A rich network of bodies of water fed by supraglacial streams has developed in the Hörbyebreen marginal zone due to intensive deglaciation. Most of them are lakelets of 0.1 to 1.0 ha in area and a mean depth of 0.3 to 1.3 m. They developed mainly after 1961. Studies were made of suspended and dissolved sediment concentration, and the ionic composition of the waters of proglacial streams and lakes, followed by an estimate of the balance of the proglacial transport of material. The calculation showed that the total net deposition of mineral material in the marginal zone amounts to 58.45 t per day. which constitutes 56.07 per cent of the total volume transported by proglacial streams. Borings proved sediments deposited in lakes at present to be of little thickness, ranging from 3 to 19 cm. As to litholology, there in a dominance of light-grey silty-clay deposits with a mean grain-size of 5.70 to 6.21 phi, sometimes with thin intercalations of coarse-grained sands and gravels. Chemical analyses shovedthat these deposits contain mostly silicates with small admixtures of Ca and Mg, and that they reflect the geological structure of the area.

Studies on the surface-active agents added during the cultivation process proved their effect on the synthesized bioproducts. The biosynthesis and accumulation of exopolysaccharide and biomass by Antarctic producer Cryptococcus laurentii AL65 were studied in submerged cultivation using different carbon sources in the culture medium added to a one-percent concentration (pentoses, hexoses and oligosaccharides). Sucrose was chosen as the most appropriate carbon source for the cell growth and extracellular polymer biosynthesis. Absorption of sucrose by a strain producer was monitored and the residual sugars were traced in the dynamics of the fermentation process. The effect of polyoxyethylene sorbitan monooleate (Tween 80) on the cell growth and the accumulation of the synthesized biopolymer were studied for the first time with the Antarctic producer. The optimal increase in the amount of accumulated exopolysaccharide was recorded at a concentration of 6% Tween 80 at 24 h from the start of fermentation. The surfactant treatment contributed to an increase in the total amount of lipids in the cell, to the increased biosynthesis of unsaturated fatty acids compared to saturated ones, and to the increased cellular synthesis of valuable metabolites such as phosphatidylinositol, phosphatidylserine and phosphatidylethanolamine. The impact of Tween 80 on intracellular and extracellular metabolites is a valuable asset in a possible scale-up of the process in industrial settings.