reflected in the following equation:
О
Н
СО
О
О
Н
С
2
2
2
6
12
6
6
6
6
+
=
+
,
(1)
Since any synthesis process is based on the rate of biomass growth, this allows us to
establish an algorithm of delivering nutrients to the medium. Under these conditions, the
growth rate of the biomass
d
dM
y
is a function of time dτ, thus:
()
d
dM
d
dM
y
y
=
,
(2)
and the dynamic of sugar consumption is:
()
d
dM
k
d
dM
y
sug
=
,
(3)
where k is a ratio coefficient.
In technical calculations, the rate of biomass growth of is expressed in percentages,
but if the initial mass is known, its absolute growth can be determined. For example, the
initial mass of yeast
()
in
y
М
and an hourly gain of 17% gives us:
()
()
()
()
sin
17
.
1
17
.
0
y
in
y
in
y
y
in
y
M
M
M
M
M
=
+
=
+
.
(4)
Obviously, the rate of biomass growth will be:
()
()
s
kg
M
d
dMy
in
y
,
3600
17
.
0
=
.
(5)
The hourly growth in the logarithmic phase of accumulation modes when the volume
of the medium increases and in subtraction modes when the volume is stable can be
constant if expressed in percentages, and in subtraction modes the absolute growth
stabilizes as well. Based on conditions (3) and (5):
()
s
kg
GM
k
d
dM
in
y
sug
,
3600
=
,
(6)
where G is the coefficient of hourly yeast growth, and the ratio coefficient k shows
the numerical ratio between the masses of used sugar and synthesized yeast.
The developed equations of sugar destruction dynamics allow us to estimate oxygen
consumption in the system. If the molecular weight of sugar is 180 units and the molecular
weight of six oxygen molecules is 192 units, their ratio is:
067
.
1
180
192=
=
х
,
(7)
The latter means that the medium must contain 1.067 kg of oxygen for every
kilogram of consumed sugar. Then:
()
s
kg
GM
k
d
dM
in
y
ox
,
3600
067
.
1
=
,
(8)
The proposed condition (8) reflects the matter balance in the form of equation (1),
which means its accuracy irrespective of the course of biochemical reactions, the result of
which is part of the condition of glucose oxidation. The latter should be emphasized, since
the synthesis of biomass cannot end with only the formation of carbon dioxide and water,
- 1780 -