Corallina Mediterranea Research Articles

Pools of Free Amino Acids in Greek Marine Algae

Isolation, identification and quantitative determination of 17 free amino acids was carried out in 39 marine plant organisms of the Greek coasts. Among them 10 were green algae ( Chlorophyceae ), 10 brown algae ( Phaeophyceae ), 17 red algae ( Rhodophyceae ) and 2 phanerogams. The distribution pattern in their free amino acid pools was the following. Glutamic acid was the main amino acid in all the algae examined with the exception of Halimeda tuna, Dictyopteris membranacea, Pterocladia capillacea, Corallina mediterranea, Antithamnion cruciatum f. fragilissima and the phanerogam Halophila stipulacea . Aspartic acid, alanine and threonine, serine, glutamine, asparagine followed in relative abundance. There was a trend for more alanine in the brown algae compared with the green and red algae. Glycine was a constant constituent of all the algae examined, but it was absent from Polysiphonia sp. This amino acid was present in a quantitatively lower degree than the foregoing amino acids. Leucine, isoleucine, valine, phenylalanine, lysine and arginine were less common than the eight above-mentioned constituents and were found occasionally in large amounts. Lastly, cysteine, tyrosine and histidine were rare and mostly detected in small quantities. Methionine was totally absent from all the algae and phanerogams examined. The comparison of the free amino acid patterns for each species does not provid'e sound evidence for its use in taxonomic studies of the natural occuring marine algae.

Osservazioni Ecologiche Su Alcune Alghe Del Golfo di Napoli in Relazione Alla Loro Distribuzione Verticale

Abstract Ecological observations dealing with some seaweeds of Bay of Naples in connection to their vertical zonation. — The algal zonation in a basaltic locality of the Bay of Naples was studied by the A. in order to get some data about the environmental requirements of seaweeds living in that locality. He pointed out the vegetation girdles of: a) « Bangia fuscopurpurea », « Gelidium pusillum », « Nemalion helmintoides » in the supra-littoral belt; b) « Corallina mediterranea » and « Enteromorpha compressa » in the eu-littoral belt; c) « Pterocladia capillacea », « Scytosiphon lomentarius », « Callithamnion granulatum » and « Derbesia tenuissima » in the infra-littoral belt, studied to 70 cm below the water mark. All these belts are overlapped by that of « Porphyra leucosticta ». « Bangia fuscopurpurea » seems to have a scarce adaptability, since it vegetates exclusively on the rocks spraied by the waves, but never submerged, so that this girdle is very large only in the more exposed localities; this sea...