Amino Acids in Sea Water

1984 ◽  
Vol 2 (1) ◽  
pp. 11-21 ◽  
Author(s):  
James Braven ◽  
Roger Evens ◽  
E. Ian Butler
Keyword(s):  
1966 ◽  
Vol 13 (6) ◽  
pp. 1115-1124 ◽  
Author(s):  
Y.K. Chau ◽  
J.P. Riley
Keyword(s):  

1971 ◽  
Vol 178 (1050) ◽  
pp. 111-129 ◽  

When symbiotic coelenterates, especially hermatypic corals, were incubated in the light in sea water containing NaH 14 CO 3 , small quantities of fixed 14 C were released from the tissues at a steady rate over 4 h. The rate of release was greatly increased in the presence of glycerol, glucose and alanine; the additional 14 C released was in the same substance as that added to the medium. The following related compounds had little or no effect on 14 C release : ethylene glycol, sorbose, fructose, glucosamine, glycine, proline, serine and glutamic acid. Such results have been previously reported in other symbiotic systems, and the substances causing the specific release of fixed 14 C are believed to be those which move from the autotrophic to the heterotrophic symbiont. This belief is supported here by previous observations that glycerol, glucose and alanine are among the most important organic substances released by freshly isolated zooxanthellae. Ammonium chloride increased the amount of fixed 14 C released by corals into alanine media, possibly due to conversion of ammonia to amino acids by zooxanthellae. Appreciable release of 14 C fixed in the dark also occurred into alanine solutions. These results suggest possible roles of zooxanthellae in supplying organic nitrogen compounds to the host cell at night as well as during the day. The involvement of zooxanthellae in ‘recycling’ nitrogen compounds within the association may help to explain the success of corals in seas poor in nutrients. There was substantial utilization of external glycerol and glucose when supplied at either high or low concentrations. Corals may well be able to utilize some of the small amounts of organic matter dissolved in sea water in the natural environment.


1962 ◽  
Vol 39 (3) ◽  
pp. 345-352
Author(s):  
H. BARNES

1. The results of some chemical analyses for inorganic and organic constituents of the seminal plasma of Balanus balanus are presented. 2. The inorganic ions show a cation deficit of 178 m-equiv./l., which is probably made up by free amino-acids. 3. Cystine is a prominent amino acid present. 4. Potassium and calcium are present in excess of their quantities in sea water. 5. Reducing sugars, compared with the amount found in sea-urchin spermatozoa, are found in moderate quantities, 1 mg./ml. 6. Phosphorus of all kinds is present in only small quantities (total of o.14 mg./ml.). 7. Some phosphatases are present. 8. There are 21 /µg./ml. of ascorbic acid; the function of this is discussed in relation to its possible contribution to the protective action against the poisoning of -SH groups by thiol-reactive agents.


1968 ◽  
Vol 3 (4) ◽  
pp. 515-527
Author(s):  
J. PIATIGORSKY ◽  
A. TYLER

Unfertilized and fertilized eggs of the sea urchin Lytechinus pictus were preloaded with [14C]valine and exposed to individual solutions of each of the twenty ‘coded’ [12C]amino acids in artificial sea water. After 1 h incubation the amount of radioactivity in the medium was determined. The radioactivity was effectively displaced by most of the other neutral [12C]amino acids that are known to compete with valine for uptake. A chromatographic test with fertilized eggs showed the displaced radioactivity to be [14C]valine and not some metabolic product. Addition of acidic, basic or some neutral amino acids that are known to be poor inhibitors of valine uptake did not cause significant quantities of label to appear in the medium. For the unfertilized eggs, the concentration of acid-soluble label remained many hundreds of times greater in the egg fluid than in the sea water. Tests indicated that efflux of [14C]valine and subsequent competition for re-entry is a primary factor responsible for the displacement phenomenon. That this may not be the sole factor is suggested by the fact that some amino acids that are known to be powerful inhibitors of valine uptake were found to be only weak displacers of [14C]valine. Neither [14C]arginine nor [14C]glutamic acid were displaced in significant amounts from preloaded unfertilized or fertilized eggs by any of the tested [12C]amino acids. Attempts were made to utilize the displacement of [12C]valine to elevate the incorporation of [14C]valine and of other labelled amino acids into protein by intact eggs. Unfertilized and fertilized eggs were pretreated with related [12C]amino acids and then exposed to [14C]valine or a mixture of [14C]amino acids. The results varied in the different tests, ranging from no significant increase to 2-fold.


1969 ◽  
Vol 50 (2) ◽  
pp. 319-326
Author(s):  
R. R. HARRIS

1. Non-protein and protein nitrogen fractions of the isopod Sphaeroma rugicauda were measured in animals adapted to 100 and 2% sea water. 2. The non-protein nitrogen component was reduced in animals acclimatized to the lower salinity. 3. Free amino acids accounted for 88 and 74% respectively of the non-protein nitrogen in the two salinities. 4. In 2% sea water taurine, proline, glycine, alanine and glutamic acid showed the greatest decreases in concentration compared to the levels measured in animals adapted to 100% sea water. 5. The decrease in total free amino acids of animals acclimatized to 100% sea water and transferred to 2% sea water was measured. 6. The total free amino acid concentration is reduced to the 2% sea water level within 12 hr. after transfer. 7. Free amino acid, haemolymph sodium and total body sodium levels after transfer to 2% sea water were compared. 8. The asymmetry between the fall in haemolymph sodium concentration and the decrease in total body sodium under these conditions is thought to be due to a water shift from the haemolymph into the tissues. 9. It is suggested that the osmotic pressure of the cells falls at a slower rate than that of the haemolymph.


1994 ◽  
Vol 19 (6) ◽  
pp. 609-615 ◽  
Author(s):  
Takayuki Shoji ◽  
Ken-ichi Fujita ◽  
Masatoshi Ban ◽  
Osamu Hiroi ◽  
Hiroshi Ueda ◽  
...  

Parasitology ◽  
1978 ◽  
Vol 76 (1) ◽  
pp. 29-37 ◽  
Author(s):  
D. W. Halton

SummaryAn in vitro investigation has been made of the relative roles of the gut and tegument in the absorption of the neutral amino acids L-alanine and L-leucine by a marine fish-gill parasite, Diclidophora merlangi. The use of ligatures to preclude oral ingestion of trace-labelled medium has proved inadequate, invariably damaging the tegument, as revealed by stereoscan electron microscopy, and resulting in artifactual levels of absorption. Three alternative procedures have given consistently reliable data on the route of entry of low molecular weight substrates. (1) Ultrastructural examination of worms previously incubated in electron-dense cationic tracers has shown that, in vitro, there is no oral intake of sea water. (2) The suspending of worms in trace-labelled medium with the mouth out of the medium and comparing amino acid uptake with that of worms totally immersed in medium has revealed no statistically significant difference in the absorption levels. (3) Application of section (freeze-dried) auto-radiography to detect diffusible isotope has demonstrated directly transtegumental absorption of a neutral amino acid. It is concluded from these experiments that Diclidophora has a tegumental transport system for absorbing certain neutral amino acids, and whilst, clearly, the worm is sanguinivorous and digests blood in a well-developed gut, it may also be capable of supplementing this diet with low molecular weight organic nutrient absorbed directly from sea water via the tegument.


Author(s):  
C. B. Cowey ◽  
E. D. S. Corner

Amino acids, both free and combined as protein, and some other nitrogenous constituents of Calanus finmarchicus have been examined. Seventy-six per cent of the total nitrogen in C. finmarchicus was present in protein amino acids, 14% in the free amino acid fraction, 6% in trimethylamine oxide, and 1·5% in betaine. These findings are discussed in relation to previous work on nitrogenous constituents of Calanus.The free amino acid fraction of Calanus is compared with that of higher Crustacea and it is suggested that this fraction may be important in the adaptation of the animal to dilute sea water.Amino acid nitrogen made up 40% of the total nitrogen of particulate material from Clyde sea water. This finding is compared with other recent analyses of the phytoplanktonic nitrogen and total particulate nitrogen of inshore waters.


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