PARTICULATE ORGANIC MATTER I N SEA WATER
53
water left. It was held for a final analysis twenty days later, and at
that time the level of particulate carbon had gone up again and was
0.61 mg C/litre in one bottle and 1.08 mg in the other. Some of the
water was plated, and it was found that the original inoculum had been
contaminated by growth of about five other species. It remains uncertain as to whether the increase at the end of the experiment represented
a second cycle of growth by these other species or was simply the result
of suspension of materials which previously had been adhering too
tightly t o the carboy t o be included in the analysis.
Visual examination from time to time had revealed the presence of
bacteria, flakes, and amorphous aggregates. The form of the curve for
0
5
1 0
15
TIME IN DAYS
FIG. 5. I n situ formation and utilization of particulate organic matter. This experiment
is similar to the ones shown in Fig. 4 except that Pseudomonas was added directly
to filtered water without prior bubbling.
total carbon suggested a typical laboratory cycle of bacterial growth,
with an initial phase of logarithmic increase followed by decline and
senescence, yet all evidence pointed toward the conclusion that living
bacteria were a minor part of the total organic matter. Thus it seemed
likely that bacterial growth was basically responsible for initial aggregation of organic matter and for utilization of the portion that could
be metabolized readily, so that the living and non-living fractions
varied together.
Fig. 5 shows the results of an experiment in which Pseudomonas was
added to filtered water which had not been bubbled. A similar curve
A.M.B.-8
3
53
water left. It was held for a final analysis twenty days later, and at
that time the level of particulate carbon had gone up again and was
0.61 mg C/litre in one bottle and 1.08 mg in the other. Some of the
water was plated, and it was found that the original inoculum had been
contaminated by growth of about five other species. It remains uncertain as to whether the increase at the end of the experiment represented
a second cycle of growth by these other species or was simply the result
of suspension of materials which previously had been adhering too
tightly t o the carboy t o be included in the analysis.
Visual examination from time to time had revealed the presence of
bacteria, flakes, and amorphous aggregates. The form of the curve for
0
5
1 0
15
TIME IN DAYS
FIG. 5. I n situ formation and utilization of particulate organic matter. This experiment
is similar to the ones shown in Fig. 4 except that Pseudomonas was added directly
to filtered water without prior bubbling.
total carbon suggested a typical laboratory cycle of bacterial growth,
with an initial phase of logarithmic increase followed by decline and
senescence, yet all evidence pointed toward the conclusion that living
bacteria were a minor part of the total organic matter. Thus it seemed
likely that bacterial growth was basically responsible for initial aggregation of organic matter and for utilization of the portion that could
be metabolized readily, so that the living and non-living fractions
varied together.
Fig. 5 shows the results of an experiment in which Pseudomonas was
added to filtered water which had not been bubbled. A similar curve
A.M.B.-8
3