Batch fermentation
For aerobic cultivation of yeast the cell mass concentration, Xt, and the concentration of the limiting substrate component (glucose), St, has been determined.
|
Time (min)
|
0
|
30
|
60
|
90
|
120
|
150
|
180
|
210
|
240
|
|
Xt (gDCM*/l)
|
5.0
|
5.2
|
6.6
|
8.4
|
10.8
|
13.8
|
17.7
|
19.0
|
20.0
|
|
St ( g glu/l)
|
30.0
|
29.6
|
26.8
|
23.2
|
18.4
|
12.4
|
4.6
|
2.0
|
0.0
|
*Dry Cell Mass
a. Calculate the average cell mass yield factor, YX/S in this fermentation.
b. Calculate the maximum specific growth rate, mMAX, in the logarithmic growth phase.
c. Calculate the volumetric growth rate, dX/dt = rX at time=125 min.
d. Calculate the volumetric substrate utilization rate, rS, and the specific substrate utilization rate, qS, of the yeast at time = 170 min, assuming that the average yield factor can be used to determine rS.
e.Calculate the concentration of left over substrate at time = 130, again assuming that the average yield factor can be used.