Aiba 1968

6. Aiba et al.(1968) reported the results of a chemostat study on the growth of a species strain of baker’s yeast as shown in the following table. The inlet stream of the chemostat did not containany cells or products.

Dilution Inlet Steady-state Steady-state Steady-state
Rate Glucose Conc. Glucose Conc. Ethanol Conc. Cell Conc.
D,hr-1 Csi,g/l Cs,g/l Cp ,g/l Cx ,g/l
0.084 21.5 0.054 7.97 2.00
0.100 10.9 0.079 4.70 1.200.160 21.2 0.138 8.57 2.40
0.198 20.7 0.186 8.44 2.33
0.242 10.8 0.226 4.51 1.25
(a) Find therate equation for cell growth.
(b) Find the rate equation for product (ethanol) formation.

6. Soln:
(a) rx = ?
(b) rp = ?
μ =
= +
y = m x + cD = μ hr-1 CS g/l


0.084 0.054 11.9 18.5
0.1 0.16 10 12.6
0.16 0.13 6.25 7.25
0.198 0186 5.05 5.38
0.2420.226 4.13 4.42

From graph,
C = = 1.6
μmax = = 0.625
m = = = 0.667
ks = 0.42 g/l
6. (a) rx = ?
rx =

rx =
6.(b) rp = ?
rp =
=
= =
=
=

= 0.27
rp =

rp =

6. (a) Cxi= 0 , Csi = 0



Plot
Intercept

D =μ hr-1 CS g/l


0.084 0.054 11.9 18.5
0.1 0.16 10 12.6
0.16 0.13 6.25 7.25
0.198 0186 5.05 5.38
0.242 0.2264.13 4.42
Slope = , Intercept = 1.2



6. (b) Material balance for Pdt in CSTF ,





For S.S CSTF with sterile feed,
,
From Manod,...