32
GORDON A. RILEY
B. Biochemical composition
The work of Parsons and Strickland (1962a) is the most complete
of the early accounts of the biochemical composition of oceanic particulate matter. Their analyses of carbon and nitrogen were discussed in
the previous section, and the remainder of the work will be outlined
now. Measurements of carbon, nitrogen and carbohydrate were obtained at three stations. These comprised two samples from the surface
layer and nine samples at various depths from 300-3 000 in. I n addition,
a composite sample from 400 m was used for more detailed biochemical
study. Seven amino acids were identified in the protein hydrolysate.
Glycine and alanine predominated, with lesser amounts of aspartic
acid, lysine, arginine, serine and proline. There were indications that
a considerable fraction of the total nitrogenous components was not
recovered.
I n the carbohydrate fraction, 70% was crude fibre. Glucose constituted 50% of the carbohydrate hydrolysate. Other sugars included
galactose, mannose, arabinose, and xylose.
No glucosamine was detected, indicating that chitin is not an
important constituent, nor hexuronic acids. Fat content was less
than 1%.
The two surface samples averaged 202 pg C/litre, equivalent to
about 400 pg of organic matter. Carbohydrate, calculated as glucose,
was 115 pg. Protein, estimated as N X 6.25, was 219 pg, leaving an
unidentified remainder of roughly 65 pg of organic matter per litre.
The deep water samples averaged 40.7 pg/litre of glucose equivalent
and 87.3 pg of protein, calculated in the same way as indicated above.
These two fractions added together would account for more than the
organic matter that could reasonably be expected to be present since
the total carbon averaged 50 pg/litre.
Attempting to resolve this dilemma in another way, the carbohydrate is subtracted out, leaving an average of 34 pg of non-carbohydrate carbon. The C : N ratio of this material would be 2.4 :1, which
seems anomalously low for proteins but is not entirely out of reason
in view of the predominance of nitrogen rich amino acids such as
glycine and alanine. This helps to resolve the dilemma but does not
imply that it is the whole story. Some of the " crude fibre )' may be
complex polysaccharides containing nitrogen.
The paper by Holm-Hansen et al. (1966), which was discussed at
some length in the previous section, contained notes on biochemical
composition which will be summarized here. They assumed that
organic phosphorus was present as a nucleic acid component because
GORDON A. RILEY
B. Biochemical composition
The work of Parsons and Strickland (1962a) is the most complete
of the early accounts of the biochemical composition of oceanic particulate matter. Their analyses of carbon and nitrogen were discussed in
the previous section, and the remainder of the work will be outlined
now. Measurements of carbon, nitrogen and carbohydrate were obtained at three stations. These comprised two samples from the surface
layer and nine samples at various depths from 300-3 000 in. I n addition,
a composite sample from 400 m was used for more detailed biochemical
study. Seven amino acids were identified in the protein hydrolysate.
Glycine and alanine predominated, with lesser amounts of aspartic
acid, lysine, arginine, serine and proline. There were indications that
a considerable fraction of the total nitrogenous components was not
recovered.
I n the carbohydrate fraction, 70% was crude fibre. Glucose constituted 50% of the carbohydrate hydrolysate. Other sugars included
galactose, mannose, arabinose, and xylose.
No glucosamine was detected, indicating that chitin is not an
important constituent, nor hexuronic acids. Fat content was less
than 1%.
The two surface samples averaged 202 pg C/litre, equivalent to
about 400 pg of organic matter. Carbohydrate, calculated as glucose,
was 115 pg. Protein, estimated as N X 6.25, was 219 pg, leaving an
unidentified remainder of roughly 65 pg of organic matter per litre.
The deep water samples averaged 40.7 pg/litre of glucose equivalent
and 87.3 pg of protein, calculated in the same way as indicated above.
These two fractions added together would account for more than the
organic matter that could reasonably be expected to be present since
the total carbon averaged 50 pg/litre.
Attempting to resolve this dilemma in another way, the carbohydrate is subtracted out, leaving an average of 34 pg of non-carbohydrate carbon. The C : N ratio of this material would be 2.4 :1, which
seems anomalously low for proteins but is not entirely out of reason
in view of the predominance of nitrogen rich amino acids such as
glycine and alanine. This helps to resolve the dilemma but does not
imply that it is the whole story. Some of the " crude fibre )' may be
complex polysaccharides containing nitrogen.
The paper by Holm-Hansen et al. (1966), which was discussed at
some length in the previous section, contained notes on biochemical
composition which will be summarized here. They assumed that
organic phosphorus was present as a nucleic acid component because