A range of 27 marine phytoplankton species, representative of several of the principal classes, has been grown under similar conditions in Erd-Schreiber medium with abundant nutrients. Harvesting was carried out 20 days after inoculation while vigorous growth was proceeding. The component fatty acids of the lipids extractable with chloroform-methanol were determined by gas-liquid chromatography. In all, 40 fatty acids were determined. It is likely that the component fatty-acid distribution may be valuable for taxonomic purposes. Thus, specific fatty-acid assemblages may characterize particular Phyla or even classes. For example, the Bacillariophyceae are differentiated from the other organisms examined by the virtual absence of 18:2, 18:3 and 1814; the Cryptophyta are distinguished by their high content of 20:1. The fatty-acid arrays of species belonging to the same genus are frequently very similar, e.g. Dunaliella primolecta and D. tertiolecta.

Text-figs. 1 and 2)Gas-liquid and thin-layer chromatography have been used for the determination of 25 amino acids in the hydrolysates of 25 species of marine phytoplankton which had been grown in Erd-Schreiber medium. The general pattern of their distribution agrees with that found by earlier workers; the principal amino acids being glutamic acid, alanine, leucine and aspartic acids. Small amounts of 2-amino-M-butyric and 2-amino-wo-butyric acid together with compounds which have been tentatively identified as 4-amino-«-butyric acid and the 2-amino-and 2,5-diamino derivations of adipic acid were detected in many of the organisms. No differences were found which could be related to the taxonomy of the organisms.

No abstract

An investigation has been made of the occurrence of 25 amino acids in the hydrolysates of five species of diatoms which had been grown in Erd-Schreiber medium. Their distribution pattern in general resembles that found in other species. However, there are characteristic differences; thus, they contain more serine and 2-amino wo-butyric acid than the other species of phytoplankton.

No abstract