RELEASE OF EXTRACELLULAR POLYSACCHARIDE BY SPONDYLOSIUM-PANDURIFORME (DESMIDIACEAE)

The filamentous desmid Spondylosium panduriforme (Heimerl) Teiling var . panduriforme f. limneticum has a large rigid mucilaginous sheath and releases great amounts of extracellular dissolved polysaccharide. Exp eriments on the kinetics release of labelled extracellular dissolved p olysaccharide and on the labelling of the sheath polysaccharides were carried out during 28 hours the dissolved polysaccharide could be dete cted one hour after addition of C-14 and its amount increased continuo usly with time even during dark period. Labelled sheath material could be detected half an hour after addition. The results show that the vi scosity of the culture medium was not due to the dissolution of ageing sheaths. There are evidences that the origin of the dissolved polysac charide could be from an active physiological process of production of this polymer.