Ν ON-FILAMENTOUS AQUATIC FUNGI
57
and Turian, 1961 ; Goldstein and Cantino, 1962) and cannot be discussed
further now.
However, we should like to use this opportunity to re-emphasize the
previous theme regarding differential synthesis (Fig. 4). During the
period between 30% and 60% of the generation time, the rate of
exponential synthesis of polysaccharide and total weight per cell in the
light is greater by 13% and 8% respectively, than it is in the dark. For
soluble protein, however, this value is 21% (Goldstein and Cantino,
1962). On the other hand, the exponential rate of accumulation of total
glucose-6-phosphate dehydrogenase activity per cell is the same in light
or dark ; it is almost identical with the rate of protein synthesis in the
light. Thus, the differential exponential rates of synthesis of these
components in the dark are, themselves, affected differentially by visible
illumination. If 'unbalanced growth' (Cohen and Barner, 1954) is
referred to somewhat loosely here—as a system in which the rate of
exponential synthesis of one component relative to another is disturbed
—then we are dealing with systems of unbalanced growth. If the growth
of the cell incubated in the dark is taken as our point of reference and
labelled as 'unbalanced' (it does cease growth before its light-grown
counterpart; Cantino and Horenstein, 1957, 1959; Goldstein and
Cantino, 1962), then one might say that light restores the balance. On
the other hand, if 'balanced growth' is viewed as a situation wherein
every
. . extensive property of the growing system . . .' (Campbell,
1957) increases by the same factor over a given time interval, then
balanced growth does not occur in either system ; in terms of parameters
thus far examined, the composition of the cell of Blastocladiella during
exponential growth simply does not stay constant in either light or
dark.
The mechanisms by which bacteria control overproduction (Wilson
and Pardee, 1962) and adjust their rates of macromolecular synthesis to
alterations of external environments is receiving much attention (see,
for example, Fraenkel and Neidhart, 1961, and references therein).
Non-filamentous fungi such as Blastocladiella
emersonii should serve
admirably for studies of these phenomena in the future.
2. Exponential Growth Along the RS Path
The necessary conditions for growing massive, agitated, synchronized,
single-generation cultures of RS cells were also worked out some time
ago (Lovett and Cantino, 1960b). Here, too, extensive data on a per-cel]
basis have been accumulated: information about respiration, uptake of
substrates, production of metabolic products, cell content of soluble and
insoluble pools, total enzyme activities, etc. (Cantino and Lovett, 1960;
Lovett and Cantino, 1960a; McCurdy and Cantino, 1960). As a con-
57
and Turian, 1961 ; Goldstein and Cantino, 1962) and cannot be discussed
further now.
However, we should like to use this opportunity to re-emphasize the
previous theme regarding differential synthesis (Fig. 4). During the
period between 30% and 60% of the generation time, the rate of
exponential synthesis of polysaccharide and total weight per cell in the
light is greater by 13% and 8% respectively, than it is in the dark. For
soluble protein, however, this value is 21% (Goldstein and Cantino,
1962). On the other hand, the exponential rate of accumulation of total
glucose-6-phosphate dehydrogenase activity per cell is the same in light
or dark ; it is almost identical with the rate of protein synthesis in the
light. Thus, the differential exponential rates of synthesis of these
components in the dark are, themselves, affected differentially by visible
illumination. If 'unbalanced growth' (Cohen and Barner, 1954) is
referred to somewhat loosely here—as a system in which the rate of
exponential synthesis of one component relative to another is disturbed
—then we are dealing with systems of unbalanced growth. If the growth
of the cell incubated in the dark is taken as our point of reference and
labelled as 'unbalanced' (it does cease growth before its light-grown
counterpart; Cantino and Horenstein, 1957, 1959; Goldstein and
Cantino, 1962), then one might say that light restores the balance. On
the other hand, if 'balanced growth' is viewed as a situation wherein
every
. . extensive property of the growing system . . .' (Campbell,
1957) increases by the same factor over a given time interval, then
balanced growth does not occur in either system ; in terms of parameters
thus far examined, the composition of the cell of Blastocladiella during
exponential growth simply does not stay constant in either light or
dark.
The mechanisms by which bacteria control overproduction (Wilson
and Pardee, 1962) and adjust their rates of macromolecular synthesis to
alterations of external environments is receiving much attention (see,
for example, Fraenkel and Neidhart, 1961, and references therein).
Non-filamentous fungi such as Blastocladiella
emersonii should serve
admirably for studies of these phenomena in the future.
2. Exponential Growth Along the RS Path
The necessary conditions for growing massive, agitated, synchronized,
single-generation cultures of RS cells were also worked out some time
ago (Lovett and Cantino, 1960b). Here, too, extensive data on a per-cel]
basis have been accumulated: information about respiration, uptake of
substrates, production of metabolic products, cell content of soluble and
insoluble pools, total enzyme activities, etc. (Cantino and Lovett, 1960;
Lovett and Cantino, 1960a; McCurdy and Cantino, 1960). As a con-