[Carbohydrates synthesized by the spirulines].

Carbohydrates roughly constitute 15 p. 100 of the dry matter of Sirulina. They are extracted after complete delipidation, by successive exhaustions: first with ethanol of decreasing title, then with cold water slightly acidified by chlorhydric acid in order to drain out the calcium of the phytate; then by neutral boiling water; at last by alkaline or acidic warm solutions. After neutralization, suitable defecation and concentration, carbohydrates are either purified by a slow cristalization or hydrolyzed and analysed by usual techniques of chromatography on paper or on column of borated resins. Glucose, levulose, sucrose, glycerol and several polyols are so detected. They are in small amounts and of little nutritional interest. There is no trehalose. The carbohydrate storage products are mainly a glucosan and a rhamnosan, both containing glucosamine. There is about 2 p. 100 of the glucosan and 10 p. 100 of the rhamnosan, the composition of which are, in molar ratio: (see text). More or less phosphated cyclitols constitute, together with a small amount of glycogen, the rest of the metabolisable part. The cell-walls which could not be perfectly purified were degraded either by HC1 or by enzymes (pronase, neuraminidase). So have been found glucosamine and muramic acid, associated with peptides rich in glycine, serine, alanine, glutamic acid. These results joined to the presence, formerly signaled, of a rhamnosan, reveal a relationship between Spirulina and some Gram(+) bacteria. It is a fact that the celle-walls of Spirulina actually, though weakly, take the Gram coloration. To conclude, Spirulina presents some alimental interest.