death.
Hence the demand of pO2 was not high.
From the graph, we can observe that
the stirring speed and pO2 values are correlated to each other.
Stirring rate
- The stirring rate will be constant until the pO2 probe
detected that there was a decrease in the pO2 value.
- Level of pO2 increases = constant stirring rate
= no or less demand of oxygen from the cells.
- Level of pO2 decreases = Stirring rate increases
= demand of oxygen from the cells.
pH
pH
- pH value was low initially as cells grow and produced
toxic metabolite substances which causes the pH to drop.
- As the pH probe detected the decrease in pH,
it will adjust the pH to the optimum value which is required.
Temperature
- Temperature was low at the start of the run
as cells were trying to adapt into the new environment.
- After about an hour later,
the temperature is remained constant throughout the whole run.
Labels: results