NON-FILAMENTOUS AQUATIC FUNGI
55
sake of this discussion, that enzyme activities measured in cell-free
extracts reflect quantities of enzyme proteins, then the latter are also
synthesized differentially during exponential growth of B. emersonii.
For example, the total glucose-6-phosphate dehydrogenase per cell
(Goldstein and Cantino, 1962) increases exponentially; between 30%
and 60% of the generation time, this rate of synthesis is significantly
greater than the exponential rate of synthesis of soluble protein and is,
in fact, identical to that shown in Fig. 4 for the dry weight per cell. A
FIG. 4. Differential exponential rates of synthesis of selected materials during
exponential growth of OC cells of Blastocladiella emersonii at 24° C. Log values for
polysaccharide/cell, protein/cell, and weight/cell (all χ 10
10
) at 30% of cell's generation
time were set at zero on the vertical axis. (Derived from unpublished data; see Goldstein
and Cantino, 1962.)
second example will suffice to make the point. The spore of Blastocladiella
contains both glycine-alanine transaminase and isocitritase activities
(the enzymes having been partially purified ca. 80-fold and 50-fold,
respectively, and then characterized before further work was done;
McCurdy and Cantino, 1960). Following germination, the total activity
per cell of the glycine-alanine transaminase increases exponentially. In
sharp contrast, the total activity of the isocitritase per cell does not
increase at all; it is continuously diluted during exponential growth
until almost half of the cell's generation time has gone by (Cantino,
1961a; McCurdy and Cantino, 1960).
Thus, B. emersonii should prove to be an excellent vehicle for studying
polysaccharide
( light)
0
30
40
50
60
% generation
time
70
c
55
sake of this discussion, that enzyme activities measured in cell-free
extracts reflect quantities of enzyme proteins, then the latter are also
synthesized differentially during exponential growth of B. emersonii.
For example, the total glucose-6-phosphate dehydrogenase per cell
(Goldstein and Cantino, 1962) increases exponentially; between 30%
and 60% of the generation time, this rate of synthesis is significantly
greater than the exponential rate of synthesis of soluble protein and is,
in fact, identical to that shown in Fig. 4 for the dry weight per cell. A
FIG. 4. Differential exponential rates of synthesis of selected materials during
exponential growth of OC cells of Blastocladiella emersonii at 24° C. Log values for
polysaccharide/cell, protein/cell, and weight/cell (all χ 10
10
) at 30% of cell's generation
time were set at zero on the vertical axis. (Derived from unpublished data; see Goldstein
and Cantino, 1962.)
second example will suffice to make the point. The spore of Blastocladiella
contains both glycine-alanine transaminase and isocitritase activities
(the enzymes having been partially purified ca. 80-fold and 50-fold,
respectively, and then characterized before further work was done;
McCurdy and Cantino, 1960). Following germination, the total activity
per cell of the glycine-alanine transaminase increases exponentially. In
sharp contrast, the total activity of the isocitritase per cell does not
increase at all; it is continuously diluted during exponential growth
until almost half of the cell's generation time has gone by (Cantino,
1961a; McCurdy and Cantino, 1960).
Thus, B. emersonii should prove to be an excellent vehicle for studying
polysaccharide
( light)
0
30
40
50
60
% generation
time
70
c