Sandip Bankar
Problem (Shuler and Kargi, pp 202)
A biochemical engineer has determined in her laboratory that the
optimal productivity of a valuable antibiotic is achieved when the
carbon nutrient (molasses) is metered into the fermenter at a rate
proportional to the growth rate. However, she cannot implement
her discovery in the antibiotic plant, since there is no reliable way
to measure the growth rate (dX/dt) or biomass concentration (X)
during the course of fermentation. It is suggested that an oxygen
analyzer be installed on the plant fermenters so that the OUR
(oxygen uptake rate, g/l-h) may be measured.
1. Derive expressions that may be used to estimate X and
dX/dt from OUR and time data, assuming that a simple
yield and maintenance model may be used to describe the
rate of oxygen consumption by the culture.
2. Calculate values for the yield(YX/O2) parameter from the
data
Time
OUR((g/h)
X((g/l)
1
0,011
0,6
2
0,008
0,63
3
0,084
0,63
4
0,153
0,76
5
0,198
1,06
6
0,273
1,56
7
0,393
2,23
8
0,493
2,85
9
0,642
4,15
10
0,915
5,37
11
1,031
7,59
12
1,12
9,4
13
1,37
11,4
14
1,58
12,22
15
1,26
13
16
1,58
13,37
17
1,26
14,47
18
1,12
15,37
19
1,2
16,12
20
0,99
16,18
21
0,86
16,67
22
0,9
17,01
