LIFE ACTIVITY OF SOME ALGAE OF THE CLASS CHLOROCOCCALES AND THE ACCUMULATION OF ORGANIC-MATTER IN CULTURE-MEDIUM

The accumulation of organic matter (OM) in nutrient medium was studied with respect to the life activity of two cultured algae, Chlorella an d Scenedesmus. The content of extracellular OM was as high as 35% of t he cell biomass on the first day of culture. During the exponential gr owth phase (days 2-5), when the cells had a high rate of photosynthesi s and high viability, the number of dead cells was not more than 3% of total number, and the content of OM in the medium was only about 5-8% of the cell biomass. It is suggested that the contribution of OM from living cells to the total OM in the medium could not exceed this valu e throughout the whole culture cycle. Later, during the linear and sta tionary phases, the accumulation of extracellular OM continued, althou gh the life activity of the cells decreased. With culture age, extrace llular OM accumulated mainly as a result of its passive exit and cell autolysis.